Seasonal variation in nutritional status and anemia among lactating mothers in two agro-ecological zones of rural Ethiopia: A longitudinal study.

PubMed

Roba, Kedir Teji; O'Connor, Thomas P; Belachew, Tefera; O'Brien, Nora M

2015-10-01

The aim of this study was to determine seasonal and agro-ecological variations in nutritional status, anemia, and associated factors among lactating women in rural Ethiopia. We conducted a longitudinal study with 216 mothers in pre- and postharvest seasons in two agro-ecological zones of rural Ethiopia. We conducted interviews using a structured questionnaire, anthropometric measurements, and blood tests for anemia. We used multivariable linear regression models to identify independent predictors. The prevalence of anemia increased from postharvest (21.8%) to preharvest seasons (40.9%). Increases were from 8.6% to 34.4% in midland and from 34.2% to 46.3% in lowland agro-ecological zones. Of the mothers, 15% were anemic during both seasons. The prevalence of undernutrition, assessed using body mass index (BMI) < 18.5 kg/m(2), increased from 41.7% to 54.7% between the two seasons. Prevalence of maternal mid upper arm circumferences <22 cm also increased from 43.1% to 55.2% during the preharvest season. The seasonal effect was generally more pronounced in the midland community for all forms of malnutrition. Predictors of anemia were high parity of mother and low dietary diversity. Parity, number of children under the age of 5 y, and regional variation were predictors of low BMI among lactating mothers. The magnitude of malnutrition and anemia was significantly influenced by variations in season and agro-ecological zones. Interventions focused on agro-ecology and seasonal variation should be considered in addition to current strategies to alleviate malnutrition in lactating mothers. Copyright © 2015 Elsevier Inc. All rights reserved.

Household Food Insecurity along an Agro-Ecological Gradient Influences Children’s Nutritional Status in South Africa

PubMed Central

Chakona, Gamuchirai; Shackleton, Charlie M.

2018-01-01

The burden of food insecurity and malnutrition is a severe problem experienced by many poor households and children under the age of five are at high risk. The objective of the study was to examine household food insecurity, dietary diversity, and child nutritional status in relation to local context which influences access to and ability to grow food in South Africa and explore the links and associations between these and household socio-economic status. Using a 48-h dietary recall method, we interviewed 554 women from randomly selected households along a rural–urban continuum in three towns situated along an agro-ecological gradient. The Household Dietary Diversity Scores (HDDS) and the Household Food Insecurity Access Scale (HFIAS) tools were used to measure household dietary diversity and food insecurity, respectively. Anthropometric measurements with 216 children (2–5 years) from the sampled households were conducted using height-for-age and mid-upper arm circumference (MUAC) as indicators of stunting and wasting, respectively. The key findings were that mean HDDS declined with decreasing agro-ecological potential from the wettest site (8.44 ± 1.72) to the other two drier sites (7.83 ± 1.59 and 7.76 ± 1.63). The mean HFIAS followed the opposite trend. Stunted growth was the dominant form of malnutrition detected in 35% of children and 18% of children were wasted. Child wasting was greatest at the site with lowest agro-ecological potential. Children from households with low HDDS had large MUAC which showed an inverse association among HDDS and obesity. Areas with agro-ecological potential had lower prevalence of food insecurity and wasting in children. Agro-ecological potential has significant influence on children’s nutritional status, which is also related to household food security and socio-economic status. Dependence on food purchasing and any limitations in households’ income, access to land and food, can result in different forms

The Campesino-to-Campesino agroecology movement of ANAP in Cuba: social process methodology in the construction of sustainable peasant agriculture and food sovereignty.

PubMed

Rosset, Peter Michael; Sosa, Braulio Machín; Jaime, Adilén María Roque; Lozano, Dana Rocío Ávila

2011-01-01

Agroecology has played a key role in helping Cuba survive the crisis caused by the collapse of the socialist bloc in Europe and the tightening of the US trade embargo. Cuban peasants have been able to boost food production without scarce and expensive imported agricultural chemicals by first substituting more ecological inputs for the no longer available imports, and then by making a transition to more agroecologically integrated and diverse farming systems. This was possible not so much because appropriate alternatives were made available, but rather because of the Campesino-a-Campesino (CAC) social process methodology that the National Association of Small Farmers (ANAP) used to build a grassroots agroecology movement. This paper was produced in a 'self-study' process spearheaded by ANAP and La Via Campesina, the international agrarian movement of which ANAP is a member. In it we document and analyze the history of the Campesino-to-Campesino Agroecology Movement (MACAC), and the significantly increased contribution of peasants to national food production in Cuba that was brought about, at least in part, due to this movement. Our key findings are (i) the spread of agroecology was rapid and successful largely due to the social process methodology and social movement dynamics, (ii) farming practices evolved over time and contributed to significantly increased relative and absolute production by the peasant sector, and (iii) those practices resulted in additional benefits including resilience to climate change.

Effect of agro-ecological zone, season of birth and sex on pre-weaning performance of Nguni calves in Limpopo Province, South Africa.

PubMed

Mpofu, T J; Ginindza, M M; Siwendu, N A; Nephawe, K A; Mtileni, B J

2017-01-01

The study was conducted to determine the effect of agro-ecological zone, season of birth and sex on Nguni calves' pre-weaning performance. Production indices such as birth weight (BW), weaning weight (WW), pre-weaning average daily gain (P-ADG) and pre-weaning gain (P-WG) were assessed in the different agro-ecological zones. Herd records on performance of 826 Nguni calves' from nine Nguni herds representing different agro-ecological zones: arid zone (n = 217); semi-arid zone (n = 296); dry sub-humid zone (n = 118) and humid zone (n = 195) were used for the analysis of pre-weaning calf performance. General linear model (GLM) procedure of SAS (2013) was used to analyse data, whereas mean separation was conducted using Tukey's HSD test. Agro-ecological zone had a great influence (P < 0.01) on performance levels arising from pasture conditions which were dependent on rain, temperature, topography and soil type. Fluctuations in WW, P-ADG and P-WG performance across agro-ecological zones depicted the sensitivity of Nguni calves' to postnatal stress. Calves' in humid zone had higher performance with 121.21 kg for WW, 96.83 kg for P-WG and 0.477 kg/day for P-ADG. The lowest WW (114.51 kg), P-WG (89.98 kg) and P-ADG (0.438 kg/day) were observed in arid zone. Male calves were heavier at weaning (128.18 kg), P-ADG (0.503 kg/day) and total gain (103.03 kg); however, similar BW of 25 kg was observed for both male and female calves. Season had a significant (P < 0.05) effect on BW, P-ADG and P-WG. The P-ADG was 0.461 kg/day for calves born in summer and 0.449 kg/day for calves born in winter season. Calves born in summer gained 94.69 kg and calves born in winter gained 92.10 kg. Summer calves gained 2.59 kg more than winter calves. Summer heifer calves performed poorly whilst summer male calves outperformed heifer calves in terms of WW, P-WG and P-ADG. Pre-weaned calves in humid zone outperformed all calves in other agro-ecological zones

The Cook Agronomy Farm LTAR: Knowledge Intensive Precision Agro-ecology

NASA Astrophysics Data System (ADS)

Huggins, D. R.

2015-12-01

Drowning in data and starving for knowledge, agricultural decision makers require evidence-based information to enlighten sustainable intensification. The agro-ecological footprint of the Cook Agronomy Farm (CAF) Long-Term Agro-ecosystem Research (LTAR) site is embedded within 9.4 million ha of diverse land uses primarily cropland (2.9 million ha) and rangeland (5.3 million ha) that span a wide annual precipitation gradient (150 mm through 1400 mm) with diverse social and natural capital (see Figure). Sustainable intensification hinges on the development and adoption of precision agro-ecological practices that rely on meaningful spatio-temporal data relevant to land use decisions at within-field to regional scales. Specifically, the CAF LTAR will provide the scientific foundation (socio-economical and bio-physical) for enhancing decision support for precision and conservation agriculture and synergistic cropping system intensification and diversification. Long- and short-term perspectives that recognize and assess trade-offs in ecosystem services inherent in any land use decision will be considered so as to promote the development of more sustainable agricultural systems. Presented will be current and future CAF LTAR research efforts required for the development of sustainable agricultural systems including cropping system cycles and flows of nutrients, water, carbon, greenhouse gases and other biotic and abiotic factors. Evaluation criteria and metrics associated with long-term agro-ecosystem provisioning, supporting, and regulating services will be emphasized.

Agro-ecological class stability decreases in response to climate change projections for the Pacific Northwest, USA

USDA-ARS?s Scientific Manuscript database

Climate change will impact bioclimatic drivers that regulate the geospatial distribution of dryland agro-ecological classes (AECs). Characterizing the geospatial relationship between present AECs and their bioclimatic controls will provide insights into potential future shifts in AECs as climate cha...

Agroecology and the Sustainable Production of Food and Fiber: Emergy Evaluation of Agriculture in the Montado

EPA Science Inventory

The silvopastoral, agricultural system of the montado in Southern Portugal is an example of the self-organization of an agroecological system adapted to the climate and soil conditions of the Mediterranean basin. This system with its consistent production of food, fiber, and ecos...

The Brazilian Experience with Agroecological Extension: A Critical Analysis of Reform in a Pluralistic Extension System

ERIC Educational Resources Information Center

Diesel, Vivien; Miná Dias, Marcelo

2016-01-01

Purpose: To analyze the Brazilian experience in designing and implementing a recent extension policy reform based on agroecology, and reflect on its wider theoretical implications for extension reform literature. Design/methodology/approach: Using a critical public analysis we characterize the evolution of Brazilian federal extension policy…

Identification and characterization of agro-ecological infrastructures by remote sensing

NASA Astrophysics Data System (ADS)

Ducrot, D.; Duthoit, S.; d'Abzac, A.; Marais-Sicre, C.; Chéret, V.; Sausse, C.

2015-10-01

Agro-Ecological Infrastructures (AEIs) include many semi-natural habitats (hedgerows, grass strips, grasslands, thickets…) and play a key role in biodiversity preservation, water quality and erosion control. Indirect biodiversity indicators based on AEISs are used in many national and European public policies to analyze ecological processes. The identification of these landscape features is difficult and expensive and limits their use. Remote sensing has a great potential to solve this problem. In this study, we propose an operational tool for the identification and characterization of AEISs. The method is based on segmentation, contextual classification and fusion of temporal classifications. Experiments were carried out on various temporal and spatial resolution satellite data (20-m, 10-m, 5-m, 2.5-m, 50-cm), on three French regions southwest landscape (hilly, plain, wooded, cultivated), north (open-field) and Brittany (farmland closed by hedges). The results give a good idea of the potential of remote sensing image processing methods to map fine agro-ecological objects. At 20-m spatial resolution, only larger hedgerows and riparian forests are apparent. Classification results show that 10-m resolution is well suited for agricultural and AEIs applications, most hedges, forest edges, thickets can be detected. Results highlight the multi-temporal data importance. The future Sentinel satellites with a very high temporal resolution and a 10-m spatial resolution should be an answer to AEIs detection. 2.50-m resolution is more precise with more details. But treatments are more complicated. At 50-cm resolution, accuracy level of details is even higher; this amplifies the difficulties previously reported. The results obtained allow calculation of statistics and metrics describing landscape structures.

Persistence of highly pathogenic avian influenza H5N1 virus defined by agro-ecological niche

USGS Publications Warehouse

Hogerwerf, Lenny; Wallace, Rob G.; Ottaviani, Daniela; Slingenbergh, Jan; Prosser, Diann; Bergmann, Luc; Gilbert, Marius

2010-01-01

The highly pathogenic avian influenza (HPAI) H5N1 virus has spread across Eurasia and into Africa. Its persistence in a number of countries continues to disrupt poultry production, impairs smallholder livelihoods, and raises the risk a genotype adapted to human-to-human transmission may emerge. While previous studies identified domestic duck reservoirs as a primary risk factor associated with HPAI H5N1 persistence in poultry in Southeast Asia, little is known of such factors in countries with different agro-ecological conditions, and no study has investigated the impact of such conditions on HPAI H5N1 epidemiology at the global scale. This study explores the patterns of HPAI H5N1 persistence worldwide, and for China, Indonesia, and India includes individual provinces that have reported HPAI H5N1 presence during the 2004–2008 period. Multivariate analysis of a set of 14 agricultural, environmental, climatic, and socio-economic factors demonstrates in quantitative terms that a combination of six variables discriminates the areas with human cases and persistence: agricultural population density, duck density, duck by chicken density, chicken density, the product of agricultural population density and chicken output/input ratio, and purchasing power per capita. The analysis identifies five agro-ecological clusters, or niches, representing varying degrees of disease persistence. The agro-ecological distances of all study areas to the medoid of the niche with the greatest number of human cases are used to map HPAI H5N1 risk globally. The results indicate that few countries remain where HPAI H5N1 would likely persist should it be introduced.

[Research progress and trend on grassland agroecology].

PubMed

Ren, Jizhou; Li, Xianglin; Hou, Fujiang

2002-08-01

The connotation, progress, research frontiers and developmental trend of grassland agroecology are discussed in this paper. The interface theory, structure and function, coupling and discordance, and health assessment of grassland agroecosystems were recognized as the four research frontiers of the discipline. There exist three primary interfaces in a grassland agroecosystem, i.e., vegetation-site, grassland-animal and production-management. Research into a series of the ecological processes that occurred at these interfaces is the key to revealing the features of the system behavior. There are four sections in a grassland agroecosystem, i.e., pre-plant, plant, animal and post-biotic sections. System coupling and discordance are the two important concepts to describe interactions among the production sections. System coupling among the sections can lead to system improvement by exerting the potential of system capacity. Health of an ecosystem is a reflection of its structure and function, and health assessment is a measurement of its orderliness and service value.

Multiclass Classification of Agro-Ecological Zones for Arabica Coffee: An Improved Understanding of the Impacts of Climate Change

PubMed Central

Bunn, Christian; Läderach, Peter; Pérez Jimenez, Juan Guillermo; Montagnon, Christophe; Schilling, Timothy

2015-01-01

Cultivation of Coffea arabica is highly sensitive to and has been shown to be negatively impacted by progressive climatic changes. Previous research contributed little to support forward-looking adaptation. Agro-ecological zoning is a common tool to identify homologous environments and prioritize research. We demonstrate here a pragmatic approach to describe spatial changes in agro-climatic zones suitable for coffee under current and future climates. We defined agro-ecological zones suitable to produce arabica coffee by clustering geo-referenced coffee occurrence locations based on bio-climatic variables. We used random forest classification of climate data layers to model the spatial distribution of these agro-ecological zones. We used these zones to identify spatially explicit impact scenarios and to choose locations for the long-term evaluation of adaptation measures as climate changes. We found that in zones currently classified as hot and dry, climate change will impact arabica more than those that are better suited to it. Research in these zones should therefore focus on expanding arabica's environmental limits. Zones that currently have climates better suited for arabica will migrate upwards by about 500m in elevation. In these zones the up-slope migration will be gradual, but will likely have negative ecosystem impacts. Additionally, we identified locations that with high probability will not change their climatic characteristics and are suitable to evaluate C. arabica germplasm in the face of climate change. These locations should be used to investigate long term adaptation strategies to production systems. PMID:26505637

Multiclass Classification of Agro-Ecological Zones for Arabica Coffee: An Improved Understanding of the Impacts of Climate Change.

PubMed

Bunn, Christian; Läderach, Peter; Pérez Jimenez, Juan Guillermo; Montagnon, Christophe; Schilling, Timothy

2015-01-01

Cultivation of Coffea arabica is highly sensitive to and has been shown to be negatively impacted by progressive climatic changes. Previous research contributed little to support forward-looking adaptation. Agro-ecological zoning is a common tool to identify homologous environments and prioritize research. We demonstrate here a pragmatic approach to describe spatial changes in agro-climatic zones suitable for coffee under current and future climates. We defined agro-ecological zones suitable to produce arabica coffee by clustering geo-referenced coffee occurrence locations based on bio-climatic variables. We used random forest classification of climate data layers to model the spatial distribution of these agro-ecological zones. We used these zones to identify spatially explicit impact scenarios and to choose locations for the long-term evaluation of adaptation measures as climate changes. We found that in zones currently classified as hot and dry, climate change will impact arabica more than those that are better suited to it. Research in these zones should therefore focus on expanding arabica's environmental limits. Zones that currently have climates better suited for arabica will migrate upwards by about 500m in elevation. In these zones the up-slope migration will be gradual, but will likely have negative ecosystem impacts. Additionally, we identified locations that with high probability will not change their climatic characteristics and are suitable to evaluate C. arabica germplasm in the face of climate change. These locations should be used to investigate long term adaptation strategies to production systems.

Prospects from agroecology and industrial ecology for animal production in the 21st century.

PubMed

Dumont, B; Fortun-Lamothe, L; Jouven, M; Thomas, M; Tichit, M

2013-06-01

Agroecology and industrial ecology can be viewed as complementary means for reducing the environmental footprint of animal farming systems: agroecology mainly by stimulating natural processes to reduce inputs, and industrial ecology by closing system loops, thereby reducing demand for raw materials, lowering pollution and saving on waste treatment. Surprisingly, animal farming systems have so far been ignored in most agroecological thinking. On the basis of a study by Altieri, who identified the key ecological processes to be optimized, we propose five principles for the design of sustainable animal production systems: (i) adopting management practices aiming to improve animal health, (ii) decreasing the inputs needed for production, (iii) decreasing pollution by optimizing the metabolic functioning of farming systems, (iv) enhancing diversity within animal production systems to strengthen their resilience and (v) preserving biological diversity in agroecosystems by adapting management practices. We then discuss how these different principles combine to generate environmental, social and economic performance in six animal production systems (ruminants, pigs, rabbits and aquaculture) covering a long gradient of intensification. The two principles concerning economy of inputs and reduction of pollution emerged in nearly all the case studies, a finding that can be explained by the economic and regulatory constraints affecting animal production. Integrated management of animal health was seldom mobilized, as alternatives to chemical drugs have only recently been investigated, and the results are not yet transferable to farming practices. A number of ecological functions and ecosystem services (recycling of nutrients, forage yield, pollination, resistance to weed invasion, etc.) are closely linked to biodiversity, and their persistence depends largely on maintaining biological diversity in agroecosystems. We conclude that the development of such ecology

Analysis and prediction of agricultural pest dynamics with Tiko'n, a generic tool to develop agroecological food web models

NASA Astrophysics Data System (ADS)

Malard, J. J.; Rojas, M.; Adamowski, J. F.; Anandaraja, N.; Tuy, H.; Melgar-Quiñonez, H.

2016-12-01

While several well-validated crop growth models are currently widely used, very few crop pest models of the same caliber have been developed or applied, and pest models that take trophic interactions into account are even rarer. This may be due to several factors, including 1) the difficulty of representing complex agroecological food webs in a quantifiable model, and 2) the general belief that pesticides effectively remove insect pests from immediate concern. However, pests currently claim a substantial amount of harvests every year (and account for additional control costs), and the impact of insects and of their trophic interactions on agricultural crops cannot be ignored, especially in the context of changing climates and increasing pressures on crops across the globe. Unfortunately, most integrated pest management frameworks rely on very simple models (if at all), and most examples of successful agroecological management remain more anecdotal than scientifically replicable. In light of this, there is a need for validated and robust agroecological food web models that allow users to predict the response of these webs to changes in management, crops or climate, both in order to predict future pest problems under a changing climate as well as to develop effective integrated management plans. Here we present Tiko'n, a Python-based software whose API allows users to rapidly build and validate trophic web agroecological models that predict pest dynamics in the field. The programme uses a Bayesian inference approach to calibrate the models according to field data, allowing for the reuse of literature data from various sources and reducing the need for extensive field data collection. We apply the model to the cononut black-headed caterpillar (Opisina arenosella) and associated parasitoid data from Sri Lanka, showing how the modeling framework can be used to rapidly develop, calibrate and validate models that elucidate how the internal structures of food webs

Seroprevalence of and agroecological risk factors for Mycobacterium avium subspecies paratuberculosis and Neospora caninum infection among adult beef cattle in cow-calf herds in Alberta, Canada

PubMed Central

Scott, H. Morgan; Sorensen, Ole; Wu, John T.Y.; Chow, Eva Y.W.; Manninen, Ken

2007-01-01

A province-wide cross-sectional seroprevalence and agroecological risk factor study of Mycobacterium avium subspecies paratuberculosis (MAP) and Neospora caninum (NC) infection among cattle in 100 cow-calf herds in Alberta was conducted. The seroprevalence of MAP in adult cattle was 1.5% across all herds. Using a widely accepted herd test cutpoint of 2 or more seropositive cows out of 30 animals tested, 7.9% of herds were estimated to be infected (95% confidence interval (CI): 2.3–23.4%). Seroprevalence of MAP differed by agroecological region; specifically, cattle and herds in areas with high soil pH (> 7.0), southern latitudes, and arid climates had a moderately reduced risk of infection (P < 0.10). Seroprevalence of NC infection was 9.7% among adult beef cattle province-wide — these levels also varied by agroecological region — with 91.0% of herds infected overall. PMID:17494367

Soil cover patterns influence on the land environmental functions, agroecological quality, land-use and monitoring efficiency in the Central Russia

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Yashin, Ivan; Lukin, Sergey; Valentini, Riccardo

2015-04-01

First decades of XXI century actualized for soil researches the principal methodical problem of most modern geosciences: what spatial and temporal scale would be optimal for land quality evaluation and land-use practice optimizing? It is becoming obvious that this question cannot have one solution and have to be solved with especial attention on the features of concrete region and landscape, land-use history and practical issues, land current state and environmental functions, soil cover patterns and variability, governmental requirements and local society needs, best available technologies and their potential profitability. Central Russia is one of the most dynamical economic regions with naturally high and man-made complicated landscape and soil cover variability, long-term land-use history and self-contradictory issues, high potential of profitable farming and increased risks of land degradation. Global climate and technological changes essentially complicate the originally high and sharply increased in XX century farming land heterogeneity in the Central Russia that actualizes system analysis of its zonal, intra-zonal and azonal soil cover patterns according to their influence on land environmental functions, agroecological quality, and land-use and monitoring efficiency variability. Developed by the Laboratory of agroecological monitoring, ecosystem modeling & prediction (LAMP / RTSAU with support of RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) regional systems of greenhouse gases environmental monitoring RusFluxNet (6 fixed & 1 mobile eddy covariance stations with zonal functional sets of key plots with chamber investigations in 5 Russian regions) and of agroecological monitoring (in representative key plots with different farming practice in 9 RF regions) allow to do this analysis in frame of enough representative regional multi-factorial matrix of soil cover patterns, bioclimatic conditions, landscape features, and land-use history and

Farmers' Visions on Soils: A Case Study among Agroecological and Conventional Smallholders in Minas Gerais, Brazil

ERIC Educational Resources Information Center

Klingen, Klarien Elisabeth; De Graaff, Jan; Botelho, Maria Izabel Vieira; Kessler, Aad

2012-01-01

Purpose: Why do farmers not take better care of their soils? This article aims to give insight into how farmers look at soil quality management. Design/methodology/approach: It analyses diverse land management practices and visions on soils and soil quality of ten agroecological and 14 conventional smallholder farmers in Araponga, Minas Gerais,…

The impact of different agroecological conditions on the nutritional composition of quinoa seeds.

PubMed

Reguera, María; Conesa, Carlos Manuel; Gil-Gómez, Alejandro; Haros, Claudia Mónika; Pérez-Casas, Miguel Ángel; Briones-Labarca, Vilbett; Bolaños, Luis; Bonilla, Ildefonso; Álvarez, Rodrigo; Pinto, Katherine; Mujica, Ángel; Bascuñán-Godoy, Luisa

2018-01-01

Quinoa cultivation has been expanded around the world in the last decade and is considered an exceptional crop with the potential of contributing to food security worldwide. The exceptional nutritional value of quinoa seeds relies on their high protein content, their amino acid profile that includes a good balance of essential amino acids, the mineral composition and the presence of antioxidants and other important nutrients such as fiber or vitamins. Although several studies have pointed to the influence of different environmental stresses in certain nutritional components little attention has been paid to the effect of the agroecological context on the nutritional properties of the seeds what may strongly impact on the consumer food's quality. Thus, aiming to evaluate the effect of the agroecological conditions on the nutritional profile of quinoa seeds we analyzed three quinoa cultivars (Salcedo-INIA, Titicaca and Regalona) at different locations (Spain, Peru and Chile). The results revealed that several nutritional parameters such as the amino acid profile, the protein content, the mineral composition and the phytate amount in the seeds depend on the location and cultivar while other parameters such as saponin or fiber were more stable across locations. Our results support the notion that nutritional characteristics of seeds may be determined by seed's origin and further analysis are needed to define the exact mechanisms that control the changes in the seeds nutritional properties.

Open-Ended Cases in Agroecology: Farming and Food Systems in the Nordic Region and the US Midwest

ERIC Educational Resources Information Center

Francis, Charles; King, James; Lieblein, Geir; Breland, Tor Arvid; Salomonsson, Lennart; Sriskandarajah, Nadarajah; Porter, Paul; Wiedenhoeft, Mary

2009-01-01

Our aim is to describe open-ended case studies for learning real-life problem solving skills, and relate this approach to conventional, closed-ended decision case studies. Teaching methods are open-ended cases in agroecology, an alternative to traditional strategies that lead students through prepared materials and structured discussions to…

The impact of different agroecological conditions on the nutritional composition of quinoa seeds

PubMed Central

Conesa, Carlos Manuel; Gil-Gómez, Alejandro; Haros, Claudia Mónika; Pérez-Casas, Miguel Ángel; Briones-Labarca, Vilbett; Bolaños, Luis; Bonilla, Ildefonso; Álvarez, Rodrigo; Pinto, Katherine; Mujica, Ángel; Bascuñán-Godoy, Luisa

2018-01-01

Quinoa cultivation has been expanded around the world in the last decade and is considered an exceptional crop with the potential of contributing to food security worldwide. The exceptional nutritional value of quinoa seeds relies on their high protein content, their amino acid profile that includes a good balance of essential amino acids, the mineral composition and the presence of antioxidants and other important nutrients such as fiber or vitamins. Although several studies have pointed to the influence of different environmental stresses in certain nutritional components little attention has been paid to the effect of the agroecological context on the nutritional properties of the seeds what may strongly impact on the consumer food’s quality. Thus, aiming to evaluate the effect of the agroecological conditions on the nutritional profile of quinoa seeds we analyzed three quinoa cultivars (Salcedo-INIA, Titicaca and Regalona) at different locations (Spain, Peru and Chile). The results revealed that several nutritional parameters such as the amino acid profile, the protein content, the mineral composition and the phytate amount in the seeds depend on the location and cultivar while other parameters such as saponin or fiber were more stable across locations. Our results support the notion that nutritional characteristics of seeds may be determined by seed’s origin and further analysis are needed to define the exact mechanisms that control the changes in the seeds nutritional properties. PMID:29576944

“Tertius gaudens”: germplasm exchange networks and agroecological knowledge among home gardeners in the Iberian Peninsula

PubMed Central

2013-01-01

Background The idea that knowledge flows through social networks is implicit in research on traditional knowledge, but researchers have paid scant attention to the role of social networks in shaping its distribution. We bridge those two bodies of research and investigate a) the structure of network of exchange of plant propagation material (germplasm) and b) the relation between a person’s centrality in such network and his/her agroecological knowledge. Methods We study 10 networks of germplasm exchange (n = 363) in mountain regions of the Iberian Peninsula. Data were collected through participant observation, semi-structured interviews, and a survey. Results The networks display some structural characteristics (i.e., decentralization, presence of external actors) that could enhance the flow of knowledge and germplasm but also some characteristics that do not favor such flow (i.e., low density and fragmentation). We also find that a measure that captures the number of contacts of an individual in the germplasm exchange network is associated with the person’s agroecological knowledge. Conclusion Our findings highlight the importance of social relations in the construction of traditional knowledge. PMID:23883296

Agroecological evaluation of the principal microelements content in Chernozems at the Central Chernozemic Region of Russia

NASA Astrophysics Data System (ADS)

Lukin, Sergey; Vasenev, Ivan

2015-04-01

The ecological evaluation of the principal microelements content in soil cover of the agroecosystems is the important issue of the regional agroecological monitoring which results are actively used for landscape-adaptive land-use design with rational, environmental friendly fertilizing systems. The virgin forest-steppe plots without anthropogenous impacts are usually used as background data of microelements content in dominated zonal Chernozems. The average background content of zinc, copper, cobalt and manganese mobile forms (extracted with рН 4,8 buffer) in 10-20 cm layer of virgin Leached Chernozem at the federal reserve «Belogorye» (monitoring site «Jamskaya Steppe») are accordingly 0.75, 0.19, 0.14 and 12.8 mg/kg. According to RF actual evaluation scale for arable soils the background microelements content in the investigated virgin Chernozems have been corresponded to low level for mobile forms of zinc, copper and cobalt, and to middle level - for manganese ones that essentially limits their natural fertility. The results of carried out in the Belgorod Region in 2010-2014 agroecological monitoring have shown, that most of the arable soils are characterized by low content of the mobile forms of manganese (60 %) zinc (99,2 % of total area), cobalt (94,1 %) and copper (100 %) too that became a serious problem for intensive farming active development in the region. During active agroecological monitoring period since 1990-1994 to 2010-2014 the average regional contents of the principal microelements mobile forms have been essentially decreased: from 1,44 to 0,53 mg/kg in case of zinc, from 17,5 to 9,2 mg/kg in case of manganese - due to low level of micronutrient fertilizers and manure application. It determined the current priority in the agrochemical service development in the region with new DSS-supported agrotechnologies design and essentially increased level of profitable application of traditional and non-traditional organic and mineral

Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes. II. Breeding strategies.

PubMed

Phocas, F; Belloc, C; Bidanel, J; Delaby, L; Dourmad, J Y; Dumont, B; Ezanno, P; Fortun-Lamothe, L; Foucras, G; Frappat, B; González-García, E; Hazard, D; Larzul, C; Lubac, S; Mignon-Grasteau, S; Moreno, C R; Tixier-Boichard, M; Brochard, M

2016-11-01

Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could

Maize Cropping Systems Mapping Using RapidEye Observations in Agro-Ecological Landscapes in Kenya.

PubMed

Richard, Kyalo; Abdel-Rahman, Elfatih M; Subramanian, Sevgan; Nyasani, Johnson O; Thiel, Michael; Jozani, Hosein; Borgemeister, Christian; Landmann, Tobias

2017-11-03

Cropping systems information on explicit scales is an important but rarely available variable in many crops modeling routines and of utmost importance for understanding pests and disease propagation mechanisms in agro-ecological landscapes. In this study, high spatial and temporal resolution RapidEye bio-temporal data were utilized within a novel 2-step hierarchical random forest (RF) classification approach to map areas of mono- and mixed maize cropping systems. A small-scale maize farming site in Machakos County, Kenya was used as a study site. Within the study site, field data was collected during the satellite acquisition period on general land use/land cover (LULC) and the two cropping systems. Firstly, non-cropland areas were masked out from other land use/land cover using the LULC mapping result. Subsequently an optimized RF model was applied to the cropland layer to map the two cropping systems (2nd classification step). An overall accuracy of 93% was attained for the LULC classification, while the class accuracies (PA: producer's accuracy and UA: user's accuracy) for the two cropping systems were consistently above 85%. We concluded that explicit mapping of different cropping systems is feasible in complex and highly fragmented agro-ecological landscapes if high resolution and multi-temporal satellite data such as 5 m RapidEye data is employed. Further research is needed on the feasibility of using freely available 10-20 m Sentinel-2 data for wide-area assessment of cropping systems as an important variable in numerous crop productivity models.

Impacts of terracing on soil erosion control and crop yield in two agro-ecological zones of Rwanda

NASA Astrophysics Data System (ADS)

Rutebuka, Jules; Ryken, Nick; Uwimanzi, Aline; Nkundwakazi, Olive; Verdoodt, Ann

2017-04-01

Soil erosion remains a serious limiting factor to the agricultural production in Rwanda. Terracing has been widely adopted in many parts of the country in the past years, but its effectiveness is not yet known. Besides the standard radical (bench) terraces promoted by the government, also progressive terraces (with living hedges) become adopted mainly by the farmers. The aim of this study was to measure short-term (two consecutive rainy seasons 2016A and 2016B) run-off and soil losses for existing radical (RT) and progressive (PT) terraces versus non-protected (NP) fields using erosion plots installed in two agro-ecological zones, i.e. Buberuka highlands (site Tangata) and Eastern plateau (site Murehe) and determine their impacts on soil fertility and crop production. The erosion plot experiment started with a topsoil fertility assessment and during the experiment, maize was grown as farmer's cropping preference in the area. Runoff data were captured after each rainfall event and the collected water samples were dried to determine soil loss. Both erosion control measures reduced soil losses in Tangata, with effectiveness indices ranging from 43 to 100% when compared to the NP plots. RT showed the highest effectiveness, especially in season A. In Murehe, RT minimized runoff and soil losses in both seasons. Yet, the PT were largely inefficient, leading to soil losses exceeding those on the NP plots (ineffectiveness index of -78% and -65% in season A and B, respectively). Though topsoil fertility assessment in the erosion plots showed that the soil quality parameters were significantly higher in RT and NP plots compared to the PT plots on both sites, maize grain yield was not correlated with the physical effectiveness of the erosion control measures. Finally, the effectiveness of soil erosion control measures as well as their positive impacts on soil fertility and production differ not only by terracing type but also by agro-ecological zone and the management or

Is there willingness to buy and pay a surcharge for agro-ecological products? Case study of the production of vegetables in Xochimilco, Mexico.

PubMed

Revollo-Fernández, Daniel

2016-04-01

Around the world there are approximately 2.5 trillion small-scale farmers, most of them subsistence farmers. In the 1970s the green revolution unfolded, which brought benefits to some producers, but it also brought costs, especially for small producers. Agro-ecology is presented as an alternative, but it is necessary to examine whether it is accepted in the markets, especially in developing countries. This study proves that there is a potential market, in this case in Mexico, but that it will depend on some socio-economic variables such as age, income, gender, product information, among others. Similarly, it is evident that buyers are willing to make an additional payment as compensation. Agro-ecology should not be considered as subsistence farming incompatible with the markets. It offers good prospects for increasing production and improving the sustainability of agriculture in marginal areas with few economic resources. © 2015 Society of Chemical Industry.

The role of trees in agroecology and sustainable agriculture in the tropics.

PubMed

Leakey, Roger R B

2014-01-01

Shifting agriculture in the tropics has been replaced by sedentary smallholder farming on a few hectares of degraded land. To address low yields and low income both, the soil fertility, the agroecosystem functions, and the source of income can be restored by diversification with nitrogen-fixing trees and the cultivation of indigenous tree species that produce nutritious and marketable products. Biodiversity conservation studies indicate that mature cash crop systems, such as cacao and coffee with shade trees, provide wildlife habitat that supports natural predators, which, in turn, reduce the numbers of herbivores and pathogens. This review offers suggestions on how to examine these agroecological processes in more detail for the most effective rehabilitation of degraded land. Evidence from agroforestry indicates that in this way, productive and environmentally friendly farming systems that provide food and nutritional security, as well as poverty alleviation, can be achieved in harmony with wildlife.

Evaluation of Performance of Introduced Yam Bean (Pachyrhizus spp.) in Three Agro-Ecological Zones of Rwanda.

PubMed

Jean, Ndirigwe; Patrick, Rubaihayo; Phenihas, Tukamuhabwa; Rolland, Agaba; Placide, Rukundo; Robert, Mwanga O M; Silver, Tumwegamire; Vestine, Kamarirwa; Evrard, Kayinamura; Grüneberg, Wolfgang J

2017-01-01

The yam bean ( Pachyrizhus spp ) was recently introduced as a root crop with high-yield potential, considerable protein and micro-nutrient concentration to investigate its potential for food production in Rwanda. Except for Chuin types ( Pachyrizhus tuberosus ) which have high storage root dry matter (RDM) (26 to 36%), most accessions are consumed raw and are reported to have low RDM. The present study aimed to evaluate and identify adapted high yielding yam bean accessions in major agro-ecological zones of Rwanda. Field experiments with 22 accessions were conducted in 2012 at three research sites representing the major agro-ecologies of Rwanda. Strict reproductive pruning was followed to enhance fresh storage root yields. Across locations, ANOVA indicated highly significant differences ( p  < 0.01) for genotypes (G), locations (L), seasons (S) and G x L effects for storage root yield, vine yield and harvest index and accounted for 21.88%, 43.41%, 1.43% and 13.25% of the treatment sum of squares, respectively. The GGE bi-plot revealed that EC209018 is high yielding but unstable. However, genotypes, AC209034, AC209035 and EC209046, were outstanding in terms of adaptation and relative stability across the 3 locations, suggesting consistent root yields irrespective of location and environmental conditions. The GGE scatter plot showed that all genotypes formed one mega-environment for storage root yield (Karama, Musanze and Rubona) and two mega-environments for biomass yield (Karama and Rubona as one mega-environment and Musanze the second one). This study revealed that Karama is the most suitable environment for evaluation and selection of yam bean for yield components in Rwanda.

Agroecology and the Sustainable Production of Food and ...

EPA Pesticide Factsheets

The silvopastoral, agricultural system of the montado in Southern Portugal is an example of the self-organization of an agroecological system adapted to the climate and soil conditions of the Mediterranean basin. This system with its consistent production of food, fiber, and ecosystem services along with its concomitant rural social organization has been sustained in the region for over 1000 years. However, the system has been gradually decreasing in extent since the 19th century and its rate of decline has accelerated since the 1980s. The causes of this decline have been traced in descending order of importance to land managment choices, spatial factors and environmental factors. In addition, past studies have shown that there is an optimum livestock support capacity for maintaining the health of the montado agroecosystem. In this study, we used the results of an emergy evaluation of a cattle farm as part of a montado agroecosystem to examine the effects of the European Union’s (EU) Common Agricultural Policy (CAP) on the viability of both cattle rearing and the long term regional sustainability of montado agroecosystems. We found that the CAP and its two pillars for providing subsidies, (1) Common Market Organization (CMO) and (2) Rural Development Policy (RDP) are complex and take into account many aspects of prices and markets for particular products, e.g., beef and veal (CMO) and sustainable rural development, e.g., silvopastoral agroecosystems (RDP). How

Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries.

PubMed

Kantanen, Juha; Løvendahl, Peter; Strandberg, Erling; Eythorsdottir, Emma; Li, Meng-Hua; Kettunen-Præbel, Anne; Berg, Peer; Meuwissen, Theo

2015-01-01

Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production's effects on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources. There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability to a future with altered production systems. Some animals with useful phenotypes and genotypes may be more useful than others in the changing environment. Robust animal breeds with the potential to adapt to new agro-ecological conditions and tolerate new diseases will be needed. The key issue in mitigation of harmful greenhouse gas effects induced by livestock production is the reduction of methane (CH4) emissions from ruminants. There are differences in CH4 emissions among breeds and among individual animals within breeds that suggest a potential for improvement in the trait through genetic selection. Characterization of breeds and individuals with modern genomic tools should be applied to identify breeds that have genetically adapted to marginal conditions and to get critical information for breeding and conservation programs for farm animal genetic resources. We conclude that phenotyping and genomic technologies and adoption of new breeding approaches, such as genomic selection introgression, will promote breeding for useful characters in livestock species.

Utilization of farm animal genetic resources in a changing agro-ecological environment in the Nordic countries

PubMed Central

Kantanen, Juha; Løvendahl, Peter; Strandberg, Erling; Eythorsdottir, Emma; Li, Meng-Hua; Kettunen-Præbel, Anne; Berg, Peer; Meuwissen, Theo

2015-01-01

Livestock production is the most important component of northern European agriculture and contributes to and will be affected by climate change. Nevertheless, the role of farm animal genetic resources in the adaptation to new agro-ecological conditions and mitigation of animal production’s effects on climate change has been inadequately discussed despite there being several important associations between animal genetic resources and climate change issues. The sustainability of animal production systems and future food security require access to a wide diversity of animal genetic resources. There are several genetic questions that should be considered in strategies promoting adaptation to climate change and mitigation of environmental effects of livestock production. For example, it may become important to choose among breeds and even among farm animal species according to their suitability to a future with altered production systems. Some animals with useful phenotypes and genotypes may be more useful than others in the changing environment. Robust animal breeds with the potential to adapt to new agro-ecological conditions and tolerate new diseases will be needed. The key issue in mitigation of harmful greenhouse gas effects induced by livestock production is the reduction of methane (CH4) emissions from ruminants. There are differences in CH4 emissions among breeds and among individual animals within breeds that suggest a potential for improvement in the trait through genetic selection. Characterization of breeds and individuals with modern genomic tools should be applied to identify breeds that have genetically adapted to marginal conditions and to get critical information for breeding and conservation programs for farm animal genetic resources. We conclude that phenotyping and genomic technologies and adoption of new breeding approaches, such as genomic selection introgression, will promote breeding for useful characters in livestock species. PMID:25767477

The effect of substrate, season, and agroecological zone on mycoflora and aflatoxin contamination of poultry feed from Khyber Pakhtunkhwa, Pakistan.

PubMed

Alam, Sahib; Shah, Hamid Ullah; Khan, Habibullah; Magan, Naresh

2012-10-01

To study the effects of and interactions among feed types, seasons, and agroecological zones on the total fungal viable count and aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2) production in poultry feed, an experiment was conducted using three-factorial design. A total of 216 samples of poultry feed ingredients, viz. maize, wheat, rice, cotton seed meal (CSM), and finished products, that is, starter and finisher broilers' rations, were collected from Peshawar, Swat, and D. I. Khan districts of Khyber Pakhtunkhwa, Pakistan, during the winter, spring, summer, and autumn seasons of the year 2007/2008. Analysis of variance showed that there was a complex interaction among all these factors and that this influenced the total fungal viable count and relative concentrations of the aflatoxins produced. Minimum total culturable fungi (6.43 × 10³ CFUs/g) were counted in CSM from D. I. Khan region in winter season while maximum (26.68 × 10³ CFUs/g) in starter ration from Peshawar region in summer. Maximum concentrations of AFB1 (191.65 ng/g), AFB2 (86.85 ng/g), and AFG2 (89.90 ng/g) were examined during the summer season whereas the concentration of AFG1 was maximum (167.82 ng/g) in autumn in finisher ration from Peshawar region. Minimum aflatoxins were produced in the winter season across all the three agroecological zones.

Research on the integration of teaching content of core courses in Agro-ecological environmental specialties of higher vocational colleges

NASA Astrophysics Data System (ADS)

Chen, Juan; Ma, Guosheng

2018-02-01

Curriculum is the means to cultivate higher vocational talents. On the basis of analyzing the core curriculum problems of curriculum reform and Agro-ecological environmental specialties in higher vocational colleges, this paper puts forward the optimization and integration measures of 6 core courses, including “Eco-environment Repair Technology”, “Agro-environmental Management Plan”, “Environmental Engineering Design”, “Environmental Pest Management Technology”, “Agro-chemical Pollution Control Technology”, “Agro-environmental Testing and Analysis”. It integrates the vocational qualification certificate education and professional induction certificate training items, and enhances the adaptability, skills and professionalism of professional core curriculum.

Assessment of Aflatoxin Contamination of Maize, Peanut Meal and Poultry Feed Mixtures from Different Agroecological Zones in Cameroon

PubMed Central

Kana, Jean Raphaël; Gnonlonfin, Benoit Gbemenou Joselin; Harvey, Jagger; Wainaina, James; Wanjuki, Immaculate; Skilton, Robert A.; Teguia, Alexis

2013-01-01

Mycotoxins affect poultry production by being present in the feed and directly causing a negative impact on bird performance. Carry-over rates of mycotoxins in animal products are, in general, small (except for aflatoxins in milk and eggs) therefore representing a small source of mycotoxins for humans. Mycotoxins present directly in human food represent a much higher risk. The contamination of poultry feed by aflatoxins was determined as a first assessment of this risk in Cameroon. A total of 201 samples of maize, peanut meal, broiler and layer feeds were collected directly at poultry farms, poultry production sites and poultry feed dealers in three agroecological zones (AEZs) of Cameroon and analyzed for moisture content and aflatoxin levels. The results indicate that the mean of the moisture content of maize (14.1%) was significantly (P < 0.05) higher than all other commodities (10.0%–12.7%). Approximately 9% of maize samples were positive for aflatoxin, with concentrations overall ranging from <2 to 42 µg/kg. Most of the samples of peanut meal (100%), broiler (93.3%) and layer feeds (83.0%) were positive with concentrations of positive samples ranging from 39 to 950 µg/kg for peanut meal, 2 to 52 µg/kg for broiler feed and 2 to 23 µg/kg for layer feed. The aflatoxin content of layer feed did not vary by AEZ, while the highest (16.8 µg/kg) and the lowest (8.2 µg/kg) aflatoxin content of broiler feed were respectively recorded in Western High Plateau and in Rainforest agroecological zones. These results suggest that peanut meal is likely to be a high risk feed, and further investigation is needed to guide promotion of safe feeds for poultry in Cameroon. PMID:23628785

Evolutionary Agroecology: the potential for cooperative, high density, weed-suppressing cereals.

PubMed

Weiner, Jacob; Andersen, Sven B; Wille, Wibke K-M; Griepentrog, Hans W; Olsen, Jannie M

2010-09-01

Evolutionary theory can be applied to improve agricultural yields and/or sustainability, an approach we call Evolutionary Agroecology. The basic idea is that plant breeding is unlikely to improve attributes already favored by millions of years of natural selection, whereas there may be unutilized potential in selecting for attributes that increase total crop yield but reduce plants' individual fitness. In other words, plant breeding should be based on group selection. We explore this approach in relation to crop-weed competition, and argue that it should be possible to develop high density cereals that can utilize their initial size advantage over weeds to suppress them much better than under current practices, thus reducing or eliminating the need for chemical or mechanical weed control. We emphasize the role of density in applying group selection to crops: it is competition among individuals that generates the 'Tragedy of the Commons', providing opportunities to improve plant production by selecting for attributes that natural selection would not favor. When there is competition for light, natural selection of individuals favors a defensive strategy of 'shade avoidance', but a collective, offensive 'shading' strategy could increase weed suppression and yield in the high density, high uniformity cropping systems we envision.

Effects of Introduced and Indigenous Viruses on Native Plants: Exploring Their Disease Causing Potential at the Agro-Ecological Interface

PubMed Central

Vincent, Stuart J.; Coutts, Brenda A.; Jones, Roger A. C.

2014-01-01

The ever increasing movement of viruses around the world poses a major threat to plants growing in cultivated and natural ecosystems. Both generalist and specialist viruses move via trade in plants and plant products. Their potential to damage cultivated plants is well understood, but little attention has been given to the threat such viruses pose to plant biodiversity. To address this, we studied their impact, and that of indigenous viruses, on native plants from a global biodiversity hot spot in an isolated region where agriculture is very recent (<185 years), making it possible to distinguish between introduced and indigenous viruses readily. To establish their potential to cause severe or mild systemic symptoms in different native plant species, we used introduced generalist and specialist viruses, and indigenous viruses, to inoculate plants of 15 native species belonging to eight families. We also measured resulting losses in biomass and reproductive ability for some host–virus combinations. In addition, we sampled native plants growing over a wide area to increase knowledge of natural infection with introduced viruses. The results suggest that generalist introduced viruses and indigenous viruses from other hosts pose a greater potential threat than introduced specialist viruses to populations of native plants encountered for the first time. Some introduced generalist viruses infected plants in more families than others and so pose a greater potential threat to biodiversity. The indigenous viruses tested were often surprisingly virulent when they infected native plant species they were not adapted to. These results are relevant to managing virus disease in new encounter scenarios at the agro-ecological interface between managed and natural vegetation, and within other disturbed natural vegetation situations. They are also relevant for establishing conservation policies for endangered plant species and avoiding spread of damaging viruses to undisturbed

The agroecological matrix as alternative to the land-sparing/agriculture intensification model.

PubMed

Perfecto, Ivette; Vandermeer, John

2010-03-30

Among the myriad complications involved in the current food crisis, the relationship between agriculture and the rest of nature is one of the most important yet remains only incompletely analyzed. Particularly in tropical areas, agriculture is frequently seen as the antithesis of the natural world, where the problem is framed as one of minimizing land devoted to agriculture so as to devote more to conservation of biodiversity and other ecosystem services. In particular, the "forest transition model" projects an overly optimistic vision of a future where increased agricultural intensification (to produce more per hectare) and/or increased rural-to-urban migration (to reduce the rural population that cuts forest for agriculture) suggests a near future of much tropical aforestation and higher agricultural production. Reviewing recent developments in ecological theory (showing the importance of migration between fragments and local extinction rates) coupled with empirical evidence, we argue that there is little to suggest that the forest transition model is useful for tropical areas, at least under current sociopolitical structures. A model that incorporates the agricultural matrix as an integral component of conservation programs is proposed. Furthermore, we suggest that this model will be most successful within a framework of small-scale agroecological production.

Variation in village chicken production systems among agro-ecological zones of Zimbabwe.

PubMed

Muchadeyi, F C; Wollny, C B A; Eding, H; Weigend, S; Makuza, S M; Simianer, H

2007-08-01

The degree to which village chickens are integrated in the smallholder farming systems differs depending on the socio-economic, cultural and biological factors within each system. The objective of this study was to characterise the village chicken farming systems and identify possible threats to, and opportunities for, local chickens in the agro-ecological zones of Zimbabwe. A pre-tested questionnaire was administered to households randomly selected from five districts, Risitu (n=97), Hurungwe (n=56), Gutu (n=77), Gokwe-South (n=104) and Beitbridge (n=37) in eco-zones I-V, respectively. Age of head of household averaged 47 years (SD = 14.3). Land holdings per household averaged 4.82 ha (SD = 3.6). Overall, 17.7 percent of the households ranked livestock as the major source of income compared to 70.8 percent who ranked crops as the main contributor. Chicken flock size averaged 16.7 (SD = 12.4), and the highest flock sizes were observed in eco-zones I and IV. Households owning cattle, goats and other livestock assigned less important ranks to chickens. Chickens were usedmainly for the provision of meat and eggs whilst the use of chicken feathers and investment were uncommon practises. Results indicate that more support is necessary for village chickens in the non-cropping regions of the country.

Spatial distribution of Brucella antibodies with reference to indigenous cattle populations among contrasting agro-ecological zones of Uganda.

PubMed

Kabi, Fredrick; Muwanika, Vincent; Masembe, Charles

2015-09-01

Indigenous cattle populations exhibit various degrees of agro-ecological fitness and provide desirable opportunities for investments to improve sustainable production for better rural small-scale farmers' incomes globally. However, they could be a source of infection to their attendants and other susceptible livestock if their brucellosis status remains unknown. This study investigated the spatial distribution of Brucella antibodies among indigenous cattle populations in Uganda. Sera from a total of 925 indigenous cattle (410 Ankole Bos taurus indicus, 50 Nganda and 465 East African Shorthorn Zebu (EASZ) - B. indicus) obtained randomly from 209 herds spread throughout Uganda were sequentially analysed for Brucella antibodies using the indirect (I) and competitive (C) enzyme linked Immuno-sorbent assays (ELISA). Recent incidences of abortion within the previous 12 months and routine hygienic practices during parturition were explored for public health risks. Brucella antibodies occurred in approximately 8.64% (80/925) and 28.70% (95% CI: 22.52, 34.89) of the sampled individual cattle and herds, respectively. Findings have shown that Ankole and EASZ cattle had similar seroprevalences. Indigenous cattle from the different study agro-ecological zones (AEZs) exhibited varying seroprevalences ranging from approximately 1.78% (95% CI: 0, 5.29) to 19.67% (95% CI: 8.99, 30.35) in the Lake Victoria Crescent (LVC) and North Eastern Drylands (NED) respectively. Significantly higher odds for Brucella antibodies occurred in the NED (OR: 3.40, 95% CI: 1.34, 8.57, p=0.01) inhabited by EASZ cattle compared to the KP (reference category) AEZ. Recent incidences of abortions within the previous 12 months were significantly (p<0.001) associated with seropositive herds. These findings add critical evidence to existing information on the widespread occurrence of brucellosis among indigenous cattle populations in Uganda and could guide allocation of meagre resources for awareness creation

The century experiment: the first twenty years of UC Davis' Mediterranean agroecological experiment.

PubMed

Wolf, Kristina M; Torbert, Emma E; Bryant, Dennis; Burger, Martin; Denison, R Ford; Herrera, Israel; Hopmans, Jan; Horwath, Will; Kaffka, Stephen; Kong, Angela Y Y; Norris, R F; Six, Johan; Tomich, Thomas P; Scow, Kate M

2018-02-01

The Century Experiment at the Russell Ranch Sustainable Agriculture Facility at the University of California, Davis provides long-term agroecological data from row crop systems in California's Central Valley starting in 1993. The Century Experiment was initially designed to study the effects of a gradient of water and nitrogen availability on soil properties and crop performance in ten different cropping systems to measure tradeoffs and synergies between agricultural productivity and sustainability. Currently systems include 11 different cropping systems-consisting of four different crops and a cover crop mixture-and one native grass system. This paper describes the long-term core data from the Century Experiment from 1993-2014, including crop yields and biomass, crop elemental contents, aerial-photo-based Normalized Difference Vegetation Index data, soil properties, weather, chemical constituents in irrigation water, winter weed populations, and operational data including fertilizer and pesticide application amounts and dates, planting dates, planting quantity and crop variety, and harvest dates. This data set represents the only known long-term set of data characterizing food production and sustainability in irrigated and rainfed Mediterranean annual cropping systems. There are no copyright restrictions associated with the use of this dataset. © 2018 by the Ecological Society of America.

Land agroecological quality assessment in conditions of high spatial soil cover variability at the Pereslavskoye Opolye.

NASA Astrophysics Data System (ADS)

Morev, Dmitriy; Vasenev, Ivan

2015-04-01

The essential spatial variability is mutual feature for most natural and man-changed soils at the Central region of European territory of Russia. The original spatial heterogeneity of forest soils has been further complicated by a specific land-use history and human impacts. For demand-driven land-use planning and decision making the quantitative analysis and agroecological interpretation of representative soil cover spatial variability is an important and challenging task that receives increasing attention from private companies, governmental and environmental bodies. Pereslavskoye Opolye is traditionally actively used in agriculture due to dominated high-quality cultivated soddy-podzoluvisols which are relatively reached in organic matter (especially for conditions of the North part at the European territory of Russia). However, the soil cover patterns are often very complicated even within the field that significantly influences on crop yield variability and have to be considered in farming system development and land agroecological quality evaluation. The detailed investigations of soil regimes and mapping of the winter rye yield have been carried in conditions of two representative fields with slopes sharply contrasted both in aspects and degrees. Rye biological productivity and weed infestation have been measured in elementary plots of 0.25 m2 with the following analysis the quality of the yield. In the same plot soil temperature and moisture have been measured by portable devices. Soil sampling was provided from three upper layers by drilling. The results of ray yield detailed mapping shown high differences both in average values and within-field variability on different slopes. In case of low-gradient slope (field 1) there is variability of ray yield from 39.4 to 44.8 dt/ha. In case of expressed slope (field 2) the same species of winter rye grown with the same technology has essentially lower yield and within-field variability from 20 to 29.6 dt/ha. The

Amplifying the benefits of agroecology by using the right cultivars.

PubMed

Noguera, D; Laossi, K-R; Lavelle, P; De Carvalho, M H Cruz; Asakawa, N; Botero, C; Barot, S

2011-10-01

Tropical soils are particularly vulnerable to fertility losses due to their low capacity to retain organic matter and mineral nutrients. This urges the development of new agricultural practices to manage mineral nutrients and organic matter in a more sustainable way while relying less on fertilizer inputs. Two methods pertaining to ecological engineering and agroecology have been tested with some success: (1) the addition of biochar to the soil, and (2) the maintenance of higher earthworm densities. However, modern crop varieties have been selected to be adapted to agricultural practices and to the soil conditions they lead to and common cultivars might not be adapted to new practices. Using rice as a model plant, we compared the responsiveness to biochar and earthworms of five rice cultivars with contrasted selection histories. These cultivars had contrasted responsivenesses to earthworms, biochar, and the combination of both. The mean relative increase in grain biomass, among all treatments and cultivars, was 94% and 32%, respectively, with and without fertilization. Choosing the best combination of cultivar and treatment led to a more than fourfold increase in this mean benefit (a 437% and a 353% relative increase in grain biomass, respectively, with and without fertilization). Besides, the more rustic cultivar, a local landrace adapted to diverse and difficult conditions, responded the best to earthworms in terms of total biomass, while a modern common cultivar responded the best in term of grain biomass. This suggests that cultivars could be selected to amplify the benefit of biochar- and earthworm-based practices. Overall, selecting new cultivars interacting more closely with soil organisms and soil heterogeneity could increase agriculture sustainability, fostering the positive feedback loop between soils and plants that has evolved in natural ecosystems.

Caregivers' nutrition knowledge and attitudes are associated with household food diversity and children's animal source food intake across different agro-ecological zones in Ghana.

PubMed

Christian, Aaron K; Marquis, Grace S; Colecraft, Esi K; Lartey, Anna; Sakyi-Dawson, Owuraku; Ahunu, Ben K; Butler, Lorna M

2016-01-28

Caregivers' nutrition knowledge and attitudes may influence the variety of foods available in the household and the quality of children's diets. To test the link, this study collected data on caregivers' (n 608) nutrition knowledge and feeding attitudes as well as the diets of their household and of their 2-5-year-old children in twelve rural communities nested in the three main agro-ecological zones of Ghana. Household foods and children's animal source foods (ASF) consumed in the past 7 d were categorised into one of fourteen and ten groups, respectively. About 28 % of caregivers believed that their children needed to be fed only 2-3 times/d. Reasons for having adult supervision during child meal times, feeding diverse foods, prioritising a child to receive ASF and the perceived child benefits of ASF differed across zones (P<0·001). Households with caregivers belonging to the highest tertile of nutrition knowledge and attitude scores consumed more diverse diets compared with those of caregivers in the lowest tertile group (11·2 (sd 2·2) v. 10·0 (sd 2·4); P<0·001). After controlling for the effect of agro-ecological zone, caregivers' nutrition knowledge and feeding attitudes positively predicted household dietary diversity and the frequency and diversity of children's ASF intakes (P<0·001). The number of years of formal education of caregivers also positively predicted household dietary diversity and children's ASF diversity (P<0·001). A key component to improving child nutrition is to understand the context-specific nutrition knowledge and feeding attitudes in order to identify relevant interventions.

Molecular diversity and multifarious plant growth promoting attributes of Bacilli associated with wheat (Triticum aestivum L.) rhizosphere from six diverse agro-ecological zones of India.

PubMed

Verma, Priyanka; Yadav, Ajar Nath; Khannam, Kazy Sufia; Kumar, Sanjay; Saxena, Anil Kumar; Suman, Archna

2016-01-01

The diversity of culturable Bacilli was investigated in six wheat cultivating agro-ecological zones of India viz: northern hills, north western plains, north eastern plains, central, peninsular, and southern hills. These agro-ecological regions are based on the climatic conditions such as pH, salinity, drought, and temperature. A total of 395 Bacilli were isolated by heat enrichment and different growth media. Amplified ribosomal DNA restriction analysis using three restriction enzymes AluI, MspI, and HaeIII led to the clustering of these isolates into 19-27 clusters in the different zones at >70% similarity index, adding up to 137 groups. Phylogenetic analysis based on 16S rRNA gene sequencing led to the identification of 55 distinct Bacilli that could be grouped in five families, Bacillaceae (68%), Paenibacillaceae (15%), Planococcaceae (8%), Staphylococcaceae (7%), and Bacillales incertae sedis (2%), which included eight genera namely Bacillus, Exiguobacterium, Lysinibacillus, Paenibacillus, Planococcus, Planomicrobium, Sporosarcina, and Staphylococcus. All 395 isolated Bacilli were screened for their plant growth promoting attributes, which included direct-plant growth promoting (solubilization of phosphorus, potassium, and zinc; production of phytohormones; 1-aminocyclopropane-1-carboxylate deaminase activity and nitrogen fixation), and indirect-plant growth promotion (antagonistic, production of lytic enzymes, siderophore, hydrogen cyanide, and ammonia). To our knowledge, this is the first report for the presence of Bacillus endophyticus, Paenibacillus xylanexedens, Planococcus citreus, Planomicrobium okeanokoites, Sporosarcina sp., and Staphylococcus succinus in wheat rhizosphere and exhibit multifunctional PGP attributes. These niche-specific and multifarious PGP Bacilli may serve as inoculants for crops growing in respective climatic conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Proliferation of the biocontrol agent Fusarium oxysporum f. sp. strigae and its impact on indigenous rhizosphere fungal communities in maize under different agro-ecologies.

PubMed

Zimmermann, Judith; Musyoki, Mary K; Cadisch, Georg; Rasche, Frank

2016-06-01

Our objectives were to (1) monitor the proliferation of the biocontrol agent (BCA) Fusarium oxysporum f. sp. strigae strain "Foxy-2", an effective soil-borne BCA against the parasitic weed Striga hermonthica , in the rhizosphere of maize under different agro-ecologies, and (2) investigate its impact on indigenous rhizosphere fungal community abundance and composition. Field experiments were conducted in Busia and Homa Bay districts in western Kenya during two cropping seasons to account for effects of soil type, climate, growth stage and seasonality. Maize seeds were coated with or without "Foxy-2" and soils were artificially infested with S. hermonthica seeds. One treatment with nitrogen rich organic residues ( Tithonia diversifolia ) was established to compensate hypothesized resource competition between "Foxy-2" and the indigenous fungal community. Rhizosphere soil samples collected at three growth stages (i.e., EC30, EC60, EC90) of maize were subjected to abundance measurement of "Foxy-2" and total indigenous fungi using quantitative polymerase chain reaction (qPCR) analysis. Terminal restriction fragment length polymorphism (TRFLP) analysis was used to assess potential alterations in the fungal community composition in response to "Foxy-2" presence. "Foxy-2" proliferated stronger in the soils with a sandy clay texture (Busia) than in those with a loamy sand texture (Homa Bay) and revealed slightly higher abundance in the second season. "Foxy-2" had, however, only a transient suppressive effect on total indigenous fungal abundance which ceased in the second season and was further markedly compensated after addition of T. diversifolia residues. Likewise, community structure of the indigenous fungal community was mainly altered by maize growth stages, but not by "Foxy-2". In conclusion, no adverse effects of "Foxy-2" inoculation on indigenous fungal rhizosphere communities were observed corroborating the safety of this BCA under the given agro-ecologies.

The agro-ecological suitability of Atriplex nummularia and A. halimus for biomass production in Argentine saline drylands.

PubMed

Falasca, Silvia Liliana; Pizarro, María José; Mezher, Romina Nahir

2014-09-01

The choice of the best species to cultivate in semi-arid and arid climates is of fundamental importance, and is determined by many factors, including temperature and rainfall, soil type, water availability for irrigation and crop purposes. Soil or water salinity represents one of the major causes of crop stress. Species of the genus Atriplex are characterized by high biomass productivity, high tolerance to drought and salinity, and high efficiency in use of solar radiation and water. Based on a search of the international literature, the authors outline an agro-climatic zoning model to determine potential production areas in Argentina for Atriplex halimus and Atriplex numularia. Using the agroclimatic limits presented in this work, this model may be applied to any part of the world. When superimposed on the saline areas map, the agroclimatic map shows the suitability of agro-ecological zoning for both species for energy purposes on land unsuitable for food production. This innovative study was based on the implementation of a geographic information system that can be updated by further incorporation of complementary information, with consequent improvement of the original database.

The agro-ecological suitability of Atriplex nummularia and A. halimus for biomass production in Argentine saline drylands

NASA Astrophysics Data System (ADS)

Falasca, Silvia Liliana; Pizarro, María José; Mezher, Romina Nahir

2014-09-01

The choice of the best species to cultivate in semi-arid and arid climates is of fundamental importance, and is determined by many factors, including temperature and rainfall, soil type, water availability for irrigation and crop purposes. Soil or water salinity represents one of the major causes of crop stress. Species of the genus Atriplex are characterized by high biomass productivity, high tolerance to drought and salinity, and high efficiency in use of solar radiation and water. Based on a search of the international literature, the authors outline an agro-climatic zoning model to determine potential production areas in Argentina for Atriplex halimus and Atriplex numularia. Using the agroclimatic limits presented in this work, this model may be applied to any part of the world. When superimposed on the saline areas map, the agroclimatic map shows the suitability of agro-ecological zoning for both species for energy purposes on land unsuitable for food production. This innovative study was based on the implementation of a geographic information system that can be updated by further incorporation of complementary information, with consequent improvement of the original database.

Survey of farmers' knowledge of cassava mosaic disease and their preferences for cassava cultivars in three agro-ecological zones in Benin.

PubMed

Houngue, Jerome Anani; Pita, Justin S; Cacaï, Gilles Habib Todjro; Zandjanakou-Tachin, Martine; Abidjo, Emmanuel A E; Ahanhanzo, Corneille

2018-04-25

Cassava is an important crop in Africa that is widely cultivated for its starchy tuberous root, which constitutes a major source of dietary carbohydrates. Cassava mosaic disease (CMD) is the most devastating disease affecting cassava in Africa and causes enormous losses in yield. In Benin, specifically, cultivars resistant to CMD are not commonly planted, and even when CMD is observed in fields, farmers do not implement control measures, presumably because they lack proper knowledge and training. Our study aimed to evaluate farmers' knowledge of CMD to determine whether there is consistency between farmers' criteria for selecting cassava cultivars and the currently CMD-recommended cassava varieties. We conducted structured interviews with 369 farmers in 20% of townships in each of three agro-ecological zones in Benin between November 2015 and February 2016. Farmers were selected randomly in each household, and their fields were assessed for CMD incidence and severity. All farmers surveyed, representing a broad demographic pool with regard to education level, age group, and years of experience in cassava production, successfully recognized CMD symptoms in photos, but most (98.60%) said they did not know the causes and vectors of the disease. Most farmers (93.51%) reported that they obtain planting material from neighboring fields or their own fields. In total, 52 unique cultivars were identified, of which 3 (5.76%) were preferred based on their yield and precocity and 3 (5.76%) were preferred based on taste or ability for transformation. The assessment of disease incidence and severity showed that the areas most affected by CMD were Comè Township (37.77% of fields affected) and agro-ecological zone VIII (26.33%). Farmers already know how to recognize the symptoms of CMD and could implement control measures against it if they are trained by researchers. Across all surveyed areas, we identified six preferred cultivars based on the four most commonly stated preference

Dynamic Agroecological Zones for the Inland Pacific Northwest, USA

NASA Astrophysics Data System (ADS)

Huggins, D. R.; Rupp, R.; Gessler, P.; Pan, W.; Brown, D. J.; Machado, S.; Walden, V. P.; Eigenbrode, S.; Abatzoglou, J. T.

2011-12-01

Agroecological zones (AEZ's) have traditionally been defined by integrating multiple layers of biophysical (e.g. climate, soil, terrain) and occasionally socioeconomic data to create unique zones with specific ranges of land use constraints and potentials. Our approach to defining AEZ's assumes that current agricultural land uses have emerged as a consequence of biophysical and socioeconomic drivers. Therefore, we explore the concept that AEZ's can be derived from classifying the geographic distribution of current agricultural systems (e.g. the wheat-fallow cropping system zone) based on spatially geo-referenced annual cropland use data that is currently available through the National Agricultural Statistical Service (NASS). By defining AEZ's in this way, we expect to: (1) provide baseline information that geographically delineates the boundaries of current AEZ's and subzones and therefore the capacity to evaluate shifts in AEZ boundaries over time; (2) assess the biophysical (e.g. climate, soils, terrain) and socioeconomic factors (e.g. commodity prices) that are most useful for predicting and correctly classifying current AEZ's, subzones or future shifts in AEZ boundaries; (3) identify and develop AEZ-relevant climate mitigation and adaptation strategies; and (4) integrate biophysical and socioeconomic data sources to pursue a transdisciplinary examination of climate-driven AEZ futures. Achieving these goals will aid in realizing major objectives for a USDA National Institute of Food and Agriculture, Agriculture and Food Research Initiative, Cooperative Agricultural Project entitled "Regional Approaches to Climate Change (REACCH) for Pacific Northwest Agriculture". REACCH is a research, education and extension project under the leadership of the University of Idaho with significant collaboration from Washington State University, Oregon State University and the USDA Agricultural Research Service that is working towards increasing the capacity of Inland Pacific

Pathogen evolution across the agro-ecological interface: implications for disease management.

PubMed

Burdon, Jeremy J; Thrall, Peter H

2008-02-01

Infectious disease is a major causal factor in the demography of human, plant and animal populations. While it is generally accepted in medical, veterinary and agricultural contexts that variation in host resistance and pathogen virulence and aggressiveness is of central importance to understanding patterns of infection, there has been remarkably little effort to directly investigate causal links between population genetic structure and disease dynamics, and even less work on factors influencing host-pathogen coevolution. The lack of empirical evidence is particularly surprising, given the potential for such variation to not only affect disease dynamics and prevalence, but also when or where new diseases or pathotypes emerge. Increasingly, this lack of knowledge has led to calls for an integrated approach to disease management, incorporating both ecological and evolutionary processes. Here, we argue that plant pathogens occurring in agro-ecosystems represent one clear example where the application of evolutionary principles to disease management would be of great benefit, as well as providing model systems for advancing our ability to generalize about the long-term coevolutionary dynamics of host-pathogen systems. We suggest that this is particularly the case given that agro-ecological host-pathogen interactions represent a diversity of situations ranging from those that only involve agricultural crops through to those that also include weedy crop relatives or even unrelated native plant communities. We begin by examining some of the criteria that are important in determining involvement in agricultural pathogen evolution by noncrop plants. Throughout we use empirical examples to illustrate the fact that different processes may dominate in different systems, and suggest that consideration of life history and spatial structure are central to understanding dynamics and direction of the interaction. We then discuss the implications that such interactions have for

Survey of smallholder beef cattle production systems in different agro-ecological zones of Cambodia.

PubMed

Samkol, Pok; Sath, Keo; Patel, Mikaela; Windsor, Peter Andrew; Holtenius, Kjell

2015-10-01

A survey was conducted to better understand the contribution of farm productivity to rural household income and identify differences in production systems, feeding practices and development constraints to smallholder beef cattle producers in the four agro-ecological zones (AEZs) of Cambodia. A semi-structured questionnaire was used to interview 360 households in the four AEZs: I, the Great Lake Floodplain; II, the Mekong Floodplain; III, the Coastal and IV, the Plateau/Mountainous. In addition, samples of common nutritional resources used for cattle feed were collected for nutrient composition analysis, plus cattle were scored for body condition. Rice farming and cattle production were the most common sources of income in all AEZs. The average cattle herd size was 3.7 (SD = 2.4), but the majority of households raised 1-3 animals. The most common cattle management system was grazing with supplementation, mainly with rice straw and 'cut-and-carry' natural grasses fed during the wet season in all AEZs. The body condition score of all cattle types was 3.2 (SD = 0.8), except for cows in lactation that were 1.8. Major constraints to cattle production in AEZs I, II and III were lack of quality feed resources, capital for cattle production and concerns on breed quality, whereas in AEZ IV, diseases were identified as the main constraint. This survey confirms the importance of cattle to smallholders in the four AEZs. Interventions including farmer education to improve husbandry skills, increase the utilisation of forages and crop residues and address disease issues are necessary to enhance cattle production and rural livelihoods in Cambodia.

Epidemiological study of bovine brucellosis in three agro-ecological areas of central Oromiya, Ethiopia.

PubMed

Jergefa, T; Kelay, B; Bekana, M; Teshale, S; Gustafson, H; Kindahl, H

2009-12-01

A cross-sectional sero-epidemiological study of bovine brucellosis was conducted between September 2005 and March 2006 in three separate agroecological areas of central Oromiya, Ethiopia. In this study, a total of 176 clusters (farms) and 1,238 animals were selected, using the one-stage cluster sampling method. Fifty-nine clusters and 423 animals were selected from the lowland areas; 58 clusters and 385 animals from the midland areas and 59 clusters and 430 animals from the highlands. Serum samples were collected from a total of 1,238 animals older than six months. The rose bengal plate test and complement fixation test were used as screening and confirmatory tests, respectively, to detect Brucella seropositivity. Questionnaires were also administered to 176 households to gather information on the farm and livestock. Results showed that the overall seroprevalence of bovine brucellosis at the individual animal level was 2.9% (low). The seroprevalence was 4.2% in the lowlands, 1.0% in the midlands and 3.4% in the highlands. The overall seroprevalence at the herd level was 13.6% (moderate). At the herd level, seroprevalence in the lowlands was 17%; in the midlands: 5.1%; and in highland areas: 18.6%. Logistic regression analysis, revealed that the breed of cattle and the method of disposing of aborted foetuses and foetal membranes had a statistically significant effect on individual animal seroprevalence (p < 0.05). In lowland areas, the breed (p < 0.05), animal management system (p <0.05), mating method (p < 0.05), herd size (p < 0.05) and source of replacement stock (p <0.05) all had significant effects on individual animal seroprevalence.

A Survey of Aflatoxin-Producing Aspergillus sp. from Peanut Field Soils in Four Agroecological Zones of China

PubMed Central

Zhang, Chushu; Selvaraj, Jonathan Nimal; Yang, Qingli; Liu, Yang

2017-01-01

Peanut pods are easily infected by aflatoxin-producing Aspergillus sp.ecies from field soil. To assess the aflatoxin-producing Aspergillus sp. in different peanut field soils, 344 aflatoxin-producing Aspergillus strains were isolated from 600 soil samples of four agroecological zones in China (the Southeast coastal zone (SEC), the Yangtze River zone (YZR), the Yellow River zone (YR) and the Northeast zone (NE)). Nearly 94.2% (324/344) of strains were A. flavus and 5.8% (20/344) of strains were A. parasiticus. YZR had the highest population density of Aspergillus sp. and positive rate of aflatoxin production in isolated strains (1039.3 cfu·g−1, 80.7%), the second was SEC (191.5 cfu·g−1, 48.7%), the third was YR (26.5 cfu·g−1, 22.7%), and the last was NE (2.4 cfu·g−1, 6.6%). The highest risk of AFB1 contamination on peanut was in YZR which had the largest number of AFB1 producing isolates in 1g soil, followed by SEC and YR, and the lowest was NE. The potential risk of AFB1 contamination in peanuts can increase with increasing population density and a positive rate of aflatoxin-producing Aspergillus sp. in field soils, suggesting that reducing aflatoxigenic Aspergillus sp. in field soils could prevent AFB1 contamination in peanuts. PMID:28117685

A Survey of Aflatoxin-Producing Aspergillus sp. from Peanut Field Soils in Four Agroecological Zones of China.

PubMed

Zhang, Chushu; Selvaraj, Jonathan Nimal; Yang, Qingli; Liu, Yang

2017-01-20

Peanut pods are easily infected by aflatoxin-producing Aspergillus sp.ecies from field soil. To assess the aflatoxin-producing Aspergillus sp. in different peanut field soils, 344 aflatoxin-producing Aspergillus strains were isolated from 600 soil samples of four agroecological zones in China (the Southeast coastal zone (SEC), the Yangtze River zone (YZR), the Yellow River zone (YR) and the Northeast zone (NE)). Nearly 94.2% (324/344) of strains were A. flavus and 5.8% (20/344) of strains were A. parasiticus . YZR had the highest population density of Aspergillus sp. and positive rate of aflatoxin production in isolated strains (1039.3 cfu·g -1 , 80.7%), the second was SEC (191.5 cfu·g -1 , 48.7%), the third was YR (26.5 cfu·g -1 , 22.7%), and the last was NE (2.4 cfu·g -1 , 6.6%). The highest risk of AFB₁ contamination on peanut was in YZR which had the largest number of AFB₁ producing isolates in 1g soil, followed by SEC and YR, and the lowest was NE. The potential risk of AFB₁ contamination in peanuts can increase with increasing population density and a positive rate of aflatoxin-producing Aspergillus sp. in field soils, suggesting that reducing aflatoxigenic Aspergillus sp. in field soils could prevent AFB₁ contamination in peanuts.

Toxigenic Potential of Aspergillus Species Occurring on Maize Kernels from Two Agro-Ecological Zones in Kenya

PubMed Central

Okoth, Sheila; Nyongesa, Beatrice; Ayugi, Vincent; Kang’ethe, Erastus; Korhonen, Hannu; Joutsjoki, Vesa

2012-01-01

Two agro-ecological zones in Kenya were selected to compare the distribution in maize of Aspergillus spp. and their toxigenicity. These were Nandi County, which is the main maize growing region in the country but where no human aflatoxicoses have been reported, and Makueni County where most of the aflatoxicosis cases have occurred. Two hundred and fifty-five households were sampled in Nandi and 258 in Makueni, and Aspergillus was isolated from maize. Aspergillus flavus and A. parasiticus isolates were tested for the presence of aflD and aflQ genes. Positive strains were induced to produce aflatoxins on yeast extract sucrose and quantified using liquid chromatography-tandem mass spectrometry (LCMSMS). Aspergillus flavus was the most common contaminant, and the incidence of occurrence in Nandi and Makueni was not significantly different (82.33% and 73.26%, respectively). Toxigenic strains were more prevalent than non-toxigenic strains. All the toxigenic strains from Makueni were of the S-type while those from Nandi belonged to the L-type. Quantitative differences in aflatoxin production in vitro between isolates and between strains were detected with S strains producing relatively larger amounts of total aflatoxins, B toxins and lower values for G toxins. This was in accord with the frequent aflatoxicosis outbreaks in Makueni. However some L strains produced considerable amounts of B toxins. Given the widespread distribution of toxigenic strains in both regions, the risk of aflatoxin poisoning is high when favorable conditions for toxin production occur. PMID:23202303

What are the effects of Agro-Ecological Zones and land use region boundaries on land resource projection using the Global Change Assessment Model?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Vittorio, Alan V.; Kyle, Page; Collins, William D.

Understanding potential impacts of climate change is complicated by spatially mismatched land representations between gridded datasets and models, and land use models with larger regions defined by geopolitical and/or biophysical criteria. Here in this study, we quantify the sensitivity of Global Change Assessment Model (GCAM) outputs to the delineation of Agro-Ecological Zones (AEZs), which are normally based on historical (1961–1990) climate. We reconstruct GCAM's land regions using projected (2071–2100) climate, and find large differences in estimated future land use that correspond with differences in agricultural commodity prices and production volumes. Importantly, historically delineated AEZs experience spatially heterogeneous climate impacts overmore » time, and do not necessarily provide more homogenous initial land productivity than projected AEZs. Finally, we conclude that non-climatic criteria for land use region delineation are likely preferable for modeling land use change in the context of climate change, and that uncertainty associated with land delineation needs to be quantified.« less

What are the effects of Agro-Ecological Zones and land use region boundaries on land resource projection using the Global Change Assessment Model?

DOE PAGES

Di Vittorio, Alan V.; Kyle, Page; Collins, William D.

2016-09-03

Understanding potential impacts of climate change is complicated by spatially mismatched land representations between gridded datasets and models, and land use models with larger regions defined by geopolitical and/or biophysical criteria. Here in this study, we quantify the sensitivity of Global Change Assessment Model (GCAM) outputs to the delineation of Agro-Ecological Zones (AEZs), which are normally based on historical (1961–1990) climate. We reconstruct GCAM's land regions using projected (2071–2100) climate, and find large differences in estimated future land use that correspond with differences in agricultural commodity prices and production volumes. Importantly, historically delineated AEZs experience spatially heterogeneous climate impacts overmore » time, and do not necessarily provide more homogenous initial land productivity than projected AEZs. Finally, we conclude that non-climatic criteria for land use region delineation are likely preferable for modeling land use change in the context of climate change, and that uncertainty associated with land delineation needs to be quantified.« less

Manipulating Crop Density to Optimize Nitrogen and Water Use: An Application of Precision Agroecology

NASA Astrophysics Data System (ADS)

Brown, T. T.; Huggins, D. R.; Smith, J. L.; Keller, C. K.; Kruger, C.

2011-12-01

Rising levels of reactive nitrogen (Nr) in the environment coupled with increasing population positions agriculture as a major contributor for supplying food and ecosystem services to the world. The concept of Precision Agroecology (PA) explicitly recognizes the importance of time and place by combining the principles of precision farming with ecology creating a framework that can lead to improvements in Nr use efficiency. In the Palouse region of the Pacific Northwest, USA, relationships between productivity, N dynamics and cycling, water availability, and environmental impacts result from intricate spatial and temporal variations in soil, ecosystem processes, and socioeconomic factors. Our research goal is to investigate N use efficiency (NUE) in the context of factors that regulate site-specific environmental and economic conditions and to develop the concept of PA for use in sustainable agroecosystems and science-based Nr policy. Nitrogen and plant density field trials with winter wheat (Triticum aestivum L.) were conducted at the Washington State University Cook Agronomy Farm near Pullman, WA under long-term no-tillage management in 2010 and 2011. Treatments were imposed across environmentally heterogeneous field conditions to assess soil, crop and environmental interactions. Microplots with a split N application using 15N-labeled fertilizer were established in 2011 to examine the impact of N timing on uptake of fertilizer and soil N throughout the growing season for two plant density treatments. Preliminary data show that plant density manipulation combined with precision N applications regulated water and N use and resulted in greater wheat yield with less seed and N inputs. These findings indicate that improvements to NUE and agroecosystem sustainability should consider landscape-scale patterns driving productivity (e.g., spatial and temporal dynamics of water availability and N transformations) and would benefit from policy incentives that promote a PA

Evaluations on the potential productivity of winter wheat based on agro-ecological zone in the world

NASA Astrophysics Data System (ADS)

Wang, H.; Li, Q.; Du, X.; Zhao, L.; Lu, Y.; Li, D.; Liu, J.

2015-04-01

Wheat is the most widely grown crop globally and an essential source of calories in human diets. Maintaining and increasing global wheat production is therefore strongly linked to food security. In this paper, the evaluation model of winter wheat potential productivity was proposed based on agro-ecological zone and the historical winter wheat yield data in recent 30 years (1983-2011) obtained from FAO. And the potential productions of winter wheat in the world were investigated. The results showed that the realistic potential productivity of winter wheat in Western Europe was highest and it was more than 7500 kg/hm2. The realistic potential productivity of winter wheat in North China Plain were also higher, which was about 6000 kg/hm2. However, the realistic potential productivity of winter wheat in the United States which is the main winter wheat producing country were not high, only about 3000 kg/hm2. In addition to these regions which were the main winter wheat producing areas, the realistic potential productivity in other regions of the world were very low and mainly less than 1500 kg/hm2, like in southwest region of Russia. The gaps between potential productivity and realistic productivity of winter wheat in Kazakhstan and India were biggest, and the percentages of the gap in realistic productivity of winter wheat in Kazakhstan and India were more than 40%. In Russia, the gap between potential productivity and realistic productivity of winter wheat was lowest and the percentage of the gap in realistic productivity of winter wheat in Russia was only 10%.

Agro-ecological potential of the cup plant (Silphium perfoliatum L.) from a biodiversity perspective

NASA Astrophysics Data System (ADS)

Schrader, Stefan; Schorpp, Quentin; Lena Müller, Anna; Dauber, Jens

2017-04-01

The cup plant (Silphium perfoliatum L.) is an alternative bioenergy crop that may contribute to a more environmentally friendly production of renewable resources. The potential benefits of the cup plant are the perennial cultivation without tillage and its flowering-characteristics. Hence it can be hypothesized that beneficial organisms are promoted which in turn improves the provision of ecosystem services like soil fertility and pollination. To date biomass production in Germany is based mainly on cropping systems like intensive maize cultivation that bear a risk for biodiversity and ecosystem services. The importance to counteract this development increases considering the large land requirements for significant generation of energy from biomass. To what extent cropping of the cup plant meets the expectations of a sustainable biomass production was investigated within a comprehensive assessment of soil fauna communities (earthworms, collembolans, nematodes) including their functional groups as well as pollinating insects (bees and hoverflies) including the quantification of pollen and nectar in cup-plant cultivation systems with a crop management close to agricultural practice. From the results it became obvious that the cup plant as a bioenergy crop has got the necessary potential to mitigate the negative development of biodiversity and ecosystem services, especially in regions with a large share of maize monocultures. This agro-ecological potential can only be reached if certain agronomic requirements are met, i.e. a late harvest and cultivation periods of at least five years. Under these conditions the landscape context has to be considered. Semi-natural habitats in the surrounding landscape are required for nesting and larval development of wild pollinator groups. The development of biological functions in soil is tied to the land use history i.e. previous land use: Positive developments are expected for conversion of intensively managed crop fields to the

Enteric methane emissions and their response to agro-ecological and livestock production systems dynamics in Zimbabwe.

PubMed

Svinurai, Walter; Mapanda, Farai; Sithole, Dingane; Moyo, Elisha N; Ndidzano, Kudzai; Tsiga, Alois; Zhakata, Washington

2018-03-01

Without disregarding its role as one of the key sources of sustainable livelihoods in Zimbabwe and other developing countries, livestock production contributes significantly to greenhouse gas (GHG) emissions through enteric fermentation. For the livestock sector to complement global efforts to mitigate climate change, accurate estimations of GHG emissions are required. Methane emissions from enteric fermentation in Zimbabwe were quantified over 35years under four production systems and five agro-ecological regions. The Intergovernmental Panel on Climate Change emission factor methodology was used to derive CH 4 emissions from seven livestock categories at national level. Emission intensities based on human population, domestic export of livestock meat and climate variables were used to assess emission drivers and predict future emission trends. Over the past 35years, enteric fermentation CH 4 emissions from all livestock categories ranged between 158.3 and 204.3Ggyear -1 . Communal lands, typified by indigenous livestock breeds, had the highest contribution of between 58% and 75% of the total annual emissions followed by livestock from large scale commercial (LSC) farms. The decreasing livestock population on LSC farms and consequent decline in production could explain the lack of a positive response of CH 4 emissions to human population growth, and decreasing emissions per capita over time at -0.3kg CH 4 capita -1 year -1 . The emissions trend showed that even if Zimbabwe's national livestock population doubles in 2030 relative to the 2014 estimates, the country would still remain with similar magnitude of CH 4 emission intensity as that of 1980. No significant correlations (P>0.05) were found between emissions and domestic export of beef and pork. Further research on enhanced characterisation of livestock species, population and production systems, as well as direct measurements and modelling of emissions from indigenous and exotic livestock breeds were

Spatial analysis of agro-ecological data: Detection of spatial patterns combining three different methodical approaches

NASA Astrophysics Data System (ADS)

Heuer, A.; Casper, M. C.; Vohland, M.

2009-04-01

Processes in natural systems and the resulting patterns occur in ecological space and time. To study natural structures and to understand the functional processes it is necessary to identify the relevant spatial and temporal space at which these all occur; or with other words to isolate spatial and temporal patterns. In this contribution we will concentrate on the spatial aspects of agro-ecological data analysis. Data were derived from two agricultural plots, each of about 5 hectares, in the area of Newel, located in Western Palatinate, Germany. The plots had been conventionally cultivated with a crop rotation of winter rape, winter wheat and spring barley. Data about physical and chemical soil properties, vegetation and topography were i) collected by measurements in the field during three vegetation periods (2005-2008) and/or ii) derived from hyperspectral image data, acquired by a HyMap airborne imaging sensor (2005). To detect spatial variability within the plots, we applied three different approaches that examine and describe relationships among data. First, we used variography to get an overview of the data. A comparison of the experimental variograms facilitated to distinguish variables, which seemed to occur in related or dissimilar spatial space. Second, based on data available in raster-format basic cell statistics were conducted, using a geographic information system. Here we could make advantage of the powerful classification and visualization tool, which supported the spatial distribution of patterns. Third, we used an approach that is being used for visualization of complex highly dimensional environmental data, the Kohonen self-organizing map. The self-organizing map (SOM) uses multidimensional data that gets further reduced in dimensionality (2-D) to detect similarities in data sets and correlation between single variables. One of SOM's advantages is its powerful visualization capability. The combination of the three approaches leads to

Agro-ecology, household economics and malaria in Uganda: empirical correlations between agricultural and health outcomes

PubMed Central

2014-01-01

Background This paper establishes empirical evidence relating the agriculture and health sectors in Uganda. The analysis explores linkages between agricultural management, malaria and implications for improving community health outcomes in rural Uganda. The goal of this exploratory work is to expand the evidence-base for collaboration between the agricultural and health sectors in Uganda. Methods The paper presents an analysis of data from the 2006 Uganda National Household Survey using a parametric multivariate Two-Limit Tobit model to identify correlations between agro-ecological variables including geographically joined daily seasonal precipitation records and household level malaria risk. The analysis of agricultural and environmental factors as they affect household malaria rates, disaggregated by age-group, is inspired by a complimentary review of existing agricultural malaria literature indicating a gap in evidence with respect to agricultural management as a form of malaria vector management. Crop choices and agricultural management practices may contribute to vector control through the simultaneous effects of reducing malaria transmission, improving housing and nutrition through income gains, and reducing insecticide resistance in both malaria vectors and agricultural pests. Results The econometric results show the existence of statistically significant correlations between crops, such as sweet potatoes/yams, beans, millet and sorghum, with household malaria risk. Local environmental factors are also influential- daily maximum temperature is negatively correlated with malaria, while daily minimum temperature is positively correlated with malaria, confirming trends in the broader literature are applicable to the Ugandan context. Conclusions Although not necessarily causative, the findings provide sufficient evidence to warrant purposefully designed work to test for agriculture health causation in vector management. A key constraint to modeling the

Homestead Food Production and Maternal and Child Dietary Diversity in Nepal: Variations in Association by Season and Agroecological Zone.

PubMed

Dulal, Bishnu; Mundy, Gary; Sawal, Rojee; Rana, Pooja Pandey; Cunningham, Kenda

2017-09-01

Suaahara, a large-scale integrated program, aimed to improve diets and nutritional status among women and children, in part by facilitating enhanced homestead food production (EHFP). This study examines associations between EHFP and maternal and child dietary diversity and variations by season and agroecological zone (AEZ): mountains and terai. We used data from household monitoring surveys (n = 2101 mothers; n = 994 children, 6-23 months), which included a 7-day dietary recall and maternal report on participation in 5 EHFP activities-received vegetable seeds, chicks, and technical support and participated in training and EHFP groups. We constructed binary variables for each activity and a scale (0-5) summing participation. For dietary diversity, we used the Women's Dietary Diversity Score using 10 food groups and 7 food groups for child diets. Multivariable linear regression analyses were used to assess associations between EHFP participation and dietary diversity by season and AEZ, controlling for potential confounders and clustering. In adjusted models, we found positive associations between dietary diversity and chicks, technical support, and EHFP beneficiary groups; the magnitude of the associations varied by season and AEZ. The degree of participation in 5 EHFP activities was positively associated with maternal dietary diversity in the terai (β = .24, P < .001) and mountains (β = .12, P = .01) and child dietary diversity in the terai (β = .35, P < .001) during the winter. No associations were found in the rainy season. Our findings highlight the potential for EHFP to address dietary diversity constraints among this population. Variation by subnational setting and seasonality suggest that policies and programs should be contextualized.

Agro-ecological analysis for the EU water framework directive: an applied case study for the river contract of the Seveso basin (Italy).

PubMed

Bocchi, Stefano; La Rosa, Daniele; Pileri, Paolo

2012-10-01

The innovative approach to the protection and management of water resources at the basin scale introduced by the European Union water framework directive (WFD) requires new scientific tools. WFD implementation also requires the participation of many stakeholders (administrators, farmers and citizens) with the aim of improving the quality of river waters and basin ecosystems through cooperative planning. This approach encompasses different issues, such as agro-ecology, land use planning and water management. This paper presents the results of a methodology suggested for implementing the WFD in the case of the Seveso river contract in Italy, one of the recent WFD applications. The Seveso basin in the Lombardy region has been one of the most rapidly urbanizing areas in Italy over the last 50 years. First, land use changes in the last 50 years are assessed with the use of historical aerial photos. Then, elements of an ecological network along the river corridor are outlined, and different scenarios for enhancing existing ecological connections are assessed using indicators from graph theory. These scenarios were discussed in technical workshops with involved stakeholders of the river contract. The results show a damaged rural landscape, where urbanization processes have decimated the system of linear green features (hedges/rows). Progressive reconnections of some of the identified network nodes may significantly increase the connectivity and circuitry of the study area.

History of malaria control in Tajikistan and rapid malaria appraisal in an agro-ecological setting.

PubMed

Matthys, Barbara; Sherkanov, Tohir; Karimov, Saifudin S; Khabirov, Zamonidin; Mostowlansky, Till; Utzinger, Jürg; Wyss, Kaspar

2008-10-26

Reported malaria cases in rice growing areas in western Tajikistan were at the root of a rapid appraisal of the local malaria situation in a selected agro-ecological setting where only scarce information was available. The rapid appraisal was complemented by a review of the epidemiology and control of malaria in Tajikistan and Central Asia from 1920 until today. Following a resurgence in the 1990s, malaria transmission has been reduced considerably in Tajikistan as a result of concerted efforts by the government and international agencies. The goal for 2015 is transmission interruption, with control interventions and surveillance currently concentrated in the South, where foci of Plasmodium vivax and Plasmodium falciparum persist. The rapid malaria appraisal was carried out in six communities of irrigated rice cultivation during the peak of malaria transmission (August/September 2007) in western Tajikistan. In a cross-sectional survey, blood samples were taken from 363 schoolchildren and examined for Plasmodium under a light microscope. A total of 56 farmers were interviewed about agricultural activities and malaria. Potential Anopheles breeding sites were characterized using standardized procedures. A literature review on the epidemiology and control of malaria in Tajikistan was conducted. One case of P. vivax was detected among the 363 schoolchildren examined (0.28%). The interviewees reported to protect themselves against mosquito bites and used their own concepts on fever conditions, which do not distinguish between malaria and other diseases. Three potential malaria vectors were identified, i.e. Anopheles superpictus, Anopheles pulcherrimus and Anopheles hyrcanus in 58 of the 73 breeding sites examined (79.5%). Rice paddies, natural creeks and man-made ponds were the most important Anopheles habitats. The presence of malaria vectors and parasite reservoirs, low awareness of, and protection against malaria in the face of population movements and inadequate

East Europe Report, Economic and Industrial Affairs

DTIC Science & Technology

1984-05-25

participation of all workers in this process. An effective production intensification with differentiation according to agroecological conditions, with...to concrete agroecological and economic conditions. 16 In connection with crop production specialization, particular attention must be paid to...locality in the CSSR possesses specific agroecological conditions. They predetermine the natural propriety of growing individual types of field

Distribution and Phylogeny of Microsymbionts Associated with Cowpea (Vigna unguiculata) Nodulation in Three Agroecological Regions of Mozambique

PubMed Central

Chidebe, Ifeoma N.

2017-01-01

ABSTRACT Cowpea derives most of its N nutrition from biological nitrogen fixation (BNF) via symbiotic bacteroids in root nodules. In Sub-Saharan Africa, the diversity and biogeographic distribution of bacterial microsymbionts nodulating cowpea and other indigenous legumes are not well understood, though needed for increased legume production. The aim of this study was to describe the distribution and phylogenies of rhizobia at different agroecological regions of Mozambique using PCR of the BOX element (BOX-PCR), restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP), and sequence analysis of ribosomal, symbiotic, and housekeeping genes. A total of 122 microsymbionts isolated from two cowpea varieties (IT-1263 and IT-18) grouped into 17 clades within the BOX-PCR dendrogram. The PCR-ITS analysis yielded 17 ITS types for the bacterial isolates, while ITS-RFLP analysis placed all test isolates in six distinct clusters (I to VI). BLASTn sequence analysis of 16S rRNA and four housekeeping genes (glnII, gyrB, recA, and rpoB) showed their alignment with Rhizobium and Bradyrhizobium species. The results revealed a group of highly diverse and adapted cowpea-nodulating microsymbionts which included Bradyrhizobium pachyrhizi, Bradyrhizobium arachidis, Bradyrhizobium yuanmingense, and a novel Bradyrhizobium sp., as well as Rhizobium tropici, Rhizobium pusense, and Neorhizobium galegae in Mozambican soils. Discordances observed in single-gene phylogenies could be attributed to horizontal gene transfer and/or subsequent recombinations of the genes. Natural deletion of 60 bp of the gyrB region was observed in isolate TUTVU7; however, this deletion effect on DNA gyrase function still needs to be confirmed. The inconsistency of nifH with core gene phylogenies suggested differences in the evolutionary history of both chromosomal and symbiotic genes. IMPORTANCE A diverse group of both Bradyrhizobium and Rhizobium species responsible for cowpea

Chemical Denudation and Cation Depletion in a Semi-Arid Catchment of the Long-Term Agroecological Research Observatory

NASA Astrophysics Data System (ADS)

Shaljian, M.; Keller, C. K.; Jones, K. B.; Brooks, E. S.; Huggins, D. R.

2016-12-01

The Long-Term Agroecosystem Research (LTAR) network of the USDA is a nationwide observatory and decadal-timescale field-experimental study of sustainable food production. The LTAR thus supports investigation of hydroecological and biogeochemical processes that could affect agricultural sustainability over the course of the 21st century. Mineral-derived nutrient cations are essential to fertility, and acidification of soils due to chemical fertilization may result in unsustainable chemical denudation of the soil exchange pool. Mineral weathering also contributes to base cation denudation. This study investigated base cation losses for one year in drainage from a semi-arid, rain-fed catchment at the Cook Agronomy Farm (CAF) LTAR site in southeastern Washington. We measured flows, analyzed drainage samples and estimated hydrologic effluxes of base cations from the catchment. The total dissolved base cation denudation rate at CAF-LTAR is about 40 kg ha-1 yr-1, which is comparable to other catchments on silicate terranes. The 2.1keq ha-1 yr-1 of denuded cationic charge is dominated by Ca2+ (61%) and Mg2+ (35%). Principal counter-ions are HCO3- (43%), NO3- (38%) and SO42- (16%), suggesting that both H2CO3 and HNO3 are important acids. Comparing 2008 soil pH and base saturation at CAF-LTAR to a nearby native prairie site, we preliminarily estimate a loss of 120 keq ha-1 of base cations from the upper 1.5m of the soil exchangeable cation pool. Dividing this depletion by the estimated denudation flux returns 60 years, which is approximately the interval of chemically intensive agriculture here. This may suggest that the source of exported base cations in drainage is primarily cation exchange rather than mineral weathering. The LTAR observatory will support ongoing monitoring and experimentation necessary to better understand base cation depletion and how it interacts with agroecological changes over the next several decades.

Distribution and Phylogeny of Microsymbionts Associated with Cowpea (Vigna unguiculata) Nodulation in Three Agroecological Regions of Mozambique.

PubMed

Chidebe, Ifeoma N; Jaiswal, Sanjay K; Dakora, Felix D

2018-01-15

Cowpea derives most of its N nutrition from biological nitrogen fixation (BNF) via symbiotic bacteroids in root nodules. In Sub-Saharan Africa, the diversity and biogeographic distribution of bacterial microsymbionts nodulating cowpea and other indigenous legumes are not well understood, though needed for increased legume production. The aim of this study was to describe the distribution and phylogenies of rhizobia at different agroecological regions of Mozambique using PCR of the BOX element (BOX-PCR), restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP), and sequence analysis of ribosomal, symbiotic, and housekeeping genes. A total of 122 microsymbionts isolated from two cowpea varieties (IT-1263 and IT-18) grouped into 17 clades within the BOX-PCR dendrogram. The PCR-ITS analysis yielded 17 ITS types for the bacterial isolates, while ITS-RFLP analysis placed all test isolates in six distinct clusters (I to VI). BLAST n sequence analysis of 16S rRNA and four housekeeping genes ( glnII , gyrB , recA , and rpoB ) showed their alignment with Rhizobium and Bradyrhizobium species. The results revealed a group of highly diverse and adapted cowpea-nodulating microsymbionts which included Bradyrhizobium pachyrhizi , Bradyrhizobium arachidis , Bradyrhizobium yuanmingense , and a novel Bradyrhizobium sp., as well as Rhizobium tropici , Rhizobium pusense , and Neorhizobium galegae in Mozambican soils. Discordances observed in single-gene phylogenies could be attributed to horizontal gene transfer and/or subsequent recombinations of the genes. Natural deletion of 60 bp of the gyrB region was observed in isolate TUTVU7; however, this deletion effect on DNA gyrase function still needs to be confirmed. The inconsistency of nifH with core gene phylogenies suggested differences in the evolutionary history of both chromosomal and symbiotic genes. IMPORTANCE A diverse group of both Bradyrhizobium and Rhizobium species responsible for cowpea

Factors influencing the prevalence and infestation levels of Varroa destructor in honeybee colonies in two highland agro-ecological zones of Uganda.

PubMed

Chemurot, Moses; Akol, Anne M; Masembe, Charles; de Smet, Lina; Descamps, Tine; de Graaf, Dirk C

2016-04-01

Varroa mites are ecto-parasites of honeybees and are a threat to the beekeeping industry. We identified the haplotype of Varroa mites and evaluated potential factors that influence their prevalence and infestation levels in the eastern and western highland agro-ecological zones of Uganda. This was done by collecting samples of adult worker bees between December 2014 and September 2015 in two sampling moments. Samples of bees were screened for Varroa using the ethanol wash method and the mites were identified by molecular techniques. All DNA sequences obtained from sampled mite populations in the two zones were 100 % identical to the Korean Haplotype (AF106899). Mean mite prevalence in the apiaries was 40 and 53 % for the western and eastern zones, respectively, during the first sampling. Over the second sampling, mean mite prevalence increased considerably in the western (59 %) but not in the eastern (51 %) zone. Factors that were associated with Varroa mite infestation levels include altitude, nature of apiary slope and apiary management practices during the first sampling. Our results further showed that Varroa mites were spreading from lower to higher elevations. Feral colonies were also infested with Varroa mites at infestation levels not significantly different from those in managed colonies. Colony productivity and strength were not correlated to mite infestation levels. We recommend a long-term Varroa mite monitoring strategy in areas of varying landscape and land use factors for a clear understanding of possible changes in mite infestation levels among African honeybees for informed decision making.

Economy and political ecology perspective of Indonesian food security at South Sulawesi

NASA Astrophysics Data System (ADS)

Fahmid, I. M.; Harun, H.; Fahmid, M. M.; Saadah; Busthanul, N.

2018-05-01

The purposes of this study are: firstly, to demonstrate the relations of agro-ecological function, agricultural innovation system, social-ecological system and political ecology to encourage production for Indonesian Food Security Program (PKP) in South Sulawesi. Secondly, to identify the most influential and interested stakeholders in the success of PKP program. The study conducted by applying an interdisciplinary analysis of triangulation method. The result showed, the success of PKP in South Sulawesi with the achievement of 2 million rice overstock mainly impacted by the application of agro-ecological concept, agricultural innovation system, and political ecology while disregarding the concept of social agroecology.

Field Level RNAi-Mediated Resistance to Cassava Brown Streak Disease across Multiple Cropping Cycles and Diverse East African Agro-Ecological Locations

PubMed Central

Wagaba, Henry; Beyene, Getu; Aleu, Jude; Odipio, John; Okao-Okuja, Geoffrey; Chauhan, Raj Deepika; Munga, Theresia; Obiero, Hannington; Halsey, Mark E.; Ilyas, Muhammad; Raymond, Peter; Bua, Anton; Taylor, Nigel J.; Miano, Douglas; Alicai, Titus

2017-01-01

Cassava brown streak disease (CBSD) presents a serious threat to cassava production in East and Central Africa. Currently, no cultivars with high levels of resistance to CBSD are available to farmers. Transgenic RNAi technology was employed to combat CBSD by fusing coat protein (CP) sequences from Ugandan cassava brown streak virus (UCBSV) and Cassava brown streak virus (CBSV) to create an inverted repeat construct (p5001) driven by the constitutive Cassava vein mosaic virus promoter. Twenty-five plant lines of cultivar TME 204 expressing varying levels of small interfering RNAs (siRNAs) were established in confined field trials (CFTs) in Uganda and Kenya. Within an initial CFT at Namulonge, Uganda, non-transgenic TME 204 plants developed foliar and storage root CBSD incidences at 96–100% by 12 months after planting. In contrast, 16 of the 25 p5001 transgenic lines showed no foliar symptoms and had less than 8% of their storage roots symptomatic for CBSD. A direct positive correlation was seen between levels of resistance to CBSD and expression of transgenic CP-derived siRNAs. A subsequent CFT was established at Namulonge using stem cuttings from the initial trial. All transgenic lines established remained asymptomatic for CBSD, while 98% of the non-transgenic TME 204 stake-derived plants developed storage roots symptomatic for CBSD. Similarly, very high levels of resistance to CBSD were demonstrated by TME 204 p5001 RNAi lines grown within a CFT over a full cropping cycle at Mtwapa, coastal Kenya. Sequence analysis of CBSD causal viruses present at the trial sites showed that the transgenic lines were exposed to both CBSV and UCBSV, and that the sequenced isolates shared >90% CP identity with transgenic CP sequences expressed by the p5001 inverted repeat expression cassette. These results demonstrate very high levels of field resistance to CBSD conferred by the p5001 RNAi construct at diverse agro-ecological locations, and across the vegetative cropping cycle

Aflatoxin contamination of groundnut and maize in Zambia: observed and potential concentrations.

PubMed

Kachapulula, P W; Akello, J; Bandyopadhyay, R; Cotty, P J

2017-06-01

The aims of the study were to quantify aflatoxins, the potent carcinogens associated with stunting and immune suppression, in maize and groundnut across Zambia's three agroecologies and to determine the vulnerability to aflatoxin increases after purchase. Aflatoxin concentrations were determined for 334 maize and groundnut samples from 27 districts using lateral-flow immunochromatography. Seventeen per cent of crops from markets contained aflatoxin concentrations above allowable levels in Zambia (10 μg kg -1 ). Proportions of crops unsafe for human consumption differed significantly (P < 0·001) among agroecologies with more contamination (38%) in the warmest (Agroecology I) and the least (8%) in cool, wet Agroecology III. Aflatoxin in groundnut (39 μg kg -1 ) and maize (16 μg kg -1 ) differed (P = 0·032). Poor storage (31°C, 100% RH, 1 week) increased aflatoxin in safe crops by over 1000-fold in both maize and groundnut. The L morphotype of Aspergillus flavus was negatively correlated with postharvest increases in groundnut. Aflatoxins are common in Zambia's food staples with proportions of unsafe crops dependent on agroecology. Fungal community structure influences contamination suggesting Zambia would benefit from biocontrol with atoxigenic A. flavus. Aflatoxin contamination across the three agroecologies of Zambia is detailed and the case for aflatoxin management with atoxigenic biocontrol agents provided. The first method for evaluating the potential for aflatoxin increase after purchase is presented. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of The Society for Applied Microbiology.

Forty research issues for the redesign of animal production systems in the 21st century.

PubMed

Dumont, B; González-García, E; Thomas, M; Fortun-Lamothe, L; Ducrot, C; Dourmad, J Y; Tichit, M

2014-08-01

Agroecology offers a scientific and operational framework for redesigning animal production systems (APS) so that they better cope with the coming challenges. Grounded in the stimulation and valorization of natural processes to reduce inputs and pollutions in agroecosystems, it opens a challenging research agenda for the animal science community. In this paper, we identify key research issues that define this agenda. We first stress the need to assess animal robustness by measurable traits, to analyze trade-offs between production and adaptation traits at within-breed and between-breed level, and to better understand how group selection, epigenetics and animal learning shape performance. Second, we propose research on the nutritive value of alternative feed resources, including the environmental impacts of producing these resources and their associated non-provisioning services. Third, we look at how the design of APS based on agroecological principles valorizes interactions between system components and promotes biological diversity at multiple scales to increase system resilience. Addressing such challenges requires a collection of theories and models (concept-knowledge theory, viability theory, companion modeling, etc.). Acknowledging the ecology of contexts and analyzing the rationales behind traditional small-scale systems will increase our understanding of mechanisms contributing to the success or failure of agroecological practices and systems. Fourth, the large-scale development of agroecological products will require analysis of resistance to change among farmers and other actors in the food chain. Certifications and market-based incentives could be an important lever for the expansion of agroecological alternatives in APS. Finally, we question the suitability of current agriculture extension services and public funding mechanisms for scaling-up agroecological practices and systems.

Analyzing anthropogenic pressures in soils of agro-ecological protected coastal wetlands in L'Albufera de Valencia Natural Park, Spain

NASA Astrophysics Data System (ADS)

Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Gimeno, Eugenia; Picó, Yolanda

2013-04-01

Coastal wetlands, despite the importance of their environmental and ecological functions, are areas that suffer of great pressures. Most of them are produced by the rapid development of the surrounding artificial landscapes. Socio-economic factors such as population growth and urban-industrial surfaces expansion introduce pressures on the nearby environment affecting the quality of natural and agricultural landscapes. The present research analyses interconnections among landscapes (urban, agricultural and natural) under the hypothesis that urban-artificial impacts could be detected on soils of an agro-ecological protected area, L'Albufera de Valencia, Natural Park, located in the vicinity or the urban area of the City of Valencia, Spain. It has been developed based on Environmental Forensics criteria witch attend two types of anthropogenic pressures: (1) direct, due to artificialization of soil covers that produce anthropogenic soil sealing, and (2) indirect, which are related to water flows coming from urban populations throw artificial water networks (sewage and irrigation systems) and that ultimately will be identified by the presence of o emerging-pharmaceuticals contaminants in soils of the protected area. For the first case, soil sealing a methodology based on temporal comparison of two digital layers for the years 1991 and 2011 applying Geographical Information Systems and Landscapes Metrics were undertaken. To determine presence of emerging contaminants 15 soil samples within the Natural Park were analyzed applying liquid chromatography tandem mass spectrometry for the detection of 17 pharmaceutical compounds. Results show that both processes are present in the Natural Park with a clear geographical pattern. Either soil sealing or detection of pharmaceuticals are more intensive in the northern part of the study area. This is related to population density (detection of pharmaceuticals) and land cover conversion from agricultural and natural surfaces to

Detection and spatial distribution of multiple-contaminants in agro-ecological Mediterranean wetlands (Marjal de Pego-Oliva, Spain)

NASA Astrophysics Data System (ADS)

Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Gimeno-García, Eugenia; Picó, Yolanda; Masia, Ana

2015-04-01

Socio economic activities are more and more producing amounts (in quantity and quality) of non desirable chemical substances (contaminants) that can be found in open air environments. As many of these products persist and may also circulate among environmental compartments, the cumulative incidence of such multiple contaminants combination may be a cause of treat that should not exists taking only in consideration concentrations of each contaminant individually because the number and the type of compounds are not known, as well as their cumulative and interaction effects. Thus prior to any further work analyzing the environmental risk of multiple contaminants their identification and level of concentration is required. In this work the potential presence of multiple contaminants of anthropogenic origin in a protected agro-ecological Mediterranean wetland is studied: the Pego-Oliva Marsh Natural Park (Valencian Community, Spain), which is characterized by a long history of human pressures, such as marsh transformation for agricultural uses. Two major groups of relevant pollutants have been targeted according o two distinct environmental matrices: seven heavy metals in soils (Cd, Co, Cr, Cu, Ni, Pb and Zn) and fourteen emerging contaminants /drugs of abuse in surface waters of the natural lagoon, rivers and artificial irrigation networks (6-ACMOR, AMP, BECG, COC, ECGME, HER, KET, MAMP, MDA, MDMA, MET, MOR, THC, THC-COOH). The wetland was divided in nine representative zones with different types of land cover and land use. For soils, 24 samples were collected and for waters 33 taking in consideration the spatial representativeness of the above mention nine environments. Spatial analysis applying Geographical Information Systems to determine areas with greater incidence of both types of contaminants were also performed. With regard to heavy metals, Zn showed values under the detection limits in all samples, the remainder metals appeared in concentrations surpassing the

Calibration of Daycent biogeochemical model for rice paddies in three agro-ecological zones in Peninsular India to optimize cropping practices and predict GHG emissions

NASA Astrophysics Data System (ADS)

Rajan, S.; Kritee, K.; Keough, C.; Parton, W. J.; Ogle, S. M.

2014-12-01

Rice is a staple for nearly half of the world population with irrigated and rainfed lowland rice accounting for about 80% of the worldwide harvested rice area. Increased atmospheric CO2 and rising temperatures are expected to adversely affect rice yields by the end of the 21st century. In addition, different crop management practices affect methane and nitrous oxide emissions from rice paddies antagonistically warranting a review of crop management practices such that farmers can adapt to the changing climate and also help mitigate climate change. The Daily DayCent is a biogeochemical model that operates on a daily time step, driven by four ecological drivers, i.e. climate, soil, vegetation, and management practices. The model is widely used to simulate daily fluxes of various gases, plant productivity, nutrient availability, and other ecosystem parameters in response to changes in land management and climate. We employed the DayCent model as a tool to optimize rice cropping practices in Peninsular India so as to develop a set of farming recommendations to ensure a triple win (i.e. higher yield, higher profit and lower GHG emissions). We applied the model to simulate both N2O and CH4 emissions, and crop yields from four rice paddies in three different agro-ecological zones under different management practices, and compared them with measured GHG and yield data from these plots. We found that, like all process based models, the biggest constraint in using the model was input data acquisition. Lack of accurate documentation of historic land use and management practices, missing historical daily weather data, and difficulty in obtaining digital records of soil and crop/vegetation parameters related to our experimental plots came in the way of our execution of this model. We will discuss utilization of estimates based on available literature, or knowledge-based values in lieu of missing measured parameters in our simulations with DayCent which could prove to be a

Effect of agro-ecological zone and grazing system on incidence of East Coast Fever in calves in Mbale and Sironko Districts of Eastern Uganda.

PubMed

Rubaire-Akiiki, Christopher M; Okello-Onen, Joseph; Musunga, David; Kabagambe, Edmond K; Vaarst, Mettee; Okello, David; Opolot, Charles; Bisagaya, A; Okori, C; Bisagati, C; Ongyera, S; Mwayi, M T

2006-08-17

Between May 2002 and February 2003 a longitudinal survey was carried out in Mbale and Sironko Districts of Eastern Uganda to determine the influence of agro-ecological zones (AEZ) and grazing systems on tick infestation patterns and incidence of East Coast Fever (ECF) in bovine calves. The study area was stratified into AEZ (lowland, midland and upland) and grazing systems {zero grazing (ZG), restricted-outdoor grazing (ROG) and communal grazing (CG)}, whose strata had previously been shown to influence the prevalence of ECF, babesiosis and anaplasmosis. One hundred and eighty-five smallholder dairy farms with a total of 198 calves of both sexes, between the ages of 1 day and 6 weeks, were purposively selected from the AEZ-grazing system strata. Nine dynamic cohorts (11-51 calves in each) of these calves were examined and sampled monthly. Ticks infesting the calves were counted from one side of the animal body and categorized into the different species, sex and feeding status. Sera were collected at recruitment and monthly thereafter and antibodies against Theileria parva, T. mutans, Babesia bigemina, B. bovis and Anaplasma marginale were measured using ELISA. Tick challenge (total and specific) varied with AEZ and grazing system. The risk of infection with T. parva was higher in the lowland zone compared to the upland zone (hazard ratio (HR)=2.59; 95% CI: 1.00-6.34). The risk of infection with T. parva was higher in the CG system than the ZG system (HR=10.00; 95% CI: 3.61-27.92). The incidence risk for sero-conversion, over the 10 months study period, was 62, 16 and 9% in the lowland, midland and upland zones, respectively. Ninety-eight percent of the calves in lowland-CG stratum sero-converted by the age of 6 months, while 56 and 8% did so in the lowland-ROG and the lowland-ZG stratum, respectively. The results of this study show the need to consider farm circumstances and the variation in ECF risk, both spatially and temporally when designing control strategies

Assessing the value of transgenic crops.

PubMed

Lacey, Hugh

2002-10-01

In the current controversy about the value of transgenic crops, matters open to empirical inquiry are centrally at issue. One such matter is a key premise in a common argument (that I summarize) that transgenic crops should be considered to have universal value. The premise is that there are no alternative forms of agriculture available to enable the production of sufficient food to feed the world. The proponents of agroecology challenge it, claiming that agroecology provides an alternative, and they deny the claim that it is well founded on empirical evidence. It is, therefore, a matter of both social and scientific importance that this premise and the criticisms of it be investigated rigorously and empirically, so that the benefits and disadvantages of transgenic-intensive agriculture and agroecology can be compared in a reliable way. Conducting adequate investigation about the potential contribution of agroecology requires that the cultural conditions of its practice (and, thus, of the practices and movements of small-scale farmers in the "third world") be strengthened--and this puts the interests of investigation into tension with the socio-economic interests driving the development of transgenics. General issues about relationship between ethical argument and empirical (scientific) investigation are raised throughout the article.

The California Biomass Crop Adoption Model estimates biofuel feedstock crop production across diverse agro-ecological zones within the state, under different future climates

NASA Astrophysics Data System (ADS)

Kaffka, S.; Jenner, M.; Bucaram, S.; George, N.

2012-12-01

Both regulators and businesses need realistic estimates for the potential production of biomass feedstocks for biofuels and bioproducts. This includes the need to understand how climate change will affect mid-tem and longer-term crop performance and relative advantage. The California Biomass Crop Adoption Model is a partial mathematical programming optimization model that estimates the profit level needed for new crop adoption, and the crop(s) displaced when a biomass feedstock crop is added to the state's diverse set of cropping systems, in diverse regions of the state. Both yield and crop price, as elements of profit, can be varied. Crop adoption is tested against current farmer preferences derived from analysis of 10 years crop production data for all crops produced in California, collected by the California Department of Pesticide Regulation. Analysis of this extensive data set resulted in 45 distinctive, representative farming systems distributed across the state's diverse agro-ecological regions. Estimated yields and water use are derived from field trials combined with crop simulation, reported elsewhere. Crop simulation is carried out under different weather and climate assumptions. Besides crop adoption and displacement, crop resource use is also accounted, derived from partial budgets used for each crop's cost of production. Systematically increasing biofuel crop price identified areas of the state where different types of crops were most likely to be adopted. Oilseed crops like canola that can be used for biodiesel production had the greatest potential to be grown in the Sacramento Valley and other northern regions, while sugar beets (for ethanol) had the greatest potential in the northern San Joaquin Valley region, and sweet sorghum in the southern San Joaquin Valley. Up to approximately 10% of existing annual cropland in California was available for new crop adoption. New crops are adopted if the entire cropping system becomes more profitable. In

Transpiration Response and Growth in Pearl Millet Parental Lines and Hybrids Bred for Contrasting Rainfall Environments

PubMed Central

Medina, Susan; Gupta, S. K.; Vadez, Vincent

2017-01-01

Under conditions of high vapor pressure deficit (VPD) and soil drying, restricting transpiration is an important avenue to gain efficiency in water use. The question we raise in this article is whether breeding for agro-ecological environments that differ for the rainfall have selected for traits that control plant water use. These are measured in pearl millet materials bred for zones varying in rainfall (8 combinations of parent and F1-hybrids, 18 F1-hybrids and then 40 F1-hybrids). In all cases, we found an agro-ecological variation in the slope of the transpiration response to increasing VPD, and parental line variation in the transpiration response to soil drying within hybrids/parent combinations. The hybrids adapted to lower rainfall had higher transpiration response curves than those from the highest rainfall zones, but showed no variation in how transpiration responded to soil drying. The genotypes bred for lower rainfall zones showed lower leaf area, dry matter, thicker leaves, root development, and exudation, than the ones bred for high rainfall zone when grown in the low VPD environment of the greenhouse, but there was no difference in their root length neither on the root/shoot index in these genotypes. By contrast, when grown under high VPD conditions outdoors, the lower rainfall hybrids had the highest leaf, tiller, and biomass development. Finally, under soil drying the genotypes from the lower rainfall accumulated less biomass than the ones from higher rainfall zone, and so did the parental lines compared to the hybrids. These differences in the transpiration response and growth clearly showed that breeding for different agro-ecological zones also bred for different genotype strategies in relation to traits related to plant water use. Highlights: • Variation in transpiration response reflected breeding for agro-ecological zones • Different growth strategies depended on the environmental conditions • Different ideotypes reflected rainfall

Transpiration Response and Growth in Pearl Millet Parental Lines and Hybrids Bred for Contrasting Rainfall Environments.

PubMed

Medina, Susan; Gupta, S K; Vadez, Vincent

2017-01-01

Under conditions of high vapor pressure deficit (VPD) and soil drying, restricting transpiration is an important avenue to gain efficiency in water use. The question we raise in this article is whether breeding for agro-ecological environments that differ for the rainfall have selected for traits that control plant water use. These are measured in pearl millet materials bred for zones varying in rainfall (8 combinations of parent and F 1 -hybrids, 18 F 1 -hybrids and then 40 F 1 -hybrids). In all cases, we found an agro-ecological variation in the slope of the transpiration response to increasing VPD, and parental line variation in the transpiration response to soil drying within hybrids/parent combinations. The hybrids adapted to lower rainfall had higher transpiration response curves than those from the highest rainfall zones, but showed no variation in how transpiration responded to soil drying. The genotypes bred for lower rainfall zones showed lower leaf area, dry matter, thicker leaves, root development, and exudation, than the ones bred for high rainfall zone when grown in the low VPD environment of the greenhouse, but there was no difference in their root length neither on the root/shoot index in these genotypes. By contrast, when grown under high VPD conditions outdoors, the lower rainfall hybrids had the highest leaf, tiller, and biomass development. Finally, under soil drying the genotypes from the lower rainfall accumulated less biomass than the ones from higher rainfall zone, and so did the parental lines compared to the hybrids. These differences in the transpiration response and growth clearly showed that breeding for different agro-ecological zones also bred for different genotype strategies in relation to traits related to plant water use. Highlights : • Variation in transpiration response reflected breeding for agro-ecological zones • Different growth strategies depended on the environmental conditions • Different ideotypes reflected

Agroecology for the Shrinking City

EPA Science Inventory

Many cities are experiencing long-term declines in population and economic activity. As a result, frameworks for urban sustainability need to address the unique challenges and opportunities of such shrinking cities. Shrinking, particularly in the U.S., has led to extensive vacant...

Distribution of ticks infesting ruminants and risk factors associated with high tick prevalence in livestock farms in the semi-arid and arid agro-ecological zones of Pakistan.

PubMed

Rehman, Abdul; Nijhof, Ard M; Sauter-Louis, Carola; Schauer, Birgit; Staubach, Christoph; Conraths, Franz J

2017-04-19

Tick infestation is the major problem for animal health that causes substantial economic losses, particularly in tropical and subtropical countries. To better understand the spatial distribution of tick species and risk factors associated with tick prevalence in livestock in Pakistan, ticks were counted and collected from 471 animals, including 179 cattle, 194 buffaloes, 80 goats and 18 sheep, on 108 livestock farms in nine districts, covering both semi-arid and arid agro-ecological zones. In total, 3,807 ticks representing four species were collected: Hyalomma anatolicum (n = 3,021), Rhipicephalus microplus (n = 715), Hyalomma dromedarii (n = 41) and Rhipicephalus turanicus (n = 30). The latter species is reported for the first time from the study area. Rhipicephalus microplus was the predominant species in the semi-arid zone, whereas H. anatolicum was the most abundant species in the arid zone. The overall proportion of tick-infested ruminants was 78.3% (369/471). It was highest in cattle (89.9%), followed by buffaloes (81.4%), goats (60.0%) and sheep (11.1%). The median tick burden significantly differed among animal species and was highest in cattle (median 58), followed by buffaloes (median 38), goats (median 19) and sheep (median 4.5). Female animals had significantly higher tick burdens than males and, in large ruminants, older animals carried more ticks than younger animals. The intensity of infestation was significantly lower in indigenous animals compared to exotic and crossbred cows. Analysis of questionnaire data revealed that the absence of rural poultry, not using any acaricides, traditional rural housing systems and grazing were potential risk factors associated with a higher tick prevalence in livestock farms. Absence of rural poultry, not performing acaricide treatments, traditional rural housing systems and grazing were important risk factors associated with higher tick prevalence in livestock farms. Age, gender, breed and animal

Conservation in Brazil's Chocolate Forest: The Unlikely Persistence of the Traditional Cocoa Agroecosystem.

PubMed

JOHNS

1999-01-01

/ In southern Bahia, Brazil, the traditional cocoa agroecosystem with a dense shade canopy of native trees is now recognized as a secondary conservation route for highly endangered Atlantic Rainforest species. This "chocolate forest" of the densely shaded farms persists despite a massive 20-year Brazilian government modernization program in which shade was seen as a chief impediment to raising cocoa production. The objective of this study was to determine how this traditional agroecosystem endured. Although dense shade limits cocoa yield, it provides several agroecological benefits: control of insect pests and weeds, microclimate stability, and soil fertility maintenance. A keycomponent of modernization efforts was a shade-tree removal program designed to maximize cocoa production by using low shade and fertilizer while substituting agrochemicals for many beneficial roles of the overhead trees. This research found that many farmers rejected, or only partially accepted, the shade reduction process although it promised much higher cocoa yield and profit. Farmers employing a wide range of shading were interviewed, and it was found that decisions to remove or maintain the shade trees were linked to both agroecological and risk-minimization factors. Farmers' perceptions of the agroecological functions of the shade trees and individual willingness to entertain the economic risk associated with substituting agrochemicals for these were important. A less-profitable, but lower-risk approach of occasional fertilizer and agrochemical use with the traditional shade intact was a rational and widespread choice. Policies designed to maintain the traditional agroecosystem through the current economic crisis should heed the multiple functions of the overhead trees. KEY WORDS: Conservation; Brazil; Atlantic Rainforest; Cocoa; Agroecology; Risk; Agroforestry

Indigenous food ingredients for complementary food formulations to combat infant malnutrition in Benin: a review.

PubMed

Chadare, Flora J; Madode, Yann E; Fanou-Fogny, Nadia; Kindossi, Janvier M; Ayosso, Juvencio Og; Honfo, S Hermann; Kayodé, Ap Polycarpe; Linnemann, Anita R; Hounhouigan, D Joseph

2018-01-01

This paper reviews indigenous Beninese food resources as potential ingredients for complementary infant foods with the aim to develop affordable formulations for low-income households in each agro-ecological zone of the country. Potential ingredients were selected on their documented nutritional value. The selected foods encompass 347 food resources, namely 297 plant products from home gardens or collected from natural vegetation and 50 animals, either domesticated or from the wild. The compiled data reveal that the distribution of the available food resources was unbalanced between agro-ecological zones. Only a few animal ingredients are obtainable in northern Benin. Most resources are seasonal, but their availability may be extended. A high variation was observed in energy and nutrient contents. Antinutritional factors were identified in some resources, but processing techniques were reported to reduce their presence in meals. In general, ingredients from local tree foods (Adansonia digitata, Parkia biglobosa) were adequate as sources of nutrients for complementary infant foods. Based on this review, local foods for the development of complementary food formulas for Beninese infants and children may be selected for each agro-ecological zone. The approach used is exemplary for other sub-Saharan African countries in need of complementary infant foods. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Principal factors of soil spatial heterogeneity and ecosystem services at the Central Chernozemic Region of Russia

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Valentini, Riccardo

2013-04-01

The essential spatial heterogeneity is mutual feature for most natural and man-changed soils at the Central Chernozemic Region of Russia which is not only one of the biggest «food baskets» in RF but very important regulator of ecosystem principal services at the European territory of Russia. The original spatial heterogeneity of dominated here forest-steppe and steppe Chernozems and the other soils has been further complicated by a specific land-use history and different-direction soil successions due to environmental changes and more than 1000-year history of human impacts. The carried out long-term researches of representative natural, rural and urban landscapes in Kursk, Orel, Tambov and Voronezh oblasts give us the regional multi-factorial matrix of elementary soil cover patterns (ESCP) with different land-use practices and history, soil-geomorphologic features, environmental and microclimate conditions. The validation and ranging of the limiting factors of ESCP regulation and development, ecosystem principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of regional and local GIS, soil spatial patterns mapping, traditional regression kriging, correlation tree models. The outcomes of statistical modeling show the essential amplification of erosion, dehumification and CO2 emission, acidification and alkalization, disaggregation and overcompaction processes due to violation of agroecologically sound land-use systems and traditional balances of organic matter, nutrients, Ca and Na in agrolandscapes. Due to long-term intensive and out-of-balance land-use practices the famous Russian Chernozems begin to lose not only their unique natural features of (around 1 m of humus horizon, 4-6% of Corg and favorable agrophysical features), but traditional soil cover patterns, ecosystem services and agroecological functions. Key-site monitoring

Land degradation and climate change: building climate resilience in agriculture

USDA-ARS?s Scientific Manuscript database

Land degradation and climate change pose enormous risks to global food security. Land degradation increases the vulnerability of agroecological systems to climate change and reduces the effectiveness of adaptation options. Yet these interactions have largely been omitted from climate impact assessme...

Zonal assessment of environmental driven settlement abandonment in the Trans-Tisza region (Central Europe) during the early phase of the Little Ice Age

NASA Astrophysics Data System (ADS)

Pinke, Zsolt; Ferenczi, László; F. Romhányi, Beatrix; Gyulai, Ferenc; Laszlovszky, József; Mravcsik, Zoltán; Pósa, Patricia; Gábris, Gyula

2017-02-01

This investigation focuses on the transformation of the settlement pattern of a lowland landscape as a social response to the hydrological challenges emerging in the late 13th century (c.) overture of the Little Ice Age (LIA). Results of the applied zonal analysis suggested a strong spatial connection between the geomorphological conditions, the agro-ecological suitability (good-excellent, medium and low) and the stability or instability of settlement patterns. The elevation means of archaeological sites in the deserted zones proved significantly lower than those in zones with permanent settlement pattern (Brunner-Munzel test p ≤ 0.01; n = 377). Additionally, the late medieval (14th-mid-16th centuries) site group was situated, on average, significantly higher than the high medieval (late 10th-13th centuries) site group within the permanent zones (Brunner-Munzel test p ≤ 0.01; n = 219). These outcomes statistically confirm that not only did low-lying inhabited areas shrink significantly, but they also displaced vertically in the first phase of the LIA. When analysing the relation of settlement pattern to soil conditions, the proportion of areas with good-excellent agro-ecological suitability proved 1.5-2 times higher in the permanent zones than in the deserted and uninhabited settlement suitability zones. Using the linear model, different regression coefficients appeared between the extension of the high and medium agro-ecological suitability zones and the number of high and late medieval settlements. The different coefficients in the studied two periods suggest that the issue of agroecological suitability in the High Middle Ages did not bear such importance as in the late Middle Ages. The findings of the paper may contribute to answering the question why the relatively dense settlement pattern of the deserted zones was abandoned almost completely by the end of the 13th c. in areas where flood proneness and weak agro-ecological suitability both meant a serious

Agroecology of corn production in Tlaxcala, Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Altieri, M.A.; Trujillo, J.

1987-06-01

The primary components of Tlaxcalan corn agriculture are described, including cropping patterns employed, resource management strategies, and interactions of human and biological factors. Tlaxcalan farmers grow corn in an array of polyculture and agroforestry designs that result in a series of ecological processes important for insect pest and soil fertility management. Measurements derived from a few selected fields show that trees integrated into cropping systems modify the aerial and soil environment of associated understory corn plants, influencing their growth and yields. With decreasing distance from trees, surface concentrations of most soil nutrients increase. Certain tree species affect corn yields moremore » than others. Arthropod abundance also varies depending on their degree of association with one or more of the vegetational components of the system. Densities of predators and the corn pest Macrodactylus sp. depend greatly on the presence and phenology of adjacent alfalfa strips. Although the data were derived from nonreplicated fields, they nevertheless point out some important trends, information that can be used to design new crop association that will achieve sustained soil fertility and low pest potentials.« less

Agroecological niches and thrips (Thysanoptera: Thripidae) dynamics

Treesearch

Michael E. Irwin

1991-01-01

In 1975, Illinois experienced an exceptionally mild winter, followed by a warm spring. This sequence of climatic events resulted in a massive outbreak of the soybean thrips, Sericothrips variabilis (Beach), along with large numbers of the flower thrips, Frankliniella tritici (Fitch). The outbreak covered an area of over 600...

7 CFR 600.1 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... soil, water, air, plant, and animal resources with consideration of the many human (economic and... specialties, including soil science, soil conservation, agronomy, biology, agroecology, range conservation... formerly the Soil Conservation Service (SCS) which was established by the Soil Conservation Act of 1935...

7 CFR 600.1 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... soil, water, air, plant, and animal resources with consideration of the many human (economic and... specialties, including soil science, soil conservation, agronomy, biology, agroecology, range conservation... formerly the Soil Conservation Service (SCS) which was established by the Soil Conservation Act of 1935...

7 CFR 600.1 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... soil, water, air, plant, and animal resources with consideration of the many human (economic and... specialties, including soil science, soil conservation, agronomy, biology, agroecology, range conservation... formerly the Soil Conservation Service (SCS) which was established by the Soil Conservation Act of 1935...

7 CFR 600.1 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... soil, water, air, plant, and animal resources with consideration of the many human (economic and... specialties, including soil science, soil conservation, agronomy, biology, agroecology, range conservation... formerly the Soil Conservation Service (SCS) which was established by the Soil Conservation Act of 1935...

Social vulnerability to climate change in primary producers: A typology approach

USDA-ARS?s Scientific Manuscript database

Adaptation in agro-ecological systems will be important for moderating the impacts of climate change. Vulnerability assessments provide the basis for developing strategies to reduce social vulnerability and plan for climate adaptation. Primary industries have been identified as the most vulnerable i...

Pathogenic Variation of Phakopsora pachyrhizi Infecting Soybean in Nigeria

USDA-ARS?s Scientific Manuscript database

Soybean rust is an important disease in Nigeria and many other soybean-producing countries world-wide. To determine the geographical distribution of soybean rust in Nigeria, soybean fields were surveyed in the Derived Savanna, Northern Guinea Savanna, and Southern Guinea Savanna agroecological zones...

A global spectral library to characterize the world's soil

USDA-ARS?s Scientific Manuscript database

Soil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about so...

Code modernization and modularization of APEX and SWAT watershed simulation models

USDA-ARS?s Scientific Manuscript database

SWAT (Soil and Water Assessment Tool) and APEX (Agricultural Policy / Environmental eXtender) are respectively large and small watershed simulation models derived from EPIC Environmental Policy Integrated Climate), a field-scale agroecology simulation model. All three models are coded in FORTRAN an...

Drench application of fish-derived protein hydrolysates affects lettuce growth, chlorophyll content, and gas exchange

USDA-ARS?s Scientific Manuscript database

The use of biostimulants to enhance crop production has gained considerable momentum because of its contribution to agroecological sustainability. Protein hydrolysates (PHs) are an important group of plant biostimulants that have received increasing attention in recent years due to their positive ef...

The causality analysis of climate change and large-scale human crisis.

PubMed

Zhang, David D; Lee, Harry F; Wang, Cong; Li, Baosheng; Pei, Qing; Zhang, Jane; An, Yulun

2011-10-18

Recent studies have shown strong temporal correlations between past climate changes and societal crises. However, the specific causal mechanisms underlying this relation have not been addressed. We explored quantitative responses of 14 fine-grained agro-ecological, socioeconomic, and demographic variables to climate fluctuations from A.D. 1500-1800 in Europe. Results show that cooling from A.D. 1560-1660 caused successive agro-ecological, socioeconomic, and demographic catastrophes, leading to the General Crisis of the Seventeenth Century. We identified a set of causal linkages between climate change and human crisis. Using temperature data and climate-driven economic variables, we simulated the alternation of defined "golden" and "dark" ages in Europe and the Northern Hemisphere during the past millennium. Our findings indicate that climate change was the ultimate cause, and climate-driven economic downturn was the direct cause, of large-scale human crises in preindustrial Europe and the Northern Hemisphere.

Cotton and its interaction with cotton morphology

USDA-ARS?s Scientific Manuscript database

The morphological plasticity of the cotton plant enables it to be produced in a wide variety of agro-ecological regions (Oosterhuis and Jernstedt 1999). This plasticity essentially translates to the lengthening, shortening, or interruption of its effective flowering period in response to season leng...

Prevalance of aflatoxin contamination in maize and groundnut in Ghana: Population structure, distribution, and toxigenicity of the causal agents

USDA-ARS?s Scientific Manuscript database

Aflatoxin contamination in maize and groundnut is perennial in Ghana with substantial health and economic burden on the population. The present study examined for the first time the prevalence of aflatoxin contamination in maize and groundnut in major producing regions across three agroecological zo...

Wheat landraces: A mini review

USDA-ARS?s Scientific Manuscript database

Farmers developed and utilized diverse wheat landraces to meet the complexity of a multitude of spatio-temporal, agro-ecological systems and to provide reliable sustenance and a sustainable food source to local communities. The genetic structure of wheat landraces is an evolutionary approach to surv...

Genome-wide association studies of morphological and agronomical traits in cultivated tepary beans (Phaseolus acutifolius)

USDA-ARS?s Scientific Manuscript database

Tepary bean (Phaseolus acutifolius A. Gray) is adapted to high temperature arid agroecological zones. In light of the ongoing and rapid changes in the world climate, the evaluation and development of alternate grain legume species that have similar nutritional and culinary characteristics as common ...

Genetic diversity and structure of Phakopsora pachyrhizi infecting soybean in Nigeria

USDA-ARS?s Scientific Manuscript database

The genetic structure of Nigerian field populations of the soybean rust pathogen Phakopsora pachyrhizi was determined using 18 simple sequence repeat markers. A total of 113 fungal isolates was collected by hierarchical sampling infected leaves from soybean fields in three agroecological zones in 2...

Canola integration into semi-arid wheat cropping systems of the inland Pacific Northwestern USA

USDA-ARS?s Scientific Manuscript database

The inland Pacific Northwestern USA (iPNW) wheat-producing region has a diversity of environments and soils, yet it lacks crop diversity and is one of the few semi-arid wheat-growing regions without significant integration of oilseeds. Four major agroecological zones, primarily characterised by wate...

75 FR 58356 - Mission Statement for Executive-Led Trade Mission to Jordan and Israel

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

..., geothermal energy, and agro-ecology. The Israel Ministry of National Infrastructures Web site, http://www.mni... and Tel-Aviv, Israel. A stop in Eilat, Israel, for companies involved in the renewable energies sector..., pollution control, and water and wastewater treatment. Renewable energies (solar, wind, biogas), energy...

Vermicompost affects soil properties and spinach growth, physiology, and nutritional value

USDA-ARS?s Scientific Manuscript database

The use of vermicompost to improve soil fertility and enhance crop yield has gained considerable momentum due to its contribution to agroecological sustainability. Short-term (35-days after transplanting) effects of vermicompost, applied either as a soil amendment (5% and 10%, v/v), or a drench (40 ...

Advances in tepary bean (Phaseolus acutifolius A. Gray) genetics and breeding

USDA-ARS?s Scientific Manuscript database

Tepary bean is a drought and heat-tolerant sister species of common bean with similar nutritional characteristics and with potential for expanded production in agroecological zones that are marginal due to abiotic stress. A key to expanded production of this orphan crop is the improvement of biotic ...

The causality analysis of climate change and large-scale human crisis

PubMed Central

Zhang, David D.; Lee, Harry F.; Wang, Cong; Li, Baosheng; Pei, Qing; Zhang, Jane; An, Yulun

2011-01-01

Recent studies have shown strong temporal correlations between past climate changes and societal crises. However, the specific causal mechanisms underlying this relation have not been addressed. We explored quantitative responses of 14 fine-grained agro-ecological, socioeconomic, and demographic variables to climate fluctuations from A.D. 1500–1800 in Europe. Results show that cooling from A.D. 1560–1660 caused successive agro-ecological, socioeconomic, and demographic catastrophes, leading to the General Crisis of the Seventeenth Century. We identified a set of causal linkages between climate change and human crisis. Using temperature data and climate-driven economic variables, we simulated the alternation of defined “golden” and “dark” ages in Europe and the Northern Hemisphere during the past millennium. Our findings indicate that climate change was the ultimate cause, and climate-driven economic downturn was the direct cause, of large-scale human crises in preindustrial Europe and the Northern Hemisphere. PMID:21969578

Agro-ecosystem and socio-economic role of homegarden agroforestry in Jabithenan District, North-Western Ethiopia: implication for climate change adaptation.

PubMed

Linger, Ewuketu

2014-01-01

Homegarden agroforestry is believed to be more diverse and provide multiple services for household than other monocropping system and this is due to the combination of crops, trees and livestock. The aim of this study was to assess socio-economic and agro-ecological role of homegardens in Jabithenan district, North-western Ethiopia. Two sites purposively and two villages randomly from each site were selected. Totally 96 households; in which 48 from homegarden agroforestry user and 48 from non-tree based garden user were selected for this study. Socio-economic data and potential economic and agro-ecosystem role of homegarden agroforestry over non-tree based garden were collected by using semi-structured and structured questionnaires to the households. Homegarden agroforestry significantly (P < 0.05) improved the farmers cash income than non-tree based garden. With insignificant garden size; homegarden agroforestry practice provides good socio-economical and agro-ecological service for farmers which have a higher implication for climate change adaptation than non-tree based garden.

From Collectives to Collective Decision-Making and Action: Farmer Field Schools in Vietnam

ERIC Educational Resources Information Center

van de Fliert, Elske; Dung, Ngo Tien; Henriksen, Ole; Dalsgaard, Jens Peter Tang

2007-01-01

In 1992, even before a formalized agricultural extension system existed, the Farmer Field School was introduced in Vietnam as a farmer education methodology aiming at enhancing farmers' agroecological knowledge, critical skills and collective action to support sustainable agricultural development. Over the years, the model saw a wide range of…

Regulatory considerations surrounding the deployment of Bt-expressing cowpea in Africa: Report of the deliberations of an expert panel

USDA-ARS?s Scientific Manuscript database

Cowpea (Vigna unguiculata spp. unguiculata) is adapted to the drier agro-ecological zones of West Africa where it is a major source of dietary protein and widely used as a fodder crop. Improving the productivity of cowpea can enhance food availability and security in West Africa. Insect predation -...

Towards a Political Ecology of Education: The Educational Politics of Scale in Southern Pará, Brazil

ERIC Educational Resources Information Center

Meek, David

2015-01-01

Social movements have initiated both academic programs and disciplines. I present ethnographic data that I gathered during 17 months of fieldwork with the Brazilian Landless Workers' Movement (MST) in southeastern Pará, Brazil, to explore the MST's role in creating agroecological education opportunities. My analysis highlights three factors in…

Can We Find Solutions with People? Participatory Action Research with Small Organic Producers in Andalusia

ERIC Educational Resources Information Center

Cuellar-Padilla, Mamen; Calle-Collado, Angel

2011-01-01

This paper reports on an experiment linking science with people. Taking as a paradigm the holistic scientific approach fostered by agroecology, we present a methodological proposal for the implementation of participatory action research in rural areas. Our aims were various: to solve a specific problem, i.e. the exclusion of small- and…

Rural Youths' Participation in Agriculture: Prospects, Challenges and the Implications for Policy in Nigeria

ERIC Educational Resources Information Center

Auta, Sarah Jehu; Abdullahi, Yusuf M.; Nasiru, Mohammed

2010-01-01

The study aimed at assessing rural youth participation in agriculture, their access to production resources and services and the effects of youths' access to inputs and services on farm productivity and youths' welfare. The study was conducted in three states (each randomly selected from the three agro-ecological zones of northern Nigeria). Two…

Agroecology: Implications for plant response to climate change

USDA-ARS?s Scientific Manuscript database

Agricultural ecosystems (agroecosystems) represent the balance between the physiological responses of plants and plant canopies and the energy exchanges. Rising temperature and increasing CO2 coupled with an increase in variability of precipitation will create a complex set of interactions on plant ...

Genetic differentiation in Pyrenophora teres f. teres populations from Syria and Tunisia as assessed by AFLP markers.

PubMed

Bouajila, A; Zoghlami, N; Murad, S; Baum, M; Ghorbel, A; Nazari, K

2013-06-01

To investigate the level of genetic differentiation and diversity among Pyrenophora teres isolate populations originating from different agro-ecological areas of Syria and Tunisia and to determine the potential of AFLP profiling in genotyping Pyrenophora teres f. teres. In this study, AFLP markers have been employed to identify patterns of population structure in 20 Pyrenophora teres f. teres populations from Syria and Tunisia. Ninety-four isolates were studied by the use of a protocol that involved stringent PCR amplification of fragments derived from digestion of genomic DNA with restriction enzymes EcoRI and MesI. Based on 401 amplified polymorphic DNA markers (AFLP), variance analyses indicated that most of the variation was partitioned within rather than between populations. Genotypic diversity (GD) was high for populations from Rihane, local landraces and different agro-ecological zones (GD = 0·75-0·86). There was high genetic differentiation among pathogen populations from different host populations in Syria (Gst  = 0·31, ht = 0·190) and Tunisia (Gst  = 0·39, ht = 0·263), which may be partly explained by the low gene flow around the areas sampled. A phenetic tree revealed three groups with high bootstrap values (55, 68, 76) and reflected the grouping of isolates based on host, or agro-ecological areas. AFLP profiling is an effective method for typing the genetically diverse pathogen Pyrenophora teres f. teres. The study represents a comparative analysis of the genetic diversity in P. teres isolates from two countries spanning two continents and also shows that several distinct P. teres genotypes may be found in a given environment. The implications of these findings for Pyrenophora teres f. teres evolutionary potential and net blotch-resistance breeding in Syria and Tunisia were also discussed. © 2012 The Society for Applied Microbiology.

Use of quality indicators for long-term evaluation of heavy metals content in soils of an agro-ecological protected wetland: L'Albufera de Valencia Natural Park, Valencia, Spain

NASA Astrophysics Data System (ADS)

Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Palop, Carla

2015-04-01

Due to the social, economical and environmental importance of agro-ecological wetlands, strategies for periodical evaluation of their environmental quality should be developed, particularly in those areas were a mixture of land uses are supporting the survival of wildlife and migrant species as is the case of most Mediterranean coastal wetlands. The aim of this work is to develop a strategy for a long-term assessment of the environmental quality of soils in a rice-wetland: L'Albufera Natural Park, Spain, in the surroundings of the metropolitan area of Valencia. The area was officially declared as Natural Park in 1986, integrating both the traditional irrigation system and the ecological importance derived from being a Mediterranean Wetland that is now transformed to a large extent in a rice-wetland allowing the presence of a large variety of migrant spices. The methodology consisted in the monitoring of 20 sites distributed in 5 sectors in and around the natural park of potentially contrasting anthropogenic pressure and land use. Soil samples collection were instrumented in two campaigns. The first one was in 1989 (three years after the official declaration as Natural Park of the wetland), and the second 19 years later in 2008. Seven heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) were analyzed to determine its total and extractable fractions by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of metals. To evaluate the quality of soils at each sampling date four indicators were obtained, namely, Contamination Factor (CF), Geoaccumulation Index (Igeo), Pollution Load Index (PLI) and Potential Ecological Risk Index (PERI). Results obtained with quality indicators were further compared to obtain temporal and spatial trends using Geographical Information systems procedures. In general, there is a reduction of metal contents in the study area in both dates. The trend of metals according to average

A comparative analysis of microbiomes in natural and anthropogenically disturbed soils of northwestern Kazakhstan

NASA Astrophysics Data System (ADS)

Pershina, E. V.; Ivanova, E. A.; Nagieva, A. G.; Zhiengaliev, A. T.; Chirak, E. L.; Andronov, E. E.; Sergaliev, N. Kh.

2016-06-01

The goal of this study was to determine the relationships between the structure of the soil microbiome and the agroecological state of soils by the example of natural undisturbed (steppe areas) and anthropogenically disturbed (pastures, croplands, fallows) areas in the territory of northwestern Kazakhstan. The highest abundance of proteobacteria was found in the anthropogenically disturbed of fallows and in undisturbed soils; in other cases, actinobacteria and representatives of the Firmicutes phylum predominated. Different kinds of anthropogenic impacts resulted in the decrease in the portions of bacteria from the Acidobacteria, Gemmatimonadetes, and Firmicutes phyla. In the disturbed soils, the portions of bacteria from the Erysipelothrix, Mycobacterium, Methylibium, Skermanella, Ralstonia, Lactococcus, Bdellovibrio, Candidatus nitrososphaera, Catellatospora, Cellulomonas, Stenotrophomonas, and Steroidobacter genera increased. Bacteria of the Erysipelothrix and Methylibium genera occurred only in the undisturbed soils. The anthropogenically disturbed and undisturbed soils differed significantly in the taxonomic structure of their microbiomes forming two separate clusters, which confirms the efficiency of using the data on the structure of soil microbiomes when assessing the agroecological status of soils.

Increased Productivity of a Cover Crop Mixture Is Not Associated with Enhanced Agroecosystem Services

PubMed Central

Smith, Richard G.; Atwood, Lesley W.; Warren, Nicholas D.

2014-01-01

Cover crops provide a variety of important agroecological services within cropping systems. Typically these crops are grown as monocultures or simple graminoid-legume bicultures; however, ecological theory and empirical evidence suggest that agroecosystem services could be enhanced by growing cover crops in species-rich mixtures. We examined cover crop productivity, weed suppression, stability, and carryover effects to a subsequent cash crop in an experiment involving a five-species annual cover crop mixture and the component species grown as monocultures in SE New Hampshire, USA in 2011 and 2012. The mean land equivalent ratio (LER) for the mixture exceeded 1.0 in both years, indicating that the mixture over-yielded relative to the monocultures. Despite the apparent over-yielding in the mixture, we observed no enhancement in weed suppression, biomass stability, or productivity of a subsequent oat (Avena sativa L.) cash crop when compared to the best monoculture component crop. These data are some of the first to include application of the LER to an analysis of a cover crop mixture and contribute to the growing literature on the agroecological effects of cover crop diversity in cropping systems. PMID:24847902

Molecular characterization of Hepatozoon canis from farm dogs in Pakistan.

PubMed

Ahmad, Abdullah S; Saeed, Muhammad A; Rashid, Imran; Ashraf, Kamran; Shehzad, Wasim; Traub, Rebecca J; Baneth, Gad; Jabbar, Abdul

2018-04-01

Hepatozoon canis is a tick-borne pathogen of canids, which is distributed worldwide. However, very little is known about this protozoan parasite in Pakistan. This study provides the first molecular evidence of H. canis from farm dogs from three agro-ecological zones of Punjab, Pakistan. A conventional PCR targeting the 18S rRNA gene was used to characterize H. canis from farm dogs from three districts, namely Kasur, Rawalpindi, and Muzaffargarh, in Punjab. Of 341 blood samples tested, 155 (45.5%) were positive for H. canis, 73 (61.3%) from Kasur, 46 (42.5%) from Rawalpindi, and 36 (31.5%) from Muzaffargarh. Phylogenetic analyses revealed that 18S rRNA sequences of H. canis from this study clustered in three clades with those of H. canis from previously published studies to the exclusion of all other Hepatozoon spp. included in the analysis. This study provides the first insight into H. canis from farm dogs in Pakistan. Furthermore, it lays a foundation for future studies of the parasite to assess the impact of canine hepatozoonosis in dogs from various agro-ecological zones in Pakistan where pet ownership of dogs is increasing.

Environmental services generated by organic agriculture: A view from the air

NASA Astrophysics Data System (ADS)

Bigeriego, Elena; Cabezas, José; Labrador, Juana; María Moreno, Marta

2017-04-01

This work aims to develop an alternative methodology that enables monitoring the environmental differential that agroecological management involves in order to consolidate feasible payments for environmental services generated by organic agriculture. For this purpose, LANDSAT images have been used, and the Normalized Difference Vegetation Index (NDVI) of organic fruit farms, all of them with the same species and the similar edaphic and climatic characteristics, has been compared with the NDVI obtained at other nearby fruit farms under conventional management, all of them in Extremadura (Spain). As a result, we obtained a series of statistical data that allows us to clearly differentiate between these two types of management. Among these data, remarkable differences have been detected regarding the minimum values of NDVI in the non-productive periods of the fruit, which is higher in the organic farms due to the permanent vegetation soil cover, with the subsequent effects on soil protection and carbon sequestration. The conclusions of the paper show that it is possible to distinguish different models of crop management by using satellite images obtained in a quick and inexpensive way. Keywords: LANDSAT images; NDVI; environmental services; agroecology; organic agriculture.

Parasite control in the age of drug resistance and changing agricultural practices.

PubMed

Molento, Marcelo Beltrão

2009-08-07

The benefits of using antiparasitic drugs in farm animals are unquestionable. However, despite anthelmintic use as the predominant control strategy, extreme parasite infection cases are appearing in sheep and goat production; these impact productivity and have show mortality rates reaching pre-drug use levels. This was a predictable situation resulting from the loss of efficacy by all available products, particularly when some products were used as the sole intervention. The concepts of agroecology and holistic agriculture, which advocate the use of integrated management strategies, such as target selected treatment, herbal medicine, and the application of other parasite control alternatives, are not completely new, but are undergoing a resurgence because of their more sustainable appeal. The objective of this review article is to examine the problem of parasite control in the face of parasite drug resistance and to outline some strategies that may be used in parasite control programmes. Before they are accepted and recommended by the WAAVP, agroecological methods such as those listed above and described in detail herein should be validated based on scientific evidence of their efficacy for parasite control and should be tested for both host and environmental safety.

Climate Change Vulnerability of Agro-Ecosystems: Does socio-economic factors matters?

NASA Astrophysics Data System (ADS)

Surendran Nair, S.; Preston, B. L.; King, A. W.; Mei, R.; Post, W. M.

2013-12-01

Climate variability and change has direct impacts on agriculture. Despite continual adaptation to climate as well as gains in technology innovation and adoption, agriculture is still vulnerable to changes in temperature and precipitation expected in coming decades. Generally, researchers use two major methodologies to understand the vulnerability of agro-ecosystems to climate change: process-based crop models and empirical models. However, these models are not yet designed to capture the influence of socioeconomic systems on agro-ecosystem processes and outcomes.. However, socioeconomic processes are an important factor driving agro-ecological responses to biophysical processes (climate, topography and soil), because of the role of human agency in mediating the response of agro-ecosystems to climate. We have developed a framework that integrates socioeconomic and biophysical characteristics of agro-ecosystems using cluster analysis and GIS tools. This framework has been applied to the U.S. Southeast to define unique socio-ecological domains for agriculture. The results demonstrate that socioeconomic characteristics are an important factor influencing agriculture production. These results suggest that the lack of attention to socioeconomic conditions and human agency in agro-ecological modeling creates a potential bias with respect to the representation of climate change impacts.

Enhancing Undergraduate Agro-Ecological Laboratory Employment through Experiential Learning

ERIC Educational Resources Information Center

Grossman, J. M.; Patel, M.; Drinkwater, L. E.

2010-01-01

We piloted an educational model, the Sustainable Agriculture Scholars Program, linking research in organic agriculture to experiential learning activities for summer undergraduate employees in 2007 and 2008. Our objectives were to: (1) further student understanding of sustainable agriculture research, (2) increase student interest in sustainable…

Three new species of the genus Austrophthiracarus from New Zealand (Acari: Oribatida: Phthiracaridae).

PubMed

Liu, Dong; Zhang, Zhi-Qiang

2014-03-24

Three new species of Austrophthiracarus (Oribatida: Phthiracaridae) from New Zealand are described: Austrophthiracarus matuku sp. nov. from the Bethells Matuku Reserve, Auckland, Austrophthiracarus notoporosus sp. nov. from the Tutoko Bench, Fiordland and Austrophthiracarus karioi sp. nov. from the Mt. Karioi, Waikato. Holotype specimens are deposited in the New Zealand Arthropod Collection, Landcare Research and paratypes are deposited in the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences.

Using landscape typologies to model socioecological systems: Application to agriculture of the United States Gulf Coast

DOE PAGES

Preston, Benjamin L.; King, Anthony Wayne; Mei, Rui; ...

2016-02-11

Agricultural enterprises are vulnerable to the effects of climate variability and change. Improved understanding of the determinants of vulnerability and adaptive capacity in agricultural systems is important for projecting and managing future climate risk. At present, three analytical tools dominate methodological approaches to understanding agroecological vulnerability to climate: process-based crop models, empirical crop models, and integrated assessment models. A common weakness of these approaches is their limited treatment of socio-economic conditions and human agency in modeling agroecological processes and outcomes. This study proposes a framework that uses spatial cluster analysis to generate regional socioecological typologies that capture geographic variance inmore » regional agricultural production and enable attribution of that variance to climatic, topographic, edaphic, and socioeconomic components. This framework was applied to historical corn production (1986-2010) in the U.S. Gulf of Mexico region as a testbed. The results demonstrate that regional socioeconomic heterogeneity is an important driving force in human dominated ecosystems, which we hypothesize, is a function of the link between socioeconomic conditions and the adaptive capacity of agricultural systems. Meaningful representation of future agricultural responses to climate variability and change is contingent upon understanding interactions among biophysical conditions, socioeconomic conditions, and human agency their incorporation in predictive models.« less

Assessment of the sustainability of dual-purpose farms by the IDEA method in the subtropical area of central Mexico.

PubMed

Salas-Reyes, Isela Guadalupe; Arriaga-Jordán, Carlos Manuel; Rebollar-Rebollar, Samuel; García-Martínez, Anastacio; Albarrán-Portillo, Benito

2015-08-01

The objective of this study was to assess the sustainability of 10 dual-purpose cattle farms in a subtropical area of central Mexico. The IDEA method (Indicateurs de Durabilité des Exploitations Agricoles) was applied, which includes the agroecological, socio-territorial and economic scales (scores from 0 to 100 points per scale). A sample of 47 farms from a total of 91 registered in the local livestock growers association was analysed with principal component analysis and cluster analysis. From results, 10 farms were selected for the in-depth study herein reported, being the selection criterion continuous milk production throughout the year. Farms had a score of 88 and 86 points for the agroecological scale in the rainy and dry seasons. In the socio-territorial scale, scores were 73 points for both seasons, being the component of employment and services the strongest. Scores for the economic scale were 64 and 56 points for the rainy and dry seasons, respectively, when no economic cost for family labour is charged, which decreases to 59 and 45 points when an opportunity cost for family labour is considered. Dual-purpose farms in the subtropical area of central Mexico have a medium sustainability, with the economic scale being the limiting factor, and an area of opportunity.

Using landscape typologies to model socioecological systems: Application to agriculture of the United States Gulf Coast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Preston, Benjamin L.; King, Anthony Wayne; Mei, Rui

Agricultural enterprises are vulnerable to the effects of climate variability and change. Improved understanding of the determinants of vulnerability and adaptive capacity in agricultural systems is important for projecting and managing future climate risk. At present, three analytical tools dominate methodological approaches to understanding agroecological vulnerability to climate: process-based crop models, empirical crop models, and integrated assessment models. A common weakness of these approaches is their limited treatment of socio-economic conditions and human agency in modeling agroecological processes and outcomes. This study proposes a framework that uses spatial cluster analysis to generate regional socioecological typologies that capture geographic variance inmore » regional agricultural production and enable attribution of that variance to climatic, topographic, edaphic, and socioeconomic components. This framework was applied to historical corn production (1986-2010) in the U.S. Gulf of Mexico region as a testbed. The results demonstrate that regional socioeconomic heterogeneity is an important driving force in human dominated ecosystems, which we hypothesize, is a function of the link between socioeconomic conditions and the adaptive capacity of agricultural systems. Meaningful representation of future agricultural responses to climate variability and change is contingent upon understanding interactions among biophysical conditions, socioeconomic conditions, and human agency their incorporation in predictive models.« less

Geometagenomics illuminates the impact of agriculture on the distribution and prevalence of plant viruses at the ecosystem scale.

PubMed

Bernardo, Pauline; Charles-Dominique, Tristan; Barakat, Mohamed; Ortet, Philippe; Fernandez, Emmanuel; Filloux, Denis; Hartnady, Penelope; Rebelo, Tony A; Cousins, Stephen R; Mesleard, François; Cohez, Damien; Yavercovski, Nicole; Varsani, Arvind; Harkins, Gordon W; Peterschmitt, Michel; Malmstrom, Carolyn M; Martin, Darren P; Roumagnac, Philippe

2018-01-01

Disease emergence events regularly result from human activities such as agriculture, which frequently brings large populations of genetically uniform hosts into contact with potential pathogens. Although viruses cause nearly 50% of emerging plant diseases, there is little systematic information about virus distribution across agro-ecological interfaces and large gaps in understanding of virus diversity in nature. Here we applied a novel landscape-scale geometagenomics approach to examine relationships between agricultural land use and distributions of plant-associated viruses in two Mediterranean-climate biodiversity hotspots (Western Cape region of South Africa and Rhône river delta region of France). In total, we analysed 1725 geo-referenced plant samples collected over two years from 4.5 × 4.5 km 2 grids spanning farmlands and adjacent uncultivated vegetation. We found substantial virus prevalence (25.8-35.7%) in all ecosystems, but prevalence and identified family-level virus diversity were greatest in cultivated areas, with some virus families displaying strong agricultural associations. Our survey revealed 94 previously unknown virus species, primarily from uncultivated plants. This is the first effort to systematically evaluate plant-associated viromes across broad agro-ecological interfaces. Our findings indicate that agriculture substantially influences plant virus distributions and highlight the extent of current ignorance about the diversity and roles of viruses in nature.

Analysis of factors which limited the spatial variation of barley yield on the forest-steppe chernozems of Kursk region

NASA Astrophysics Data System (ADS)

Belik, Anton; Vasenev, Ivan; Jablonskikh, Lidia; Bozhko, Svetlana

2017-04-01

The crop yield is the most important indicator of the efficiency of agricultural production. It is the function that depends on a large number of groups of independent variables, such as the weather, soil fertility and overall culture agriculture. A huge number of combinations of these factors contribute to the formation of high spatial variety of crop yields within small areas, includes the slope agrolandscapes in Kursk region. Spatial variety of yield leads to a significant reduction in the efficiency of agriculture. In this connection, evaluation and analysis of the factors, which limits the yield of field crops is a very urgent proble in agroecology. The research was conducted in the period of 2003-2004 on a representative field. The typical and leached chernozems with the varying thickness and of erosion degree are dominated in soil cover. At the time of field research studied areas were busy by barley. The reseached soils have an average and increased fertility level. Chernozem typical full-face, and the leached contain an average of 4.5-6% humus, close to neutral pH, favorable values of physico-chemical parameters, medium and high content of nutrients. The eroded chernozems differs agrogenic marked declining in fertility parameters. The diversity of meso- and micro-relief in the fields and soil cover influence to significant spatial variety of fertility. For example the content of nutrients in the soil variation can be up to 5-fold level. High spatial heterogeneity of soils fertility ifluence to barley yield variety. During research on the productivity of the field varied in the range of 20-43 c/ha, and 7-44 c/ha (2004). Analysis of the factors, which limited the yield of barley, showed that the first priorities occupy unregulated characterises: slope angle and the classification of soils (subtype and race of chernozem and the difference in the degree of erosion), which determines the development of erosion processes and redistribution available to plants

Agroecology: the key role of arbuscular mycorrhizas in ecosystem services.

PubMed

Gianinazzi, Silvio; Gollotte, Armelle; Binet, Marie-Noëlle; van Tuinen, Diederik; Redecker, Dirk; Wipf, Daniel

2010-11-01

The beneficial effects of arbuscular mycorrhizal (AM) fungi on plant performance and soil health are essential for the sustainable management of agricultural ecosystems. Nevertheless, since the 'first green revolution', less attention has been given to beneficial soil microorganisms in general and to AM fungi in particular. Human society benefits from a multitude of resources and processes from natural and managed ecosystems, to which AM make a crucial contribution. These resources and processes, which are called ecosystem services, include products like food and processes like nutrient transfer. Many people have been under the illusion that these ecosystem services are free, invulnerable and infinitely available; taken for granted as public benefits, they lack a formal market and are traditionally absent from society's balance sheet. In 1997, a team of researchers from the USA, Argentina and the Netherlands put an average price tag of US $33 trillion a year on these fundamental ecosystem services. The present review highlights the key role that the AM symbiosis can play as an ecosystem service provider to guarantee plant productivity and quality in emerging systems of sustainable agriculture. The appropriate management of ecosystem services rendered by AM will impact on natural resource conservation and utilisation with an obvious net gain for human society.

Think globally, research locally: paradigms and place in agroecological research.

PubMed

Reynolds, Heather L; Smith, Alex A; Farmer, James R

2014-10-01

Conducting science for practical ends implicates scientists, whether they wish it or not, as agents in social-ecological systems, raising ethical, economic, environmental, and political issues. Considering these issues helps scientists to increase the relevance and sustainability of research outcomes. As we rise to the worthy call to connect basic research with food production, scientists have the opportunity to evaluate alternative food production paradigms and consider how our research funds and efforts are best employed. In this contribution, we review some of the problems produced by science conducted in service of industrial agriculture and its associated economic growth paradigm. We discuss whether the new concept of "ecological intensification" can rescue the industrial agriculture/growth paradigm and present an emerging alternative paradigm of decentralized, localized, biodiversity-promoting agriculture for a steady-state economy. This "custom fit" agriculture engages constructively with complex and highly localized ecosystems, and we draw from examples of published work to demonstrate how ecologists can contribute by using approaches that acknowledge local agricultural practices and draw on community participation. © 2014 Botanical Society of America, Inc.

Air emissions from sour-gas processing plants and dairy-cattle reproduction in Alberta, Canada.

PubMed

Scott, H M; Soskolne, C L; Martin, S W; Shoukri, M M; Lissemore, K D; Coppock, R W; Guidotti, T L

2003-02-15

The dispersion of air pollutants from all 231 licensed sour-gas processing plants in Alberta, Canada, was modeled on a monthly basis over a 10-year period (1985-1994). Exposure estimates for sulfur dioxide (SO(2)-used as a surrogate for exposure to combusted emissions) then were assigned to 1382 provincial dairy farms using a geographical-information system. Individual average and peak exposure for periods prior to each of 15 months of age and conception (four exposure-averaging periods for each of two dispersion models) were estimated for 163,988 primiparous female dairy-cattle between 1986 and 1994. Monthly or annual average farm-site exposure estimates likewise were assigned to associated herd-level data sets for the biologically relevant period of interest for each of three additional reproductive outcomes: monthly herd-average calving interval, stillbirth risk, and twinning risk. In one of the main-effects models, the maximum (i.e., peak) monthly sour-gas exposure experienced by individual-animals from birth to conception was associated with an increased time to first-calving in the very-highest exposure category (hazard ratio=0.86, 95% CI=0.80, 0.92). This equates to a decreased hazard (lambda) of calving (in each month subsequent to 22 months of age) for the highest-exposure animals (lambda=0.170) versus the zero-exposure animals (lambda=0.198) in a model with referent values for agro-ecological region and season of birth. The dose-response was not consistent across the full range of exposure categories. There was significant (P=0.003) interaction of emissions with agro-ecological region. After accounting for the interaction, a more-consistent dose-response was evident for some (but not all) agro-ecological regions. This suggests that any effect of emissions on dairy-heifer reproduction is subject to modification by features of soil type, vegetative cover, and/or climate. The increase in monthly herd-average calving interval on farms exposed to the very

Aspergillus section Flavi community structure in Zambia influences aflatoxin contamination of maize and groundnut.

PubMed

Kachapulula, Paul W; Akello, Juliet; Bandyopadhyay, Ranajit; Cotty, Peter J

2017-11-16

Aflatoxins are cancer-causing, immuno-suppressive mycotoxins that frequently contaminate important staples in Zambia including maize and groundnut. Several species within Aspergillus section Flavi have been implicated as causal agents of aflatoxin contamination in Africa. However, Aspergillus populations associated with aflatoxin contamination in Zambia have not been adequately detailed. Most of Zambia's arable land is non-cultivated and Aspergillus communities in crops may originate in non-cultivated soil. However, relationships between Aspergillus populations on crops and those resident in non-cultivated soils have not been explored. Because characterization of similar fungal populations outside of Zambia have resulted in strategies to prevent aflatoxins, the current study sought to improve understanding of fungal communities in cultivated and non-cultivated soils and in crops. Crops (n=412) and soils from cultivated (n=160) and non-cultivated land (n=60) were assayed for Aspergillus section Flavi from 2012 to 2016. The L-strain morphotype of Aspergillus flavus and A. parasiticus were dominant on maize and groundnut (60% and 42% of Aspergillus section Flavi, respectively). Incidences of A. flavus L-morphotype were negatively correlated with aflatoxin in groundnut (log y=2.4990935-0.09966x, R 2 =0.79, P=0.001) but not in maize. Incidences of A. parasiticus partially explained groundnut aflatoxin concentrations in all agroecologies and maize aflatoxin in agroecology III (log y=0.1956034+0.510379x, R 2 =0.57, P<0.001) supporting A. parasiticus as the dominant etiologic agent of aflatoxin contamination in Zambia. Communities in both non-cultivated and cultivated soils were dominated by A. parasiticus (69% and 58%, respectively). Aspergillus parasiticus from cultivated and non-cultivated land produced statistically similar concentrations of aflatoxins. Aflatoxin-producers causing contamination of crops in Zambia may be native and, originate from non-cultivated areas

Navigation as a New Form of Search for Agricultural Learning Resources in Semantic Repositories

NASA Astrophysics Data System (ADS)

Cano, Ramiro; Abián, Alberto; Mena, Elena

Education is essential when it comes to raise public awareness on the environmental and economic benefits of organic agriculture and agroecology (OA & AE). Organic.Edunet, an EU funded project, aims at providing a freely-available portal where learning contents on OA & AE can be published and accessed through specialized technologies. This paper describes a novel mechanism for providing semantic capabilities (such as semantic navigational queries) to an arbitrary set of agricultural learning resources, in the context of the Organic.Edunet initiative.

Evolutionary agroecology: individual fitness and population yield in wheat (Triticum aestivum).

PubMed

Weiner, Jacob; Du, Yan-Lei; Zhang, Cong; Qin, Xiao-Liang; Li, Feng-Min

2017-09-01

Although the importance of group selection in nature is highly controversial, several researchers have argued that plant breeding for agriculture should be based on group selection, because the goal in agriculture is to optimize population production, not individual fitness. A core hypothesis behind this claim is that crop genotypes with the highest individual fitness in a mixture of genotypes will not produce the highest population yield, because fitness is often increased by "selfish" behaviors, which reduce population performance. We tested this hypothesis by growing 35 cultivars of spring wheat (Triticum aestivum L.) in mixtures and monocultures, and analyzing the relationship between population yield in monoculture and individual yield in mixture. The relationship was unimodal, as predicted. The highest-yielding populations were from cultivars that had intermediate fitness, and these produced, on average, 35% higher yields than cultivars with the highest fitness. It is unlikely that plant breeding or genetic engineering can improve traits that natural selection has been optimizing for millions of years, but there is unutilized potential in traits that increase crop yield by decreasing individual fitness. © 2017 by the Ecological Society of America.

Establishing a Regional Nitrogen Management Approach to Mitigate Greenhouse Gas Emission Intensity from Intensive Smallholder Maize Production

PubMed Central

Wu, Liang; Chen, Xinping; Cui, Zhenling; Zhang, Weifeng; Zhang, Fusuo

2014-01-01

The overuse of Nitrogen (N) fertilizers on smallholder farms in rapidly developing countries has increased greenhouse gas (GHG) emissions and accelerated global N consumption over the past 20 years. In this study, a regional N management approach was developed based on the cost of the agricultural response to N application rates from 1,726 on-farm experiments to optimize N management across 12 agroecological subregions in the intensive Chinese smallholder maize belt. The grain yield and GHG emission intensity of this regional N management approach was investigated and compared to field-specific N management and farmers' practices. The regional N rate ranged from 150 to 219 kg N ha−1 for the 12 agroecological subregions. Grain yields and GHG emission intensities were consistent with this regional N management approach compared to field-specific N management, which indicated that this regional N rate was close to the economically optimal N application. This regional N management approach, if widely adopted in China, could reduce N fertilizer use by more than 1.4 MT per year, increase maize production by 31.9 MT annually, and reduce annual GHG emissions by 18.6 MT. This regional N management approach can minimize net N losses and reduce GHG emission intensity from over- and underapplications, and therefore can also be used as a reference point for regional agricultural extension employees where soil and/or plant N monitoring is lacking. PMID:24875747

Research on agricultural ecology and environment analysis and modeling based on RS and GIS

NASA Astrophysics Data System (ADS)

Zhang, Wensheng; Chen, Hongfu; Wang, Mingsheng

2009-07-01

Analysis of agricultural ecology and environment is based on the data of agricultural resources, which are obtained by RS monitoring. The over-exploitation of farmlands will cause structural changes of the soil composition, and damage the planting environment and the agro-ecosystem. Through the research on the dynamic monitoring methods of multitemporal RS images and GIS technology, the crop growth status, crop acreage and other relevant information in agricultural production are extracted based on the monitor and analysis of the conditions of the fields and crop growth. The agro-ecological GIS platform is developed with the establishment of the agricultural resources management database, which manages spatial data, RS data and attribute data of agricultural resources. Using the RS, GIS analysis results, the reasons of agro-ecological destruction are analyzed and the evaluation methods are established. This paper puts forward the concept of utilization capacity of farmland, which describes farmland space for development and utilization that is influenced by the conditions of the land, water resources, climate, pesticides and chemical fertilizers and many other agricultural production factors. Assessment model of agricultural land use capacity is constructed with the help of Fuzzy. Assessing the utilization capacity of farmland can be helpful to agricultural production and ecological protection of farmland. This paper describes the application of the capacity evaluation model with simulated data in two aspects, namely, in evaluating the status of farmland development and utilization and in optimal planting.

A study of risk factors associated with Newcastle disease epidemics in village free-range chickens in Uganda.

PubMed

Otim, M O; Kabagambe, E K; Mukiibi, G M; Christensen, H; Bisgaard, M

2007-01-01

A prospective study of risk factors associated with outbreaks of Newcastle disease (ND) in indigenous free-range chickens was carried out in three agro-ecological zones in eastern Uganda. Sixty households keeping chickens were randomly selected and studied from March 2004 to February 2005, covering rainy and dry seasons. Data on ND outbreaks, risk factors and flock dynamics were collected using an interviewer-administered questionnaire, while ND outbreaks were confirmed by haemagglutination inhibition test. Multivariate survival analyses were performed to identify the risk factors for Newcastle disease outbreaks. Although the survival time against ND was longer (> 100 days) in the dry compared to the rainy season, incidence in the two seasons was not significantly different (p > 0.05). None of the factors investigated was significantly associated with ND. However, purchasing of restocking chickens from the market and neighbourhood (hazard ratio [HR] = 1.79; 95% confidence interval [CI] 0.89-3.60), the presence of migratory wild birds (HR = 1.70; 95% CI 0.65-4.48) and being in agro-ecological zone 1 (HR = 1.48; 95% CI 0.66-3.36) showed a positive but non-significant association with risk for ND. To understand the roles of other domestic poultry species in the epidemiology of ND in rural free-range chickens, virus isolation and molecular characterization of isolates in addition to more prospective cohort studies with a larger sample size and similarly long period of follow-up are needed.

Insect Fauna Associated With Anacardium occidentale (Sapindales: Anacardiaceae) in Benin, West Africa

PubMed Central

Agboton, C.; Onzo, A.; Ouessou, F. I.; Goergen, G.; Vidal, S.; Tamò, M.

2014-01-01

Abstract Cashew, Anacardium occidentale L. (Sapindales: Anacardiaceae), is an important cash crop in Benin. However, its production is threatened by several biotic factors, especially insects. In Benin, very few studies have focused on insects and just listed species commonly found on cashew worldwide. The present investigation fills this gap by presenting an exhaustive inventory of insect species associated with this crop in the country. The survey was carried out from September 2009 to August 2010 in 22 cashew orchards (5 young and 17 mature) distributed over three major agroecological zones where cashew is most produced in the country. Insects were collected using chemical knock-down technique and visual observation followed by capture with sweep net. In addition, infested plant organs were sampled and incubated to collect emerging insects. In total, 262 insect species were recorded and identified. Among them, the wood borer Apate terebrans Pallas, the leafminer Eteoryctis gemoniella Stainton, and the mirid bugs Helopeltis schoutedeni Reuter., and Helopeltis anacardii Miller., appeared as the most important insect species attacking cashew in Benin. Beneficial insects encountered included some predators, parasitoids, and pollinators. Few vertebrate predators were also recorded on the trees. Differences in agroecological conditions or in field cleanliness did not affect the number of insect species encountered in the cashew orchards. The results of this study represent an important baseline data for the design and implementation of strategies for cashew protection in Benin. PMID:25434033

Evaluating mountain goat dairy systems for conversion to the organic model, using a multicriteria method.

PubMed

Mena, Y; Nahed, J; Ruiz, F A; Sánchez-Muñoz, J B; Ruiz-Rojas, J L; Castel, J M

2012-04-01

Organic farming conserves natural resources, promotes biodiversity, guarantees animal welfare and obtains healthy products from raw materials through natural processes. In order to evaluate possibilities of increasing organic animal production, this study proposes a farm-scale multicriteria method for assessing the conversion of dairy goat systems to the organic model. In addition, a case study in the Northern Sierra of Seville, southern Spain, is analysed. A consensus of expert opinions and a field survey are used to validate a list of potential indicators and issues for assessing the conversion, which consider not only the European Community regulations for organic livestock farming, but also agroecological principles. As a result, the method includes 56 variables integrated in nine indicators: Nutritional management, Sustainable pasture management, Soil fertility and contamination, Weed and pest control, Disease prevention, Breeds and reproduction, Animal welfare, Food safety and Marketing and management. The nine indicators are finally integrated in a global index named OLPI (Organic Livestock Proximity Index). Application of the method to a case study with 24 goat farms reveals an OLPI value of 46.5% for dairy goat farms located in mountain areas of southern Spain. The aspects that differ most from the agroecological model include soil management, animal nutrition and product marketing. Results of the case study indicate that the proposed method is easy to implement and is useful for quantifying the approximation of conventional farms to an organic model.

Occurrence of Fusarium Mycotoxins in Cereal Crops and Processed Products (Ogi) from Nigeria

PubMed Central

Chilaka, Cynthia Adaku; De Boevre, Marthe; Atanda, Olusegun Oladimeji; De Saeger, Sarah

2016-01-01

In Nigeria, maize, sorghum, and millet are very important cash crops. They are consumed on a daily basis in different processed forms in diverse cultural backgrounds. These crops are prone to fungi infestation, and subsequently may be contaminated with mycotoxins. A total of 363 samples comprising of maize (136), sorghum (110), millet (87), and ogi (30) were collected from randomly selected markets in four agro-ecological zones in Nigeria. Samples were assessed for Fusarium mycotoxins contamination using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Subsequently, some selected samples were analysed for the occurrence of hidden fumonisins. Overall, 64% of the samples were contaminated with at least one toxin, at the rate of 77%, 44%, 59%, and 97% for maize, sorghum, millet, and ogi, respectively. Fumonisins were the most dominant, especially in maize and ogi, occurring at the rate of 65% and 93% with mean values of 935 and 1128 μg/kg, respectively. The prevalence of diacetoxyscirpenol was observed in maize (13%), sorghum (18%), and millet (29%), irrespective of the agro-ecological zone. Other mycotoxins detected were deoxynivalenol, zearalenone, and their metabolites, nivalenol, fusarenon-X, HT-2 toxin, and hidden fumonisins. About 43% of the samples were contaminated with more than one toxin. This study suggests that consumption of cereals and cereal-based products, ogi particularly by infants may be a source of exposure to Fusarium mycotoxins. PMID:27869703

Integrating Agricultural and Ecological Goals into the Management of Species-Rich Grasslands: Learning from the Flowering Meadows Competition in France

NASA Astrophysics Data System (ADS)

Magda, Danièle; de Sainte Marie, Christine; Plantureux, Sylvain; Agreil, Cyril; Amiaud, Bernard; Mestelan, Philippe; Mihout, Sarah

2015-11-01

Current agri-environmental schemes for reconciling agricultural production with biodiversity conservation are proving ineffective Europe-wide, increasing interest in results-based schemes (RBSs). We describe here the French "Flowering Meadows" competition, rewarding the "best agroecological balance" in semi-natural grasslands managed by livestock farmers. This competition, which was entered by about a thousand farmers in 50 regional nature parks between 2007 and 2014, explicitly promotes a new style of agri-environmental scheme focusing on an ability to reach the desired outcome rather than adherence to prescriptive management rules. Building on our experience in the design and monitoring of the competition, we argue that the cornerstone of successful RBSs is a collective learning process in which the reconciliation of agriculture and environment is reconsidered in terms of synergistic relationships between agricultural and ecological functioning. We present the interactive, iterative process by which we defined an original method for assessing species-rich grasslands in agroecological terms. This approach was based on the integration of new criteria, such as flexibility, feeding value, and consistency of use, into the assessment of forage production performance and the consideration of biodiversity conservation through its functional role within the grassland ecosystem, rather than simply noting the presence or abundance of species. We describe the adaptation of this methodology on the basis of competition feedback, to bring about a significant shift in the conventional working methods of agronomists and conservationists (including researchers).The potential and efficacy of RBSs for promoting ecologically sound livestock systems are discussed in the concluding remarks, and they relate to the ecological intensification debate.

Climate Variability and Yields of Major Staple Food Crops in Northern Ghana

NASA Astrophysics Data System (ADS)

Amikuzuno, J.

2012-12-01

Climate variability, the short-term fluctuations in average weather conditions, and agriculture affect each other. Climate variability affects the agroecological and growing conditions of crops and livestock, and is recently believed to be the greatest impediment to the realisation of the first Millennium Development Goal of reducing poverty and food insecurity in arid and semi-arid regions of developing countries. Conversely, agriculture is a major contributor to climate variability and change by emitting greenhouse gases and reducing the agroecology's potential for carbon sequestration. What however, is the empirical evidence of this inter-dependence of climate variability and agriculture in Sub-Sahara Africa? In this paper, we provide some insight into the long run relationship between inter-annual variations in temperature and rainfall, and annual yields of the most important staple food crops in Northern Ghana. Applying pooled panel data of rainfall, temperature and yields of the selected crops from 1976 to 2010 to cointegration and Granger causality models, there is cogent evidence of cointegration between seasonal, total rainfall and crop yields; and causality from rainfall to crop yields in the Sudano-Guinea Savannah and Guinea Savannah zones of Northern Ghana. This suggests that inter-annual yields of the crops have been influenced by the total mounts of rainfall in the planting season. Temperature variability over the study period is however stationary, and is suspected to have minimal effect if any on crop yields. Overall, the results confirm the appropriateness of our attempt in modelling long-term relationships between the climate and crop yield variables.

Comparative Epidemiology of Highly Pathogenic Avian Influenza Virus H5N1 and H5N6 in Vietnamese Live Bird Markets: Spatiotemporal Patterns of Distribution and Risk Factors

PubMed Central

Mellor, Kate C.; Meyer, Anne; Elkholly, Doaa A.; Fournié, Guillaume; Long, Pham T.; Inui, Ken; Padungtod, Pawin; Gilbert, Marius; Newman, Scott H.; Vergne, Timothée; Pfeiffer, Dirk U.; Stevens, Kim B.

2018-01-01

Highly pathogenic avian influenza (HPAI) H5N1 virus has been circulating in Vietnam since 2003, whilst outbreaks of HPAI H5N6 virus are more recent, having only been reported since 2014. Although the spatial distribution of H5N1 outbreaks and risk factors for virus occurrence has been extensively studied, there have been no comparative studies for H5N6. Data collected through active surveillance of Vietnamese live bird markets (LBMs) between 2011 and 2015 were used to explore and compare the spatiotemporal distributions of H5N1- and H5N6-positive LBMs. Conditional autoregressive models were developed to quantify spatiotemporal associations between agroecological factors and the two HPAI strains using the same set of predictor variables. Unlike H5N1, which exhibited a strong north–south divide, with repeated occurrence in the extreme south of a cluster of high-risk provinces, H5N6 was homogeneously distributed throughout Vietnam. Similarly, different agroecological factors were associated with each strain. Sample collection in the months of January and February and higher average maximum temperature were associated with higher likelihood of H5N1-positive market-day status. The likelihood of market days being positive for H5N6 increased with decreased river density, and with successive Rounds of data collection. This study highlights marked differences in spatial patterns and risk factors for H5N1 and H5N6 in Vietnam, suggesting the need for tailored surveillance and control approaches. PMID:29675418

Comparative Epidemiology of Highly Pathogenic Avian Influenza Virus H5N1 and H5N6 in Vietnamese Live Bird Markets: Spatiotemporal Patterns of Distribution and Risk Factors.

PubMed

Mellor, Kate C; Meyer, Anne; Elkholly, Doaa A; Fournié, Guillaume; Long, Pham T; Inui, Ken; Padungtod, Pawin; Gilbert, Marius; Newman, Scott H; Vergne, Timothée; Pfeiffer, Dirk U; Stevens, Kim B

2018-01-01

Highly pathogenic avian influenza (HPAI) H5N1 virus has been circulating in Vietnam since 2003, whilst outbreaks of HPAI H5N6 virus are more recent, having only been reported since 2014. Although the spatial distribution of H5N1 outbreaks and risk factors for virus occurrence has been extensively studied, there have been no comparative studies for H5N6. Data collected through active surveillance of Vietnamese live bird markets (LBMs) between 2011 and 2015 were used to explore and compare the spatiotemporal distributions of H5N1- and H5N6-positive LBMs. Conditional autoregressive models were developed to quantify spatiotemporal associations between agroecological factors and the two HPAI strains using the same set of predictor variables. Unlike H5N1, which exhibited a strong north-south divide, with repeated occurrence in the extreme south of a cluster of high-risk provinces, H5N6 was homogeneously distributed throughout Vietnam. Similarly, different agroecological factors were associated with each strain. Sample collection in the months of January and February and higher average maximum temperature were associated with higher likelihood of H5N1-positive market-day status. The likelihood of market days being positive for H5N6 increased with decreased river density, and with successive Rounds of data collection. This study highlights marked differences in spatial patterns and risk factors for H5N1 and H5N6 in Vietnam, suggesting the need for tailored surveillance and control approaches.

An operational approach to high resolution agro-ecological zoning in West-Africa.

PubMed

Le Page, Y; Vasconcelos, Maria; Palminha, A; Melo, I Q; Pereira, J M C

2017-01-01

The objective of this work is to develop a simple methodology for high resolution crop suitability analysis under current and future climate, easily applicable and useful in Least Developed Countries. The approach addresses both regional planning in the context of climate change projections and pre-emptive short-term rural extension interventions based on same-year agricultural season forecasts, while implemented with off-the-shelf resources. The developed tools are applied operationally in a case-study developed in three regions of Guinea-Bissau and the obtained results, as well as the advantages and limitations of methods applied, are discussed. In this paper we show how a simple approach can easily generate information on climate vulnerability and how it can be operationally used in rural extension services.

Tropical grasslands: A pivotal place for a more multi-functional agriculture.

PubMed

Boval, Maryline; Angeon, Valérie; Rudel, Tom

2017-02-01

Tropical grasslands represent a pivotal arena for the sustainable intensification of agriculture in the coming decades. The abundant ecosystem services provided by the grasslands, coupled with the aversion to further forest destruction, makes sustainable intensification of tropical grasslands a high policy priority. In this article, we provide an inventory of agricultural initiatives that would contribute to the sustainable intensification of the tropical grassland agro-ecosystem, and we recommend a shift in the scientific priorities of animal scientists that would contribute to realization of a more agro-ecological and multi-functional agriculture in the world's tropical grasslands.

The importance of baobab (Adansonia digitata L.) in rural West African subsistence--suggestion of a cautionary approach to international market export of baobab fruits.

PubMed

Buchmann, Christine; Prehsler, Sarah; Hartl, Anna; Vogl, Christian R

2010-01-01

The European Commission recently authorized the import of baobab (Adansonia digitata L.) fruit pulp as a novel food. In rural West Africa the multipurpose baobab is used extensively for subsistence. Three hundred traditional uses of the baobab were documented in Benin, Mali, and Senegal across 11 ethnic groups and 4 agroecological zones. Baobab fruits and leaves are consumed throughout the year. The export of baobab fruits could negatively influence livelihoods, including reduced nutritional intake, change of power relations, and access rights. Capacity building and certification could encourage a sustainable and ethical trade of baobab fruits without neglecting baobab use in subsistence.

Sequestration of carbon in soil organic matter in Senegal: an overview

USGS Publications Warehouse

Tieszen, Larry L.; Tappan, G. Gray; Toure, A.

2004-01-01

The project focuses on four objectives in specific locations across the agroecological zones of Senegal. These objectives are: use of soil sampling and biogeochemical modeling to quantify the biophysical potential for carbon sequestration and to determine the sensitivity of the carbon stocks to various management and climate scenarios, to evaluate the socio-economic and cultural requirements necessary for successful project implementation directed toward an aggregation of smallholders to sequester around 100,000 t carbon (C), to support capacity building to develop a Carbon Specialist Team, and to initiate extrapolation from site-specific project areas to the Sahel region and the national level.

Projected climate change impacts and short term predictions on staple crops in Sub-Saharan Africa

NASA Astrophysics Data System (ADS)

Mereu, V.; Spano, D.; Gallo, A.; Carboni, G.

2013-12-01

Agriculture in Sub-Saharan Africa (SSA) drives the economy of many African countries and it is mainly rain-fed agriculture used for subsistence. Increasing temperatures, changed precipitation patterns and more frequent droughts may lead to a substantial decrease of crop yields. The projected impacts of future climate change on agriculture are expected to be significant and extensive in the SSA due to the shortening of the growing seasons and the increasing of water-stress risk. Differences in Agro-Ecological Zones and geographical characteristics of SSA influence the diverse impacts of climate change, which can greatly differ across the continent and within countries. The vulnerability of African Countries to climate change is aggravated by the low adaptive capacity of the continent, due to the increasing of its population, the widespread poverty, and other social factors. In this contest, the assessment of climate change impact on agricultural sector has a particular interest to stakeholder and policy makers, in order to identify specific agricultural sectors and Agro-Ecological Zones that could be more vulnerable to changes in climatic conditions and to develop the most appropriate policies to cope with these threats. For these reasons, the evaluation of climate change impacts for key crops in SSA was made exploring climate uncertainty and focusing on short period monitoring, which is particularly useful for food security and risk management analysis. The DSSAT-CSM (Decision Support System for Agrotechnology Transfer - Cropping System Model) software, version 4.5 was used for the analysis. Crop simulation models included in DSSAT-CSM are tools that allow to simulate physiological process of crop growth, development and production, by combining genetic crop characteristics and environmental (soil and weather) conditions. For each selected crop, the models were used, after a parameterization phase, to evaluate climate change impacts on crop phenology and production

Quantifying climatic variability in monsoonal northern China over the last 2200 years and its role in driving Chinese dynastic changes

NASA Astrophysics Data System (ADS)

Li, Jianyong; Dodson, John; Yan, Hong; Zhang, David D.; Zhang, Xiaojian; Xu, Qinghai; Lee, Harry F.; Pei, Qing; Cheng, Bo; Li, Chunhai; Ni, Jian; Sun, Aizhi; Lu, Fengyan; Zong, Yongqiang

2017-03-01

Our understanding on the spatial-temporal patterns of climatic variability over the last few millennia in the East Asian monsoon-dominated northern China (NC), and its role at a macro-scale in affecting the prosperity and depression of Chinese dynasties is limited. Quantitative high-resolution, regionally-synthesized palaeoclimatic reconstructions as well as simulations, and numerical analyses of their relationships with various fine-scale, numerical agro-ecological, social-economic, and geo-political historical records during the period of China's history, are presented here for NC. We utilize pollen data together with climate modeling to reconstruct and simulate decadal- to centennial-scale variations in precipitation or temperature for NC during the last 2200 years (-200-2000 AD). We find an overall cyclic-pattern (wet/warm or dry/cold) in the precipitation and temperature anomalies on centennial- to millennial-scale that can be likely considered as a representative for the entire NC by comparison with other related climatic records. We suggest that solar activity may play a key role in driving the climatic fluctuations in NC during the last 22 centuries, with its quasi ∼100, 50, 23, or 22-year periodicity clearly identified in our climatic reconstructions. We employ variation partitioning and redundancy analysis to quantify the independent effects of climatic factors on accounting for the total variation of 17 fine-grained numerical Chinese historical records. We quantitatively illustrate that precipitation (67.4%) may have been more important than temperature (32.5%) in causing the overall agro-ecological and macro-geopolitical shifts in imperial China with NC as the central ruling region and an agricultural heartland over the last 2200 years.

Suitability Analysis and Projected Climate Change Impact on Banana and Coffee Production Zones in Nepal

PubMed Central

Sujakhu, Nani M.; Merz, Juerg; Kindt, Roeland; Xu, Jianchu; Matin, Mir A.; Ali, Mostafa; Zomer, Robert J.

2016-01-01

The Government of Nepal has identified opportunities in agricultural commercialization, responding to a growing internal demand and expansion of export markets to reduce the immense trade deficit. Several cash crops, including coffee and bananas, have been identified in the recently approved Agriculture Development Strategy. Both of these crops have encouraged smallholder farmers to convert their subsistence farming practices to more commercial cultivation. Identification of suitable agro-ecological zones and understanding climate-related issues are important for improved production and livelihoods of smallholder farmers. Here, the suitability of coffee and banana crops is analyzed for different agro-ecological zones represented by Global Environmental Stratification (GEnS). Future shifts in these suitability zones are also predicted. Plantation sites in Nepal were geo-referenced and used as input in species distribution modelling. The multi-model ensemble model suggests that climate change will reduce the suitable growing area for coffee by about 72% across the selected emission scenarios from now to 2050. Impacts are low for banana growing, with a reduction in suitability by about 16% by 2050. Bananas show a lot of potential for playing an important role in Nepal as a sustainable crop in the context of climate change, as this study indicates that the amount of area suited to banana growing will grow by 40% by 2050. Based on our analysis we recommend possible new locations for coffee plantations and one method for mitigating climate change-related problems on existing plantations. These findings are expected to support planning and policy dialogue for mitigation and support better informed and scientifically based decision-making relating to these two crops. PMID:27689354

Determinants of adaptation choices to climate change by sheep and goat farmers in Northern Ethiopia: the case of Southern and Central Tigray, Ethiopia.

PubMed

Feleke, Fikeremaryam Birara; Berhe, Melaku; Gebru, Getachew; Hoag, Dana

2016-01-01

The livestock sector serves as a foremost source of revenue for rural people, particularly in many developing countries. Among the livestock species, sheep and goats are the main source of livelihood for rural people in Ethiopia; they can quickly multiply, resilient and are easily convertible to cash to meet financial needs of the rural producers. The multiple contributions of sheep and goat and other livestock to rural farmers are however being challenged by climate change and variability. Farmers are responding to the impacts of climate change by adopting different mechanisms, where choices are largely dependent on many factors. This study, therefore, aims to analyze the determinants of choices of adaptation practices to climate change that causes scarcity of feed, heat stress, shortage of water and pasture on sheep and goat production. The study used 318 sample households drawn from potential livestock producing districts representing 3 agro-ecological settings. Data was analyzed using simple descriptive statistical tools, a multivariate probit model and Ordinary Least Squares (OLS). Most of the respondents (98.6 %) noted that climate is changing. Respondents' perception is that climate change is expressed through increased temperature (88 %) and decline in rainfall (73 %) over the last 10 years. The most commonly used adaptation strategy was marketing during forage shock (96.5 %), followed by home feeding (89.6 %). The estimation from the multivariate probit model showed that access to information, farming experience, number of households in one village, distance to main market, income of household, and agro-ecological settings influenced farmers' adaptation choices to climate change. Furthermore, OLS revealed that the adaptation strategies had positive influence on the household income.

Modelling the distribution of chickens, ducks, and geese in China

USGS Publications Warehouse

Prosser, Diann J.; Wu, Junxi; Ellis, Erie C.; Gale, Fred; Van Boeckel, Thomas P.; Wint, William; Robinson, Tim; Xiao, Xiangming; Gilbert, Marius

2011-01-01

Global concerns over the emergence of zoonotic pandemics emphasize the need for high-resolution population distribution mapping and spatial modelling. Ongoing efforts to model disease risk in China have been hindered by a lack of available species level distribution maps for poultry. The goal of this study was to develop 1 km resolution population density models for China's chickens, ducks, and geese. We used an information theoretic approach to predict poultry densities based on statistical relationships between poultry census data and high-resolution agro-ecological predictor variables. Model predictions were validated by comparing goodness of fit measures (root mean square error and correlation coefficient) for observed and predicted values for 1/4 of the sample data which were not used for model training. Final output included mean and coefficient of variation maps for each species. We tested the quality of models produced using three predictor datasets and 4 regional stratification methods. For predictor variables, a combination of traditional predictors for livestock mapping and land use predictors produced the best goodness of fit scores. Comparison of regional stratifications indicated that for chickens and ducks, a stratification based on livestock production systems produced the best results; for geese, an agro-ecological stratification produced best results. However, for all species, each method of regional stratification produced significantly better goodness of fit scores than the global model. Here we provide descriptive methods, analytical comparisons, and model output for China's first high resolution, species level poultry distribution maps. Output will be made available to the scientific and public community for use in a wide range of applications from epidemiological studies to livestock policy and management initiatives.

Climatic, Edaphic Factors and Cropping History Help Predict Click Beetle (Coleoptera: Elateridae) (Agriotes spp.) Abundance.

PubMed

Kozina, A; Lemic, D; Bazok, R; Mikac, K M; Mclean, C M; Ivezić, M; Igrc Barčić, J

2015-01-01

It is assumed that the abundance of Agriotes wireworms (Coleoptera: Elateridae) is affected by agro-ecological factors such as climatic and edaphic factors and the crop/previous crop grown at the sites investigated. The aim of this study, conducted in three different geographic counties in Croatia from 2007 to 2009, was to determine the factors that influence the abundance of adult click beetle of the species Agriotes brevis Cand., Agriotes lineatus (L.), Agriotes obscurus (L.), Agriotes sputator (L.), and Agriotes ustulatus Schall. The mean annual air temperature, total rainfall, percentage of coarse and fine sand, coarse and fine silt and clay, the soil pH, and humus were investigated as potential factors that may influence abundance. Adult click beetle emergence was monitored using sex pheromone traps (YATLORf and VARb3). Exploratory data analysis was preformed via regression tree models and regional differences in Agriotes species' abundance were predicted based on the agro-ecological factors measured. It was found that the best overall predictor of A. brevis abundance was the previous crop grown. Conversely, the best predictor of A. lineatus abundance was the current crop being grown and the percentage of humus. The best predictor of A. obscurus abundance was soil pH in KCl. The best predictor of A. sputator abundance was rainfall. Finally, the best predictors of A. ustulatus abundance were soil pH in KCl and humus. These results may be useful in regional pest control programs or for predicting future outbreaks of these species. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Socio-economic and climate change impacts on agriculture: an integrated assessment, 1990–2080

PubMed Central

Fischer, Günther; Shah, Mahendra; N. Tubiello, Francesco; van Velhuizen, Harrij

2005-01-01

A comprehensive assessment of the impacts of climate change on agro-ecosystems over this century is developed, up to 2080 and at a global level, albeit with significant regional detail. To this end an integrated ecological–economic modelling framework is employed, encompassing climate scenarios, agro-ecological zoning information, socio-economic drivers, as well as world food trade dynamics. Specifically, global simulations are performed using the FAO/IIASA agro-ecological zone model, in conjunction with IIASAs global food system model, using climate variables from five different general circulation models, under four different socio-economic scenarios from the intergovernmental panel on climate change. First, impacts of different scenarios of climate change on bio-physical soil and crop growth determinants of yield are evaluated on a 5′×5′ latitude/longitude global grid; second, the extent of potential agricultural land and related potential crop production is computed. The detailed bio-physical results are then fed into an economic analysis, to assess how climate impacts may interact with alternative development pathways, and key trends expected over this century for food demand and production, and trade, as well as key composite indices such as risk of hunger and malnutrition, are computed. This modelling approach connects the relevant bio-physical and socio-economic variables within a unified and coherent framework to produce a global assessment of food production and security under climate change. The results from the study suggest that critical impact asymmetries due to both climate and socio-economic structures may deepen current production and consumption gaps between developed and developing world; it is suggested that adaptation of agricultural techniques will be central to limit potential damages under climate change. PMID:16433094

Modelling the distribution of chickens, ducks, and geese in China

PubMed Central

Prosser, Diann J.; Wu, Junxi; Ellis, Erle C.; Gale, Fred; Van Boeckel, Thomas P.; Wint, William; Robinson, Tim; Xiao, Xiangming; Gilbert, Marius

2011-01-01

Global concerns over the emergence of zoonotic pandemics emphasize the need for high-resolution population distribution mapping and spatial modelling. Ongoing efforts to model disease risk in China have been hindered by a lack of available species level distribution maps for poultry. The goal of this study was to develop 1 km resolution population density models for China’s chickens, ducks, and geese. We used an information theoretic approach to predict poultry densities based on statistical relationships between poultry census data and high-resolution agro-ecological predictor variables. Model predictions were validated by comparing goodness of fit measures (root mean square error and correlation coefficient) for observed and predicted values for ¼ of the sample data which was not used for model training. Final output included mean and coefficient of variation maps for each species. We tested the quality of models produced using three predictor datasets and 4 regional stratification methods. For predictor variables, a combination of traditional predictors for livestock mapping and land use predictors produced the best goodness of fit scores. Comparison of regional stratifications indicated that for chickens and ducks, a stratification based on livestock production systems produced the best results; for geese, an agro-ecological stratification produced best results. However, for all species, each method of regional stratification produced significantly better goodness of fit scores than the global model. Here we provide descriptive methods, analytical comparisons, and model output for China’s first high resolution, species level poultry distribution maps. Output will be made available to the scientific and public community for use in a wide range of applications from epidemiological studies to livestock policy and management initiatives. PMID:21765567

AGRO-ECOLOGICAL DRIVERS OF RURAL OUT-MIGRATION TO THE MAYA BIOSPHERE RESERVE, GUATEMALA.

PubMed

López-Carr, David

2012-01-01

Migration necessarily precedes environmental change in the form of deforestation and soil degradation in tropical agricultural frontiers. But what environmental factors may contribute to these migration streams in the first place? Identifying environmental characteristics related to this process is crucial for understanding how environmental change and migration may form recurrent feedback loops. Further understanding this process could be useful for developing policies to reduce both environmentally induced migration from origin areas and also to palliate significant environmental change unleashed by settler deforestation in destination areas. Evidently, apprehending this holistic process cannot be approached only from the destination since this ignores environmental and other antecedents to rural out-migration. This paper presents data from surveys conducted in areas of high out-migration to the agricultural frontier in northern Guatemala. Results suggest that land scarcity and degradation in origin communities are linked to out-migration in general and to the forest frontier of northern Guatemala in particular.

The Quality of Sustainability: Agroecological Partnerships and the Geographic Branding of California Winegrapes

ERIC Educational Resources Information Center

Warner, Keith Douglass

2007-01-01

Quality and sustainability are both socially constructed, ambiguous terms, but they have not been heretofore linked in the rural studies literature. The "quality turn" has received particular attention from researchers for its potential to organize linkages among various forces in agrofood systems, providing more income to producers by…

Coupled Effects of Climatic and Socio-economic Factors on Winter Cropping in India

NASA Astrophysics Data System (ADS)

Jain, M.; Mondal, P.; Galford, G. L.; DeFries, R. S.

2015-12-01

India is predicted to be one of the most vulnerable regions in terms of agricultural sensitivity to future climate changes. Approximately 69% of India's population is rural, and over 55% of the working population relies on agriculture for sustenance and livelihoods. Indian smallholder farmers who own less than 2 ha of farmland represent 78% of the total Indian farmers and produce 41% of the country's food crops. These smallholder farmers are among some of the most vulnerable communities to climatic and economic changes due to limited access to technology, infrastructure, markets, and institutional or financial support in the case of adverse climatic events. Baseline information on agricultural sensitivity to climate variability will provide useful information for regional-level, and eventually state- and national-level, strategies and policies that promote adaption to climate variability. We use a decade of remote sensing analysis of cropping patterns and climatic factors along with census data for irrigation and demographic factors to understand winter cropping trajectories across agro-ecological zones in India. Findings from multiple agro-ecological zones indicate that there are three primary trajectories in winter cropping in India - increasing, fluctuating, and decreasing. In the Central Indian Highlands, for example, the most dominant trend is that of fluctuating cropped area, ranging between ~37,300 km2 in 2010 and ~21,100 km2 in 2013, which is associated with village-level access to irrigation and local labor dynamics. Clay soil type and increasing irrigation coverage were associated with intensification. Yet, suitable soil type and access to irrigation do not reduce vulnerability to high daytime temperatures that is negatively associated with winter crop cover. With pronounced winter warming projected in the coming decades, effective adaptation by smallholder farmers would require additional strategies, such as access to fine-scale temperature forecasts

Serological survey of bovine brucellosis in Fulani nomadic cattle breeds (Bos indicus) of North-central Nigeria: Potential risk factors and zoonotic implications.

PubMed

Alhaji, N B; Wungak, Y S; Bertu, W J

2016-01-01

A cross sectional study was conducted to investigate seroprevalence and associated risk factors of bovine brucellosis in Fulani nomadic herds in the 3 agro-ecological zones of Niger State, North-central Nigeria between January and August 2013. A total of 672 cattle in 113 herds were screened for Brucella antibodies using Rose Bengal Plate Test (RBPT) and confirmed by Lateral flow Assay (LFA). Data on herd characteristics and zoonotic factors were collected using structured questionnaire administered on Fulani herd owners. Factors associated with Brucella infection were tested using Chi-square test and multivariable logistic model. The overall cattle-level seroprevalence was 1.9% (95% CI: 1.1-3.2) with highest in agro-zone C (3.2%). Herd-level seroprevalence was 9.7% (95% CI: 5.23-16.29) and highest in agro-zone C (13.5%). Sex and agro-ecological zones were significantly (P<0.006 and P<0.01, respectively) associated with Brucella abortus seropositivity. Herd composition, abortion in herd, exchange of bulls for mating, introduction of new cattle, and socio-cultural practices were significantly associated with brucellosis occurrence. Inhalation of droplets from milk of infected cows, and drinking raw milk were less likely [OR 0.27; 95% CI: 0.09-0.82 and OR 0.27; 95% CI: 0.08-0.99, respectively] not to predisposed to brucellosis in humans. Eating infected raw meat, and contact with infected placenta were more likely [OR 7.49; 95% CI: 2.06-28.32 and OR 5.74; 95% CI: 1.78-18.47, respectively] to be risks for the disease in humans. These results highlighted the important risk factors for bovine brucellosis in Fulani herds. Thus, brucellosis control programs which take these factors into consideration will be beneficial. Copyright © 2015 Elsevier B.V. All rights reserved.

Landscape-based upstream-downstream prevalence of land-use/cover change drivers in southeastern rift escarpment of Ethiopia.

PubMed

Temesgen, Habtamu; Wu, Wei; Legesse, Abiyot; Yirsaw, Eshetu; Bekele, Belew

2018-02-23

Characterized by high population density on a rugged topography, the Gedeo-Abaya landscape dominantly contains a multi-strata traditional agroforests showing the insight of Gedeo farmers on natural resource management practices. Currently, this area has been losing its resilience and is becoming unable to sustain its inhabitants. Based on both RS-derived and GIS-computed land-use/cover changes (LUCC) as well as socioeconomic validations, this article explored the LUCC and agroecological-based driver patterns in Gedeo-Abaya landscape from 1986 to 2015. A combination of geo-spatial technology and cross-sectional survey design were employed to detect the drivers behind these changes. The article discussed that LUCC and the prevalence of drivers are highly diverse and vary throughout agroecological zones. Except for the population, most downstream top drivers are perceived as insignificant in the upstream region and vice versa. In the downstream, land-use/cover (LUC) classes are more dynamic, diverse, and challenged by nearly all anticipated drivers than are upstream ones. Agroforestry LUC has been increasing (by 25% of its initial cover) and is becoming the predominant cover type, although socioeconomic analysis and related findings show its rapid LUC modification. A rapid reduction of woodland/shrubland (63%) occurred in the downstream, while wetland/marshy land increased threefold (158%), from 1986 to 2015 with annual change rates of - 3.7 and + 6%, respectively. Land degradation induced by changes in land use is a serious problem in Africa, especially in the densely populated sub-Saharan regions such as Ethiopia (FAO 2015). Throughout the landscape, LUCC is prominently affecting land-use system of the study landscape due to population pressure in the upstream region and drought/rainfall variability, agribusiness investment, and charcoaling in the downstream that necessitate urgent action.

Regional, holocene records of the human dimension of global change: sea-level and land-use change in prehistoric Mexico

NASA Astrophysics Data System (ADS)

Sluyter, Andrew

1997-02-01

Regional, Holocene records hold particular relevance for understanding the reciprocal nature of global environmental change and one of its major human dimensions: "sustainable agriculture", i.e., food production strategies which entail fewer causes of and are less susceptible to environmental change. In an epoch of accelerating anthropogenic transformation, those records reveal the protracted regional causes and consequences of change (often agricultural) in the global system as well as informing models of prehistoric, intensive agriculture which, because of long tenures and high productivities, suggest strategies for sustainable agricultural in the present. This study employs physiographic analysis and the palynological, geochemical record from cores of basin fill to understand the reciprocal relation between environmental and land-use change in the Gulf of Mexico tropical lowland, focusing on a coastal basin sensitive to sea-level change and containing vestiges of prehistoric settlement and wetland agriculture. Fossil pollen reveals that the debut of maize cultivation in the Laguna Catarina watershed dates to ca. 4100 BC, predating the earliest evidence for that cultivar anywhere else in the lowlands of Middle America. Such an early date for a cultivar so central to Neotropical agroecology and environmental change, suggests the urgency of further research in the study region. Moreover, the longest period of continuous agriculture in the basin lasted nearly three millennia (ca. 2400 BC-AD 550) despite eustatic sea-level rise. Geochemical fluxes reveal the reciprocity between land-use and environmental change: slope destabilization, basin aggradation, and eutrophication. The consequent theoretical implications pertain to both applied and basic research. Redeploying ancient agroecologies in dynamic environments necessitates reconstructing the changing operational contexts of putative high productivity and sustainability. Adjusting land use in the face of global

Modeling and improving Ethiopian pasture systems

NASA Astrophysics Data System (ADS)

Parisi, S. G.; Cola, G.; Gilioli, G.; Mariani, L.

2018-01-01

The production of pasture in Ethiopia was simulated by means of a dynamic model. Most of the country is characterized by a tropical monsoon climate with mild temperatures and precipitation mainly concentrated in the June-September period (main rainy season). The production model is driven by solar radiation and takes into account limitations due to relocation, maintenance respiration, conversion to final dry matter, temperature, water stress, and nutrients availability. The model also considers the senescence of grassland which strongly limits the nutritional value of grasses for livestock. The simulation for the 1982-2009 period, performed on gridded daily time series of rainfall and maximum and minimum temperature with a resolution of 0.5°, provided results comparable with values reported in literature. Yearly mean yield in Ethiopia ranged between 1.8 metric ton per hectare (t ha-1) (2002) and 2.6 t ha-1 (1989) of dry matter with values above 2.5 t ha-1 attained in 1983, 1985, 1989, and 2008. The Ethiopian territory has been subdivided in 1494 cells and a frequency distribution of the per-cell yearly mean pasture production has been obtained. This distribution ranges from 0 to 7 t ha-1 and it shows a right skewed distribution and a modal class between 1.5-2 t ha-1. Simulation carried out on long time series for this peculiar tropical environment give rise to as lot of results relevant by the agroecological point of view on space variability of pasture production, main limiting factors (solar radiation, precipitation, temperature), and relevant meteo-climatic cycles affecting pasture production (seasonal and inter yearly variability, ENSO). These results are useful to establish an agro-ecological zoning of the Ethiopian territory.

Traditional ecological knowledge underlying herding decisions of pastoralists.

PubMed

Tamou, C; de Boer, I J M; Ripoll-Bosch, R; Oosting, S J

2018-04-01

Pastoralists have traditional ecological knowledge (TEK), which is important for their livelihoods and for policies and interventions. Pastoralism is under pressure, however, which may result in a decline of pastoral lifestyle and its related TEK. We, therefore, addressed the following objectives (i) to inventorise and assess how pastoralists characterise and value soils and forages in their environment, (ii) to analyse how soil, forage and livestock (i.e. cattle) characteristics relate to herding decisions and (iii) to determine whether TEK underlying herding decisions differs across generations. Data were collected through focus groups and individual interviews with 72 pastoralists, belonging to three generations and to three agro-ecological zones. Using a three-point scale (high, medium, low), four grasses and three tree forages were assessed in terms of nutritional quality for milk, meat, health and strength. Using their own visual criteria, pastoralists identified five different soils, which they selected for herding at different times of the year. Pastoralists stated that Pokuri was the best soil because of its low moisture content, whereas Karaal was the worst because forage hardly grows on it. They stated that perennials, such as Andropogon gayanus and Loxoderra ledermannii, were of high nutritional quality, whereas annuals such as Andropogon pseudapricus and Hyparrhenia involucrata were of low nutritional quality. Afzelia africana was perceived of high quality for milk production, whereas Khaya senegalensis had the highest quality for meat, health and strength. Pastoralists first used soil, then forage and finally livestock characteristics in their herding decisions. Pastoralists' TEK was not associated with their generations, but with their agro-ecological zones. This study suggests that pastoralists had common and detailed TEK about soils, forages and livestock characteristics, underlying their herding decisions. To conclude, pastoralists use a holistic

Economic contribution and viability of dairy goats: implications for a breeding programme.

PubMed

Ogola, T D O; Nguyo, W K; Kosgey, I S

2010-06-01

To augment the incomes of smallholder farmers in Kenya and consequently improve their nutrition and income, many development organisations and policy makers are increasingly promoting dairy goat farming. Among the key organisations supporting the initiative is Heifer Project International-Kenya (HPIK). However, the economic contribution and viability of dairy goats under the HPIK project have not been studied so far. The aim of the present study was to determine the contribution of dairy goats to household income and the performance of the dairy goat enterprise using gross and net margins from dairy goat farming as an indicator of economic viability. A survey covering 71 farmers was carried out in the Coast, Nyanza, and the Rift Valley provinces of Kenya using a set of pre-tested structured and semi-structured questionnaires. Results showed that, on average, the dairy goat enterprise contributed, correspondingly, about 15.2% and 4.8% to the total livestock and overall household income and was viable. Differences in gross and net margins across agroecological zones were attributed to milk prices. Despite the existence of non-viable enterprises in two of the provinces, the few present suggest the possibility of obtaining reliable incomes from the enterprise. Redoubling of effort or re-orientation of production to match the local and external requirements would, however, be necessary. Costs and revenues were similar across the agroecological zones. Farmers with positive gross margins had better milk and stock sales and vice versa. The success of a dairy goat enterprise is attributed to location and good management. Besides, farmers' awareness of the market demands within and outside the community is important in establishing production goals and may be crucial to achieving a positive gross margin.

Comparison of nucleotide sequences of recent and previous lineages of peste-des-petits-ruminants viruses of sheep and goats in Nigeria.

PubMed

Mantip, Samuel; Quan, Melvyn; Shamaki, David; Van Vuuren, Moritz

2016-08-31

Peste-des-petits-ruminants virus (PPRV) is a highly contagious, fatal and economically important viral disease of small ruminants that is still endemic and militates against the production of sheep and goats in endemic areas of the world. The aim of this study was to describe the viral strains within the country. This was carried out by collecting tissue and swab samples from sheep and goats in various agro-ecological zones of Nigeria. The phylogeny of archived PPRV strains or isolates and those circulating and causing recent outbreaks was determined by sequencing of the nucleoprotein (N)-gene. Twenty tissue and swab samples from apparently healthy and sick sheep and goats were collected randomly from 18 states, namely 3 states in each of the 6 agro-ecological zones visited. A total of 360 samples were collected. A total of 35 samples of 360 (9.7%) tested positive by reverse transcriptase-polymerase chain reaction, of which 25 were from oculo-nasal swabs and 10 were from tissue samples. Neighbour-joining phylogenetic analysis using Phylogenetic Analysis Using Parsimony (PAUP) identified four different lineages, that is, lineages I, II, III and IV. Interestingly, the Nigerian strains described in this study grouped in two separate major lineages, that is, lineages II and IV. Strains from Sokoto, Oyo, Plateau and Ondo states grouped according to the historical distribution of PPRV together with the Nigerian 75/1 strain of lineage II, while other strains from Sokoto, Oyo, Plateau, Akwa-Ibom, Adamawa, Kaduna, Lagos, Bauchi, Niger and Kano states grouped together with the East African and Asian strains of lineage IV. This finding confirms that both lineage II and IV strains of PPRV are circulating in Nigeria. Previously, only strains of lineage II were found to be present in the country.

Modeling and improving Ethiopian pasture systems

NASA Astrophysics Data System (ADS)

Parisi, S. G.; Cola, G.; Gilioli, G.; Mariani, L.

2018-05-01

The production of pasture in Ethiopia was simulated by means of a dynamic model. Most of the country is characterized by a tropical monsoon climate with mild temperatures and precipitation mainly concentrated in the June-September period (main rainy season). The production model is driven by solar radiation and takes into account limitations due to relocation, maintenance respiration, conversion to final dry matter, temperature, water stress, and nutrients availability. The model also considers the senescence of grassland which strongly limits the nutritional value of grasses for livestock. The simulation for the 1982-2009 period, performed on gridded daily time series of rainfall and maximum and minimum temperature with a resolution of 0.5°, provided results comparable with values reported in literature. Yearly mean yield in Ethiopia ranged between 1.8 metric ton per hectare (t ha-1) (2002) and 2.6 t ha-1 (1989) of dry matter with values above 2.5 t ha-1 attained in 1983, 1985, 1989, and 2008. The Ethiopian territory has been subdivided in 1494 cells and a frequency distribution of the per-cell yearly mean pasture production has been obtained. This distribution ranges from 0 to 7 t ha-1 and it shows a right skewed distribution and a modal class between 1.5-2 t ha-1. Simulation carried out on long time series for this peculiar tropical environment give rise to as lot of results relevant by the agroecological point of view on space variability of pasture production, main limiting factors (solar radiation, precipitation, temperature), and relevant meteo-climatic cycles affecting pasture production (seasonal and inter yearly variability, ENSO). These results are useful to establish an agro-ecological zoning of the Ethiopian territory.

EO based Agro-ecosystem approach for climate change adaptation in enhancing the crop production efficiency in the Indo-gangetic plains of India

NASA Astrophysics Data System (ADS)

Pandey, Suraj

This study develops a spatial mapping of agro-ecological zones based on earth observation model using MODIS regional dataset as a tool to guide key areas of cropping system and targeting to climate change strategies. This tool applies to the Indo-gangetic Plains of north India to target the domains of bio-physical characteristics and socio-economics with respect to changing climate in the region. It derive on secondary data for spatially-explicit variables at the state/district level, which serve as indicators of climate variability based on sustainable livelihood approach, natural, social and human. The study details the methodology used and generates the spatial climate risk maps for composite indicators of livelihood and vulnerability index in the region.

Evaluation of vegetable-faba bean (Vicia faba L.) intercropping under Latvian agro-ecological conditions.

PubMed

Lepse, Līga; Dane, Sandra; Zeipiņa, Solvita; Domínguez-Perles, Raul; Rosa, Eduardo As

2017-10-01

Monoculture is used mostly in conventional agriculture, where a single crop is cultivated on the same land for a period of at least 12 months. In an organic and integrated growing approach, more attention is paid to plant-environment interactions and, as a result, diverse growing systems applying intercropping, catch crops, and green manure are being implemented. Thus, field experiments for evaluation of vegetable/faba bean full intercropping efficiency, in terms of vegetable and faba bean yield and protein content, were set up during two consecutive growing seasons (2014 and 2015). Data obtained showed that the most efficient intercropping variants were cabbage/faba bean (cabbage yield 1.27-2.91 kg m -2 , immature faba bean pods 0.20-0.43 kg m -2 ) and carrot/faba bean (carrot yield 1.67-2.28 kg m -2 , immature faba bean pods 0.10-0.52 kg m -2 ), whilst onion and faba bean intercrop is not recommended for vegetable growing since it induces a very low onion yield (0.66-1.09 kg m -2 ), although the highest immature faba bean pod yield was found in the onion/faba bean intercropping scheme (up to 0.56 kg m -2 ). Vegetable/faba bean intercropping can be used in practical horticulture for carrot and cabbage growing in order to ensure sustainable farming and environmentally friendly horticultural production. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Functional traits in agriculture: agrobiodiversity and ecosystem services.

PubMed

Wood, Stephen A; Karp, Daniel S; DeClerck, Fabrice; Kremen, Claire; Naeem, Shahid; Palm, Cheryl A

2015-09-01

Functional trait research has led to greater understanding of the impacts of biodiversity in ecosystems. Yet, functional trait approaches have not been widely applied to agroecosystems and understanding of the importance of agrobiodiversity remains limited to a few ecosystem processes and services. To improve this understanding, we argue here for a functional trait approach to agroecology that adopts recent advances in trait research for multitrophic and spatially heterogeneous ecosystems. We suggest that trait values should be measured across environmental conditions and agricultural management regimes to predict how ecosystem services vary with farm practices and environment. This knowledge should be used to develop management strategies that can be easily implemented by farmers to manage agriculture to provide multiple ecosystem services. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comprehensive assessment of soil erosion risk for better land use planning in river basins: Case study of the Upper Blue Nile River.

PubMed

Haregeweyn, Nigussie; Tsunekawa, Atsushi; Poesen, Jean; Tsubo, Mitsuru; Meshesha, Derege Tsegaye; Fenta, Ayele Almaw; Nyssen, Jan; Adgo, Enyew

2017-01-01

In the drought-prone Upper Blue Nile River (UBNR) basin of Ethiopia, soil erosion by water results in significant consequences that also affect downstream countries. However, there have been limited comprehensive studies of this and other basins with diverse agroecologies. We analyzed the variability of gross soil loss and sediment yield rates under present and expected future conditions using a newly devised methodological framework. The results showed that the basin generates an average soil loss rate of 27.5tha -1 yr -1 and a gross soil loss of ca. 473Mtyr -1 , of which, at least 10% comes from gully erosion and 26.7% leaves Ethiopia. In a factor analysis, variation in agroecology (average factor score=1.32) and slope (1.28) were the two factors most responsible for this high spatial variability. About 39% of the basin area is experiencing severe to very severe (>30tha -1 yr -1 ) soil erosion risk, which is strongly linked to population density. Severe or very severe soil erosion affects the largest proportion of land in three subbasins of the UBNR basin: Blue Nile 4 (53.9%), Blue Nile 3 (45.1%), and Jema Shet (42.5%). If appropriate soil and water conservation practices targeted ca. 77.3% of the area with moderate to severe erosion (>15tha -1 yr -1 ), the total soil loss from the basin could be reduced by ca. 52%. Our methodological framework identified the potential risk for soil erosion in large-scale zones, and with a more sophisticated model and input data of higher spatial and temporal resolution, results could be specified locally within these risk zones. Accurate assessment of soil erosion in the UBNR basin would support sustainable use of the basin's land resources and possibly open up prospects for cooperation in the Eastern Nile region. Copyright © 2016 Office national des forêts. Published by Elsevier B.V. All rights reserved.

Seroprevalence of Schmallenberg virus in dairy cattle in Ethiopia.

PubMed

Sibhat, Berhanu; Ayelet, Gelagay; Gebremedhin, Endrias Zewdu; Skjerve, Eystein; Asmare, Kassahun

2018-02-01

Schmallenberg virus (SBV) is a recently identified member of the genus Orthobunyavirus of the family Bunyaviridae. It is an arbovirus transmitted by different members of Culicoides spp of biting midges. The virus is more recognized for its effect on reproductive disorders in ruminants characterised by abortion, stillbirth and birth of congenitally defective newborns with hydranencephaly-arthrogryposis syndrome. The current study was undertaken with the objectives of exploring the presence of SBV exposure and identification of factors affecting its distribution among dairy cattle in Ethiopia. A cross-sectional study was conducted on 1379 dairy cattle sampled from 149 dairy herds in central, southern and western Ethiopia during September 2011 to May 2012. Serum samples were examined using competitive enzyme linked immunosorbent assay (cELISA). Data on hypothesised risk factors were collected from farm records where available and semi-structured questionnaire-based interview. The apparent seroprevalence of exposure to SBV was 56.6% (95% confidence interval (CI): 53.9-59.3). True prevalence adjusted for sensitivity and specificity of the cELISA kit used was 58.3% (95% CI 55.7-60.9). Among the sampled herds, 82.6% (95% CI: 75.5-88.3) had at least one seropositive animal. Seropositive cattle were found in all of the 15 conurbations studied. Adult dairy cows [odds ratio (OR)=1.6] were more commonly affected than young heifers. Dairy cattle kept in commercial (OR=1.6) and breeding farms (OR=3.5) and Midland agroecology (OR=2.5) showed statistically significant seroconversion than cattle kept under small-holder dairy farms and Highland agroecology respectively (p<0.05). Reproductive disorders including abortion, retention of the fetal membranes, and metritis were associated with serostatus of SBV. In conclusion, the seroprevalence of SBV is high and widely distributed in the studied parts of Ethiopia. This being the first study of its kind on SBV in Ethiopia, further

Comparative analysis of diversity and utilization of edible plants in arid and semi-arid areas in Benin.

PubMed

Segnon, Alcade C; Achigan-Dako, Enoch G

2014-12-23

Agrobiodiversity is said to contribute to the sustainability of agricultural systems and food security. However, how this is achieved especially in smallholder farming systems in arid and semi-arid areas is rarely documented. In this study, we explored two contrasting regions in Benin to investigate how agroecological and socioeconomic contexts shape the diversity and utilization of edible plants in these regions. Data were collected through focus group discussions in 12 villages with four in Bassila (semi-arid Sudano-Guinean region) and eight in Boukoumbé (arid Sudanian region). Semi-structured interviews were carried out with 180 farmers (90 in each region). Species richness and Shannon-Wiener diversity index were estimated based on presence-absence data obtained from the focus group discussions using species accumulation curves. Our results indicated that 115 species belonging to 48 families and 92 genera were used to address food security. Overall, wild species represent 61% of edible plants collected (60% in the semi-arid area and 54% in the arid area). About 25% of wild edible plants were under domestication. Edible species richness and diversity in the semi-arid area were significantly higher than in the arid area. However, farmers in the arid area have developed advanced resource-conserving practices compared to their counterparts in the semi-arid area where slash-and-burn cultivation is still ongoing, resulting in natural resources degradation and loss of biodiversity. There is no significant difference between the two areas for cultivated species richness. The interplay of socio-cultural attributes and agroecological conditions explains the diversity of food plants selected by communities. We conclude that if food security has to be addressed, the production and consumption policies must be re-oriented toward the recognition of the place of wild edible plants. For this to happen we suggest a number of policy and strategic decisions as well as research

Decision Support Systems To Manage Water Resources At Irrigation District Level In Southern Italy Using Remote Sensing Information. An Integrated Project (AQUATER)

NASA Astrophysics Data System (ADS)

Rinaldi, M.; Castrignanò, A.; Mastrorilli, M.; Rana, G.; Ventrella, D.; Acutis, M.; D'Urso, G.; Mattia, F.

2006-08-01

An efficient management of water resources is crucial point for Italy and in particular for southern areas characterized by Mediterranean climate in order to improve the economical and environmental sustainability of the agricultural activity. A three-year Project (2005-2008) has been funded by the Italian Ministry of Agriculture and Forestry Policies; it involves four Italian research institutions: the Agricultural Research Council (ISA, Bari), the National Research Council (ISSIA, Bari) and two Universities (Federico II-Naples and Milan). It is focused on the remote sensing, the plant and the climate and, for interdisciplinary relationships, the project working group consists of agronomists, engineers and physicists. The aims of the Project are: a) to produce a Decision Support System (DSS) combining remote sensing information, spatial data and simulation models to manage water resources in irrigation districts; b) to simulate irrigation scenarios to evaluate the effects of water stress on crop yield using agro-ecological indicators; c) to identify the most sensitive areas to drought risk in Southern Italy. The tools used in this Project will be: 1. Remote sensing images, topographic maps, soil and land use maps; 2. Geographic Information Systems; 3. Geostatistic methodologies; 4. Ground truth measurements (land use, canopy and soil temperatures, soil and plant water status, Normalized Difference Vegetation Index, Crop Water Stress Index, Leaf Area Index, actual evapotranspiration, crop coefficients, crop yield, agro-ecological indicators); 5. Crop simulation models. The Project is structured in four work packages with specific objectives, high degree of interaction and information exchange: 1) Remote Sensing and Image Analysis; 2) Cropping Systems; 3) Modelling and Softwares Development; 4) Stakeholders. The final product will be a DSS with the purpose of integrating remote sensing images, to estimate crop and soil variables related to drought, to assimilate

Nested archetypes of vulnerability in African drylands: where lies potential for sustainable agricultural intensification?

NASA Astrophysics Data System (ADS)

Sietz, D.; Ordoñez, J. C.; Kok, M. T. J.; Janssen, P.; Hilderink, H. B. M.; Tittonell, P.; Van Dijk, H.

2017-09-01

Food production is key to achieving food security in the drylands of sub-Saharan Africa. Since agricultural productivity is limited, however, due to inherent agro-ecological constraints and land degradation, sustainable agricultural intensification has been widely discussed as an opportunity for improving food security and reducing vulnerability. Yet vulnerability determinants are distributed heterogeneously in the drylands of sub-Saharan Africa and sustainable intensification cannot be achieved everywhere in cost-effective and efficient ways. To better understand the heterogeneity of farming systems’ vulnerability in order to support decision making at regional scales, we present archetypes, i.e. socio-ecological patterns, of farming systems’ vulnerability in the drylands of sub-Saharan Africa and reveal their nestedness. We quantitatively indicated the most relevant farming systems’ properties at a sub-national resolution. These factors included water availability, agro-ecological potential, erosion sensitivity, population pressure, urbanisation, remoteness, governance, income and undernourishment. Cluster analysis revealed eight broad archetypes of vulnerability across all drylands of sub-Saharan Africa. The broad archetype representing better governance and highest remoteness in extremely dry and resource-constrained regions encompassed the largest area share (19%), mainly indicated in western Africa. Moreover, six nested archetypes were identified within those regions with better agropotential and prevalent agricultural livelihoods. Among these patterns, the nested archetype depicting regions with highest erosion sensitivity, severe undernourishment and lower agropotential represented the largest population (30%) and area (28%) share, mainly found in the Sahel region. The nested archetype indicating medium undernourishment, better governance and lowest erosion sensitivity showed particular potential for sustainable agricultural intensification, mainly in

Fields of dreams: Agriculture, economy and nature in Midwest United States biofuel production

NASA Astrophysics Data System (ADS)

Gillon, Sean Thomas

This work explores the social and ecological dimensions of recent biofuel production increases in the United States (US), focusing on the case of Iowa. Biofuels are proposed to mitigate the greenhouse gas emissions that cause climate change, improve US energy security, and support rural economies. Little research has examined how increased US Midwestern biofuels production will change social and ecological outcomes at farm and regional levels or interact with broader governance processes at the nexus of agriculture, energy and environment. These broad questions guide my research: (1) How does biofuel production reconfigure agricultural practice and landscapes in Iowa? (2) What are the costs, benefits and risks of increased biofuels production as seen by farmers and rural residents, and how do these factors influence farmer decisions about agriculture and conservation practice? (3) How and with what effects are biofuels initiatives constituted as a form of environmental governance through scientific knowledge and practice and political economic dynamics? To address these questions, this research integrates both qualitative and quantitative methods, drawing on a political ecological approach complemented by agroecological analysis and theoretical insights from geographical analyses of nature-society relations. Quantitative analysis focuses on changing land use patterns in agriculture and conservation practice in Iowa. Qualitative methods include extensive interviews, participant observation, and policy and document analyses. Fieldwork focused on Northeastern Iowa to understand regional changes in agricultural and conservation practice, the renegotiated position of farmers in agriculture and biofuel production, and biofuel industry development. I find that biofuel production presents significant social and ecological challenges for rural places of production. Longstanding, unequal political economic relations in industrialized agriculture limit rural economic benefits

Food sovereignty: an alternative paradigm for poverty reduction and biodiversity conservation in Latin America.

PubMed

Chappell, M Jahi; Wittman, Hannah; Bacon, Christopher M; Ferguson, Bruce G; Barrios, Luis García; Barrios, Raúl García; Jaffee, Daniel; Lima, Jefferson; Méndez, V Ernesto; Morales, Helda; Soto-Pinto, Lorena; Vandermeer, John; Perfecto, Ivette

2013-01-01

Strong feedback between global biodiversity loss and persistent, extreme rural poverty are major challenges in the face of concurrent food, energy, and environmental crises. This paper examines the role of industrial agricultural intensification and market integration as exogenous socio-ecological drivers of biodiversity loss and poverty traps in Latin America. We then analyze the potential of a food sovereignty framework, based on protecting the viability of a diverse agroecological matrix while supporting rural livelihoods and global food production. We review several successful examples of this approach, including ecological land reform in Brazil, agroforestry, milpa, and the uses of wild varieties in smallholder systems in Mexico and Central America. We highlight emergent research directions that will be necessary to assess the potential of the food sovereignty model to promote both biodiversity conservation and poverty reduction.

Food webs: a ladder for picking strawberries or a practical tool for practical problems?

PubMed Central

Memmott, Jane

2009-01-01

While food webs have provided a rich vein of research material over the last 50 years, they have largely been the subject matter of the pure ecologist working in natural habitats. While there are some notable exceptions to this trend, there are, as I explain in this paper, many applied questions that could be answered using a food web approach. The paper is divided into two halves. The first half provides a brief review of six areas where food webs have begun to be used as an applied tool: restoration ecology, alien species, biological control, conservation ecology, habitat management and global warming. The second half outlines five areas in which a food web approach could prove very rewarding: urban ecology, agroecology, habitat fragmentation, cross-habitat food webs and ecosystem services. PMID:19451120

Food webs: a ladder for picking strawberries or a practical tool for practical problems?

PubMed

Memmott, Jane

2009-06-27

While food webs have provided a rich vein of research material over the last 50 years, they have largely been the subject matter of the pure ecologist working in natural habitats. While there are some notable exceptions to this trend, there are, as I explain in this paper, many applied questions that could be answered using a food web approach. The paper is divided into two halves. The first half provides a brief review of six areas where food webs have begun to be used as an applied tool: restoration ecology, alien species, biological control, conservation ecology, habitat management and global warming. The second half outlines five areas in which a food web approach could prove very rewarding: urban ecology, agroecology, habitat fragmentation, cross-habitat food webs and ecosystem services.

Spatial diversification of agroecosystems to enhance biological control and other regulating services: An agroecological perspective.

PubMed

Hatt, Séverin; Boeraeve, Fanny; Artru, Sidonie; Dufrêne, Marc; Francis, Frédéric

2018-04-15

Spatial diversification of crop and non-crop habitats in farming systems is promising for enhancing natural regulation of insect pests. Nevertheless, results from recent syntheses show variable effects. One explanation is that the abundance and diversity of pests and natural enemies are affected by the composition, design and management of crop and non-crop habitats. Moreover, interactions between both local and landscape elements and practices carried out at different spatial scales may affect the regulation of insect pests. Hence, research is being conducted to understand these interdependencies. However, insects are not the only pests and pests are not the only elements to regulate in agroecosystems. Broadening the scope could allow addressing multiple issues simultaneously, but also solving them together by enhancing synergies. Indeed, spatial diversification of crop and non-crop habitats can allow addressing the issues of weeds and pathogens, along with being beneficial to several other regulating services like pollination, soil conservation and nutrient cycling. Although calls rise to develop multifunctional landscapes that optimize the delivery of multiple ecosystem services, it still represents a scientific challenge today. Enhancing interdisciplinarity in research institutions and building interrelations between scientists and stakeholders may help reach this goal. Despite obstacles, positive results from research based on such innovative approaches are encouraging for engaging science in this path. Hence, the aim of the present paper is to offer an update on these issues by exploring the most recent findings and discussing these results to highlight needs for future research. Copyright © 2017 Elsevier B.V. All rights reserved.

In Vitro Morphological Characteristics of Pyrenophora tritici-repentis Isolates from Several Algerian Agro-Ecological Zones

PubMed Central

Benslimane, Hamida; Aouali, Souhila; Khalfi, Assia; Ali, Shaukat; Bouznad, Zouaoui

2017-01-01

Tan spot caused by the fungus Pyrenophora triticirepentis is a serious disease of wheat, which is on increase in recent years in Mediterranean region. In the field this fungus produces a diamond-shaped necrotic lesions with a yellow halo on wheat foliage. The objective of this study was to characterize and compare several monospore isolates of P. tritici-repentis collected from different infected wheat fields in various locations of Algeria, and find the morphological differences between them, if any. The results revealed wide morphologically variation among the isolates based on colony colors and texture, mycelial radial growth and conidial size. PMID:28381957

Data and monitoring needs for a more ecological agriculture

NASA Astrophysics Data System (ADS)

Zaks, David P. M.; Kucharik, Christopher J.

2011-01-01

Information on the life-cycle environmental impacts of agricultural production is often limited. As demands grow for increasing agricultural output while reducing its negative environmental impacts, both existing and novel data sources can be leveraged to provide more information to producers, consumers, scientists and policy makers. We review the components and organization of an agroecological sensor web that integrates remote sensing technologies and in situ sensors with models in order to provide decision makers with effective management options at useful spatial and temporal scales for making more informed decisions about agricultural productivity while reducing environmental burdens. Several components of the system are already in place, but by increasing the extent and accessibility of information, decision makers will have the opportunity to enhance food security and environmental quality. Potential roadblocks to implementation include farmer acceptance, data transparency and technology deployment.

Food sovereignty: an alternative paradigm for poverty reduction and biodiversity conservation in Latin America

PubMed Central

Chappell, M Jahi

2013-01-01

Strong feedback between global biodiversity loss and persistent, extreme rural poverty are major challenges in the face of concurrent food, energy, and environmental crises. This paper examines the role of industrial agricultural intensification and market integration as exogenous socio-ecological drivers of biodiversity loss and poverty traps in Latin America. We then analyze the potential of a food sovereignty framework, based on protecting the viability of a diverse agroecological matrix while supporting rural livelihoods and global food production. We review several successful examples of this approach, including ecological land reform in Brazil, agroforestry, milpa, and the uses of wild varieties in smallholder systems in Mexico and Central America. We highlight emergent research directions that will be necessary to assess the potential of the food sovereignty model to promote both biodiversity conservation and poverty reduction. PMID:24555109

The Myth of Coexistence: Why Transgenic Crops Are Not Compatible With Agroecologically Based Systems of Production

ERIC Educational Resources Information Center

Altieri, Miguel

2005-01-01

The coexistence of genetically modified (GM) crops and non-GM crops is a myth because the movement of transgenes beyond their intended destinations is a certainty, and this leads to genetic contamination of organic farms and other systems. It is unlikely that transgenes can be retracted once they have escaped, thus the damage to the purity of…

Distribution of Aspergillus section flavi in soils of maize fields in three agroecological zones of Nigeria

USDA-ARS?s Scientific Manuscript database

Fungal communities in soils of Nigerian maize fields were examined to determine distributions of aflatoxin-producing fungi and to identify endemic atoxigenic strains of potential value as biological control agents for limiting aflatoxin contamination in West African crops. Over 1,000 isolates belon...

The main characteristics of qualitative studies carried out by doctors in Brazil: a literature review.

PubMed

Taquette, Stella Regina; Minayo, Maria Cecília de Souza

2015-08-01

This paper explores the possibilities of the nutrition-sensitive agriculture approach in the context of the programs and actions towards promoting food and nutrition sovereignty and security in Brazil. To analyze the links between nutrition and agriculture, this paper presents the conceptual framework related to food and nutrition security, and stresses the correlations among concepts, institutional structures and program design in Brazil. Dominant models of food production and consumption are scrutinized in the light of these relationships. This paper also highlights differences amongst different ways to promote nutrition-sensitive agriculture through food-acquisition programs from family farmers, experiences in agro-ecology and bio-fortification programs. In the closing remarks, the paper draws some lessons learned from the Brazilian experience that highlight the advantages of family farming and rapid food production, distribution and consumption cycles in order to promote access to an affordable, diversified and more adequate diet in nutritional terms.

Nutrition-sensitive agriculture and the promotion of food and nutrition sovereignty and security in Brazil.

PubMed

Maluf, Renato Sergio; Burlandy, Luciene; Santarelli, Mariana; Schottz, Vanessa; Speranza, Juliana Simões

2015-08-01

This paper explores the possibilities of the nutrition-sensitive agriculture approach in the context of the programs and actions towards promoting food and nutrition sovereignty and security in Brazil. To analyze the links between nutrition and agriculture, this paper presents the conceptual framework related to food and nutrition security, and stresses the correlations among concepts, institutional structures and program design in Brazil. Dominant models of food production and consumption are scrutinized in the light of these relationships. This paper also highlights differences amongst different ways to promote nutrition-sensitive agriculture through food-acquisition programs from family farmers, experiences in agro-ecology and bio-fortification programs. In the closing remarks, the paper draws some lessons learned from the Brazilian experience that highlight the advantages of family farming and rapid food production, distribution and consumption cycles in order to promote access to an affordable, diversified and more adequate diet in nutritional terms.

Reframing the Food-Biodiversity Challenge.

PubMed

Fischer, Joern; Abson, David J; Bergsten, Arvid; French Collier, Neil; Dorresteijn, Ine; Hanspach, Jan; Hylander, Kristoffer; Schultner, Jannik; Senbeta, Feyera

2017-05-01

Given the serious limitations of production-oriented frameworks, we offer here a new conceptual framework for how to analyze the nexus of food security and biodiversity conservation. We introduce four archetypes of social-ecological system states corresponding to win-win (e.g., agroecology), win-lose (e.g., intensive agriculture), lose-win (e.g., fortress conservation), and lose-lose (e.g., degraded landscapes) outcomes for food security and biodiversity conservation. Each archetype is shaped by characteristic external drivers, exhibits characteristic internal social-ecological features, and has characteristic feedbacks that maintain it. This framework shifts the emphasis from focusing on production only to considering social-ecological dynamics, and enables comparison among landscapes. Moreover, examining drivers and feedbacks facilitates the analysis of possible transitions between system states (e.g., from a lose-lose outcome to a more preferred outcome). Copyright © 2017 Elsevier Ltd. All rights reserved.

LivestockPlus: Forages, sustainable intensification, and food security in the tropics.

PubMed

Rudel, Thomas K; Paul, Birthe; White, Douglas; Rao, I M; Van Der Hoek, Rein; Castro, Aracely; Boval, Maryline; Lerner, Amy; Schneider, Laura; Peters, Michael

2015-11-01

The increased use of grain-based feed for livestock during the last two decades has contributed, along with other factors, to a rise in grain prices that has reduced human food security. This circumstance argues for feeding more forages to livestock, particularly in the tropics where many livestock are reared on small farms. Efforts to accomplish this end, referred to as the 'LivestockPlus' approach, intensify in sustainable ways the management of grasses, shrubs, trees, and animals. By decoupling the human food and livestock feed systems, these efforts would increase the resilience of the global food system. Effective LivestockPlus approaches take one of two forms: (1) simple improvements such as new forage varieties and animal management practices that spread from farmer to farmer by word of mouth, or (2) complex sets of new practices that integrate forage production more closely into farms' other agricultural activities and agro-ecologies.

Sustainable Food Security in the Mountains of Pakistan: Towards a Policy Framework.

PubMed

Rasul, Golam; Hussain, Abid

2015-01-01

The nature and causes of food and livelihood security in mountain areas are quite different to those in the plains. Rapid socioeconomic and environmental changes added to the topographical constraints have exacerbated the problem of food insecurity in the Hindu Kush-Himalayan (HKH) region. In Pakistan, food insecurity is significantly higher in the mountain areas than in the plains as a result of a range of biophysical and socioeconomic factors. The potential of mountain niche products such as fruit, nuts, and livestock has remained underutilized. Moreover, the opportunities offered by globalization, market integration, remittances, and non-farm income have not been fully tapped. This paper analyzes the opportunities and challenges of food security in Pakistan's mountain areas, and outlines a framework for addressing the specific issues in terms of four different types of area differentiated by agro-ecological potential and access to markets, information, and institutional services.

Trends in Global Agricultural Land Use: Implications for Environmental Health and Food Security.

PubMed

Ramankutty, Navin; Mehrabi, Zia; Waha, Katharina; Jarvis, Larissa; Kremen, Claire; Herrero, Mario; Rieseberg, Loren H

2018-04-29

The eighteenth-century Malthusian prediction of population growth outstripping food production has not yet come to bear. Unprecedented agricultural land expansions since 1700, and technological innovations that began in the 1930s, have enabled more calorie production per capita than was ever available before in history. This remarkable success, however, has come at a great cost. Agriculture is a major cause of global environmental degradation. Malnutrition persists among large sections of the population, and a new epidemic of obesity is on the rise. We review both the successes and failures of the global food system, addressing ongoing debates on pathways to environmental health and food security. To deal with these challenges, a new coordinated research program blending modern breeding with agro-ecological methods is needed. We call on plant biologists to lead this effort and help steer humanity toward a safe operating space for agriculture.

Climate variability and causes: from the perspective of the Tharaka people of eastern Kenya

NASA Astrophysics Data System (ADS)

Recha, Charles W.; Makokha, George L.; Shisanya, Chris A.

2017-12-01

The study assessed community understanding of climate variability in semi-arid Tharaka sub-county, Kenya. The study used four focus group discussions (FGD) ( N = 48) and a household survey ( N = 326) to obtain information from four agro-ecological zones (AEZs). The results were synthesized and descriptively presented. People in Tharaka sub-county are familiar with the term climate change and associate it with environmental degradation. There are, however, misconceptions and gaps in understanding the causes of climate change. There was a mismatch between community and individual perception of onset and cessation of rainfall—evidence that analysis of the impact of climate change should take into account the scale of interaction. To improve climate change knowledge, there is a need for climate change education by scientific institutions—to provide information on local climatic conditions and global and regional drivers of climate change to local communities.

Gene diversity, agroecological structure and introgression patterns among village chicken populations across North, West and Central Africa

PubMed Central

2012-01-01

Background Chickens represent an important animal genetic resource for improving farmers’ income in Africa. The present study provides a comparative analysis of the genetic diversity of village chickens across a subset of African countries. Four hundred seventy-two chickens were sampled in 23 administrative provinces across Cameroon, Benin, Ghana, Côte d’Ivoire, and Morocco. Geographical coordinates were recorded to analyze the relationships between geographic distribution and genetic diversity. Molecular characterization was performed with a set of 22 microsatellite markers. Five commercial lines, broilers and layers, were also genotyped to investigate potential gene flow. A genetic diversity analysis was conducted both within and between populations. Results High heterozygosity levels, ranging from 0.51 to 0.67, were reported for all local populations, corresponding to the values usually found in scavenging populations worldwide. Allelic richness varied from 2.04 for a commercial line to 4.84 for one population from Côte d’Ivoire. Evidence of gene flow between commercial and local populations was observed in Morocco and in Cameroon, which could be related to long-term improvement programs with the distribution of crossbred chicks. The impact of such introgressions seemed rather limited, probably because of poor adaptation of exotic birds to village conditions, and because of the consumers’ preference for local chickens. No such gene flow was observed in Benin, Ghana, and Côte d’Ivoire, where improvement programs are also less developed. The clustering approach revealed an interesting similarity between local populations found in regions sharing high levels of precipitation, from Cameroon to Côte d’Ivoire. Restricting the study to Benin, Ghana, and Côte d’Ivoire, did not result in a typical breed structure but a south-west to north-east gradient was observed. Three genetically differentiated areas (P < 0.01) were identified, matching with Major Farming Systems (namely Tree Crop, Cereal-Root Crop, and Root Crop) described by the FAO. Conclusions Local chickens form a highly variable gene pool constituting a valuable resource for human populations. Climatic conditions, farming systems, and cultural practices may influence the genetic diversity of village chickens in Africa. A higher density of markers would be needed to identify more precisely the relative importance of these factors. PMID:22564251

Dark gray soils on two-layered deposits in the north of Tambov Plain: Agroecology, properties, and diagnostics

NASA Astrophysics Data System (ADS)

Zaidelman, F. R.; Nikiforova, A. S.; Stepantsova, L. V.; Volokhina, V. P.

2012-05-01

Dark gray soils in the Tambov Plain are developed from the light-textured glaciofluvial deposits underlain by the calcareous loam. Their morphology, water regime, and productivity are determined by the depth of the slightly permeable calcareous loamy layer, relief, and the degree of gleyzation. The light texture of the upper layer is responsible for its weak structure, high density, the low content of productive moisture, and the low water-holding capacity. If the calcareous loam is at a depth of 100-130 cm, dark gray soils are formed; if it lies at a depth of 40-70 cm, temporary perched water appears in the profile, and dark gray contact-gleyed soils are formed. Their characteristic pedofeatures are skeletans in the upper layers, calcareous nodules in the loamy clay layer, and iron nodules in the podzolized humus and podzolic horizons. The appearance of Fe-Mn concretions is related to gleyzation. The high yield of winter cereals is shown to be produced on the dark gray soils; the yields of spring crops are less stable. Spring cereals should not be grown on the contact-gleyed dark gray soils.

Organize or Die: Farm School Pedagogy and the Political Ecology of the Agroecological Transition in Rural Haiti

ERIC Educational Resources Information Center

Moore, Sophie Sapp

2017-01-01

This article examines the political and pedagogical role of the farm school in Haiti's largest and oldest peasants' movement, the Peasants' Movement of Papaye (MPP). It draws upon ongoing ethnographic research with MPP as well as documentary and historical analyses of agrarian politics in Haiti to situate the movement's land-based decolonial…

From novice to expert: agroecological competences of children orphaned by AIDS compared to non-orphans in Benin.

PubMed

Fagbemissi, Rose C; Price, Lisa L

2011-01-10

AIDS has created new vulnerabilities for rural African households due to prime-age adult mortality and is assumed to lead to impairment of the intergenerational transfer of farming knowledge. There has been scant research to date, however, on the impacts of parental death on farming knowledge of children made orphans by AIDS. The question we investigate is if there is a difference in agricultural expertise between AIDS affected and non-affected adults and children. The research was carried out in rural Benin with 77 informants randomly selected according to their AIDS status: 13 affected and 13 non-affected adults; 13 paternal, 13 maternal and 13 double orphans; and 12 non-orphan children. Informants descriptions from pile sorting exercises of maize and cowpea pests were categorized and then aggregated into descriptions based form (morphology) and function (utility) and used to determine whether the moving from novice to expert is impaired by children orphaned by AIDS. Differences and similarities in responses were determined using the Fischer exact test and the Cochran-Mantzel-Haenszel test. No significant differences were found between AIDS affected and non-affected adults. Results of the study do reveal differences in the use of form and function descriptors among the children. There is a statistically significant difference in the use of form descriptors between one-parent orphans and non-orphans and in descriptors of specific damages to maize. One-parent paternal orphans were exactly like non-affected adults in their 50/50 balanced expertise in the use of both form and function descriptors. One-parent orphans also had the highest number of descriptors used by children overall and these descriptors are spread across the various aspects of the knowledge domain relative to non-orphans. Rather than a knowledge loss for one-parent orphans, particularly paternal orphans, we believe we are witnessing acceleration into adult knowledge frames. This expertise of one-parent orphans may be a result of a combination of factors deserving further investigation including enhanced hands-on work experience with the food crops in the field and the expertise available from the surviving parent coupled with the value of the food resource to the household.

From novice to expert: agroecological competences of children orphaned by AIDS compared to non-orphans in Benin

PubMed Central

2011-01-01

Background AIDS has created new vulnerabilities for rural African households due to prime-age adult mortality and is assumed to lead to impairment of the intergenerational transfer of farming knowledge. There has been scant research to date, however, on the impacts of parental death on farming knowledge of children made orphans by AIDS. The question we investigate is if there is a difference in agricultural expertise between AIDS affected and non-affected adults and children. Methods The research was carried out in rural Benin with 77 informants randomly selected according to their AIDS status: 13 affected and 13 non-affected adults; 13 paternal, 13 maternal and 13 double orphans; and 12 non-orphan children. Informants descriptions from pile sorting exercises of maize and cowpea pests were categorized and then aggregated into descriptions based form (morphology) and function (utility) and used to determine whether the moving from novice to expert is impaired by children orphaned by AIDS. Differences and similarities in responses were determined using the Fischer exact test and the Cochran-Mantzel-Haenszel test. Results No significant differences were found between AIDS affected and non-affected adults. Results of the study do reveal differences in the use of form and function descriptors among the children. There is a statistically significant difference in the use of form descriptors between one-parent orphans and non-orphans and in descriptors of specific damages to maize. One-parent paternal orphans were exactly like non-affected adults in their 50/50 balanced expertise in the use of both form and function descriptors. One-parent orphans also had the highest number of descriptors used by children overall and these descriptors are spread across the various aspects of the knowledge domain relative to non-orphans. Conclusions Rather than a knowledge loss for one-parent orphans, particularly paternal orphans, we believe we are witnessing acceleration into adult knowledge frames. This expertise of one-parent orphans may be a result of a combination of factors deserving further investigation including enhanced hands-on work experience with the food crops in the field and the expertise available from the surviving parent coupled with the value of the food resource to the household. PMID:21219626

Global gridded crop specific agricultural areas from 1961-2014

NASA Astrophysics Data System (ADS)

Konar, M.; Jackson, N. D.

2017-12-01

Current global cropland datasets are limited in crop specificity and temporal resolution. Time series maps of crop specific agricultural areas would enable us to better understand the global agricultural geography of the 20th century. To this end, we develop a global gridded dataset of crop specific agricultural areas from 1961-2014. To do this, we downscale national cropland information using a probabilistic approach. Our method relies upon gridded Global Agro-Ecological Zones (GAEZ) maps, the History Database of the Global Environment (HYDE), and crop calendars from Sacks et al. (2010). We estimate crop-specific agricultural areas for a 0.25 degree spatial grid and annual time scale for all major crops. We validate our global estimates for the year 2000 with Monfreda et al. (2008) and our time series estimates within the United States using government data. This database will contribute to our understanding of global agricultural change of the past century.

Balancing the Needs of China's Wetland Conservation and Rice Production.

PubMed

Chen, Hongjun; Wang, Guoping; Lu, Xianguo; Jiang, Ming; Mendelssohn, Irving A

2015-06-02

China's rice policy for protecting paddy fields and constructing rice production bases is in conflict with its wetland conservation strategy. The policy will increase the rice planting area, the loss of remaining wetlands, and environmental pollution, with intensive application of fertilizers and heavy use of pesticides. The key to resolving this conflict is to bring rice production in compliance with wetland conservation and sustainable agriculture. An operational, sound regulatory program is needed to improve China's wetland conservation. Using wetland conservation in the US as an example, we argue that more effective technical guidelines for wetland inventory and monitoring are necessary to support the implementation of the regulatory program. Agricultural conservation programs are also needed to stop further wetland loss from agricultural usages. An ecoagricultural strategy and practice should be adopted for rice production to reduce pollution and loss of remaining wetlands. Agroecological engineering tools can be used to reduce the impacts of nutrient- and pesticide-enriched agricultural runoff to wetlands.

Adapting agriculture to climate change in Kenya: household strategies and determinants.

PubMed

Bryan, Elizabeth; Ringler, Claudia; Okoba, Barrack; Roncoli, Carla; Silvestri, Silvia; Herrero, Mario

2013-01-15

Countries in Sub-Saharan Africa are particularly vulnerable to climate change, given dependence on agricultural production and limited adaptive capacity. Based on farm household and Participatory Rural Appraisal data collected from districts in various agroecological zones in Kenya, this paper examines farmers' perceptions of climate change, ongoing adaptation measures, and factors influencing farmers' decisions to adapt. The results show that households face considerable challenges in adapting to climate change. While many households have made small adjustments to their farming practices in response to climate change (in particular, changing planting decisions), few households are able to make more costly investments, for example in agroforestry or irrigation, although there is a desire to invest in such measures. This emphasizes the need for greater investments in rural and agricultural development to support the ability of households to make strategic, long-term decisions that affect their future well-being. Copyright © 2012 Elsevier Ltd. All rights reserved.

Aflatoxin-producing fungi in maize field soils from sea level to over 2000 masl: a three year study in Sonora, Mexico.

PubMed

Ortega-Beltran, Alejandro; Jaime, Ramon; Cotty, Peter J

2015-04-01

Aflatoxins, highly toxic carcinogens produced by several members of Aspergillus section Flavi, contaminate crops in temperate zones. In the state of Sonora, Mexico, maize is cultivated from 0 to 2100 masl with diverse cultivation practices. This is typical of the nation. In order to design better sampling strategies across Mexico, aflatoxin-producing fungal communities associated with maize production during 2006, 2007, and 2008 in Sonora were investigated in four agro-ecological zones (AEZ) at varying elevation. Fungal communities were dominated by the Aspergillus flavus L strain morphotype (46%), but variation occurred between years and among AEZ. Several atoxigenic isolates with potential to be used as biocontrol agents for aflatoxin mitigation were detected in all AEZ. The characteristics of each AEZ had minimal influences on fungal community structure and should not be a major consideration for future sampling designs for Mexico. Insights into the dynamics and stability of aflatoxin-producing fungal communities across AEZ are discussed. Published by Elsevier Ltd.

The politics of biofuels, land and agrarian change: editors' introduction.

PubMed

Borras, Saturnino M

2010-01-01

This introduction frames key questions on biofuels, land and agrarian change within agrarian political economy, political sociology and political ecology. It identifies and explains big questions that provide the starting point for the contributions to this collection. We lay out some of the emerging themes which define the politics of biofuels, land and agrarian change revolving around global (re)configurations; agro-ecological visions; conflicts, resistances and diverse outcomes; state, capital and society relations; mobilising opposition, creating alternatives; and change and continuity. An engaged agrarian political economy combined with global political economy, international relations and social movement theory provides an important framework for analysis and critique of the conditions, dynamics, contradictions, impacts and possibilities of the emerging global biofuels complex. Our hope is that this collection demonstrates the significance of a political economy of biofuels in capturing the complexity of the "biofuels revolution" and at the same time opening up questions about its sustainability in social and environmental terms that provide pathways towards alternatives.

[Epidemiology of Newcastle disease in village poultry farming in Madagascar].

PubMed

Maminiaina, O F; Koko, M; Ravaomanana, J; Rakotonindrina, S J

2007-12-01

An epidemiological investigation into Newcastle disease in village poultry farming was carried out for 12 months (from May 1999 to June 2000) in Ambohimangakely and Moramanga, two agro-ecologic zones of Madagascar. The thirty families that were surveyed stated that they had incurred losses from an epizootic with high mortality rates at least once prior to the investigation. The results of serological tests and virus isolation showed that the disease, responsible for 44.3% of all the mortality recorded during the twelve-month period, was Newcastle disease. Maximum incidence of the disease (71%), affecting 75% of the families, occurred in October 1999, and seroprevalence often reached 100% after the outbreak had ended. The infection was brought to the villages either by newly introduced hens or recovered birds. All forms of Newcastle disease (epidemic, endemic and asymptomatic) were observed. The way farmers reacted contributed to the spread of the virus within a village and to neighbouring locations.

Environmental impacts of modern agricultural technology diffusion in Bangladesh: an analysis of farmers' perceptions and their determinants.

PubMed

Rahman, Sanzidur

2003-06-01

Farmers' perception of the environmental impacts of modern agricultural technology diffusion and factors determining such awareness were examined using survey data from 21 villages in three agro-ecological regions of Bangladesh. Results reveal that farmers are well aware of the adverse environmental impacts of modern agricultural technology, although their awareness remains confined within visible impacts such as soil fertility, fish catches, and health effects. Their perception of intangible impacts such as, toxicity in water and soils is weak. Level and duration of modern agricultural technology adoption directly influence awareness of its adverse effects. Education and extension contacts also play an important role in raising awareness. Awareness is higher among farmers in developed regions, fertile locations and those with access to off-farm income sources. Promotion of education and strengthening extension services will boost farmers' environmental awareness. Infrastructure development and measures to replenish depleting soil fertility will also play a positive role in raising awareness.

Determination of Winter Wheat Phenology in Bavaria- A Contribution to Regional Crop Health Monitoring from Space

NASA Astrophysics Data System (ADS)

Bruggemann, Lena; Bach, Heike; Ruf, Tobias; Appel, Florian; Migdall, Silke; Hank, Tobias; Mauser, Wolfram; Eiblmeier, Peter

2016-08-01

The central topic of this study is the monitoring of winter wheat phenology and the detection of anthesis (flowering) using remotely sensed data as well as crop growth modeling. It is not possible to directly observe the flowering of wheat with optical satellite sensors. Thus, an approach that combines crop growth modeling with remote sensing data covering optical and microwave spectral ranges was developed. This was done in three steps: The hydro-agroecological land surface model PROMET was first run in a stand-alone version for selected sites distributed throughout Bavaria using only static input parameters (e.g. soil map) and current meteorological data as driving factors. Thus, multitemporal information from optical remote sensing data was assimilated into the model runs in a second step to improve the accuracy of the results. Finally, the use of radar data for anthesis detection in winter wheat was tested using Sentinel-1 data of 2015 in dual polarization mode (VV+VH).

Evidence for suppression of immunity as a driver for genomic introgressions and host range expansion in races of Albugo candida, a generalist parasite

PubMed Central

McMullan, Mark; Gardiner, Anastasia; Bailey, Kate; Kemen, Eric; Ward, Ben J; Cevik, Volkan; Robert-Seilaniantz, Alexandre; Schultz-Larsen, Torsten; Balmuth, Alexi; Holub, Eric; van Oosterhout, Cock; Jones, Jonathan DG

2015-01-01

How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies of five isolates, we show they represent three races that are genetically diverged by ∼1%. Despite this divergence, their genomes are mosaic-like, with ∼25% being introgressed from other races. Sequential infection experiments show that infection by adapted races enables subsequent infection of hosts by normally non-infecting races. This facilitates introgression and the exchange of effector repertoires, and may enable the evolution of novel races that can undergo clonal population expansion on new hosts. We discuss recent studies on hybridization in other eukaryotes such as yeast, Heliconius butterflies, Darwin's finches, sunflowers and cichlid fishes, and the implications of introgression for pathogen evolution in an agro-ecological environment. DOI: http://dx.doi.org/10.7554/eLife.04550.001 PMID:25723966

Exploring the nexus between climate change, food security, and deforestation in Q'eqchi' Maya communities, Guatemala

NASA Astrophysics Data System (ADS)

Pope, I.; Harbor, J.

2013-12-01

The challenges of food security in the central Highlands of Guatemala are linked to deforestation, land degradation, and climate change. The Q'eqchi' Maya people that inhabit this region are smallholder farmers who rely on subsistence agriculture for survival. The Q'eqchi' support themselves with timber products and ecosystem services provided by the cloud forest, a unique ecosystem where a substantial portion of water is obtained through the condensation of water droplets onto vegetation via cloud filtration. Over the past 30 years, small-scale deforestation of the cloud forest in the Sierra Yalijux and Sacranix has increased as demand for agricultural land has risen. A link between the decline of cloud forest cover and an increase in severe precipitation events that drive soil erosion has been observed in the study area. As a result, land degradation poses a serious threat to the long-term food security of Q'eqchi' communities. We have examined the social, cultural, and land tenure dynamics that impact the ability of the Q'eqchi' to adapt to the rapidly changing climate, as well as to implement recommendations for grassroots initiatives to enhance these adaptations. Using remote-sensing we constructed three land use change maps that show that deforestation rates have increased by over 200% between 1986-2006 in the Sierra Yaljux and Sacranix mountain ranges, largely due to slash and burn agriculture. Using these land use change maps as an input into the Revised Universal Soil Loss Equation we show that implementation of agroecological techniques to counter the impacts of land use change drastically reduces soil erosion and is the best management practice. Surveys and focus groups in several Q'eqchi' villages revealed that precipitation events have become less frequent and more intense over the past 30 years, and temperatures have generally been increasing as well. Q'eqchi' people have observed that increasing severe precipitation events have accelerated soil

Seasonal variation of strongylosis in working donkeys of Ethiopia: a cross-sectional and longitudinal studies.

PubMed

Dibaba, Motuma Debelo; Getachew, A M; Assefa, Zerihun; Fanta, Alemayehu; Etana, Manyahilishal; Firew, Seyoum; Goshu, Lemessa; Burden, F

2017-07-01

Helminths are one of the major health problems of working donkeys, often with heavy worm burden and contributing to their early demise and/or reduction in their work output. Cross-sectional and longitudinal studies were conducted to investigate the current infection prevalence and level of strongyles infection donkeys would acquire through different seasons in the mid-lowland agro-ecological zones of Ethiopia. For this purpose, faecal samples from 206 (cross-sectional study) and 102 (longitudinal study) randomly selected donkeys were directly collected from the rectum and analysed. For the longitudinal study, the 102 donkeys dewormed at the end of main rainy season, beginning of October, were monitored for the level of strongyle infection they would acquire during subsequent dry and short rainy seasons. The cross-sectional study of 206 donkey has revealed an overall infection prevalence of 89.3% (95% confidence interval (CI) = 84.4, 92.9). Donkeys in the lowland zone showed a significantly higher strongyle infection prevalence (P = 0.0126) and mean eggs per gramme of faces (EPG) (P = 0.001; 2775 EPG) compared to donkeys in the midland zone (980.8 EPG). Age, sex and body condition did not have any significant effect on either the infection prevalence or level of infection (P > 0.05). The longitudinal study has shown a significantly lower strongyle infection prevalence (P = 0.003) and level of infection donkeys acquired (P = 0.001) in the subsequent dry and short rainy seasons compared to the main rainy season following October deworming. However, these values were not significantly different between the two agro-ecological zones (P > 0.05). This study clearly showed that parasitic infections are primarily acquired during the main rainy season when pasture/herbage coverage is relatively better, and the environment is conducive for parasites survival and development. On the other hand, the finding of majority of donkeys shedding low or no eggs during the

Indigenous knowledge, use and on-farm management of enset (Ensete ventricosum (Welw.) Cheesman) diversity in Wolaita, Southern Ethiopia

PubMed Central

2014-01-01

Background Ensete ventricosum (Welw.) Cheesman is a major food security crop in Southern Ethiopia, where it was originally domesticated and during millennia became pivotal crop around which an entire farming system has developed. Although its cultivation is highly localized, the enset-based farming system provides sustenance to more than 20 million people. Precise ethnobotanical information of intra-specific enset diversity and local knowledge on how communities maintain, manage and benefit from enset genetic resources is imperative for the promotion, conservation and improvement of this crop and its farming system. Methods This study was conducted in Southern Ethiopia among the Wolaita 'enset culture' community. The research sample consisted of 270 households from 12 Kebeles (villages) representing three agro-ecological ranges. By establishing Participatory Rural Appraisal (PRA) based interactions and applying ethnobotanical interviewing methods of free-listing and open-ended questionnaires, information on the use and management of enset diversity, and its associated folk-biosystematics, food traditions and material culture was collected and analyzed. Results While enset agriculture is seen as cultural heritage and identity for the Wolaita, enset intra-specific diversity holds scenic, prestige and symbolic values for the household. In the present study we recorded 67 enset landraces under cultivation, and through a comprehensive literature review we identified 28 landraces reported from other areas of Wolaita, but not encountered in our survey. Landraces, identified using 11 descriptors primarily related to agro-morphological traits, are named after perceived places of origin, agro-morphological characteristics and cooking quality attributes. Folk classification of enset is based on its domestication status, 'gender', agro-ecological adaptability and landrace suitability for different food and other uses (fiber, feed, medicinal). Enset as a food crop is used to

Productivity, fertilizer responses and nutrient balances of farming systems in central Tigray, Ethiopia: a multi-perspective view in relation to degradation.

NASA Astrophysics Data System (ADS)

Kraaijvanger, Richard; Veldkamp, Tom; Nyssen, Jan

2014-05-01

In many rural livelihoods in sub-Saharan Africa, crop productivity plays an important role since it links with food insecurity, which again is a major constraining factor in livelihood development. Sustainable livelihood development and land degradation are closely connected: lacking sustainability often results in land degradation, whereas the incidence of land degradation frequently frustrates sustainable development. Important forms of land degradation are soil erosion and nutrient depletion, both often being attributed to exhaustive land use practices and both having a direct and major impact on crop productivity. Application of nutrients is an important way to increase productivity. In our study area, central Tigray, development agents recommend the application of fertilizers at high rates in order to boost productivity and to deal with nutrient depletion. In the discussion about the use of fertilizers different perspectives can be taken, in which especially responses and nutrient balances are important issues, linking respectively with socio-economic and agro-ecological livelihood aspects. Ethiopian soils for example are, based on large scale nutrient balances, considered to be depleted, at field scale fertilizer responses are frequently disappointing and achieving sustainable nutrient balances at farm level seems difficult. At a temporal scale however, agricultural systems remained almost unchanged for over 2500 years, suggesting at least some degree of sustainability. With respect to productivity data resulting from on-farm experimentation with natural and artificial fertilizers in 26 sites, we took four perspectives, different in ownership and scale, on nutrient related land degradation and its assumed impact on crop productivity. Taking a farmer perspective we found no significant difference between responses to recommended and current farmer based practices. Taking a more scientific perspective highlighted that, based on the positive correlation between

The illuminating role of laser scanning digital elevation models in precision agriculture experimental designs - an agro-ecology perspective

USDA-ARS?s Scientific Manuscript database

Laser scanning data streams, when linked with multi-spectral, hyperspectral, apparent soil electro-conductivity (ECa), or other kinds of geo-referenced data streams, aid in the creation of maps that allow useful applications in agricultural systems. These combinations of georeferenced information p...

Genetic diversity of cultivated lentil (Lens culinaris Medik.) and its relation to the world’s agro-ecological zones

USDA-ARS?s Scientific Manuscript database

Assessment of genetic diversity and population structure of germplasm collections plays a critical role in supporting conservation and crop genetic enhancement strategies. We used a cultivated lentil (Lens culinaris Medik.) collection consisting of 352 accessions originating from 54 diverse countrie...

Light Gray Surface-Gleyed Loamy Sandy Soils of the Northern Part of Tambov Plain: Agroecology, Properties, and Diagnostics

NASA Astrophysics Data System (ADS)

Zaidel'man, F. R.; Stepantsova, L. V.; Nikiforova, A. S.; Krasin, V. N.; Dautokov, I. M.; Krasina, T. V.

2018-04-01

Light gray soils of Tambov oblast mainly develop from sandy and loamy sandy parent materials; these are the least studied soils in this region. Despite their coarse texture, these soils are subjected to surface waterlogging. They are stronger affected by the agrogenic degradation in comparison with chernozems and dark gray soils. Morphology, major elements of water regime, physical properties, and productivity of loamy sandy light gray soils with different degrees of gleyzation have been studied in the northern part of Tambov Plain in order to substantiate the appropriate methods of their management. The texture of these soils changes at the depth of 70-100 cm. The upper part is enriched in silt particles (16-30%); in the lower part, the sand content reaches 80-85%. In the nongleyed variants, middle-profile horizons contain thin iron-cemented lamellae (pseudofibers); in surface-gleyed variants, iron nodules are present in the humus horizon. The removal of clay from the humus horizon and its accumulation at the lithological contact and in pseudofibers promote surface subsidence and formation of microlows in the years with moderate and intense winter precipitation. The low range of active moisture favors desiccation of the upper horizons to the wilting point in dry years. The yield of cereal crops reaches 3.5-4.5 t/ha in the years with high and moderate summer precipitation on nongleyed and slightly gleyed light gray soils and decreases by 20-50% on strongly gleyed light gray soils. On light gray soils without irrigation, crop yields are unstable, and productivity of pastures is low. High yields of cereals and vegetables can be obtained on irrigated soils. In this case, local drainage measures should be applied to microlows; liming can be recommended to improve soil productivity.

Positive and Negative Feedbacks and Free-Scale Pattern Distribution in Rural-Population Dynamics

PubMed Central

Alados, Concepción L.; Errea, Paz; Gartzia, Maite; Saiz, Hugo; Escós, Juan

2014-01-01

Depopulation of rural areas is a widespread phenomenon that has occurred in most industrialized countries, and has contributed significantly to a reduction in the productivity of agro-ecological resources. In this study, we identified the main trends in the dynamics of rural populations in the Central Pyrenees in the 20th C and early 21st C, and used density independent and density dependent models and identified the main factors that have influenced the dynamics. In addition, we investigated the change in the power law distribution of population size in those periods. Populations exhibited density-dependent positive feedback between 1960 and 2010, and a long-term positive correlation between agricultural activity and population size, which has resulted in a free-scale population distribution that has been disrupted by the collapse of the traditional agricultural society and by emigration to the industrialized cities. We concluded that complex socio-ecological systems that have strong feedback mechanisms can contribute to disruptive population collapses, which can be identified by changes in the pattern of population distribution. PMID:25474704

The electronic Rothamsted Archive (e-RA), an online resource for data from the Rothamsted long-term experiments

PubMed Central

Perryman, Sarah A. M.; Castells-Brooke, Nathalie I. D.; Glendining, Margaret J.; Goulding, Keith W. T.; Hawkesford, Malcolm J.; Macdonald, Andy J.; Ostler, Richard J.; Poulton, Paul R.; Rawlings, Christopher J.; Scott, Tony; Verrier, Paul J.

2018-01-01

The electronic Rothamsted Archive, e-RA (www.era.rothamsted.ac.uk) provides a permanent managed database to both securely store and disseminate data from Rothamsted Research’s long-term field experiments (since 1843) and meteorological stations (since 1853). Both historical and contemporary data are made available via this online database which provides the scientific community with access to a unique continuous record of agricultural experiments and weather measured since the mid-19th century. Qualitative information, such as treatment and management practices, plans and soil information, accompanies the data and are made available on the e-RA website. e-RA was released externally to the wider scientific community in 2013 and this paper describes its development, content, curation and the access process for data users. Case studies illustrate the diverse applications of the data, including its original intended purposes and recent unforeseen applications. Usage monitoring demonstrates the data are of increasing interest. Future developments, including adopting FAIR data principles, are proposed as the resource is increasingly recognised as a unique archive of data relevant to sustainable agriculture, agroecology and the environment. PMID:29762552

Genetic diversity and population structure of Mongolian domestic Bactrian camels (Camelus bactrianus)

PubMed Central

Chuluunbat, B; Charruau, P; Silbermayr, K; Khorloojav, T; Burger, P A

2014-01-01

The tradition of animal husbandry in the context of a nomadic lifestyle has been of great significance in the Mongolian society. Both Bactrian camels and horses have been invaluable for the survival and development of human activities in the harsh arid environment of the Mongolian steppe. As camels offer unique and sustainable opportunities for livestock production in marginal agro-ecological zones, we investigated the current genetic diversity of three local Mongolian camel breeds and compared their levels of variation with common native Mongolian camels distributed throughout the country. Based on mitochondrial and nuclear markers, we found levels of genetic diversity in Mongolian populations similar to that reported for Chinese Bactrian camels and for dromedaries. Little differentiation was detected between single breeds, except for a small group originating from the northwestern Mongolian Altai. We found neither high inbreeding levels in the different breeds nor evidence for a population decline. Although the Mongolian camel census size has severely declined over the past 20 years, our analyses suggest that there still exists a stable population with adequate genetic variation for continued sustainable utilization. PMID:24749721

The electronic Rothamsted Archive (e-RA), an online resource for data from the Rothamsted long-term experiments.

PubMed

Perryman, Sarah A M; Castells-Brooke, Nathalie I D; Glendining, Margaret J; Goulding, Keith W T; Hawkesford, Malcolm J; Macdonald, Andy J; Ostler, Richard J; Poulton, Paul R; Rawlings, Christopher J; Scott, Tony; Verrier, Paul J

2018-05-15

The electronic Rothamsted Archive, e-RA (www.era.rothamsted.ac.uk) provides a permanent managed database to both securely store and disseminate data from Rothamsted Research's long-term field experiments (since 1843) and meteorological stations (since 1853). Both historical and contemporary data are made available via this online database which provides the scientific community with access to a unique continuous record of agricultural experiments and weather measured since the mid-19 th century. Qualitative information, such as treatment and management practices, plans and soil information, accompanies the data and are made available on the e-RA website. e-RA was released externally to the wider scientific community in 2013 and this paper describes its development, content, curation and the access process for data users. Case studies illustrate the diverse applications of the data, including its original intended purposes and recent unforeseen applications. Usage monitoring demonstrates the data are of increasing interest. Future developments, including adopting FAIR data principles, are proposed as the resource is increasingly recognised as a unique archive of data relevant to sustainable agriculture, agroecology and the environment.

Organic matter-solid phase interactions are critical for predicting arsenic release and plant uptake in Bangladesh paddy soils.

PubMed

Williams, Paul N; Zhang, Hao; Davison, William; Meharg, Andrew A; Hossain, Mahmud; Norton, Gareth J; Brammer, Hugh; Islam, M Rafiqul

2011-07-15

Agroecological zones within Bangladesh with low levels of arsenic in groundwater and soils produce rice that is high in arsenic with respect to other producing regions of the globe. Little is known about arsenic cycling in these soils and the labile fractions relevant for plant uptake when flooded. Soil porewater dynamics of field soils (n = 39) were recreated under standardized laboratory conditions to investigate the mobility and interplay of arsenic, Fe, Si, C, and other elements, in relation to rice grain element composition, using the dynamic sampling technique diffusive gradients in thin films (DGT). Based on a simple model using only labile DGT measured arsenic and dissolved organic carbon (DOC), concentrations of arsenic in Aman (Monsoon season) rice grain were predicted reliably. DOC was the strongest determinant of arsenic solid-solution phase partitioning, while arsenic release to the soil porewater was shown to be decoupled from that of Fe. This study demonstrates the dual importance of organic matter (OM), in terms of enhancing arsenic release from soils, while reducing bioavailability by sequestering arsenic in solution.

Genome-nutrition divergence: evolving understanding of the malnutrition spectrum.

PubMed

Eaton, Jacob C; Iannotti, Lora L

2017-11-01

Humans adapted over a period of 2.3 million years to a diet high in quality and diversity. Genome-nutrition divergence describes the misalignment between modern global diets and the genome formed through evolution. A survey of hominin diets over time shows that humans have thrived on a broad range of foods. Earlier diets were highly diverse and nutrient dense, in contrast to modern food systems in which monotonous diets of staple cereals and ultraprocessed foods play a more prominent role. Applying the lens of genome-nutrition divergence to malnutrition reveals shared risk factors for undernutrition and overnutrition at nutrient, food, and environmental levels. Mechanisms for food system shifts, such as crop-neutral agricultural policy, agroecology, and social policy, are explored as a means to realign modern diets with the nutritional patterns to which humans may be better adapted to thrive. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Food system policy, public health, and human rights in the United States.

PubMed

Shannon, Kerry L; Kim, Brent F; McKenzie, Shawn E; Lawrence, Robert S

2015-03-18

The US food system functions within a complex nexus of social, political, economic, cultural, and ecological factors. Among them are many dynamic pressures such as population growth, urbanization, socioeconomic inequities, climate disruption, and the increasing demand for resource-intensive foods that place immense strains on public health and the environment. This review focuses on the role that policy plays in defining the food system, particularly with regard to agriculture. It further examines the challenges of making the food supply safe, nutritious, and sustainable, while respecting the rights of all people to have access to adequate food and to attain the highest standard of health. We conclude that the present US food system is largely unhealthy, inequitable, environmentally damaging, and insufficiently resilient to endure the impacts of climate change, resource depletion, and population increases, and is therefore unsustainable. Thus, it is imperative that the US embraces policy reforms to transform the food system into one that supports public health and reflects the principles of human rights and agroecology for the benefit of current and future generations.

[Effectiveness of Beauveria bassiana (Baubassil®) on the common cattle tick Rhipicephalus microplus in the Department of Guajira, Colombia].

PubMed

Tofiño Rivera, Adriana P; Ortega Cuadros, Mailen; Pedraza Claros, Bertilda; Perdomo Ayola, Sandra C; Moya Romero, Diana Carolina

2018-02-02

The effectiveness of Baubassil ® (Beauveria bassiana) on the tick Rhipicephalus (Boophilus) microplus was evaluated. In the in vitro phase, the optimal germination temperature of the fungus was determined by microcultures at 25, 30 and 35°C and the mortality of ticks. In the field, in a randomized design, 30 cebuine cows; 15 cows were treated with Baubassil ® once a week at a 1×10 6 conidia/ml, and a control group was left untreated. It was observed that at temperatures of 25, 30 and 35°C, germination of the entomopathogen was 97.5, 94.7 and 6.3%, respectively. In animals treated with Baubassil ® obtained a corrected effectiveness of 96.8% on ticks in the fifth week of application. The use of Baubassil ® would be a valid alternative for controlling the cattle tick under the agroecological conditions of the Dry Caribbean. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Global climate shocks to agriculture from 1950 - 2015

NASA Astrophysics Data System (ADS)

Jackson, N. D.; Konar, M.; Debaere, P.; Sheffield, J.

2016-12-01

Climate shocks represent a major disruption to crop yields and agricultural production, yet a consistent and comprehensive database of agriculturally relevant climate shocks does not exist. To this end, we conduct a spatially and temporally disaggregated analysis of climate shocks to agriculture from 1950-2015 using a new gridded dataset. We quantify the occurrence and magnitude of climate shocks for all global agricultural areas during the growing season using a 0.25-degree spatial grid and daily time scale. We include all major crops and both temperature and precipitation extremes in our analysis. Critically, we evaluate climate shocks to all potential agricultural areas to improve projections within our time series. To do this, we use Global Agro-Ecological Zones maps from the Food and Agricultural Organization, the Princeton Global Meteorological Forcing dataset, and crop calendars from Sacks et al. (2010). We trace the dynamic evolution of climate shocks to agriculture, evaluate the spatial heterogeneity in agriculturally relevant climate shocks, and identify the crops and regions that are most prone to climate shocks.

Agricultural Model for the Nile Basin Decision Support System

NASA Astrophysics Data System (ADS)

van der Bolt, Frank; Seid, Abdulkarim

2014-05-01

To analyze options for increasing food supply in the Nile basin the Nile Agricultural Model (AM) was developed. The AM includes state-of-the-art descriptions of biophysical, hydrological and economic processes and realizes a coherent and consistent integration of hydrology, agronomy and economics. The AM covers both the agro-ecological domain (water, crop productivity) and the economic domain (food supply, demand, and trade) and allows to evaluate the macro-economic and hydrological impacts of scenarios for agricultural development. Starting with the hydrological information from the NileBasin-DSS the AM calculates the available water for agriculture, the crop production and irrigation requirements with the FAO-model AquaCrop. With the global commodity trade model MAGNET scenarios for land development and conversion are evaluated. The AM predicts consequences for trade, food security and development based on soil and water availability, crop allocation, food demand and food policy. The model will be used as a decision support tool to contribute to more productive and sustainable agriculture in individual Nile countries and the whole region.

Evaluating the Potential of Marginal Land for Cellulosic Feedstock Production and Carbon Sequestration in the United States.

PubMed

Emery, Isaac; Mueller, Steffen; Qin, Zhangcai; Dunn, Jennifer B

2017-01-03

Land availability for growing feedstocks at scale is a crucial concern for the bioenergy industry. Feedstock production on land not well-suited to growing conventional crops, or marginal land, is often promoted as ideal, although there is a poor understanding of the qualities, quantity, and distribution of marginal lands in the United States. We examine the spatial distribution of land complying with several key marginal land definitions at the United States county, agro-ecological zone, and national scales, and compare the ability of both marginal land and land cover data sets to identify regions for feedstock production. We conclude that very few land parcels comply with multiple definitions of marginal land. Furthermore, to examine possible carbon-flow implications of feedstock production on land that could be considered marginal per multiple definitions, we model soil carbon changes upon transitions from marginal cropland, grassland, and cropland-pastureland to switchgrass production for three marginal land-rich counties. Our findings suggest that total soil organic carbon changes per county are small, and generally positive, and can influence life-cycle greenhouse gas emissions of switchgrass ethanol.

[Using ecology thinking reconstructing traditional agronomy: role of production ecology].

PubMed

Wang, Song-Liang

2012-08-01

Traditional agronomy, as a discipline or specialty, is originated from the reductionism thinking of neoteric experimental sciences and motivated by the great success of industrialized revolution, but loses the ensemble grasp of the relationships between agricultural organisms and their resources and environment, i.e., agroecosystem mechanism. Moreover, due to the excessively relying on exogenous fossil energy input and the monoculture with a few highly productive crop cultivars, the agricultural interior sustainability has unceasingly lost, making our mankind facing the double crises of grain security and food safety. Therefore, it is imperative to reconstruct the traditional agronomy and its educational system. In this paper, the author proposed to link traditional agronomy with ecology, establishing agroecology as the core subject and agroecosystem management as the core applied system, and in particular, establishing 'production ecology' to fill up the wide gap between the crop cultivation and farming system and the crop genetics and breeding, the two second grade disciplines under agronomy. Ideologically and methodologically, this proposal could provide disciplinary, scientific, and educational bases to authentically implement the strategy of sustainable development of agriculture.

Farms, pastures and woodlands: the fine-scale distribution of Palearctic Culicoides spp. biting midges along an agro-ecological gradient.

PubMed

Rigot, T; Drubbel, M Vercauteren; Delécolle, J-C; Gilbert, M

2013-03-01

The spatial epidemiology of Bluetongue virus (BTV) at the landscape level relates to the fine-scale distribution and dispersal capacities of its vectors, midges belonging to the genus Culicoides Latreille (Diptera: Ceratopogonidae). Although many previous researches have carried out Culicoides sampling on farms, little is known of the fine-scale distribution of Culicoides in the landscape immediately surrounding farms. The aim of this study was to gain a better understanding of Culicoides populations at increasing distances from typical dairy farms in north-west Europe, through the use of eight Onderstepoort-type black-light traps positioned along linear transects departing from farms, going through pastures and entering woodlands. A total of 16 902 Culicoides were collected in autumn 2008 and spring 2009. The majority were females, of which more than 97% were recognized as potential vectors. In pastures, we found decreasing numbers of female Culicoides as a function of the distance to the farm. This pattern was modelled by leptokurtic models, with parameters depending on season and species. By contrast, the low number of male Culicoides caught were homogeneously distributed along the transects. When transects entered woodlands, we found a higher abundance of Culicoides than expected considering the distance of the sampling sites to the farm, although this varied according to species. © 2012 The Authors. Medical and Veterinary Entomology © 2012 The Royal Entomological Society.

Evaluation of drought using SPEI drought class transitions and log-linear models for different agro-ecological regions of India

NASA Astrophysics Data System (ADS)

Alam, N. M.; Sharma, G. C.; Moreira, Elsa; Jana, C.; Mishra, P. K.; Sharma, N. K.; Mandal, D.

2017-08-01

Markov chain and 3-dimensional log-linear models were attempted to model drought class transitions derived from the newly developed drought index the Standardized Precipitation Evapotranspiration Index (SPEI) at a 12 month time scale for six major drought prone areas of India. Log-linear modelling approach has been used to investigate differences relative to drought class transitions using SPEI-12 time series derived form 48 yeas monthly rainfall and temperature data. In this study, the probabilities of drought class transition, the mean residence time, the 1, 2 or 3 months ahead prediction of average transition time between drought classes and the drought severity class have been derived. Seasonality of precipitation has been derived for non-homogeneous Markov chains which could be used to explain the effect of the potential retreat of drought. Quasi-association and Quasi-symmetry log-linear models have been fitted to the drought class transitions derived from SPEI-12 time series. The estimates of odds along with their confidence intervals were obtained to explain the progression of drought and estimation of drought class transition probabilities. For initial months as the drought severity increases the calculated odds shows lower value and the odds decreases for the succeeding months. This indicates that the ratio of expected frequencies of occurrence of transition from drought class to the non-drought class decreases as compared to transition to any drought class when the drought severity of the present class increases. From 3-dimensional log-linear model it is clear that during the last 24 years the drought probability has increased for almost all the six regions. The findings from the present study will immensely help to assess the impact of drought on the gross primary production and to develop future contingent planning in similar regions worldwide.

Soil cover patterns and dynamics impact on GHG fluxes in RF native and man-changed ecosystems

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Nesterova, Olga

2017-04-01

The increased soil spatial-temporal variability is mutual feature for most mature natural and particularly man-changed terrestrial ecosystems in Central and Far-East regions of Russia with soil cover strongly pronounced bioclimatic zoning and landscape-geomorphologic differentiation. Soil cover patterns (SCP) detailed morphogenetic analysis and typification is useful tool for soil forming and degradation processes quantitative evaluation, land ecological state and functional quality quantitative assessment. Quantitative analysis and functional-ecological interpretation of representative SCP spatial variability is especially important for environmentally friendly and demand-driven land-use planning and decision making. The carried out 33-years region- and local-scale researches of the wide zonal-provincial set of representative ecosystems and SCP with different types and history of land-use (forest, meadow-steppe, agricultural and recreational ones) give us the interregional multi-factorial matrix of elementary soil cover patterns (ESCP) with different land-use practices and history, soil-geomorphologic features, environmental and microclimate conditions. Succession process-based analysis of modern evolution of man-changed and natural soils and ESCP essentially increases accuracy of quantitative assessments of dominant soil forming and degradation processes rate and potential, their influence on land and soil cover quality and ecosystem services. Their results allow developing the regional and landscape adapted versions of automated land evaluation systems and land-use DSS. The validation and ranging of the limiting factors of ESCP regulation and develop¬ment, ecosystem principal services (with especial attention on greenhouse gases emissions, soil carbon dynamics and sequestration potential, biodiversity and productivity, hydrological regimes and geomorphologic stabilization), land functional qualities and agroecological state have been done for dominating and

Soil ecology and agricultural technology; An integrated approach towards improved soil management for sustainable farming

NASA Astrophysics Data System (ADS)

Pulleman, Mirjam; Pérès, Guénola; Crittenden, Stephen; Heddadj, Djilali; Sukkel, Wijnand

2014-05-01

Intensive arable food production systems are in need of smart solutions that combine ecological knowledge and farm technology to maximize yields while protecting natural resources. The huge diversity of soil organisms and their interactions is of crucial importance for soil functions and ecosystem services, such as organic matter incorporation and break down, nutrient mineralization, soil structure formation, water regulation and disease and pest control. Soil management decisions that take into account the soil biodiversity and associated functions are thus essential to (i) maintain soil productivity in the long term, (ii) reduce the dependency on external inputs and non-renewables such as fossil fuels, and (iii) make agroecosystems more resilient against biotic and abiotic stresses. Organic farming systems and reduced tillage systems are two approaches that aim to increase soil biodiversity and general soil quality, through improved management of organic matter but differ in their emphasis on the use of chemical inputs for crop protection or soil disturbance, respectively. In North-western Europe experience with and knowledge of reduced tillage systems is still scarce, both in conventional and organic farming. Our study targeted both conventional and organic farming and aimed at 1) documenting reduced tillage practices within different agroecological contexts in NW Europe; 2) evaluating the effects of reduced tillage systems on soil biodiversity and soil ecosystem services; 3) increase understanding of agroecological factors that determine trade-offs between different ecosystem services. Earthworm species and nematode taxa were selected as indicator organisms to be studied for their known response to soil management and effects on soil functions. Additionally, soil organic matter, physical soil parameters and processes, and crop yields have been measured across multiple sites. Data have been collected over several cropping seasons in long term field experiments

Mapping agroecological zones and time lag in vegetation growth by means of Fourier analysis of time series of NDVI images

NASA Technical Reports Server (NTRS)

Menenti, M.; Azzali, S.; Verhoef, W.; Van Swol, R.

1993-01-01

Examples are presented of applications of a fast Fourier transform algorithm to analyze time series of images of Normalized Difference Vegetation Index values. The results obtained for a case study on Zambia indicated that differences in vegetation development among map units of an existing agroclimatic map were not significant, while reliable differences were observed among the map units obtained using the Fourier analysis.

Food security politics and the Millennium Development Goals.

PubMed

McMichael, Philip; Schneider, Mindi

2011-01-01

This article reviews proposals regarding the recent food crisis in the context of a broader, threshold debate on the future of agriculture and food security. While the MDGs have focused on eradicating extreme poverty and hunger, the food crisis pushed the hungry over the one billion mark. There is thus a renewed focus on agricultural development, which pivots on the salience of industrial agriculture (as a supply source) in addressing food security. The World Bank's new 'agriculture for development' initiative seeks to improve small-farmer productivity with new inputs, and their incorporation into global markets via value-chains originating in industrial agriculture. An alternative claim, originating in 'food sovereignty' politics, demanding small-farmer rights to develop bio-regionally specific agro-ecological methods and provision for local, rather than global, markets, resonates in the IAASTD report, which implies agribusiness as usual ''is no longer an option'. The basic divide is over whether agriculture is a servant of economic growth, or should be developed as a foundational source of social and ecological sustainability. We review and compare these different paradigmatic approaches to food security, and their political and ecological implications.

Modeling the impact of conservation agriculture on crop production and soil properties in Mediterranean climate

NASA Astrophysics Data System (ADS)

Moussadek, Rachid; Mrabet, Rachid; Dahan, Rachid; Laghrour, Malika; Lembiad, Ibtissam; ElMourid, Mohamed

2015-04-01

In Morocco, rainfed agriculture is practiced in the majority of agricultural land. However, the intensive land use coupled to the irregular rainfall constitutes a serious threat that affect country's food security. Conservation agriculture (CA) represents a promising alternative to produce more and sustainably. In fact, the direct seeding showed high yield in arid regions of Morocco but its extending to other more humid agro-ecological zones (rainfall > 350mm) remains scarce. In order to promote CA in Morocco, differents trials have been installed in central plateau of Morocco, to compare CA to conventional tillage (CT). The yields of the main practiced crops (wheat, lentil and checkpea) under CA and CT were analyzed and compared in the 3 soils types (Vertisol, Cambisol and Calcisol). Also, we studied the effect of CA on soil organic matter (SOM) and soil losses (SL) in the 3 different sites. The APSIM model was used to model the long term impact of CA compared to CT. The results obtained in this research have shown favorable effects of CA on crop production, SOM and soil erosion. Key words: Conservation agriculture, yield, soil properties, modeling, APSIM, Morocco.

Identifying Ant-Mirid Spatial Interactions to Improve Biological Control in Cacao-Based Agroforestry System.

PubMed

Bagny Beilhe, Leïla; Piou, Cyril; Tadu, Zéphirin; Babin, Régis

2018-06-06

The use of ants for biological control of insect pests was the first reported case of conservation biological control. Direct and indirect community interactions between ants and pests lead to differential spatial pattern. We investigated spatial interactions between mirids, the major cocoa pest in West Africa and numerically dominant ant species, using bivariate point pattern analysis to identify potential biological control agents. We assume that potential biological control agents should display negative spatial interactions with mirids considering their niche overlap. The mirid/ant data were collected in complex cacao-based agroforestry systems sampled in three agroecological areas over a forest-savannah gradient in Cameroon. Three species, Crematogaster striatula Emery (Hymenoptera: Formicidae), Crematogaster clariventris Mayr (Hymenoptera: Formicidae), and Oecophylla longinoda Latreille (Hymenoptera: Formicidae) with high predator and aggressive behaviors were identified as dominant and showed negative spatial relationships with mirids. The weaver ant, O. longinoda was identified as the only potential biological control agent, considering its ubiquity in the plots, the similarity in niche requirements, and the spatial segregation with mirids resulting probably from exclusion mechanisms. Combining bivariate point pattern analysis to good knowledge of insect ecology was an effective method to identify a potentially good biological control agent.

Sustainable intensification: a multifaceted, systemic approach to international development.

PubMed

Himmelstein, Jennifer; Ares, Adrian; van Houweling, Emily

2016-12-01

Sustainable intensification (SI) is a term increasingly used to describe a type of approach applied to international agricultural projects. Despite its widespread use, there is still little understanding or knowledge of the various facets of this composite paradigm. A review of the literature has led to the formalization of three principles that convey the current characterization of SI, comprising a whole system, participatory, agroecological approach. Specific examples of potential bottlenecks to the SI approach are cited, in addition to various technologies and techniques that can be applied to overcome these obstacles. Models of similar, succcessful approaches to agricultural development are examined, along with higher level processes. Additionally, this review explores the desired end points of SI and argues for the inclusion of gender and nutrition throughout the process. To properly apply the SI approach, its various aspects need to be understood and adapted to different cultural and geographic situations. New modeling systems and examples of the effective execution of SI strategies can assist with the successful application of the SI paradigm within complex developing communities. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

'I am an Intensive Guy': The Possibility and Conditions of Reconciliation Through the Ecological Intensification Framework.

PubMed

Levain, Alix; Vertès, Françoise; Ruiz, Laurent; Delaby, Luc; Gascuel-Odoux, Chantal; Barbier, Marc

2015-11-01

The need for better conciliation between food production and environmental protection calls for new conceptual approaches in agronomy. Ecological intensification (EI) is one of the most encouraging and successful conceptual frameworks for designing more sustainable agricultural systems, though relying upon semantic ambivalences and epistemic tensions. This article discusses abilities and limits of the EI framework in the context of strong social and environmental pressure for agricultural transition. The purpose is thus to put EI at stake in the light of the results of an interdisciplinary and participatory research project that explicitly adopted EI goals in livestock semi-industrialized farming systems. Is it possible to maintain livestock production systems that are simultaneously productive, sustainable, and viable and have low nitrate emissions in vulnerable coastal areas? If so, how do local stakeholders use these approaches? The main steps of the innovation process are described. The effects of political and social dynamics on the continuity of the transition process are analyzed, with a reflexive approach. This experiment invites one to consider that making EI operational in a context of socio-technical transition toward agroecology represents system innovation, requiring on-going dialogue, reflexivity, and long-term involvement by researchers.

`I am an Intensive Guy': The Possibility and Conditions of Reconciliation Through the Ecological Intensification Framework

NASA Astrophysics Data System (ADS)

Levain, Alix; Vertès, Françoise; Ruiz, Laurent; Delaby, Luc; Gascuel-Odoux, Chantal; Barbier, Marc

2015-11-01

The need for better conciliation between food production and environmental protection calls for new conceptual approaches in agronomy. Ecological intensification (EI) is one of the most encouraging and successful conceptual frameworks for designing more sustainable agricultural systems, though relying upon semantic ambivalences and epistemic tensions. This article discusses abilities and limits of the EI framework in the context of strong social and environmental pressure for agricultural transition. The purpose is thus to put EI at stake in the light of the results of an interdisciplinary and participatory research project that explicitly adopted EI goals in livestock semi-industrialized farming systems. Is it possible to maintain livestock production systems that are simultaneously productive, sustainable, and viable and have low nitrate emissions in vulnerable coastal areas? If so, how do local stakeholders use these approaches? The main steps of the innovation process are described. The effects of political and social dynamics on the continuity of the transition process are analyzed, with a reflexive approach. This experiment invites one to consider that making EI operational in a context of socio-technical transition toward agroecology represents system innovation, requiring on-going dialogue, reflexivity, and long-term involvement by researchers.

Using genetic data to estimate diffusion rates in heterogeneous landscapes.

PubMed

Roques, L; Walker, E; Franck, P; Soubeyrand, S; Klein, E K

2016-08-01

Having a precise knowledge of the dispersal ability of a population in a heterogeneous environment is of critical importance in agroecology and conservation biology as it can provide management tools to limit the effects of pests or to increase the survival of endangered species. In this paper, we propose a mechanistic-statistical method to estimate space-dependent diffusion parameters of spatially-explicit models based on stochastic differential equations, using genetic data. Dividing the total population into subpopulations corresponding to different habitat patches with known allele frequencies, the expected proportions of individuals from each subpopulation at each position is computed by solving a system of reaction-diffusion equations. Modelling the capture and genotyping of the individuals with a statistical approach, we derive a numerically tractable formula for the likelihood function associated with the diffusion parameters. In a simulated environment made of three types of regions, each associated with a different diffusion coefficient, we successfully estimate the diffusion parameters with a maximum-likelihood approach. Although higher genetic differentiation among subpopulations leads to more accurate estimations, once a certain level of differentiation has been reached, the finite size of the genotyped population becomes the limiting factor for accurate estimation.

Vegetation structure of plantain-based agrosystems determines numerical dominance in community of ground-dwelling ants.

PubMed

Dassou, Anicet Gbéblonoudo; Tixier, Philippe; Dépigny, Sylvain; Carval, Dominique

2017-01-01

In tropics, ants can represent an important part of animal biomass and are known to be involved in ecosystem services, such as pest regulation. Understanding the mechanisms underlying the structuring of local ant communities is therefore important in agroecology. In the humid tropics of Africa, plantains are cropped in association with many other annual and perennial crops. Such agrosystems differ greatly in vegetation diversity and structure and are well-suited for studying how habitat-related factors affect the ant community. We analysed abundance data for the six numerically dominant ant taxa in 500 subplots located in 20 diversified, plantain-based fields. We found that the density of crops with foliage at intermediate and high canopy strata determined the numerical dominance of species. We found no relationship between the numerical dominance of each ant taxon with the crop diversity. Our results indicate that the manipulation of the densities of crops with leaves in the intermediate and high strata may help maintain the coexistence of ant species by providing different habitat patches. Further research in such agrosystems should be performed to assess if the effect of vegetation structure on ant abundance could result in efficient pest regulation.

Changes in the physical status of the typical and leached chernozems of Kursk oblast within 40 years

NASA Astrophysics Data System (ADS)

Kuznetsova, I. V.

2013-04-01

The changes in the physical properties of the chernozems in the Central Russian province of the forest-steppe zone (Kursk oblast) that took place from 1964 to 2002 are analyzed in relation to the corresponding changes in the agrotechnology, agroeconomy, and agroecology. Three periods of the soil transformation are distinguished. The first period was characterized by the use of machines with relatively small pressure on the soil and by the dynamic equilibrium between the physical state of the soils and the processes of the humification-mineralization of the soil organic matter. The use of power-intensive machines in the next period resulted in greater soil compaction with negative changes in the soil physical properties. At the same time, the physical properties of the chernozems remained close to optimum on the fields where heavy machines were not used. The third period was characterized by the use of heavy machines and by the decrease in the rates of the organic and mineral fertilizers and certain disturbances in the crop rotation systems because of the economic difficulties. The negative tendencies of the changes in the soil physical properties observed during the preceding period continued.

Investigating the (Mis)Match between Natural Pest Control Knowledge and the Intensity of Pesticide Use.

PubMed

Mall, David; Larsen, Ashley E; Martin, Emily A

2018-01-05

Transforming modern agriculture towards both higher yields and greater sustainability is critical for preserving biodiversity in an increasingly populous and variable world. However, the intensity of agricultural practices varies strongly between crop systems. Given limited research capacity, it is crucial to focus efforts to increase sustainability in the crop systems that need it most. In this study, we investigate the match (or mismatch) between the intensity of pesticide use and the availability of knowledge on the ecosystem service of natural pest control across various crop systems. Using a systematic literature search on pest control and publicly available pesticide data, we find that pest control literature is not more abundant in crops where insecticide input per hectare is highest. Instead, pest control literature is most abundant, with the highest number of studies published, in crops with comparatively low insecticide input per hectare but with high world harvested area. These results suggest that a major increase of interest in agroecological research towards crops with high insecticide input, particularly cotton and horticultural crops such as citrus and high value-added vegetables, would help meet knowledge needs for a timely ecointensification of agriculture.

The “Bringing into Cultivation” Phase of the Plant Domestication Process and Its Contributions to In Situ Conservation of Genetic Resources in Benin

PubMed Central

Vodouhè, R.; Dansi, A.

2012-01-01

All over the world, plant domestication is continually being carried out by local communities to support their needs for food, fibre, medicine, building materials, etc. Using participatory rapid appraisal approach, 150 households were surveyed in 5 villages selected in five ethnic groups of Benin, to investigate the local communities' motivations for plant domestication and the contributions of this process to in situ conservation of genetic resources. The results indicated differences in plant domestication between agroecological zones and among ethnic groups. People in the humid zones give priority to herbs mainly for their leaves while those in dry area prefer trees mostly for their fruits. Local communities were motivated to undertake plant domestication for foods (80% of respondents), medicinal use (40% of respondents), income generation (20% of respondents) and cultural reasons (5% of respondents). 45% of the species recorded are still at early stage in domestication and only 2% are fully domesticated. Eleven factors related to the households surveyed and to the head of the household interviewed affect farmers' decision making in domesticating plant species. There is gender influence on the domestication: Women are keen in domesticating herbs while men give priority to trees. PMID:22693431

[The green rural economy: challenges to research and to public health policies posed by agricultural modernization].

PubMed

Rigotto, Raquel Maria; Carneiro, Fernando Ferreira; Marinho, Alice Maria Correia Pequeno; Rocha, Mayara Melo; Ferreira, Marcelo José Monteiro; Pessoa, Vanira Matos; Teixeira, Ana Cláudia de Araújo; da Silva, Maria de Lourdes Vicente; Braga, Lara de Queiroz Viana; Teixeira, Maiana Maia

2012-06-01

In this paper, we ask ourselves who should, can and has the will to promote health in the rural zone today. The fields of science and public policy were chosen as our primary focus of dialogue conducted from the perspective of the right to health and a healthy environment. Seven lessons emerged: (1) in addition to the surveillance of isolated chemical risks, the relation between agrochemicals and health should be investigated in the context of conservative agricultural modernization; (2) it is mandatory and urgent to discover the health problems related to the use of agrochemicals; (3) the State has been successful in its support of agribusiness, but highly inefficient at enforcing policies to safeguard social rights; (4) sectors of society linked to rural organizations have played an important role in the public policies combating agrochemicals and protecting health; (5) studies must help deconstruct the myths surrounding the Green Revolution model; (6) we are faced with the challenge of contributing to the construction of an emerging scientific paradigm founded on an ethical-political commitment to the most vulnerable social elements; (7) rural communities are creating agro-ecological alternatives for life in semiarid areas.

Vegetation structure of plantain-based agrosystems determines numerical dominance in community of ground-dwelling ants

PubMed Central

Dassou, Anicet Gbéblonoudo; Tixier, Philippe; Dépigny, Sylvain

2017-01-01

In tropics, ants can represent an important part of animal biomass and are known to be involved in ecosystem services, such as pest regulation. Understanding the mechanisms underlying the structuring of local ant communities is therefore important in agroecology. In the humid tropics of Africa, plantains are cropped in association with many other annual and perennial crops. Such agrosystems differ greatly in vegetation diversity and structure and are well-suited for studying how habitat-related factors affect the ant community. We analysed abundance data for the six numerically dominant ant taxa in 500 subplots located in 20 diversified, plantain-based fields. We found that the density of crops with foliage at intermediate and high canopy strata determined the numerical dominance of species. We found no relationship between the numerical dominance of each ant taxon with the crop diversity. Our results indicate that the manipulation of the densities of crops with leaves in the intermediate and high strata may help maintain the coexistence of ant species by providing different habitat patches. Further research in such agrosystems should be performed to assess if the effect of vegetation structure on ant abundance could result in efficient pest regulation. PMID:29152414

Gender norms among "Landless" youth: evidence for the social practice of nursing.

PubMed

Zanatta, Luiz Fabiano; Ruiz-Cantero, Maria Tereza; Chilet-Rossel, Elisa; Álvarez-Dardet, Carlos; Brêtas, José Roberto da Silva

2017-01-01

Objective Analyzing the relationship between socio-demographic characteristics of youth from the Landless Rural Workers' Movement in Brazil (MST) regarding the prevalence ratio being in accordance with gender norms. Method A cross-sectional study conducted during a Journey of Agroecology carried out in the State of Paraná with young people (15 to 29 years) of both genders. Data collection was conducted through questionnaires. Data analysis compared variables regarding gender norms with sociodemographic variables, and a Prevalence Ratio (PR) was calculated with a confidence interval (CI) set at 95% in order to determine this relationship. Results The study sample was comprised of 147 young people. A higher prevalence was found in accordance with gender norms (PR with CI at 95%) among women compared to men, and that sociodemographic characteristics (lower education level, those living in occupation camps, who do not have white skin and with religious belief) were social indicators for such positioning among both genders. Conclusion The byproduct of a patriarchal gender system has led more young girls to internalization and a reaffirmation of gender norms, highlighting an important field for social nursing practices in order to contribute to the transformation of this reality.

Use of Balanced Scorecard Methodology for Performance Measurement of the Health Extension Program in Ethiopia

PubMed Central

Teklehaimanot, Hailay D.; Teklehaimanot, Awash; Tedella, Aregawi A.; Abdella, Mustofa

2016-01-01

In 2004, Ethiopia introduced a community-based Health Extension Program to deliver basic and essential health services. We developed a comprehensive performance scoring methodology to assess the performance of the program. A balanced scorecard with six domains and 32 indicators was developed. Data collected from 1,014 service providers, 433 health facilities, and 10,068 community members sampled from 298 villages were used to generate weighted national, regional, and agroecological zone scores for each indicator. The national median indicator scores ranged from 37% to 98% with poor performance in commodity availability, workforce motivation, referral linkage, infection prevention, and quality of care. Indicator scores showed significant difference by region (P < 0.001). Regional performance varied across indicators suggesting that each region had specific areas of strength and deficiency, with Tigray and the Southern Nations, Nationalities and Peoples Region being the best performers while the mainly pastoral regions of Gambela, Afar, and Benishangul-Gumuz were the worst. The findings of this study suggest the need for strategies aimed at improving specific elements of the program and its performance in specific regions to achieve quality and equitable health services. PMID:26928842

Use of Balanced Scorecard Methodology for Performance Measurement of the Health Extension Program in Ethiopia.

PubMed

Teklehaimanot, Hailay D; Teklehaimanot, Awash; Tedella, Aregawi A; Abdella, Mustofa

2016-05-04

In 2004, Ethiopia introduced a community-based Health Extension Program to deliver basic and essential health services. We developed a comprehensive performance scoring methodology to assess the performance of the program. A balanced scorecard with six domains and 32 indicators was developed. Data collected from 1,014 service providers, 433 health facilities, and 10,068 community members sampled from 298 villages were used to generate weighted national, regional, and agroecological zone scores for each indicator. The national median indicator scores ranged from 37% to 98% with poor performance in commodity availability, workforce motivation, referral linkage, infection prevention, and quality of care. Indicator scores showed significant difference by region (P < 0.001). Regional performance varied across indicators suggesting that each region had specific areas of strength and deficiency, with Tigray and the Southern Nations, Nationalities and Peoples Region being the best performers while the mainly pastoral regions of Gambela, Afar, and Benishangul-Gumuz were the worst. The findings of this study suggest the need for strategies aimed at improving specific elements of the program and its performance in specific regions to achieve quality and equitable health services. © The American Society of Tropical Medicine and Hygiene.

Remotely sensed high resolution irrigated area mapping in India for 2000 to 2015

PubMed Central

Ambika, Anukesh Krishnankutty; Wardlow, Brian; Mishra, Vimal

2016-01-01

India is among the countries that uses a significant fraction of available water for irrigation. Irrigated area in India has increased substantially after the Green revolution and both surface and groundwater have been extensively used. Under warming climate projections, irrigation frequency may increase leading to increased irrigation water demands. Water resources planning and management in agriculture need spatially-explicit irrigated area information for different crops and different crop growing seasons. However, annual, high-resolution irrigated area maps for India for an extended historical record that can be used for water resources planning and management are unavailable. Using 250 m normalized difference vegetation index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS) and 56 m land use/land cover data, high-resolution irrigated area maps are developed for all the agroecological zones in India for the period of 2000–2015. The irrigated area maps were evaluated using the agricultural statistics data from ground surveys and were compared with the previously developed irrigation maps. High resolution (250 m) irrigated area maps showed satisfactory accuracy (R2=0.95) and can be used to understand interannual variability in irrigated area at various spatial scales. PMID:27996974

Communal goat production in Southern Africa: a review.

PubMed

Rumosa Gwaze, F; Chimonyo, M; Dzama, K

2009-10-01

Despite the fact that about 64% of goats in sub-Saharan Africa (SSA) are located in rural arid (38%) and semi-arid (26%) agro-ecological zones and that more than 90% of goats in these zones are indigenous, information on indigenous breeds is inadequate. This paper reviews the social and economic importance of goats to the communal farmer and assesses the potential of using goats in rural development in Southern Africa. Farmers in Southern Africa largely use the village goat management system. There are various goat breeds in Southern Africa, of which the Mashona, Matabele, Tswana, Nguni and the Landim are the dominant ones. It is, however, not clear if these breeds are distinct. Major constraints to goat production include high disease and parasite prevalence, low levels of management, limited forage availability and poor marketing management. Potential research areas that are required to ensure that goats are vehicles for rural development include evaluation of constraints to goat production, assessing the contribution of goats to household economies and food securities throughout the year, genetic and phenotypic characterisation of the indigenous breeds to identify appropriate strains and sustainable methods of goat improvement through either selection or crossbreeding.

Recommendations for the Regionalizing of Coffee Cultivation in Colombia: A Methodological Proposal Based on Agro-Climatic Indices

PubMed Central

García L., Juan Carlos; Posada-Suárez, Húver; Läderach, Peter

2014-01-01

The Colombian National Federation of Coffee Growers (FNC) conducted an agro-ecological zoning study based on climate, soil, and terrain of the Colombian coffee-growing regions (CCGR) located in the tropics, between 1° and 11.5° N, in areas of complex topography. To support this study, a climate baseline was constructed at a spatial resolution of 5 km. Twenty-one bioclimatic indicators were drawn from this baseline data and from yield data for different coffee genotypes evaluated under conditions at eight experimental stations (ESs) belonging to the National Center for Coffee Research (CENICAFÉ). Three topographic indicators were obtained from a digital elevation model (DEM). Zoning at a national level resulted in the differentiation of 12 agro-climatic zones. Altitude notably influenced zone differentiation, however other factors such as large air currents, low-pressure atmospheric systems, valleys of the great rivers, and physiography also played an important role. The strategy of zoning according to coffee-growing conditions will enable areas with the greatest potential for the development of coffee cultivation to be identified, criteria for future research to be generated, and the level of technology implementation to be assessed. PMID:25436456

Recommendations for the regionalizing of coffee cultivation in Colombia: a methodological proposal based on agro-climatic indices.

PubMed

García L, Juan Carlos; Posada-Suárez, Húver; Läderach, Peter

2014-01-01

The Colombian National Federation of Coffee Growers (FNC) conducted an agro-ecological zoning study based on climate, soil, and terrain of the Colombian coffee-growing regions (CCGR) located in the tropics, between 1° and 11.5° N, in areas of complex topography. To support this study, a climate baseline was constructed at a spatial resolution of 5 km. Twenty-one bioclimatic indicators were drawn from this baseline data and from yield data for different coffee genotypes evaluated under conditions at eight experimental stations (ESs) belonging to the National Center for Coffee Research (CENICAFÉ). Three topographic indicators were obtained from a digital elevation model (DEM). Zoning at a national level resulted in the differentiation of 12 agro-climatic zones. Altitude notably influenced zone differentiation, however other factors such as large air currents, low-pressure atmospheric systems, valleys of the great rivers, and physiography also played an important role. The strategy of zoning according to coffee-growing conditions will enable areas with the greatest potential for the development of coffee cultivation to be identified, criteria for future research to be generated, and the level of technology implementation to be assessed.

Investigating the (Mis)Match between Natural Pest Control Knowledge and the Intensity of Pesticide Use

PubMed Central

Larsen, Ashley E.

2018-01-01

Transforming modern agriculture towards both higher yields and greater sustainability is critical for preserving biodiversity in an increasingly populous and variable world. However, the intensity of agricultural practices varies strongly between crop systems. Given limited research capacity, it is crucial to focus efforts to increase sustainability in the crop systems that need it most. In this study, we investigate the match (or mismatch) between the intensity of pesticide use and the availability of knowledge on the ecosystem service of natural pest control across various crop systems. Using a systematic literature search on pest control and publicly available pesticide data, we find that pest control literature is not more abundant in crops where insecticide input per hectare is highest. Instead, pest control literature is most abundant, with the highest number of studies published, in crops with comparatively low insecticide input per hectare but with high world harvested area. These results suggest that a major increase of interest in agroecological research towards crops with high insecticide input, particularly cotton and horticultural crops such as citrus and high value-added vegetables, would help meet knowledge needs for a timely ecointensification of agriculture. PMID:29304005

Genomic Characterisation of the Indigenous Irish Kerry Cattle Breed

PubMed Central

Browett, Sam; McHugo, Gillian; Richardson, Ian W.; Magee, David A.; Park, Stephen D. E.; Fahey, Alan G.; Kearney, John F.; Correia, Carolina N.; Randhawa, Imtiaz A. S.; MacHugh, David E.

2018-01-01

Kerry cattle are an endangered landrace heritage breed of cultural importance to Ireland. In the present study we have used genome-wide SNP array data to evaluate genomic diversity within the Kerry population and between Kerry cattle and other European breeds. Patterns of genetic differentiation and gene flow among breeds using phylogenetic trees with ancestry graphs highlighted historical gene flow from the British Shorthorn breed into the ancestral population of modern Kerry cattle. Principal component analysis (PCA) and genetic clustering emphasised the genetic distinctiveness of Kerry cattle relative to comparator British and European cattle breeds. Modelling of genetic effective population size (Ne) revealed a demographic trend of diminishing Ne over time and that recent estimated Ne values for the Kerry breed may be less than the threshold for sustainable genetic conservation. In addition, analysis of genome-wide autozygosity (FROH) showed that genomic inbreeding has increased significantly during the 20 years between 1992 and 2012. Finally, signatures of selection revealed genomic regions subject to natural and artificial selection as Kerry cattle adapted to the climate, physical geography and agro-ecology of southwest Ireland. PMID:29520297

Evaluating the Potential of Marginal Land for Cellulosic Feedstock Production and Carbon Sequestration in the United States

DOE PAGES

Emery, Isaac; Mueller, Steffen; Qin, Zhangcai; ...

2016-12-01

Land availability for growing feedstocks at scale is a crucial concern for the bioenergy industry. Feedstock production on land not well-suited to growing conventional crops, or marginal land, is often promoted as ideal, although there is a poor understanding of the qualities, quantity, and distribution of marginal lands in the United States. In this paper, we examine the spatial distribution of land complying with several key marginal land definitions at the United States county, agro-ecological zone, and national scales, and compare the ability of both marginal land and land cover data sets to identify regions for feedstock production. We concludemore » that very few land parcels comply with multiple definitions of marginal land. Furthermore, to examine possible carbon-flow implications of feedstock production on land that could be considered marginal per multiple definitions, we model soil carbon changes upon transitions from marginal cropland, grassland, and cropland–pastureland to switchgrass production for three marginal land-rich counties. Finally, our findings suggest that total soil organic carbon changes per county are small, and generally positive, and can influence life-cycle greenhouse gas emissions of switchgrass ethanol.« less

The Big Rust and the Red Queen: Long-Term Perspectives on Coffee Rust Research.

PubMed

McCook, Stuart; Vandermeer, John

2015-09-01

Since 2008, there has been a cluster of outbreaks of the coffee rust (Hemileia vastatrix) across the coffee-growing regions of the Americas, which have been collectively described as the Big Rust. These outbreaks have caused significant hardship to coffee producers and laborers. This essay situates the Big Rust in a broader historical context. Over the past two centuries, coffee farmers have had to deal with the "curse of the Red Queen"-the need to constantly innovate in the face of an increasing range of threats, which includes the rust. Over the 20th century, particularly after World War II, national governments and international organizations developed a network of national, regional, and international coffee research institutions. These public institutions played a vital role in helping coffee farmers manage the rust. Coffee farmers have pursued four major strategies for managing the rust: bioprospecting for resistant coffee plants, breeding resistant coffee plants, chemical control, and agroecological control. Currently, the main challenge for researchers is to develop rust control strategies that are both ecologically and economically viable for coffee farmers, in the context of a volatile, deregulated coffee industry and the emergent challenges of climate change.

Evaluating the Potential of Marginal Land for Cellulosic Feedstock Production and Carbon Sequestration in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emery, Isaac; Mueller, Steffen; Qin, Zhangcai

Land availability for growing feedstocks at scale is a crucial concern for the bioenergy industry. Feedstock production on land not well-suited to growing conventional crops, or marginal land, is often promoted as ideal, although there is a poor understanding of the qualities, quantity, and distribution of marginal lands in the United States. In this paper, we examine the spatial distribution of land complying with several key marginal land definitions at the United States county, agro-ecological zone, and national scales, and compare the ability of both marginal land and land cover data sets to identify regions for feedstock production. We concludemore » that very few land parcels comply with multiple definitions of marginal land. Furthermore, to examine possible carbon-flow implications of feedstock production on land that could be considered marginal per multiple definitions, we model soil carbon changes upon transitions from marginal cropland, grassland, and cropland–pastureland to switchgrass production for three marginal land-rich counties. Finally, our findings suggest that total soil organic carbon changes per county are small, and generally positive, and can influence life-cycle greenhouse gas emissions of switchgrass ethanol.« less

Simulation-optimization of large agro-hydrosystems using a decomposition approach

NASA Astrophysics Data System (ADS)

Schuetze, Niels; Grundmann, Jens

2014-05-01

In this contribution a stochastic simulation-optimization framework for decision support for optimal planning and operation of water supply of large agro-hydrosystems is presented. It is based on a decomposition solution strategy which allows for (i) the usage of numerical process models together with efficient Monte Carlo simulations for a reliable estimation of higher quantiles of the minimum agricultural water demand for full and deficit irrigation strategies at small scale (farm level), and (ii) the utilization of the optimization results at small scale for solving water resources management problems at regional scale. As a secondary result of several simulation-optimization runs at the smaller scale stochastic crop-water production functions (SCWPF) for different crops are derived which can be used as a basic tool for assessing the impact of climate variability on risk for potential yield. In addition, microeconomic impacts of climate change and the vulnerability of the agro-ecological systems are evaluated. The developed methodology is demonstrated through its application on a real-world case study for the South Al-Batinah region in the Sultanate of Oman where a coastal aquifer is affected by saltwater intrusion due to excessive groundwater withdrawal for irrigated agriculture.

The dawn of Structural One Health: a new science tracking disease emergence along circuits of capital.

PubMed

Wallace, Robert G; Bergmann, Luke; Kock, Richard; Gilbert, Marius; Hogerwerf, Lenny; Wallace, Rodrick; Holmberg, Mollie

2015-03-01

The One Health approach integrates health investigations across the tree of life, including, but not limited to, wildlife, livestock, crops, and humans. It redresses an epistemological alienation at the heart of much modern population health, which has long segregated studies by species. Up to this point, however, One Health research has also omitted addressing fundamental structural causes underlying collapsing health ecologies. In this critical review we unpack the relationship between One Health science and its political economy, particularly the conceptual and methodological trajectories by which it fails to incorporate social determinants of epizootic spillover. We also introduce a Structural One Health that addresses the research gap. The new science, open to incorporating developments across the social sciences, addresses foundational processes underlying multispecies health, including the place-specific deep-time histories, cultural infrastructure, and economic geographies driving disease emergence. We introduce an ongoing project on avian influenza to illustrate Structural One Health's scope and ambition. For the first time researchers are quantifying the relationships among transnational circuits of capital, associated shifts in agroecological landscapes, and the genetic evolution and spatial spread of a xenospecific pathogen. Copyright © 2014 Elsevier Ltd. All rights reserved.

Adaptation and rise: Little Ice Age challenges and social responses on the Trans-Tisza Region (Hungary)

NASA Astrophysics Data System (ADS)

Pinke, Zsolt; Romhányi, Beatrix F.; Gábris, Gyula; Gyulai, Ferenc; Mravcsik, Zoltán; Pósa, Patricia; Ferenczi, László

2016-04-01

The studied 4.128 km2 Central European lowland region includes the Hortobágy landscape, a UNESCO World Heritage site and one of the most extensive protected natural grasslands of Europe. In the evolution of this semi-natural landscape human-nature interactions were characterised by gradual but extremely serious settlement abandonment during the 13th-17th centuries. The identification of the agents shaping this process has been widely discussed in the Hungarian landscape historiography. The statistical analysis of medieval archaeological sites indicating settlements showed that elevation means in the early period of the Little Ice Age (LIA) (mid-13th - mid-16th centuries) were significantly higher than in the Medieval Warm Epoch (MWE) (mid-10th - mid-13th centuries) (p≤0.01; n=549; α=0.05). This result supported our hypothesis that waterside settlements of the plain displaced vertically from the MWE to the LIA. Secondly, a GIS based zonal analysis suggested a strong spatial connection between the geomorphological zones (riparian, deep floodplain and sand plateau), the agro-ecological suitability zones (good-excellent, medium and low) and the population zones (with stable settlement pattern, deserted and uninhabited). E.g. the elevation means of archaeological sites in deserted zones proved significantly lower than those with stable settlement pattern (p≤0.01; n=381; α=0.05). Similarly, a statistical investigation of grain remains (narchaeologicalsite=79; ntaxon=751; nfindings=4.8 millions) of the Great Hungarian Plain (GHP) indicated that the early phase of the LIA saw the spreading of moorland plants and rye, the cereal most resistant to humidity and cool. When the relation of settlement patterns to soil conditions was analysed by ANOVA linear model, a significant spatial correlation appeared between the extension of the high and medium agro-ecological suitability zones and the number of settlements in each population zone of the five microregions (R2

Impacts of Changing Climate on Agricultural Variability: Implications for Smallholder Farmers in India

NASA Astrophysics Data System (ADS)

Mondal, P.; Jain, M.; DeFries, R. S.; Galford, G. L.; Small, C.

2013-12-01

Agriculture is the largest employment sector in India, where food productivity, and thus food security, is highly dependent on seasonal rainfall and temperature. Projected increase in temperature, along with less frequent but intense rainfall events, will have a negative impact on crop productivity in India in the coming decades. These changes, along with continued ground water depletion, could have serious implications for Indian smallholder farmers, who are among some of the most vulnerable communities to climatic and economic changes. Hence baseline information on agricultural sensitivity to climate variability is important for strategies and policies that promote adaptation to climate variability. This study examines how cropping patterns in different agro-ecological zones in India respond to variations in precipitation and temperature. We specifically examine: a) which climate variables most influence crop cover for monsoon and winter crops? and b) how does the sensitivity of crop cover to climate variability vary in different agro-ecological regions with diverse socio-economic factors? We use remote sensing data (2000-01 - 2012-13) for cropping patterns (developed using MODIS satellite data), climate parameters (derived from MODIS and TRMM satellite data) and agricultural census data. We initially assessed the importance of these climate variables in two agro-ecoregions: a predominantly groundwater irrigated, cash crop region in western India, and a region in central India primarily comprised of rain-fed or surface water irrigated subsistence crops. Seasonal crop cover anomaly varied between -25% and 25% of the 13-year mean in these two regions. Predominantly climate-dependent region in central India showed high anomalies up to 200% of the 13-year crop cover mean, especially during winter season. Winter daytime mean temperature is overwhelmingly the most important climate variable for winter crops irrespective of the varied biophysical and socio

GIS-based agroecological assessment of land suitability for food crop development at a regional scale: A study case of Buton Island.

NASA Astrophysics Data System (ADS)

Ramlan, A.; Baja, S.; Arif, S.; Neswati, R.

2018-05-01

Agriculture has long become a prime sector for regional development in Buton Island, although local government emphasis on perennial crops. Food crop have been developed in very limited land areas, mainly on transmigration areas, as parts of central government programs. Today, the central government has launched a national strategic program on food self-sufficiency and has imposed the local government to optimize available land for cultivating food crop. The primary aim of study is to develop rapid assessment on a spatial basis using GIS for agricultural land suitability evaluation of agriculture commodities, i.e., rice (irrigated paddy field, rainfed rice) and corn (Zea maize L.). The study was undertaken using the following procedures: (i) conducting reconnaissance soil survey based on land units; (ii) constructing soil database in a GIS; and (iii) classifying land suitability using the FAO method. Spatial data were generated from digital topographic map, soil survey, soil characteristics, as well as climate data. Preliminary results indicate that quite large area available for food crop cultivation both in the context of land suitability (mostly in S2 and S3 classes) and land availability. All data bases were managed in GIS, then it is amenable to various operations in GIS to accommodate possible additional assessment including socio-economic and policy assessment.

Agro-ecological variations of sheath rot disease of rice caused by Sarocladium oryzae and DNA fingerprinting of the pathogen's population structure.

PubMed

Tajul Islam Chowdhury, M; Salim Mian, M; Taher Mia, M A; Rafii, M Y; Latif, M A

2015-12-28

To examine the impact of regional and seasonal variations on the incidence and severity of sheath rot, a major seed-borne disease of rice caused by Sarocladium oryzae, data on incidence and severity were collected from 27 selected fields in the Gazipur, Rangpur, Bogra, Chittagong, Comilla, Gopalgonj, Jessore, Manikgonj, and Bhola districts of Bangladesh in rain-fed and irrigated conditions. Cultural variability of 29 pathogen isolates obtained from 8 different locations was studied on potato dextrose agar (PDA) and genetic variability was determined by DNA fingerprinting using variable number tandem repeat-polymerase chain reaction markers. Overall, disease incidence and severity were higher in irrigated rice. Disease incidence and severity were highest in the Bhola district in rain-fed rice and lowest in irrigated rice. Mycelial growth of 29 representative isolates was found to vary on PDA and the isolates were divided into 6 groups. The range of the overall size of conidia of the selected isolates was 2.40-7.20 x 1.20-2.40 μm. Analysis of the DNA fingerprint types of the 29 isolates of S. oryzae, obtained from the amplification reactions, revealed 10 fingerprinting types (FPTs) that were 80% similar. FPT-1 was the largest group and included 13 isolates (44.8%), while FPT-2 was the third largest group and included 3 isolates. Each of FPT-3, 4, 5, and 6 included only 1 isolate. We observed no relationship between cultural and genetic groupings.

Crop Farmers' Willingness to Pay for Agricultural Extension Services in Bangladesh: Cases of Selected Villages in Two Important Agro-Ecological Zones

ERIC Educational Resources Information Center

Uddin, Ektear MD.; Gao, Qijie; Mamun-Ur-Rashid, MD.

2016-01-01

Purpose: Globally, many extension professionals and policy-makers are advocating fee based services, in addressing the fund shortage and sustainable provision of agricultural advisory services. Hence, the article attempts to expose the farmers' willingness to pay (WTP) as agricultural extension in Bangladesh is experiencing chronic fund crisis.…

Study of nitrate leaching and nitrogen fate under intensive vegetable production pattern in northern China.

PubMed

Song, Xiao-Zong; Zhao, Chang-Xing; Wang, Xiao-Lan; Li, Ji

2009-04-01

Because of intensive vegetable production in plastic greenhouses in northern China, the potential risk of nitrate leaching to groundwater is increasingly apparent, threatening ecosystem services and the sustainability of food production. In the present work, nine drainable lysimeters were installed into vegetable fields, with in-situ loamy soils, in Shouguang City of the north China vegetable base. The experiments were conducted to quantify the magnitude and variability of nitrate leaching to groundwater and to access the fate of total fertilizer-N inputs in the area. The results obtained indicated that: under local conventional agronomic practices, there is a high discrepancy in leaching nitrate-N concentration (ranging from 17 to 457 mg L(-1)), and nitrate losses (152-347 kg N ha(-1)) were observed from 1-m soil profiles in the field. Meanwhile, high fertilizer N application resulted in low N efficiency, with only (33.0+/-13)% (mean+/-S.D.) of input N absorbed by the crops, while additionally nearly half of the total inputs of N were unaccounted in a partial N balance sheet. It is concluded that groundwater pollution associated with greenhouse-based vegetable production had been confirmed in Shouguang, adversely affecting water quality and leading to serial agro-ecological problems.

Serum enzymes levels and influencing factors in three indigenous Ethiopian goat breeds.

PubMed

Tibbo, M; Jibril, Y; Woldemeskel, M; Dawo, F; Aragaw, K; Rege, J E O

2008-12-01

Serum enzymes were studied in 163 apparently healthy goats from three indigenous goat breeds of Ethiopia. The effect of breed, age, sex and season on alanine aminotransferase (ALT) / glutamic pyruvic transaminase (GPT), aspartate aminotransferase (AST) / glutamic oxalacetic transaminases (GOT), alkaline phosphatase (ALP) and acid phosphatase (AcP) levels was assessed. The mean serum enzymes levels of the indigenous Arsi-Bale, Central Highland and Long-eared Somali goat breeds ranged from 14.0-20.2 iu L(-1) for ALT/GPT, from 43.2-49.3 iu L(-1) for AST/GOT, from 83.7-98.8 iu L(-1) for ALP, and from 2.99-4.23 iu L(-1) for AcP, were within the normal range for goats elsewhere. Breed had significant influence on AST/GOT values. Sex had significant effect on ALT/GPT for Arsi-Bale goats with higher values in males than females. Age was significant on all serum enzymes studied in the Arsi-Bale goats and on ALP in the Central Highland goats. Season had significant influence on all serum enzymes except for ALT/GPT in the Arsi-Bale goats. The serum enzyme levels of these indigenous goat breeds can be used as normal reference values for Ethiopian goat breeds adapted to similar agro-ecology and production system.

Agropastoral Mobility and Rangelands Multiple Uses in the Miombo Frontier Ecozone of Tabora Region, Western Tanzania.

PubMed

Masanja, George Felix

2017-01-01

This study aimed to examine the argument of environmental resource-use conflict as the primary cause of crop farmers and agropastoralists conflicts in Tabora Region, Tanzania. It explored the multiple interdependent phenomena that affect livelihoods relationships between crop farmers and agropastoralists and the nature of their continuing conflicts over the ecozonal resources. A primary dataset of the two groups' conflicts was used. An ex post facto and multistage sampling design was adopted. A total of 252 respondents were interviewed in three separate villages drawn from agroecological zones fringing the miombo woodland where such tensions are high. Data were analyzed using logistic regression. Results indicate that education ( β = -1.215, .297; p = .050), household size ( β = .958, 2.607; p = .017), herd size ( β = 4.276, 7.197; p = 0.001), farm size ( β = -1.734, .048; p = .176), the police ( β = -.912, 4.582; p = .043), and village leaders ( β = -.122, .885; p = .012) were the most potent predictors of causes of conflicts. The study found no support for demographic variables, like age, sex, marital status, income, duration of residence, and distance to resource base. The study recommends population growth control and strengthening of local institutions and recommends local communities to sustain management of natural resources base in the area.

Total economic value of wetlands products and services in Uganda.

PubMed

Kakuru, Willy; Turyahabwe, Nelson; Mugisha, Johnny

2013-01-01

Wetlands provide food and non-food products that contribute to income and food security in Uganda. This study determined the economic value of wetland resources and their contribution to food security in the three agroecological zones of Uganda. The values of wetland resources were estimated using primary and secondary data. Market price, Productivity, and Contingent valuation methods were used to estimate the value of wetland resources. The per capita value of fish was approximately US$ 0.49 person⁻¹. Fish spawning was valued at approximately US$ 363,815 year⁻¹, livestock pastures at US$ 4.24 million, domestic water use at US$ 34 million year⁻¹, and the gross annual value added by wetlands to milk production at US$ 1.22 million. Flood control was valued at approximately US$ 1,702,934,880 hectare⁻¹ year⁻¹ and water regulation and recharge at US$ 7,056,360 hectare⁻¹ year⁻¹. Through provision of grass for mulching, wetlands were estimated to contribute to US$ 8.65 million annually. The annual contribution of non-use values was estimated in the range of US$ 7.1 million for water recharge and regulation and to US$ 1.7 billion for flood control. Thus, resource investment for wetlands conservation is economically justified to create incentives for continued benefits.

Metabolic Profiling and Classification of Propolis Samples from Southern Brazil: An NMR-Based Platform Coupled with Machine Learning.

PubMed

Maraschin, Marcelo; Somensi-Zeggio, Amélia; Oliveira, Simone K; Kuhnen, Shirley; Tomazzoli, Maíra M; Raguzzoni, Josiane C; Zeri, Ana C M; Carreira, Rafael; Correia, Sara; Costa, Christopher; Rocha, Miguel

2016-01-22

The chemical composition of propolis is affected by environmental factors and harvest season, making it difficult to standardize its extracts for medicinal usage. By detecting a typical chemical profile associated with propolis from a specific production region or season, certain types of propolis may be used to obtain a specific pharmacological activity. In this study, propolis from three agroecological regions (plain, plateau, and highlands) from southern Brazil, collected over the four seasons of 2010, were investigated through a novel NMR-based metabolomics data analysis workflow. Chemometrics and machine learning algorithms (PLS-DA and RF), including methods to estimate variable importance in classification, were used in this study. The machine learning and feature selection methods permitted construction of models for propolis sample classification with high accuracy (>75%, reaching ∼90% in the best case), better discriminating samples regarding their collection seasons comparatively to the harvest regions. PLS-DA and RF allowed the identification of biomarkers for sample discrimination, expanding the set of discriminating features and adding relevant information for the identification of the class-determining metabolites. The NMR-based metabolomics analytical platform, coupled to bioinformatic tools, allowed characterization and classification of Brazilian propolis samples regarding the metabolite signature of important compounds, i.e., chemical fingerprint, harvest seasons, and production regions.

A survey analysis of indigenous goat production in communal farming systems of Botswana.

PubMed

Monau, P I; Visser, C; Nsoso, S J; Van Marle-Köster, E

2017-08-01

A total of 153 communal farmers in four agro-ecological regions of Botswana were interviewed using a structured questionnaire. The aims of the survey were to characterise existing communal goat production systems, evaluate the importance of goats to farmers and identify breeding practices and constraints encountered in goat production in Botswana. Data was collected on socio-economic parameters, general and breeding management practices and major constraints limiting goat production in Botswana. All respondents were small-scale communal farmers with 63% respondents practising mixed crop-livestock farming and 37% keeping livestock as their primary activity. The majority (33%) of respondents were older than 60 years. Over 80% of the farmers kept goats for cash required for tuition, school uniforms and household commodities as well as re-stocking of animals. Most farmers (62%) kept indigenous crossed genotypes. Generally, uncontrolled mating was practised with the majority of farmers (41%) using on-farm reared bucks for more than two years of breeding and communal bucks (36%) as an alternative. The major constraints limiting goat productivity in communal areas included uncontrolled breeding, predators, theft and diseases. Issues raised by farmers should be considered in designing and implementing effective breeding programs for goats to improve their overall productivity and contribution to poverty alleviation in these communities.

Evaluation of the relationship between education and sustainability in peasant movements: The experience of the National Education Program in Agrarian Reform.

PubMed

Camacho, Rodrigo Simão; Sobreiro Filho, José; Sobreiro, Vinicius Amorim; Mariano, Enzo Barberio

2016-02-01

Brazil is one of the largest agricultural producers in the world. However, its agrarian composition is based on two markedly different production models, particularly in relation to sustainability: a peasant family agriculture, which plays an important role in food production for domestic consumption and advocates agro-ecological practises; and agribusiness, the politically and economically hegemonic model that produces commodities for export based on monoculture and intensive use of pesticides. Therefore, in order to create the means to develop peasant lands, social movements and peasants have engaged themselves politically and defended an education model grounded in sustainable practises of production and social organisation. Taking this into account, the main purpose of this paper is to analyse and assess the Brazilian experience of integration between education and sustainability, in the National Education Program in Agrarian Reform (PRONERA). To accomplish this aim, a survey with a semi-structured questionnaire was carried out among teachers, students, monitors, and coordinators of the course offered by PRONERA. The surveys showed that the courses are promoting the concepts of sustainability among peasants. However, many adjustments need to be taken into consideration during the planning process for the next courses offered by PRONERA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative assessment of lowland and highland Smallholder farmers' vulnerability to climate variability in Ethiopia

NASA Astrophysics Data System (ADS)

Ayal, D. Y., Sr.; Abshare, M. W. M.; Desta, S. D.; Filho, W. L.

2015-12-01

Desalegn Yayeh Ayal P.O.BOX 150129 Addis Ababa University Ethiopia Mobil +251910824784 Abstract Smallholder farmers' near term scenario (2010-2039) vulnerability nature and magnitude was examined using twenty-two exposure, sensitivity and adaptive capacity vulnerability indicators. Assessment of smallholder farmers' vulnerability to climate variability revealed the importance of comprehending exposure, sensitivity and adaptive capacity induces. Due to differences in level of change in rainfall, temperature, drought frequency, their environmental interaction and variations on adaptive capacity the nature and magnitude of smallholder farmers vulnerability to physical, biological and epidemiological challenges of crop and livestock production varied within and across agro-ecologies. Highlanders' sensitive relates with high population density, erosion and crop disease and pest damage occurrence. Whereas lowlanders will be more sensitive to high crop disease and pest damage, provenance of livestock disease, absence of alternative water sources, less diversified agricultural practices. However, with little variations in the magnitude and nature of vulnerability, both highlanders and lowlanders are victims of climate variability and change. Given the ever increasing population, temperature and unpredictable nature of rainfall variability, the study concluded that future adaptation strategies should capitalize on preparing smallholder farmers for both extremes- excess rainfall and flooding on the one hand and severe drought on the other.

Genetic diversity and population structure of Mongolian domestic Bactrian camels (Camelus bactrianus).

PubMed

Chuluunbat, B; Charruau, P; Silbermayr, K; Khorloojav, T; Burger, P A

2014-08-01

The tradition of animal husbandry in the context of a nomadic lifestyle has been of great significance in the Mongolian society. Both Bactrian camels and horses have been invaluable for the survival and development of human activities in the harsh arid environment of the Mongolian steppe. As camels offer unique and sustainable opportunities for livestock production in marginal agro-ecological zones, we investigated the current genetic diversity of three local Mongolian camel breeds and compared their levels of variation with common native Mongolian camels distributed throughout the country. Based on mitochondrial and nuclear markers, we found levels of genetic diversity in Mongolian populations similar to that reported for Chinese Bactrian camels and for dromedaries. Little differentiation was detected between single breeds, except for a small group originating from the northwestern Mongolian Altai. We found neither high inbreeding levels in the different breeds nor evidence for a population decline. Although the Mongolian camel census size has severely declined over the past 20 years, our analyses suggest that there still exists a stable population with adequate genetic variation for continued sustainable utilization. © 2014 The Authors. Animal Genetics published by John Wiley & Sons Ltd on behalf of Stichting International Foundation for Animal Genetics.

Morphological and molecular characterization of Eurytrema cladorchis parasitizing cattle (Bos indicus) in Bangladesh.

PubMed

Mohanta, Uday Kumar; Ichikawa-Seki, Madoka; Hayashi, Kei; Itagaki, Tadashi

2015-06-01

There is always controversy regarding identification of different species in the genus Eurytrema. Identification has been based mainly on morphology, which can be misleading and subject to differing interpretation among the scientists. Therefore, the aim of this study was to identify Eurytrema flukes both by morphology and molecular properties on the basis of 18-subunit ribosomal RNA (18S rRNA) gene as well as internal transcribed spacer 2 (ITS2) to clarify their phylogenetic status. Among six different agroecological areas of Bangladesh, 22 Eurytrema flukes were recovered from the bile ducts of 22 cattle in Bandarban, a hill district. The flukes were identified as Eurytrema cladorchis through morphometric and morphological studies. Phylogenetic analyses were conducted by neighbor-joining phylogram inferred from both 18S rRNA (1784 bp) gene and ITS2 (229 bp) sequences. A monophyletic clade was constructed by the E. cladorchis from Bangladesh; however, the clade was distinct from those formed by Eurytrema pancreaticum and Eurytrema coelomaticum. This study first described the existence of E. cladorchis from Bangladesh and may provide useful information for both morphological and molecular properties that may further help to clarify phylogenetic relationships within the genus Eurytrema and also for other digeneans.

In Vitro Propagation and Conservation of Bacopa monnieri L.

PubMed

Sharma, Neelam; Singh, Rakesh; Pandey, Ruchira

2016-01-01

Bacopa monnieri L. (common name brahmi) is a traditional and renowned Indian medicinal plant with high commercial value for its memory revitalizer potential. Demand for this herb has further escalated due to popularization of various brahmi-based drugs coupled with reported anticancer property. Insufficient seed availability and problems associated with seed propagation including short seed viability are the major constraints of seed conservation in the gene banks. In vitro clonal propagation, a prerequisite for in vitro conservation by enhanced axillary branching was standardized. We have developed a simple, single step protocol for in vitro establishment, propagation and medium-term conservation of B. monnieri. Single node explants, cultured on Murashige and Skoog's medium supplemented with BA (0.2 mg/L), exhibited shoot proliferation without callus formation. Rooting was achieved on the same medium. The in vitro raised plants were successfully transferred to soil with ~80 % survival. On the same medium, shoots could also be conserved for 12 months with high survival and genetic stability was maintained as revealed by molecular markers. The protocol optimized in the present study has been applied for culture establishment, shoot multiplication and medium-term conservation of several Bacopa germplasm, procured from different agro-ecological regions of India.

Drivers of household food availability in sub-Saharan Africa based on big data from small farms

PubMed Central

Frelat, Romain; Lopez-Ridaura, Santiago; Herrero, Mario; Douxchamps, Sabine; Djurfeldt, Agnes Andersson; Erenstein, Olaf; Henderson, Ben; Kassie, Menale; Paul, Birthe K.; Rigolot, Cyrille; Ritzema, Randall S.; Rodriguez, Daniel; van Asten, Piet J. A.; van Wijk, Mark T.

2016-01-01

We calculated a simple indicator of food availability using data from 93 sites in 17 countries across contrasted agroecologies in sub-Saharan Africa (>13,000 farm households) and analyzed the drivers of variations in food availability. Crop production was the major source of energy, contributing 60% of food availability. The off-farm income contribution to food availability ranged from 12% for households without enough food available (18% of the total sample) to 27% for the 58% of households with sufficient food available. Using only three explanatory variables (household size, number of livestock, and land area), we were able to predict correctly the agricultural determined status of food availability for 72% of the households, but the relationships were strongly influenced by the degree of market access. Our analyses suggest that targeting poverty through improving market access and off-farm opportunities is a better strategy to increase food security than focusing on agricultural production and closing yield gaps. This calls for multisectoral policy harmonization, incentives, and diversification of employment sources rather than a singular focus on agricultural development. Recognizing and understanding diversity among smallholder farm households in sub-Saharan Africa is key for the design of policies that aim to improve food security. PMID:26712016

Tracking domestic ducks: A novel approach for documenting poultry market chains in the context of avian influenza transmission

USGS Publications Warehouse

Choi, Chang-Yong; Takekawa, John Y.; Xiong, Yue; Wikelski, Martin; Heine, George; Prosser, Diann J.; Newman, Scott H.; Edwards, John; Guo, Fusheng; Xiao, Xiangming

2016-01-01

Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian influenza (HPAI) are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System (GPS) locations and send them through the Groupe Spécial Mobile (GSM) cellular telephone system. For the first time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide direct, quantitative information to document the movement of poultry and reveal their market chains. Our findings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.

Drivers of household food availability in sub-Saharan Africa based on big data from small farms.

PubMed

Frelat, Romain; Lopez-Ridaura, Santiago; Giller, Ken E; Herrero, Mario; Douxchamps, Sabine; Andersson Djurfeldt, Agnes; Erenstein, Olaf; Henderson, Ben; Kassie, Menale; Paul, Birthe K; Rigolot, Cyrille; Ritzema, Randall S; Rodriguez, Daniel; van Asten, Piet J A; van Wijk, Mark T

2016-01-12

We calculated a simple indicator of food availability using data from 93 sites in 17 countries across contrasted agroecologies in sub-Saharan Africa (>13,000 farm households) and analyzed the drivers of variations in food availability. Crop production was the major source of energy, contributing 60% of food availability. The off-farm income contribution to food availability ranged from 12% for households without enough food available (18% of the total sample) to 27% for the 58% of households with sufficient food available. Using only three explanatory variables (household size, number of livestock, and land area), we were able to predict correctly the agricultural determined status of food availability for 72% of the households, but the relationships were strongly influenced by the degree of market access. Our analyses suggest that targeting poverty through improving market access and off-farm opportunities is a better strategy to increase food security than focusing on agricultural production and closing yield gaps. This calls for multisectoral policy harmonization, incentives, and diversification of employment sources rather than a singular focus on agricultural development. Recognizing and understanding diversity among smallholder farm households in sub-Saharan Africa is key for the design of policies that aim to improve food security.

A Cross-Sectional Study of Pesticide Use and Knowledge of Smallholder Potato Farmers in Uganda

PubMed Central

Okonya, Joshua Sikhu; Kroschel, Jürgen

2015-01-01

In response to increased pest and disease problems, potato farmers use pesticides, which could raise environmental and health concerns. This study sought to promote proper and safe pesticide-handling practices by providing data needed to guide pesticide regulation policy and training for extension staff and farmers. A household survey was conducted in three major potato-growing agroecological zones of Uganda. Two hundred and four potato farmers were interviewed about the type and source of pesticides they use in potato cultivation, the frequency of applications, the use of protective clothing, and cases of pesticide poisoning. The types of pesticides used in potato were fungicides (72%), insecticides (62%), and herbicides (3%). Overall, use of personal protective equipment was low, that is, gumboots (73%), gloves (7%), face masks (16%), and long sleeve shirts (42%). Forty-three percent of farmers who applied pesticides reported having experienced skin itching, 25% skin burning sensation, 43% coughing, 60% a runny nose, 27% teary eyes, and 42% dizziness. An IPM approach involving only moderately to slightly hazardous pesticides when pest and disease incidence has reached economic injury levels and by considering all safety measures during application and storage would be environmentally recommendable and result in reduced health risks. PMID:26581164

Measuring the economic impact of climate change on major South African field crops: a Ricardian approach

NASA Astrophysics Data System (ADS)

Gbetibouo, G. A.; Hassan, R. M.

2005-07-01

This study employed a Ricardian model to measure the impact of climate change on South Africa's field crops and analysed potential future impacts of further changes in the climate. A regression of farm net revenue on climate, soil and other socio-economic variables was conducted to capture farmer-adapted responses to climate variations. The analysis was based on agricultural data for seven field crops (maize, wheat, sorghum, sugarcane, groundnut, sunflower and soybean), climate and edaphic data across 300 districts in South Africa. Results indicate that production of field crops was sensitive to marginal changes in temperature as compared to changes in precipitation. Temperature rise positively affects net revenue whereas the effect of reduction in rainfall is negative. The study also highlights the importance of season and location in dealing with climate change showing that the spatial distribution of climate change impact and consequently needed adaptations will not be uniform across the different agro-ecological regions of South Africa. Results of simulations of climate change scenarios indicate many impacts that would induce (or require) very distinct shifts in farming practices and patterns in different regions. Those include major shifts in crop calendars and growing seasons, switching between crops to the possibility of complete disappearance of some field crops from some region.

Population structure of elephant foot yams (Amorphophallus paeoniifolius (Dennst.) Nicolson) in Asia

PubMed Central

Misra, Raj Shekhar; Boonkorkaew, Patchareeya; Thanomchit, Kanokwan

2017-01-01

The corms and leaves of elephant foot yams (Amorphophallus paeoniifolius (Dennst.) Nicolson) are important foods in the local diet in many Asian regions. The crop has high productivity and wide agroecological adaptation and exhibits suitability for the agroforestry system. Although the plant is assumed to reproduce via panmixia, a comprehensive study on the genetic background across regions to enhance wider consumer palatability is still lacking. Here, ten informative microsatellites were analyzed in 29 populations across regions in India, Indonesia and Thailand to understand the genetic diversity, population structure and distribution to improve breeding and conservation programs. The genetic diversity was high among and within regions. Some populations exhibited excess heterozygosity and bottlenecking. Pairwise FST indicated very high genetic differentiation across regions (FST = 0.274), and the Asian population was unlikely to be panmictic. Phylogenetic tree construction grouped the populations according to country of origin with the exception of the Medan population from Indonesia. The current gene flow was apparent within the regions but was restricted among the regions. The present study revealed that Indonesia and Thailand populations could be alternative centers of the gene pool, together with India. Consequently, regional action should be incorporated in genetic conservation and breeding efforts to develop new varieties with global acceptance. PMID:28658282

Seroprevalence of Toxoplasma gondii infection in goats and sheep in Zimbabwe.

PubMed

Hove, T; Lind, P; Mukaratirwa, S

2005-12-01

Seroprevalence rates of Toxoplasma gondii anti-antibodies in adult goats and sheep from different parts of Zimbabwe were determined. A total of 225 (67.9%) of the 335 serum samples tested were positive for anti-T. gondii IgG antibodies with the indirect fluorescent antibody test. There were differences in antibody seroprevalences among communal land goats from the different agro-ecological zones (Natural regions llb and III: 80 and 96.7%, respectively; Natural region IV: 65.9%; Natural region V: 45%; and Natural region III had a significantly higher seroprevalence than IV and V. The highest seroprevalences found in Natural regions II b and Ill are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate in sheep from a large commercial farm (10%) was significantly lower than that of sheep reared under the communal grazing system (80%). Overall, significantly higher proportions of seropositive animals had antibody titres of 1:50 (34.2% of 225) and 1:100 (44% of 225) as compared to the 9.8% and 12% with antibody titres of 1:200 and > or =1:400, respectively.

The buzz about bees and poverty alleviation: Identifying drivers and barriers of beekeeping in sub-Saharan Africa.

PubMed

Amulen, Deborah Ruth; D'Haese, Marijke; Ahikiriza, Elizabeth; Agea, Jacob Godfrey; Jacobs, Frans J; de Graaf, Dirk C; Smagghe, Guy; Cross, Paul

2017-01-01

The potential of beekeeping to mitigate the exposure of rural sub-Sahara African farmers to economic stochasticity has been widely promoted by an array of development agencies. Robust outcome indicators of the success of beekeeping to improve household well-being are unfortunately lacking. This study aimed to identify the key drivers and barriers of beekeeping adoption at the household level, and quantified the associated income contribution in three agro-ecological zones in Uganda. Beekeepers were generally the most economically disadvantaged people in the study areas and tended to adopt beekeeping following contact with non-government organisations and access to training. Whilst incomes were not statistically lower than their non-beekeeping counterparts; their mean household well-being scores were significantly lower than non-beekeeping households. The inability of beekeeping to significantly improve well-being status can in part be attributed to a lack of both training in bee husbandry and protective equipment provision such as suits, gloves and smokers. These are critical tools for beekeepers as they provide the necessary confidence to manage honey bees. Rather than focussing solely on the socio-economic conditions of farmers to effectively adopt beekeeping, future research should also attempt to evaluate the effectiveness of development agencies' provision to the beekeeping sector.

The buzz about bees and poverty alleviation: Identifying drivers and barriers of beekeeping in sub-Saharan Africa

PubMed Central

D’Haese, Marijke; Ahikiriza, Elizabeth; Agea, Jacob Godfrey; Jacobs, Frans J.; de Graaf, Dirk C.; Smagghe, Guy; Cross, Paul

2017-01-01

The potential of beekeeping to mitigate the exposure of rural sub-Sahara African farmers to economic stochasticity has been widely promoted by an array of development agencies. Robust outcome indicators of the success of beekeeping to improve household well-being are unfortunately lacking. This study aimed to identify the key drivers and barriers of beekeeping adoption at the household level, and quantified the associated income contribution in three agro-ecological zones in Uganda. Beekeepers were generally the most economically disadvantaged people in the study areas and tended to adopt beekeeping following contact with non-government organisations and access to training. Whilst incomes were not statistically lower than their non-beekeeping counterparts; their mean household well-being scores were significantly lower than non-beekeeping households. The inability of beekeeping to significantly improve well-being status can in part be attributed to a lack of both training in bee husbandry and protective equipment provision such as suits, gloves and smokers. These are critical tools for beekeepers as they provide the necessary confidence to manage honey bees. Rather than focussing solely on the socio-economic conditions of farmers to effectively adopt beekeeping, future research should also attempt to evaluate the effectiveness of development agencies’ provision to the beekeeping sector. PMID:28235072

How agro-ecological research helps to address food security issues under new IPM and pesticide reduction policies for global crop production systems.

PubMed

E Birch, A Nicholas; Begg, Graham S; Squire, Geoffrey R

2011-06-01

Drivers behind food security and crop protection issues are discussed in relation to food losses caused by pests. Pests globally consume food estimated to feed an additional one billion people. Key drivers include rapid human population increase, climate change, loss of beneficial on-farm biodiversity, reduction in per capita cropped land, water shortages, and EU pesticide withdrawals under policies relating to 91/414 EEC. IPM (Integrated Pest Management) will be compulsory for all EU agriculture by 2014 and is also being widely adopted globally. IPM offers a 'toolbox' of complementary crop- and region-specific crop protection solutions to address these rising pressures. IPM aims for more sustainable solutions by using complementary technologies. The applied research challenge now is to reduce selection pressure on single solution strategies, by creating additive/synergistic interactions between IPM components. IPM is compatible with organic, conventional, and GM cropping systems and is flexible, allowing regional fine-tuning. It reduces pests below economic thresholds utilizing key 'ecological services', particularly biocontrol. A recent global review demonstrates that IPM can reduce pesticide use and increase yields of most of the major crops studied. Landscape scale 'ecological engineering', together with genetic improvement of new crop varieties, will enhance the durability of pest-resistant cultivars (conventional and GM). IPM will also promote compatibility with semiochemicals, biopesticides, precision pest monitoring tools, and rapid diagnostics. These combined strategies are urgently needed and are best achieved via multi-disciplinary research, including complex spatio-temporal modelling at farm and landscape scales. Integrative and synergistic use of existing and new IPM technologies will help meet future food production needs more sustainably in developed and developing countries, in an era of reduced pesticide availability. Current IPM research gaps are identified and discussed.

Online decision support based on modeling with the aim of increased irrigation efficiency

NASA Astrophysics Data System (ADS)

Dövényi-Nagy, Tamás; Bakó, Károly; Molnár, Krisztina; Rácz, Csaba; Vasvári, Gyula; Nagy, János; Dobos, Attila

2015-04-01

The significant changes in the structure of ownership and control of irrigation infrastructure in the past decades resultted in the decrease of total irrigable and irrigated area (Szilárd, 1999). In this paper, the development of a model-based online service is described whose aim is to aid reasonable irrigation practice and increase water use efficiency. In order to establish a scientific background for irrigation, an agrometeorological station network has been built up by the Agrometeorological and Agroecological Monitoring Centre. A website has been launched in order to provide direct access for local agricultural producers to both the measured weather parameters and results of model based calculations. The public site provides information for general use, registered partners get a handy model based toolkit for decision support at the plot level concerning irrigation, plant protection or frost forecast. The agrometeorological reference station network was established in the recent years by the Agrometeorological and Agroecological Monitoring Centre and is distributed to cover most of the irrigated cropland areas of Hungary. From the spatial aspect, the stations have been deployed mainly in Eastern Hungary with concentrated irrigation infrastructure. The meteorological stations' locations have been carefully chosen to represent their environment in terms of soil, climatic and topographic factors, thereby assuring relevant and up-to-date input data for the models. The measured parameters range from classic meteorological data (air temperature, relative humidity, solar irradiation, wind speed etc.) to specific data which are not available from other services in the region, such as soil temperature, soil water content in multiple depths and leaf wetness. In addition to the basic grid of reference stations, specific stations under irrigated conditions have been deployed to calibrate and validate the models. A specific modeling framework (MetAgro) has been developed

What are the effects of Agro-Ecological Zones and land use region boundaries on land resource projection using the Global Change Assessment Model?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Vittorio, Alan V.; Kyle, Page; Collins, William D.

Understanding the potential impacts of climate change is complicated by mismatched spatial representations between gridded Earth System Models (ESMs) and Integrated Assessment Models (IAMs), whose regions are typically larger and defined by geopolitical and biophysical criteria. In this study we address uncertainty stemming from the construction of land use regions in an IAM, the Global Change Assessment Model (GCAM), whose regions are currently based on historical climatic conditions (1961-1990). We re-define GCAM’s regions according to projected climatic conditions (2070-2099), and investigate how this changes model outcomes for land use, agriculture, and forestry. By 2100, we find potentially large differences inmore » projected global and regional area of biomass energy crops, fodder crops, harvested forest, and intensive pasture. These land area differences correspond with changes in agricultural commodity prices and production. These results have broader implications for understanding policy scenarios and potential impacts, and for evaluating and comparing IAM and ESM simulations.« less

Agropastoral Mobility and Rangelands Multiple Uses in the Miombo Frontier Ecozone of Tabora Region, Western Tanzania

PubMed Central

2017-01-01

This study aimed to examine the argument of environmental resource-use conflict as the primary cause of crop farmers and agropastoralists conflicts in Tabora Region, Tanzania. It explored the multiple interdependent phenomena that affect livelihoods relationships between crop farmers and agropastoralists and the nature of their continuing conflicts over the ecozonal resources. A primary dataset of the two groups' conflicts was used. An ex post facto and multistage sampling design was adopted. A total of 252 respondents were interviewed in three separate villages drawn from agroecological zones fringing the miombo woodland where such tensions are high. Data were analyzed using logistic regression. Results indicate that education (β = −1.215, .297; p = .050), household size (β = .958, 2.607; p = .017), herd size (β = 4.276, 7.197; p = 0.001), farm size (β = −1.734, .048; p = .176), the police (β = −.912, 4.582; p = .043), and village leaders (β = −.122, .885; p = .012) were the most potent predictors of causes of conflicts. The study found no support for demographic variables, like age, sex, marital status, income, duration of residence, and distance to resource base. The study recommends population growth control and strengthening of local institutions and recommends local communities to sustain management of natural resources base in the area. PMID:29201492

Assessment of average exposure to organochlorine pesticides in southern Togo from water, maize (Zea mays) and cowpea (Vigna unguiculata).

PubMed

Mawussi, G; Sanda, K; Merlina, G; Pinelli, E

2009-03-01

Drinking water, cowpea and maize grains were sampled in some potentially exposed agro-ecological areas in Togo and analysed for their contamination by some common organochlorine pesticides. A total of 19 organochlorine pesticides were investigated in ten subsamples of maize, ten subsamples of cowpea and nine subsamples of drinking water. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatography-mass spectrometry (GC/MS). Estimated daily intakes (EDIs) of pesticides were also determined. Pesticides residues in drinking water (0.04-0.40 microg l(-1)) were higher than the maximum residue limit (MRL) (0.03 microg l(-1)) set by the World Health Organization (WHO). Dieldrin, endrin, heptachlor epoxide and endosulfan levels (13.16-98.79 microg kg(-1)) in cowpea grains exceeded MRLs applied in France (10-50 microg kg(-1)). Contaminants' levels in maize grains (0.53-65.70 microg kg(-1)) were below the MRLs (20-100 microg kg(-1)) set by the Food and Agriculture Organization (FAO) and the WHO. EDIs of the tested pesticides ranged from 0.02% to 162.07% of the acceptable daily intakes (ADIs). Population exposure levels of dieldrin and heptachlor epoxide were higher than the FAO/WHO standards. A comprehensive national monitoring programme on organochlorine pesticides should be undertaken to include such other relevant sources like meat, fish, eggs and milk.

Feral rice from introgression of weedy rice genes into transgenic herbicide-resistant hybrid-rice progeny.

PubMed

Zhang, Jingxu; Kang, Ye; Valverde, Bernal E; Dai, Weimin; Song, Xiaoling; Qiang, Sheng

2018-06-05

Pollen-mediated herbicide-resistance transgene flow occurs bidirectionally between transgenic cultivated rice and weedy rice. The potential risk of weedy traits introgressing into hybrid rice is underestimated and poorly understood. Two of each glufosinate-resistant transgenic rice varieties and hybrid rice (F1) and their succeeding generations (F2-F4) were planted for three years in weedy-rice-free field plots adjacent to experimental weedy-rice fields. Weedy-rice-like (feral) plants, both glufosinate-resistant and with red-pericarp seed, were initially found only among the F3 generations of the two glufosinate-resistant transgenic hybrid rice. The composite fitness (an index based on eight productivity and weediness traits) of the feral progeny was significantly higher than that of glufosinate-resistant transgenic hybrid rice (the original female parent of feral progeny) under common monoculture garden conditions. Hybrid rice progeny segregated into individuals of variable height and extended flowering. Hybrid rice F2 generations had higher outcrossing rates by pollen reception (0.96%-1.65%) than their progenitors (0.07%-0.98%). Herbicide-resistant weedy rice can rapidly arise by pollen-mediated gene flow from weedy to transgenic hybrid rice. Their segregating pollen-receptive progeny pose greater agro-ecological risk than transgenic varieties. The safety assessment and management regulations for transgenic hybrid rice should take into account the risk of bidirectional gene flow.

Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards

PubMed Central

Jedlicka, Julie A.; Greenberg, Russell; Letourneau, Deborah K.

2011-01-01

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services. PMID:22096555

Risk Distribution of Human Infections with Avian Influenza H7N9 and H5N1 virus in China

PubMed Central

Li, Xin-Lou; Yang, Yang; Sun, Ye; Chen, Wan-Jun; Sun, Ruo-Xi; Liu, Kun; Ma, Mai-Juan; Liang, Song; Yao, Hong-Wu; Gray, Gregory C.; Fang, Li-Qun; Cao, Wu-Chun

2015-01-01

It has been documented that the epidemiological characteristics of human infections with H7N9 differ significantly between H5N1. However, potential factors that may explain the different spatial distributions remain unexplored. We use boosted regression tree (BRT) models to explore the association of agro-ecological, environmental and meteorological variables with the occurrence of human cases of H7N9 and H5N1, and map the probabilities of occurrence of human cases. Live poultry markets, density of human, coverage of built-up land, relative humidity and precipitation were significant predictors for both. In addition, density of poultry, coverage of shrub and temperature played important roles for human H7N9 infection, whereas human H5N1 infection was associated with coverage of forest and water body. Based on the risks and distribution of ecological characteristics which may facilitate the circulation of the two viruses, we found Yangtze River Delta and Pearl River Delta, along with a few spots on the southeast coastline, to be the high risk areas for H7N9 and H5N1. Additional, H5N1 risk spots were identified in eastern Sichuan and southern Yunnan Provinces. Surveillance of the two viruses needs to be enhanced in these high risk areas to reduce the risk of future epidemics of avian influenza in China. PMID:26691585

Response to growth and production of green beans (Vigna radiata L.) in various cropping spots and fertilizer provision of layer chickens

NASA Astrophysics Data System (ADS)

Sitinjak, L.; Purba, E.

2018-02-01

Agroecology affecting plant growth can be influenced by factors such as plant spacing and growing media. This study aims to determine the effect of plant spacing and chicken manure on the growth and production of green beans. Plants were planted at three spacing plants (20cm x 20cm, 20cm x 30cm, and 20cm x 40cm) while manure was applied at 3.75, 7.50 and 11.25 ton/ha and without manure as a comparison. The treatments were arranged in a randomized complete block design with three replicates. The result showed that the highest diameter of stem was resulted from the application of 11.25 ton/ha of manure combined with the planting space of 20cm x 40 cm. Similarly, the highest number of branch of stem we found at the plot where chicken manure of 11.25 ton/ha with planting space of 20cm x 30cm. The highest production (4,944.4 kg/ha) was resulted from 7.50 ton/ha manure with combined with planting space of 20cm x 40cm. There was an interaction between the treatment of manure and the planting space of soybean. The production of green bean was 24% higher in 7.50 ton/ha manure combined with 20cm x 40cm planting space compared to no manure (control).

Population genetic analysis and trichothecene profiling of Fusarium graminearum from wheat in Uruguay.

PubMed

Pan, D; Mionetto, A; Calero, N; Reynoso, M M; Torres, A; Bettucci, L

2016-03-11

Fusarium graminearum sensu stricto (F. graminearum s.s.) is the major causal agent of Fusarium head blight of wheat worldwide, and contaminates grains with trichothecene mycotoxins that cause serious threats to food safety and animal health. An important aspect of managing this pathogen and reducing mycotoxin contamination of wheat is knowledge regarding its population genetics. Therefore, isolates of F. graminearum s.s. from the major wheat-growing region of Uruguay were analyzed by amplified fragment length polymorphism assays, PCR genotyping, and chemical analysis of trichothecene production. Of the 102 isolates identified as having the 15-ADON genotype via PCR genotyping, all were DON producers, but only 41 strains were also 15-ADON producers, as determined by chemical analysis. The populations were genotypically diverse but genetically similar, with significant genetic exchange occurring between them. Analysis of molecular variance indicated that most of the genetic variability resulted from differences between isolates within populations. Multilocus linkage disequilibrium analysis suggested that the isolates had a panmictic population genetic structure and that there is significant recombination occurs in F. graminearum s.s. In conclusion, tour findings provide the first detailed description of the genetic structure and trichothecene production of populations of F. graminearum s.s. from Uruguay, and expands our understanding of the agroecology of F. graminearum and of the correlation between genotypes and trichothecene chemotypes.

Food and nutritional security requires adequate protein as well as energy, delivered from whole-year crop production.

PubMed

Coles, Graeme D; Wratten, Stephen D; Porter, John R

2016-01-01

Human food security requires the production of sufficient quantities of both high-quality protein and dietary energy. In a series of case-studies from New Zealand, we show that while production of food ingredients from crops on arable land can meet human dietary energy requirements effectively, requirements for high-quality protein are met more efficiently by animal production from such land. We present a model that can be used to assess dietary energy and quality-corrected protein production from various crop and crop/animal production systems, and demonstrate its utility. We extend our analysis with an accompanying economic analysis of commercially-available, pre-prepared or simply-cooked foods that can be produced from our case-study crop and animal products. We calculate the per-person, per-day cost of both quality-corrected protein and dietary energy as provided in the processed foods. We conclude that mixed dairy/cropping systems provide the greatest quantity of high-quality protein per unit price to the consumer, have the highest food energy production and can support the dietary requirements of the highest number of people, when assessed as all-year-round production systems. Global food and nutritional security will largely be an outcome of national or regional agroeconomies addressing their own food needs. We hope that our model will be used for similar analyses of food production systems in other countries, agroecological zones and economies.

Comparison of Fungal Community in Black Pepper-Vanilla and Vanilla Monoculture Systems Associated with Vanilla Fusarium Wilt Disease.

PubMed

Xiong, Wu; Zhao, Qingyun; Xue, Chao; Xun, Weibing; Zhao, Jun; Wu, Huasong; Li, Rong; Shen, Qirong

2016-01-01

Long-term vanilla monocropping often results in the occurrence of vanilla Fusarium wilt disease, seriously affecting its production all over the world. In the present study, vanilla exhibited significantly less Fusarium wilt disease in the soil of a long-term continuously cropped black pepper orchard. The entire fungal communities of bulk and rhizosphere soils between the black pepper-vanilla system (i.e., vanilla cropped in the soil of a continuously cropped black pepper orchard) and vanilla monoculture system were compared through the deep pyrosequencing. The results showed that the black pepper-vanilla system revealed a significantly higher fungal diversity than the vanilla monoculture system in both bulk and rhizosphere soils. The UniFrac-weighted PCoA analysis revealed significant differences in bulk soil fungal community structures between the two cropping systems, and fungal community structures were seriously affected by the vanilla root system. In summary, the black pepper-vanilla system harbored a lower abundance of Fusarium oxysporum in the vanilla rhizosphere soil and increased the putatively plant-beneficial fungal groups such as Trichoderma and Penicillium genus, which could explain the healthy growth of vanilla in the soil of the long-term continuously cropped black pepper field. Thus, cropping vanilla in the soil of continuously cropped black pepper fields for maintaining the vanilla industry is executable and meaningful as an agro-ecological system.

Comparison of Fungal Community in Black Pepper-Vanilla and Vanilla Monoculture Systems Associated with Vanilla Fusarium Wilt Disease

PubMed Central

Xiong, Wu; Zhao, Qingyun; Xue, Chao; Xun, Weibing; Zhao, Jun; Wu, Huasong; Li, Rong; Shen, Qirong

2016-01-01

Long-term vanilla monocropping often results in the occurrence of vanilla Fusarium wilt disease, seriously affecting its production all over the world. In the present study, vanilla exhibited significantly less Fusarium wilt disease in the soil of a long-term continuously cropped black pepper orchard. The entire fungal communities of bulk and rhizosphere soils between the black pepper-vanilla system (i.e., vanilla cropped in the soil of a continuously cropped black pepper orchard) and vanilla monoculture system were compared through the deep pyrosequencing. The results showed that the black pepper-vanilla system revealed a significantly higher fungal diversity than the vanilla monoculture system in both bulk and rhizosphere soils. The UniFrac-weighted PCoA analysis revealed significant differences in bulk soil fungal community structures between the two cropping systems, and fungal community structures were seriously affected by the vanilla root system. In summary, the black pepper-vanilla system harbored a lower abundance of Fusarium oxysporum in the vanilla rhizosphere soil and increased the putatively plant-beneficial fungal groups such as Trichoderma and Penicillium genus, which could explain the healthy growth of vanilla in the soil of the long-term continuously cropped black pepper field. Thus, cropping vanilla in the soil of continuously cropped black pepper fields for maintaining the vanilla industry is executable and meaningful as an agro-ecological system. PMID:26903995

Total Economic Value of Wetlands Products and Services in Uganda

PubMed Central

Kakuru, Willy; Turyahabwe, Nelson; Mugisha, Johnny

2013-01-01

Wetlands provide food and non-food products that contribute to income and food security in Uganda. This study determined the economic value of wetland resources and their contribution to food security in the three agroecological zones of Uganda. The values of wetland resources were estimated using primary and secondary data. Market price, Productivity, and Contingent valuation methods were used to estimate the value of wetland resources. The per capita value of fish was approximately US$ 0.49 person−1. Fish spawning was valued at approximately US$ 363,815 year−1, livestock pastures at US$ 4.24 million, domestic water use at US$ 34 million year−1, and the gross annual value added by wetlands to milk production at US$ 1.22 million. Flood control was valued at approximately US$ 1,702,934,880 hectare−1 year−1 and water regulation and recharge at US$ 7,056,360 hectare−1 year−1. Through provision of grass for mulching, wetlands were estimated to contribute to US$ 8.65 million annually. The annual contribution of non-use values was estimated in the range of US$ 7.1 million for water recharge and regulation and to US$ 1.7 billion for flood control. Thus, resource investment for wetlands conservation is economically justified to create incentives for continued benefits. PMID:24163614

Development of a fermented quinoa-based beverage.

PubMed

Ludena Urquizo, Fanny Emma; García Torres, Silvia Melissa; Tolonen, Tiina; Jaakkola, Mari; Pena-Niebuhr, Maria Grazzia; von Wright, Atte; Repo-Carrasco-Valencia, Ritva; Korhonen, Hannu; Plumed-Ferrer, Carme

2017-05-01

Quinoa is a crop that originated from the Andes. It has high nutritional value, outstanding agro-ecological adaptability, and low water requirements. Quinoa is an excellent crop alternative to help overcome food shortages, and it can also have a role in the prevention of developed world lifestyle diseases, such as type-2 diabetes, cardiovascular diseases, osteoporosis, inflammatory and autoimmune diseases, etc. In order to expand the traditional uses of quinoa and to provide new, healthier and more nutritious food products, a fermented quinoa-based beverage was developed. Two quinoa varieties (Rosada de Huancayo and Pasankalla) were studied. The fermentation process, viscosity, acidity, and metabolic activity during the preparation and storage of the drink were monitored, as well as the preliminary organoleptic acceptability of the product. The drink had viable and stable microbiota during the storage time and the fermentation proved to be mostly homolactic. Both quinoa varieties were suitable as base for fermented products; Pasankalla, however, has the advantage due to higher protein content, lower saponin concentration, and lower loss of viscosity during the fermentation process. These results suggest that the differences between quinoa varieties may have substantial effects on food processes and on the properties of final products. This is a factor that should be taken into account when planning novel products based on this grain.

Soil response to biodynamic farming practices in estevia -Stevia Rebaudiana- (Extremadura, Spain)

NASA Astrophysics Data System (ADS)

Labrador, Juana; Colmenares, Ricardo; Sánchez, Eduardo; Creus, Juan; García, Nieves; Blázquez, Jaime; Moreno, Marta M.

2014-05-01

The first results of the evolution of an organic-biodynamic cultivation of stevia (Stevia rebaudiana) in Extremadura (Spain) are shown here. The organic-biodynamic approach permits experimentally for a more holistic view of the crop development process what means the understanding and quantification of its evolution at different scales. The research methodology applied includes not only quantitative individual parameters of the crop development but also global parameters which make a contribution of very relevant information concerning unbalances between growth and differentiation processes, as well as other aspects linked to the product intrinsic quality. The crop cultivation has been done over a plot of 2.5 has, on acid soils (pH 5.18) and very poor organic matter content (0.5 %). On this first year of cultivation two cuts were given to the plant with an average total yield of 4,500 kg/ha without any supply of solid organic matter, only with the application of the biodynamic preparations. So far results regarding soil improvement and crop productivity, taking into consideration the practices used, let us introduce this pioneer crop in Extremadura, not only as an alternative crop to the current tobacco crop in this area, but also as a development resource for the rural environment of this region. Key words: Agroecology, Organic Biodynamic Agriculture, Stevia Rebaudiana

Seroepidemiology of Brucella abortus infection in bovids in Sri Lanka.

PubMed

Silva, I; Dangolla, A; Kulachelvy, K

2000-07-03

From 1992 to 1995, 0.15% (n=3916) of the bovids (cattle and buffalo) in Sri Lanka were sampled, using a multi-stage sampling procedure. Serum antibodies for Brucella abortus were detected using the indirect enzyme-linked immunosorbent assay (ELISA). The age, the agroecological zone and the management system practiced in the farms of the sampled bovids were studied as risk factors for seropositivity. The overall seroprevalence of brucellosis in cattle was 4.7% (n=3076) and 4.2% in buffaloes (n=840). Bovids that were over 3 years of age, from the dry zone (annual rainfall 20-35 in.), and reared under an extensive management system had higher odds of being seropositive. Bovids from the dry zone were at approximately six times higher odds of being seropositive even after controlling for the possible effects of age and management system. Approximately 75% of the seropositive males were from the dry zone. Most bovids (84%) from the dry zone in this study were reared under an extensive management system (free grazing) which allows unrestricted contact between animals. These factors may have contributed to the spread of brucellosis in bovids in the dry zone. This infection might be an important cause of abortion in bovids in Sri Lanka. However, there is also evidence of other causes for abortion, repeat breeding and retained placenta.

Testing efficacy of monthly forecast application in agrometeorology: Winter wheat phenology dynamic

NASA Astrophysics Data System (ADS)

Lalic, B.; Jankovic, D.; Dekic, Lj; Eitzinger, J.; Firanj Sremac, A.

2017-02-01

Use of monthly weather forecast as input meteorological data for agrometeorological forecasting, crop modelling and plant protection can foster promising applications in agricultural production. Operational use of monthly or seasonal weather forecast can help farmers to optimize field operations (fertilizing, irrigation) and protection measures against plant diseases and pests by taking full advantage of monthly forecast information in predicting plant development, pest and disease risks and yield potentials few weeks in advance. It can help producers to obtain stable or higher yield with the same inputs and to minimise losses caused by weather. In Central and South-Eastern Europe ongoing climate change lead to shifts of crops phenology dynamics (i.e. in Serbia 4-8 weeks earlier in 2016 than in previous years) and brings this subject in the front of agronomy science and practice. Objective of this study is to test efficacy of monthly forecast in predicting phenology dynamics of different winter wheat varieties, using phenological model developed by Forecasting and Warning Service of Serbia in plant protection. For that purpose, historical monthly forecast for four months (March 1, 2005 - June 30, 2005) was assimilated from ECMWF MARS archive for 50 ensemble members and control run. Impact of different agroecological conditions is tested by using observed and forecasted data for two locations - Rimski Sancevi (Serbia) and Groß-Enzersdorf (Austria).

Mainstreaming conservation agriculture in Malawi: Knowledge gaps and institutional barriers.

PubMed

Dougill, Andrew J; Whitfield, Stephen; Stringer, Lindsay C; Vincent, Katharine; Wood, Benjamin T; Chinseu, Edna L; Steward, Peter; Mkwambisi, David D

2017-06-15

Conservation agriculture (CA) practices of reduced soil tillage, permanent organic soil coverage and intercropping/crop rotation, are being advocated globally, based on perceived benefits for crop yields, soil carbon storage, weed suppression, reduced soil erosion and improved soil water retention. However, some have questioned their efficacy due to uncertainty around the performance and trade-offs associated with CA practices, and their compatibility with the diverse livelihood strategies and varied agro-ecological conditions across African smallholder systems. This paper assesses the role of key institutions in Malawi in shaping pathways towards more sustainable land management based on CA by outlining their impact on national policy-making and the design and implementation of agricultural development projects. It draws on interviews at national, district and project levels and a multi-stakeholder workshop that mapped the institutional landscape of decision-making for agricultural land management practices. Findings identify knowledge gaps and institutional barriers that influence land management decision-making and constrain CA uptake. We use our findings to set out an integrated roadmap of research needs and policy options aimed at supporting CA as a route to enhanced sustainable land management in Malawi. Findings offer lessons that can inform design, planning and implementation of CA projects, and identify the multi-level institutional support structures required for mainstreaming sustainable land management in sub-Saharan Africa. Copyright © 2016 Elsevier Ltd. All rights reserved.

Avian conservation practices strengthen ecosystem services in California vineyards.

PubMed

Jedlicka, Julie A; Greenberg, Russell; Letourneau, Deborah K

2011-01-01

Insectivorous Western Bluebirds (Sialia mexicana) occupy vineyard nest boxes established by California winegrape growers who want to encourage avian conservation. Experimentally, the provision of available nest sites serves as an alternative to exclosure methods for isolating the potential ecosystem services provided by foraging birds. We compared the abundance and species richness of avian foragers and removal rates of sentinel prey in treatments with songbird nest boxes and controls without nest boxes. The average species richness of avian insectivores increased by over 50 percent compared to controls. Insectivorous bird density nearly quadrupled, primarily due to a tenfold increase in Western Bluebird abundance. In contrast, there was no significant difference in the abundance of omnivorous or granivorous bird species some of which opportunistically forage on grapes. In a sentinel prey experiment, 2.4 times more live beet armyworms (Spodoptera exigua) were removed in the nest box treatment than in the control. As an estimate of the maximum foraging services provided by insectivorous birds, we found that larval removal rates measured immediately below occupied boxes averaged 3.5 times greater than in the control. Consequently the presence of Western Bluebirds in vineyard nest boxes strengthened ecosystem services to winegrape growers, illustrating a benefit of agroecological conservation practices. Predator addition and sentinel prey experiments lack some disadvantages of predator exclusion experiments and were robust methodologies for detecting ecosystem services.

Enhancing Legume Ecosystem Services through an Understanding of Plant-Pollinator Interplay.

PubMed

Suso, María J; Bebeli, Penelope J; Christmann, Stefanie; Mateus, Célia; Negri, Valeria; Pinheiro de Carvalho, Miguel A A; Torricelli, Renzo; Veloso, Maria M

2016-01-01

Legumes are bee-pollinated, but to a different extent. The importance of the plant-pollinator interplay (PPI), in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: (1) optimal productivity, based on an efficient use of pollinators, and (2) biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the "pest control service" and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: (a) Farming with Alternative Pollinators and (b) Crop Design System.

Environmental assessment of bioenergy technologies application in Russia, including their impact on the balance of greenhouse gases

NASA Astrophysics Data System (ADS)

Andreeva, Irina; Vasenev, Ivan

2017-04-01

In recent years, Russia adopted a policy towards increasing of the share of renewable energy in total amount of used energy, albeit with some delay comparing to the EU countries and the USA. It was expected that the use of biofuels over time will reduce significantly the dependency of Russian economy on fossil fuels, increase its competitiveness, and increase Russian contribution to the prevention of global climate changes. Russia has significant bio-energy potential and resources which are characterized by great diversity due to the large extent of the territory, which require systematic studies and environmental assessment of used bio-energy technologies. Results of research carried at the Laboratory of agroecological monitoring, modeling and prediction of ecosystems RSAU-MTAA demonstrated significant differences in the assessment of the environmental, economic and social effects of biofuel production and use, depending on the species of bio-energy crops, regional soil-ecological and agro-climatic characteristics, applied farming systems and production processes. The total area of temporarily unused and fallow land, which could be allocated to the active agricultural use in Russia, according to various estimates, ranges from 20 to 33 million hectares, which removes the problem, typical of most European countries, of adverse agro-ecological changes in land use connected with the expansion of bio-energy crops cultivation. However, the expansion of biofuel production through the use of fallow land and conversion of natural lands has as a consequence the problem of greenhouse gas emissions due to land use changes, which, according to FAO, could be even higher than CO2 emission from fossil fuels for some of bio-energy raw materials and production systems. Assessment of the total impacts of biofuels on greenhouse gas emissions in the Russian conditions should be based on regionally adapted calculations of flows throughout the entire life cycle of production, taking

Greenhouse gas emissions from rice, peanut and millet farms in peninsular India: Effects of water and nitrogen management

NASA Astrophysics Data System (ADS)

Kritee, K.; Tiwari, R.; Nair, D.; Loecke, T. D.; Adhya, T. K.; Rudek, J.; Ahuja, R.; Hamburg, S.

2013-12-01

At Environmental Defense Fund (EDF), we recognize that any intervention to mitigate greenhouse gas (GHG) emissions should meet the interests of small scale farmers and low-carbon farming (LCF) is an integral component of our work on international climate. As a part of our Emissions Measurement and Methodology Development (EMD) Project, a joint undertaking with Indian NGO partners of the Fair Climate Network (FCN), five GHG measurement laboratories were set up across three states in peninsular (south) India. These labs represent different agro-ecological zones within the dryland agriculture belt in South India for which no reliable datasets on GHG emission have been available. Our approach for collecting gas samples was based on the Gracenet protocol. Sampling for nitrous oxide and methane emissions were made on approximately 50% of the total number of days in a growing season and once a week during fallow periods. In order to capture the peak emissions of nitrous oxide, samples were collected for 3-4 consecutive days after critical events like tillage, weeding, fertilization, and rainfall/irrigation. The research team collected field data at the time of sampling (temperature of the soil, water and air; and water levels). We also recorded parameters (e.g. water, fertilizer, labor and energy use; and yields) which were necessary for calculating farm profitability. Our data from 2012-2013 suggest that, for peninsular India, low-carbon rice cultivation techniques offer very large emission reduction potential (2-5 metric tons CO2e per acre per year), with smaller reductions from peanut and millet (0.15-0.5 metric ton CO2e per acre per season). The Tier 1 IPCC emissions factors 1) grossly underestimate both the amount of nitrous oxide emission from conventional rice cultivation practices, and the extent to which it can be reduced through better fertilizer management and 2) overestimate the methane emission reduction possible due to water management for rice paddies by a

Association between Grape Yeast Communities and the Vineyard Ecosystems

PubMed Central

Drumonde-Neves, João; Lima, Teresa; Schuller, Dorit; Pais, Célia

2017-01-01

The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Açores (Verdelho), Arinto da Terceira (Arinto) and Terrantez do Pico (Terrantez) were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viticultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions. PMID:28085916

Climate risk and food security in Mali: A historical perspective on adaptation

NASA Astrophysics Data System (ADS)

Giannini, Alessandra; Krishnamurthy, P. Krishna; Cousin, Rémi; Labidi, Naouar; Choularton, Richard J.

2017-02-01

We combine socioeconomic data from a large-scale household survey with historical climate data to map the climate sensitivity of availability and access dimensions of food security in Mali, and infer the ways in which at-risk communities may have been impacted by persistent climatic shift. Thirty years after 1982-1984, the period of most intense drought during the protracted late 20th century drying of the Sahel, the impact of drought on livelihoods and food security is still recognizable in the Sahelian center of Mali. This impact is expressed in the larger fraction of households in this Sahelian center of the country—the agro-ecological transition between pastoralism in the north, and sedentary agriculture in the south—who practice agriculture but not livestock raising, despite environmental conditions that are suitable to their combination. These households have lower food security and rely more frequently on detrimental nutrition-based coping strategies, such as reducing the quantity or quality of meals. In contrast, the more food secure households show a clear tendency toward livelihood diversification away from subsistence agriculture. These households produce less of what they consume, yet spend less on food in proportion. The analysis points to the value of interdisciplinary research—in this case bridging climate science and vulnerability analysis—to gain a dynamical understanding of complex systems, understanding which may be exploited to address real-world challenges, offering lessons about food security and local adaptation strategies in places among the most vulnerable to climate.

Social organization influences the exchange and species richness of medicinal plants in Amazonian homegardens.

PubMed

2016-03-01

Medicinal plants provide indigenous and peasant communities worldwide with means to meet their healthcare needs. Homegardens often act as medicine cabinets, providing easily accessible medicinal plants for household needs. Social structure and social exchanges have been proposed as factors influencing the species diversity that people maintain in their homegardens. Here, we assess the association between the exchange of medicinal knowledge and plant material and medicinal plant richness in homegardens. Using Tsimane' Amazonian homegardens as a case study, we explore whether social organization shapes exchanges of medicinal plant knowledge and medicinal plant material. We also use network centrality measures to evaluate people's location and performance in medicinal plant knowledge and plant material exchange networks. Our results suggest that social organization, specifically kinship and gender relations, influences medicinal plant exchange patterns significantly. Homegardens total and medicinal plant species richness are related to gardeners' centrality in the networks, whereby people with greater centrality maintain greater plant richness. Thus, together with agroecological conditions, social relations among gardeners and the culturally specific social structure seem to be important determinants of plant richness in homegardens. Understanding which factors pattern general species diversity in tropical homegardens, and medicinal plant diversity in particular, can help policy makers, health providers, and local communities to understand better how to promote and preserve medicinal plants in situ. Biocultural approaches that are also gender sensitive offer a culturally appropriate means to reduce the global and local loss of both biological and cultural diversity.

Towards a more holistic sustainability assessment framework for agro-bioenergy systems — A review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arodudu, Oludunsin, E-mail: Oludunsin.Arodudu@zalf.de; Potsdam University, Institute of Earth and Environmental Sciences, Karl-Liebknecht-Straße 24-25, 14476 Potsdam, Golm; Helming, Katharina

The use of life cycle assessment (LCA) as a sustainability assessment tool for agro-bioenergy system usually has an industrial agriculture bias. Furthermore, LCA generally has often been criticized for being a decision maker tool which may not consider decision takers perceptions. They are lacking in spatial and temporal depth, and unable to assess sufficiently some environmental impact categories such as biodiversity, land use etc. and most economic and social impact categories, e.g. food security, water security, energy security. This study explored tools, methodologies and frameworks that can be deployed individually, as well as in combination with each other for bridgingmore » these methodological gaps in application to agro-bioenergy systems. Integrating agronomic options, e.g. alternative farm power, tillage, seed sowing options, fertilizer, pesticide, irrigation into the boundaries of LCAs for agro-bioenergy systems will not only provide an alternative agro-ecological perspective to previous LCAs, but will also lead to the derivation of indicators for assessment of some social and economic impact categories. Deploying life cycle thinking approaches such as energy return on energy invested-EROEI, human appropriation of net primary production-HANPP, net greenhouse gas or carbon balance-NCB, water footprint individually and in combination with each other will also lead to further derivation of indicators suitable for assessing relevant environmental, social and economic impact categories. Also, applying spatio-temporal simulation models has a potential for improving the spatial and temporal depths of LCA analysis.« less

Climate impacts on palm oil yields in the Nigerian Niger Delta

NASA Astrophysics Data System (ADS)

Okoro, Stanley U.; Schickhoff, Udo; Boehner, Juergen; Schneider, Uwe A.; Huth, Neil

2016-04-01

Palm oil production has increased in recent decades and is estimated to increase further. The optimal role of palm oil production, however, is controversial because of resource conflicts with alternative land uses. Local conditions and climate change affect resource competition and the desirability of palm oil production. Based on this, crop yield simulations using different climate model output under different climate scenarios could be important tool in addressing the problem of uncertainty quantification among different climate model outputs. Previous studies on this region have focused mostly on single experimental fields, not considering variations in Agro-Ecological Zones, climatic conditions, varieties and management practices and, in most cases not extending to various IPCC climate scenarios and were mostly based on single climate model output. Furthermore, the uncertainty quantification of the climate- impact model has rarely been investigated on this region. To this end we use the biophysical simulation model APSIM (Agricultural Production Systems Simulator) to simulate the regional climate impact on oil palm yield over the Nigerian Niger Delta. We also examine whether the use of crop yield model output ensemble reduces the uncertainty rather than the use of climate model output ensemble. The results could serve as a baseline for policy makers in this region in understanding the interaction between potentials of energy crop production of the region as well as its food security and other negative feedbacks that could be associated with bioenergy from oil palm. Keywords: Climate Change, Climate impacts, Land use and Crop yields.

Molecular and morphological diversity in locally grown non-commercial (heirloom) mango varieties of North India.

PubMed

Bajpai, Anju; Muthukumar, M; Ahmad, Israr; Ravishankar, K V; Parthasarthy, V A; Sthapit, Bhuwon; Rao, Ramanatha; Verma, J P; Rajan, S

2016-03-01

Mango (Mangifera indica L.) has been cultivated and conserved in different agro-ecologies including Malihabad region in northern part of India, that is well known for housing diverse types (heirloom and commercial varieties). In the present study, 37 mango types comprising of 27 heirloom varieties from Malihabad region and 10 commercial varieties grown in North and Eastern India were assessed for morphological attributes and molecular diversity. The employed SSR markers amplified 2-13 alleles individually, cumulatively amplifying 124 alleles. These were studied for allelic diversity and genetic dissimilarity ranged from 0.035 to 0.892 arranging the varieties in three major clusters. The results revealed that majority of unique heirloom mangoes from Malihabad were different from the eastern part of the country. It is interesting to note Dashehari, a commercial variety from Malihabad was not aligned with heirloom varieties. Commercial varieties like Gulabkhas and Langra were placed in a separate group including Bombay Green, Himsagar, Dashehari, etc., indicating their dissimilarity with heirloom varieties at molecular level and thus, indicating importance for later from conservation point of view. Furthermore, the hierarchical clustering of varieties based on fruit morphology, assembled these into four groups largely influenced by fruit size. The maximum agreement subtree indicated seemingly good fit as thirteen varieties were arrayed in common grouping pattern. Appreciable dissimilarity among the heirloom varieties demonstrated by molecular analysis, underlines the importance for their on-farm conservation.

Molecular markers associated with aluminium tolerance in Sorghum bicolor.

PubMed

Too, Emily Jepkosgei; Onkware, Augustino Osoro; Were, Beatrice Ang'iyo; Gudu, Samuel; Carlsson, Anders; Geleta, Mulatu

2018-01-01

Sorghum ( Sorghum bicolor , L. Moench) production in many agro-ecologies is constrained by a variety of stresses, including high levels of aluminium (Al) commonly found in acid soils. Therefore, for such soils, growing Al tolerant cultivars is imperative for high productivity. In this study, molecular markers associated with Al tolerance were identified using a mapping population developed by crossing two contrasting genotypes for this trait. Four SSR ( Xtxp34 , Sb5_236 , Sb6_34 , and Sb6_342 ), one STS ( CTG29_3b ) and three ISSR ( 811_1400 , 835_200 and 884_200 ) markers produced alleles that showed significant association with Al tolerance. CTG29_3b, 811_1400 , Xtxp34 and Sb5_ 236 are located on chromosome 3 with the first two markers located close to Alt SB , a locus that underlie the Al tolerance gene ( SbMATE ) implying that their association with Al tolerance is due to their linkage to this gene. Although CTG29_3b and 811_ 1400 are located closer to Alt SB , Xtxp34 and Sb5_236 explained higher phenotypic variance of Al tolerance indices. Markers 835_200 , 884_200 , Sb6_34 and Sb6_342 are located on different chromosomes, which implies the presence of several genes involved in Al tolerance in addition to S bMATE in sorghum. These molecular markers have a high potential for use in breeding for Al tolerance in sorghum.

Patterns and perceptions of climate change in a biodiversity conservation hotspot.

PubMed

Hartter, Joel; Stampone, Mary D; Ryan, Sadie J; Kirner, Karen; Chapman, Colin A; Goldman, Abraham

2012-01-01

Quantifying local people's perceptions to climate change, and their assessments of which changes matter, is fundamental to addressing the dual challenge of land conservation and poverty alleviation in densely populated tropical regions To develop appropriate policies and responses, it will be important not only to anticipate the nature of expected changes, but also how they are perceived, interpreted and adapted to by local residents. The Albertine Rift region in East Africa is one of the world's most threatened biodiversity hotspots due to dense smallholder agriculture, high levels of land and resource pressures, and habitat loss and conversion. Results of three separate household surveys conducted in the vicinity of Kibale National Park during the late 2000s indicate that farmers are concerned with variable precipitation. Many survey respondents reported that conditions are drier and rainfall timing is becoming less predictable. Analysis of daily rainfall data for the climate normal period 1981 to 2010 indicates that total rainfall both within and across seasons has not changed significantly, although the timing and transitions of seasons has been highly variable. Results of rainfall data analysis also indicate significant changes in the intra-seasonal rainfall distribution, including longer dry periods within rainy seasons, which may contribute to the perceived decrease in rainfall and can compromise food security. Our results highlight the need for fine-scale climate information to assist agro-ecological communities in developing effective adaptive management.

Environmental impacts of beef production: Review of challenges and perspectives for durability.

PubMed

Gerber, Pierre J; Mottet, Anne; Opio, Carolyn I; Falcucci, Alessandra; Teillard, Félix

2015-11-01

Beef makes a substantial contribution to food security, providing protein, energy and also essential micro-nutrients to human populations. Rumination allows cattle - and other ruminant species - to digest fibrous feeds that cannot be directly consumed by humans and thus to make a net positive contribution to food balances. This contribution is of particular importance in marginal areas, where agro-ecological conditions and weak infrastructures do not offer much alternative. It is also valuable where cattle convert crop residues and by-products into edible products and where they contribute to soil fertility through their impact on nutrients and organic matter cycles. At the same time, environmental sustainability issues are acute. They chiefly relate to the low efficiency of beef cattle in converting natural resources into edible products. Water use, land use, biomass appropriation and greenhouse gas emissions are for example typically higher per unit of edible product in beef systems than in any other livestock systems, even when corrected for nutritional quality. This particularly causes environmental pressure when production systems are specialized towards the delivery of edible products, in large volumes. The paper discusses environmental challenges at global level, recognizing the large diversity of systems. Beef production is faced with a range of additional sustainability challenges, such as changing consumer perceptions, resilience to climate change, animal health and inequities in access to land and water resources. Entry-points for environmental sustainability improvement are discussed within this broader development context. Copyright © 2015. Published by Elsevier Ltd.

Disentangling endogenous versus exogenous pattern formation in spatial ecology: a case study of the ant Azteca sericeasur in southern Mexico.

PubMed

Li, Kevin; Vandermeer, John H; Perfecto, Ivette

2016-05-01

Spatial patterns in ecology can be described as reflective of environmental heterogeneity (exogenous), or emergent from dynamic relationships between interacting species (endogenous), but few empirical studies focus on the combination. The spatial distribution of the nests of Azteca sericeasur, a keystone tropical arboreal ant, is thought to form endogenous spatial patterns among the shade trees of a coffee plantation through self-regulating interactions with controlling agents (i.e. natural enemies). Using inhomogeneous point process models, we found evidence for both types of processes in the spatial distribution of A. sericeasur. Each year's nest distribution was determined mainly by a density-dependent relationship with the previous year's lagged nest density; but using a novel application of a Thomas cluster process to account for the effects of nest clustering, we found that nest distribution also correlated significantly with tree density in the later years of the study. This coincided with the initiation of agricultural intensification and tree felling on the coffee farm. The emergence of this significant exogenous effect, along with the changing character of the density-dependent effect of lagged nest density, provides clues to the mechanism behind a unique phenomenon observed in the plot, that of an increase in nest population despite resource limitation in nest sites. Our results have implications in coffee agroecological management, as this system provides important biocontrol ecosystem services. Further research is needed, however, to understand the effective scales at which these relationships occur.

Gastrointestinal nematode infection in small ruminants in Ethiopia: A systematic review and meta-analysis.

PubMed

Asmare, Kassahun; Sheferaw, Desie; Aragaw, Kassaye; Abera, Mesele; Sibhat, Berhanu; Haile, Aynalem; Kiara, Henry; Szonyi, Barbara; Skjerve, Eystein; Wieland, Barbara

2016-08-01

Gastrointestinal (GI) nematode infections are a major health challenge affecting productive and reproductive performance of sheep and goats in Ethiopia. However, there is no comprehensive summary on the occurrence and distribution of the infection at national level. This systematic review provides pooled prevalence estimates and assesses potential predictors of the nematode infections in small ruminants, i.e. helpful in planning interventions or control strategies. The review used 50 animal level datasets retrieved from 24 manuscripts. The studies used data collected from 9407 sheep and 3478 goats. A meta-analytical approach was employed to analyze Effect size (ES). The reported GI nematodes represented eleven genera affecting sheep and goats including: Haemonchus, Trichostrongylus, Teladorsagia/Ostertagia, Strongyloides, Bunostomum, Nematodirus, Chabertia, Trichuris, Cooperia, Skrjabinema and Oesophagostomum. The GI nematodes pooled prevalence estimate in the random effect model was 75.8% (95% CI: 69.6, 80.8). The subgroup analysis revealed significant (p<0.05) differences in the prevalence between different regions and type of diagnostic methods used. 'Postmortem technique' and 'eastern part of the country' were associated with higher GI nematode prevalence and accounted for 68.1% of the between studies heterogeneity. In light of the high parasitic prevalence in all agro-ecologies, the need for strategic intervention is recommended. Meanwhile, data need to be generated for some of the regions where dependable survey reports are lacking. Copyright © 2016 Elsevier B.V. All rights reserved.

GMDPtoolbox: A Matlab library for designing spatial management policies. Application to the long-term collective management of an airborne disease

PubMed Central

Aubertot, Jean-Noël; Peyrard, Nathalie; Sabbadin, Régis

2017-01-01

Designing management policies in ecology and agroecology is complex. Several components must be managed together while they strongly interact spatially. Decision choices must be made under uncertainty on the results of the actions and on the system dynamics. Furthermore, the objectives pursued when managing ecological systems or agroecosystems are usually long term objectives, such as biodiversity conservation or sustainable crop production. The framework of Graph-Based Markov Decision Processes (GMDP) is well adapted to the qualitative modeling of such problems of sequential decision under uncertainty. Spatial interactions are easily modeled and integrated control policies (combining several action levers) can be designed through optimization. The provided policies are adaptive, meaning that management actions are decided at each time step (for instance yearly) and the chosen actions depend on the current system state. This framework has already been successfully applied to forest management and invasive species management. However, up to now, no “easy-to-use” implementation of this framework was available. We present GMDPtoolbox, a Matlab toolbox which can be used both for the design of new management policies and for comparing policies by simulation. We provide an illustration of the use of the toolbox on a realistic crop disease management problem: the design of long term management policy of blackleg of canola using an optimal combination of three possible cultural levers. This example shows how GMDPtoolbox can be used as a tool to support expert thinking. PMID:28982151

Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary

PubMed Central

Almathen, Faisal; Charruau, Pauline; Mohandesan, Elmira; Mwacharo, Joram M.; Orozco-terWengel, Pablo; Pitt, Daniel; Abdussamad, Abdussamad M.; Uerpmann, Margarethe; Uerpmann, Hans-Peter; De Cupere, Bea; Magee, Peter; Alnaqeeb, Majed A.; Salim, Bashir; Raziq, Abdul; Dessie, Tadelle; Abdelhadi, Omer M.; Banabazi, Mohammad H.; Al-Eknah, Marzook; Walzer, Chris; Faye, Bernard; Hofreiter, Michael; Peters, Joris; Hanotte, Olivier

2016-01-01

Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species’ range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the “restocking from the wild” hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments. PMID:27162355

Regulatory considerations surrounding the deployment of Bt-expressing cowpea in Africa: report of the deliberations of an expert panel.

PubMed

Huesing, Joseph; Romeis, Jörg; Ellstrand, Norman; Raybould, Alan; Hellmich, Richard; Wolt, Jeff; Ehlers, Jeff; Dabiré, Clémentine; Fatokun, Christian; Hokanson, Karen; Ishiyaku, Mohammad F; Margam, Venu; Obokoh, Nompumelelo; Mignouna, Jacob; Nangayo, Francis; Ouedraogo, Jeremy; Pasquet, Rémy; Pittendrigh, Barry; Schaal, Barbara; Stein, Jeff; Tamò, Manuele; Murdock, Larry

2011-01-01

Cowpea (Vigna unguiculata spp unguiculata) is adapted to the drier agro-ecological zones of West Africa where it is a major source of dietary protein and widely used as a fodder crop. Improving the productivity of cowpea can enhance food availability and security in West Africa. Insect predation--predominately from the legume pod borer (Maruca vitrata), flower thrips (Megalurothrips sjostedti) and a complex of pod-sucking bugs (e.g., Clavigralla spp)--is a major yield-limiting factor in West African cowpea production. Dramatic increases in yield are shown when M. vitrata is controlled with insecticides. However, availability, costs, and safety considerations limit pesticides as a viable option for boosting cowpea production. Development of Bt-cowpea through genetic modification (GM) to control the legume pod borer is a promising approach to cowpea improvement. Cowpea expressing the lepidopteran-active Cry1Ab protein from Bacillus thuringiensis is being developed as a first generation Bt-cowpea crop for West Africa. Appropriate stewardship of Bt-cowpea to assure its sustainability under West African conditions is critical to its successful development. A first step in this process is an environmental risk assessment to determine the likelihood and magnitude of adverse effects of the Cry1Ab protein on key environmental protection goals in West Africa. Here we describe the results of an expert panel convened in 2009 to develop the problem formulation phase for Bt-cowpea and to address specific issues around gene flow, non-target arthropods, and insect resistance management.

GMDPtoolbox: A Matlab library for designing spatial management policies. Application to the long-term collective management of an airborne disease.

PubMed

Cros, Marie-Josée; Aubertot, Jean-Noël; Peyrard, Nathalie; Sabbadin, Régis

2017-01-01

Designing management policies in ecology and agroecology is complex. Several components must be managed together while they strongly interact spatially. Decision choices must be made under uncertainty on the results of the actions and on the system dynamics. Furthermore, the objectives pursued when managing ecological systems or agroecosystems are usually long term objectives, such as biodiversity conservation or sustainable crop production. The framework of Graph-Based Markov Decision Processes (GMDP) is well adapted to the qualitative modeling of such problems of sequential decision under uncertainty. Spatial interactions are easily modeled and integrated control policies (combining several action levers) can be designed through optimization. The provided policies are adaptive, meaning that management actions are decided at each time step (for instance yearly) and the chosen actions depend on the current system state. This framework has already been successfully applied to forest management and invasive species management. However, up to now, no "easy-to-use" implementation of this framework was available. We present GMDPtoolbox, a Matlab toolbox which can be used both for the design of new management policies and for comparing policies by simulation. We provide an illustration of the use of the toolbox on a realistic crop disease management problem: the design of long term management policy of blackleg of canola using an optimal combination of three possible cultural levers. This example shows how GMDPtoolbox can be used as a tool to support expert thinking.

Urinary fumonisin B1 and estimated fumonisin intake in women from high- and low-exposure communities in Guatemala.

PubMed

Torres, Olga; Matute, Jorge; Gelineau-van Waes, Janee; Maddox, Joyce R; Gregory, Simon G; Ashley-Koch, Allison E; Showker, Jency L; Zitomer, Nicholas C; Voss, Kenneth A; Riley, Ronald T

2014-05-01

Fumonisin (FB) intake can be high when maize is a dietary staple. We determined (i) urinary FB (UFB) in women consuming maize in high- and low-exposure communities in Guatemala, (ii) the FB levels in maize, (iii) the relationship between UFB and FB intake, and (iv) the relative excretion of UFB1 , UFB2 , and UFB3 . Urine and maize were analyzed for FB for 1 year in three departments. Maize consumption was estimated by an interview questionnaire. Fumonisin B1 , B2 , and B3 (FB1 , FB2 and FB3 ), were detected in 100% of maize samples. FB1 in maize and urine was significantly higher in Jutiapa compared to Chimaltenango or Escuintla. The FB intake paralleled UFB1 in a dose-dependent manner but UFB1 was present in much higher levels than UFB2 or UFB3 compared to maize. In Jutiapa, agroecological conditions favored FB production. UFB1 mirrored the estimated FB intake. UFB1 > 0.1 ng/mL resulted in a dose-dependent increase in the risk of exceeding FB intake of 2 μg/kg b.w./day compared to women with no detectable UFB1 . More than 50% exceeded 2 μg/kg b.w./day when UFB1 was >0.5 ng/mL. UFB2 and UFB3 were rarely detected confirming that FB1 is either absorbed better or preferentially excreted in urine. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spatio-temporal dynamics of genetic diversity in Sorghum bicolor in Niger.

PubMed

Deu, Monique; Sagnard, F; Chantereau, J; Calatayud, C; Vigouroux, Y; Pham, J L; Mariac, C; Kapran, I; Mamadou, A; Gérard, B; Ndjeunga, J; Bezançon, G

2010-05-01

The dynamics of crop genetic diversity need to be assessed to draw up monitoring and conservation priorities. However, few surveys have been conducted in centres of diversity. Sub-Saharan Africa is the centre of origin of sorghum. Most Sahel countries have been faced with major human, environmental and social changes in recent decades, which are suspected to cause genetic erosion. Sorghum is the second staple cereal in Niger, a centre of diversity for this crop. Niger was submitted to recurrent drought period and to major social changes during these last decades. We report here on a spatio-temporal analysis of sorghum genetic diversity, conducted in 71 villages covering the rainfall gradient and range of agro-ecological conditions in Niger's agricultural areas. We used 28 microsatellite markers and applied spatial and genetic clustering methods to investigate change in genetic diversity over a 26-year period (1976-2003). Global genetic differentiation between the two collections was very low (F (st) = 0.0025). Most of the spatial clusters presented no major differentiation, as measured by F (st), and showed stability or an increase in allelic richness, except for two of them located in eastern Niger. The genetic clusters identified by Bayesian analysis did not show a major change between the two collections in the distribution of accessions between them or in their spatial location. These results suggest that farmers' management has globally preserved sorghum genetic diversity in Niger.

Entomopathogenicity and Biological Attributes of Himalayan Treasured Fungus Ophiocordyceps sinensis (Yarsagumba)

PubMed Central

Baral, Bikash

2017-01-01

Members of the entomophagous fungi are considered very crucial in the fungal domain relative to their natural phenomenon and economic perspectives; however, inadequate knowledge of their mechanisms of interaction keeps them lagging behind in parallel studies of fungi associated with agro-ecology, forest pathology and medical biology. Ophiocordyceps sinensis (syn. Cordyceps sinensis), an intricate fungus-caterpillar complex after it parasitizes the larva of the moth, is a highly prized medicinal fungus known widely for ages due to its peculiar biochemical assets. Recent technological innovations have significantly contributed a great deal to profiling the variable clinical importance of this fungus and other related fungi with similar medicinal potential. However, a detailed mechanism behind fungal pathogenicity and fungal-insect interactions seems rather ambiguous and is poorly justified, demanding special attention. The goal of the present review is to divulge an update on the published data and provides promising insights on different biological events that have remained underemphasized in previous reviews on fungal biology with relation to life-history trade-offs, host specialization and selection pressures. The infection of larvae by a fungus is not a unique event in Cordyceps; hence, other fungal species are also reviewed for effective comparison. Conceivably, the rationale and approaches behind the inheritance of pharmacological abilities acquired and stored within the insect framework at a time when they are completely hijacked and consumed by fungal parasites, and the molecular mechanisms involved therein, are clearly documented. PMID:29371523

Defining a breeding objective for Nile tilapia that takes into account the diversity of smallholder production systems.

PubMed

Omasaki, S K; van Arendonk, J A M; Kahi, A K; Komen, H

2016-10-01

In general, livestock and fish farming systems in developing countries tend to be highly diverse in terms of agro-ecological conditions and market orientation. There are no studies that have investigated if and how this diversity translates to varying preferences for breeding objective traits. This is particularly important for breeding programmes that are organized on a national level (e.g. government-supported nucleus breeding programmes). The aim of this study was to investigate whether Nile tilapia farmers with diverse production systems and economic constraints have different preferences for breeding objective traits. The second objective was to derive a consensus breeding goal, using weighted goal programming that could be used for a national breeding programme for Nile tilapia. A survey was conducted among 100 smallholder Nile tilapia farmers in Kenya to obtain preference values for traits of economic importance, by using multiple pairwise comparisons. Individual and group preference values were estimated using analytical hierarchy process. Low-income farmers preferred harvest weight, while medium- and high-income farmers preferred growth rate and survival. Grouping farmers according to market objective (fingerling production or fattening) showed that fingerling producers preferred growth rate and survival, while fattening farmers preferred harvest weight, height and thickness. Weighted goal programming was used to obtain consensus preference values, and these were used to derive desired gains for a breeding goal of a national breeding programme that takes into account the diversity of smallholder production systems. © 2016 Blackwell Verlag GmbH.

Antibacterial Activities of Five Medicinal Plants in Ethiopia against Some Human and Animal Pathogens

PubMed Central

Admasu, Birhanu; Hiwot Gebrekidan, Tsegaye; Gebru, Gebreyohans

2018-01-01

Objective To evaluate the in vitro antibacterial activities of five plant extracts which have been used as traditional medicines by local healers against three multidrug resistant bacteria, namely, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Results The highest mean zone of inhibition (4.66 mm) was recorded from methanol extract of Calpurnia aurea (Ait.) Benth. at a concentration of 200 mg/ml against S. aureus, followed by Croton macrostachyus Del. (4.43 mm) at the same dose and solvent for the same bacterial species, while methanol and chloroform extracts of E. brucei Schwein. did not inhibit growth of any bacterial species. The lowest value (100 μg/ml) of minimum inhibitory concentration (MIC) was observed from both methanol and chloroform extracts of C. aurea (Ait.) Benth. against all the three bacteria. The results of the positive control had no statistically significant difference (P > 0.05) when compared with crude extracts of C. aurea (Ait.) Benth. at concentration of 200 mg/ml against S. aureus. Conclusion The results of the present study support the traditional uses of these medicinal plants by the local healers. Except Erythrina brucei Schwein., all the plants investigated in this study exhibited antibacterial activities against the test bacterial species. Further researches are needed to be conducted to evaluate efficacy of these medicinal plant species on other microbes in different agroecological settings and their safety levels as well as their phytochemical compositions. PMID:29552081

Antibacterial Activities of Five Medicinal Plants in Ethiopia against Some Human and Animal Pathogens.

PubMed

Romha, Gebremedhin; Admasu, Birhanu; Hiwot Gebrekidan, Tsegaye; Aleme, Hailelule; Gebru, Gebreyohans

2018-01-01

To evaluate the in vitro antibacterial activities of five plant extracts which have been used as traditional medicines by local healers against three multidrug resistant bacteria, namely, Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa . The highest mean zone of inhibition (4.66 mm) was recorded from methanol extract of Calpurnia aurea (Ait.) Benth. at a concentration of 200 mg/ml against S. aureus , followed by Croton macrostachyus Del. (4.43 mm) at the same dose and solvent for the same bacterial species, while methanol and chloroform extracts of E. brucei Schwein. did not inhibit growth of any bacterial species. The lowest value (100  μ g/ml) of minimum inhibitory concentration (MIC) was observed from both methanol and chloroform extracts of C. aurea (Ait.) Benth. against all the three bacteria. The results of the positive control had no statistically significant difference ( P > 0.05) when compared with crude extracts of C. aurea (Ait.) Benth. at concentration of 200 mg/ml against S. aureus . The results of the present study support the traditional uses of these medicinal plants by the local healers. Except Erythrina brucei Schwein., all the plants investigated in this study exhibited antibacterial activities against the test bacterial species. Further researches are needed to be conducted to evaluate efficacy of these medicinal plant species on other microbes in different agroecological settings and their safety levels as well as their phytochemical compositions.

Organic livestock production in Uganda: potentials, challenges and prospects.

PubMed

Nalubwama, Sylvia Muwanga; Mugisha, Anthony; Vaarst, Mette

2011-04-01

Development in organic farming has been stimulated by farmers and consumers becoming interested in healthy food products and sustainable environment. Organic agriculture is a holistic production management system which is based on the principles of health, ecology, care, and fairness. Organic development in Uganda has focused more on the crop sector than livestock sector and has primarily involved the private sector, like organic products export companies and non-governmental organizations. Agriculture in Uganda and many African countries is predominantly traditional, less mechanized, and is usually associated with minimum use of chemical fertilizers, pesticides, and drugs. This low external input agriculture also referred to as "organic by default" can create basis for organic farming where agroecological methods are introduced and present an alternative in terms of intensification to the current low-input/low-output systems. Traditional farming should not be confused with organic farming because in some cases, the existing traditional practices have consequences like overstocking and less attention to soil improvement as well as to animal health and welfare, which is contrary to organic principles of ecology, fairness, health, and care. Challenges of implementing sustainable organic practices in the Ugandan livestock sector threaten its future development, such as vectors and vector-borne diseases, organic feed insufficiency, limited education, research, and support to organic livestock production. The prospects of organic livestock development in Uganda can be enhanced with more scientific research in organic livestock production under local conditions and strengthening institutional support.

Evaluation of the Migration Capacity of Zn in the Soil–Plant System

NASA Astrophysics Data System (ADS)

Anisimov, V. S.; Anisimova, L. N.; Frigidova, L. M.; Dikarev, D. V.; Frigidov, R. A.; Korneev, Yu. N.; Sanzharov, A. I.; Arysheva, S. P.

2018-04-01

The mobility and migration capacity of Zn in the soil-plant system were studied in a series of pot experiments with barley as a test plant. The parameters of Zn accumulation depending on the metal concentrations in soils and soil solutions were estimated by soil and water culture methods. Experiments with barley in water culture were performed on a nutrient (soil) solution extracted from soddy-podzolic soil (Albic Retisol (Loamic, Ochric)) to which Zn2+ was added to reach working concentrations increasing from 0.07 to 430 μM. Different responses of barley plants to changes in the concentration of Zn in the studied soil were identified. Ranges of the corresponding concentrations in the soil and aboveground barley biomass were determined. Parameters of Zn accumulation by test plants were determined depending on the metal content in soddypodzolic soil and the soil solution. A new method was proposed for evaluating the buffer capacity of soils with respect to a heavy metal (Zn) using test plants (BCS(P)Zn). The method was used to evaluate the buffering capacity of loamy sandy soddy-podzolic soil. The considered methodological approach offers opportunities for using data obtained during the agroecological monitoring of agricultural lands with heavy metals (HMs), including the contents of exchangeable HMs and macroelements (C and Mg) in soils and concentrations of HMs and (Ca + Mg) in plants, in the calculation of the buffering capacity of the surveyed soils for HMs.

The use of MP-AES for determination of plant available P in soil by DL method and distribution of soils into P status classes by DL, AL and Mehlich 3 methods.

NASA Astrophysics Data System (ADS)

Toomsoo, Avo; Jürgens, Meit; Kõlli, Raimo; Künnapas, Allan; Albre, Imbi; Tõnutare, Tõnu; Rodima, Ako

2017-04-01

Only small percentage of soil total phosphorus is easily exchangeable between solid and solution phase. Plants are able to assimilate P from environment only in the form of orthophosphate ions (H2PO4- and HPO42-) from soil solution. Deficit of P in soil solution prevents plant normal growth and decreases yield quantity and quality. The excess of P in soil solution causes the pollution of environment and eutrophication of water bodies. Therefore it is important to give to the plant producers the correct fertilization recommendations. Lot of analytical methods are developed for the determination of plant available P in soils. In the Baltic Sea region seven different soils' P analysis methods in use. Each method has its own gradation and often there is more than one gradation for the same method depending from agroecological conditions. For agricultural soils in Estonia there are soil P status gradations according to Mehlich 3, DL and AL methods. Phosphate content in soil can be determined by molybdate method Vis-spectrometrically. Very often for analysis of soils' P content also ICP-OES, ICP-MS and also MP-AES instrumental methods are used The aim of our work was to investigate the possibility of using MP-AES for determination of plant available P in soil by DL method and also to compare how the analysed soils are distributed to M3, AL and DL fertilizer requirement groups according to the P content.

New Geographical Insights of the Latest Expansion of Fusarium oxysporum f.sp. cubense Tropical Race 4 Into the Greater Mekong Subregion

PubMed Central

Zheng, Si-Jun; García-Bastidas, Fernando A.; Li, Xundong; Zeng, Li; Bai, Tingting; Xu, Shengtao; Yin, Kesuo; Li, Hongxiang; Fu, Gang; Yu, Yanchun; Yang, Liu; Nguyen, Huy Chung; Douangboupha, Bounneuang; Khaing, Aye Aye; Drenth, Andre; Seidl, Michael F.; Meijer, Harold J. G.; Kema, Gert H. J.

2018-01-01

Banana is the most popular and most exported fruit and also a major food crop for millions of people around the world. Despite its importance and the presence of serious disease threats, research into this crop is limited. One of those is Panama disease or Fusarium wilt. In the previous century Fusarium wilt wiped out the “Gros Michel” based banana industry in Central America. The epidemic was eventually quenched by planting “Cavendish” bananas. However, 50 years ago the disease recurred, but now on “Cavendish” bananas. Since then the disease has spread across South-East Asia, to the Middle-East and the Indian subcontinent and leaped into Africa. Here, we report the presence of Fusarium oxysporum f.sp. cubense Tropical Race 4 (Foc TR4) in “Cavendish” plantations in Laos, Myanmar, and Vietnam. A combination of classical morphology, DNA sequencing, and phenotyping assays revealed a very close relationship between the Foc TR4 strains in the entire Greater Mekong Subregion (GMS), which is increasingly prone to intensive banana production. Analyses of single-nucleotide polymorphisms enabled us to initiate a phylogeography of Foc TR4 across three geographical areas—GMS, Indian subcontinent, and the Middle East revealing three distinct Foc TR4 sub-lineages. Collectively, our data place these new incursions in a broader agroecological context and underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further international dissemination of Foc TR4. PMID:29686692

New Geographical Insights of the Latest Expansion of Fusarium oxysporum f.sp. cubense Tropical Race 4 Into the Greater Mekong Subregion.

PubMed

Zheng, Si-Jun; García-Bastidas, Fernando A; Li, Xundong; Zeng, Li; Bai, Tingting; Xu, Shengtao; Yin, Kesuo; Li, Hongxiang; Fu, Gang; Yu, Yanchun; Yang, Liu; Nguyen, Huy Chung; Douangboupha, Bounneuang; Khaing, Aye Aye; Drenth, Andre; Seidl, Michael F; Meijer, Harold J G; Kema, Gert H J

2018-01-01

Banana is the most popular and most exported fruit and also a major food crop for millions of people around the world. Despite its importance and the presence of serious disease threats, research into this crop is limited. One of those is Panama disease or Fusarium wilt. In the previous century Fusarium wilt wiped out the "Gros Michel" based banana industry in Central America. The epidemic was eventually quenched by planting "Cavendish" bananas. However, 50 years ago the disease recurred, but now on "Cavendish" bananas. Since then the disease has spread across South-East Asia, to the Middle-East and the Indian subcontinent and leaped into Africa. Here, we report the presence of Fusarium oxysporum f.sp. cubense Tropical Race 4 (Foc TR4) in "Cavendish" plantations in Laos, Myanmar, and Vietnam. A combination of classical morphology, DNA sequencing, and phenotyping assays revealed a very close relationship between the Foc TR4 strains in the entire Greater Mekong Subregion (GMS), which is increasingly prone to intensive banana production. Analyses of single-nucleotide polymorphisms enabled us to initiate a phylogeography of Foc TR4 across three geographical areas-GMS, Indian subcontinent, and the Middle East revealing three distinct Foc TR4 sub-lineages. Collectively, our data place these new incursions in a broader agroecological context and underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further international dissemination of Foc TR4.

Evaluation of MALDI-TOF mass spectrometry for the competitiveness analysis of selected indigenous cowpea (Vigna unguiculata L. Walp.) Bradyrhizobium strains from Kenya.

PubMed

Ndungu, Samuel Mathu; Messmer, Monika M; Ziegler, Dominik; Thuita, Moses; Vanlauwe, Bernard; Frossard, Emmanuel; Thonar, Cécile

2018-06-01

Cowpea N 2 fixation and yield can be enhanced by selecting competitive and efficient indigenous rhizobia. Strains from contrasting agro-ecologies of Kilifi and Mbeere (Kenya) were screened. Two pot experiments were established consisting of 13 Bradyrhizobium strains; experiment 1 (11 Mbeere + CBA + BK1 from Burkina Faso), experiment 2 (12 Kilifi + CBA). Symbiotic effectiveness was assessed (shoot biomass, SPAD index and N uptake). Nodule occupancy of 13 simultaneously co-inoculated strains in each experiment was analyzed by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry (MS) to assess competitiveness. Strains varied in effectiveness and competitiveness. The four most efficient strains were further evaluated in a field trial in Mbeere during the 2014 short rains. Strains from bacteroids of cowpea nodules from pot and field experiments were accurately identified as Bradyrhizobium by MALDI-TOF based on the SARAMIS™ database. In the field, abundant indigenous populations 7.10 × 10 3 rhizobia g -1 soil, outcompeted introduced strains. As revealed by MALDI-TOF, indigenous strains clustered into six distinct groups (I, II, III, IV, V and VI), group III were most abundant occupying 80% of nodules analyzed. MALDI-TOF was rapid, affordable and reliable to identify Bradyrhizobium strains directly from nodule suspensions in competition pot assays and in the field with abundant indigenous strains thus, its suitability for future competition assays. Evaluating strain competitiveness and then symbiotic efficacy is proposed in bioprospecting for potential cowpea inoculant strains.

Patterns and Perceptions of Climate Change in a Biodiversity Conservation Hotspot

PubMed Central

Hartter, Joel; Stampone, Mary D.; Ryan, Sadie J.; Kirner, Karen; Chapman, Colin A.; Goldman, Abraham

2012-01-01

Quantifying local people's perceptions to climate change, and their assessments of which changes matter, is fundamental to addressing the dual challenge of land conservation and poverty alleviation in densely populated tropical regions To develop appropriate policies and responses, it will be important not only to anticipate the nature of expected changes, but also how they are perceived, interpreted and adapted to by local residents. The Albertine Rift region in East Africa is one of the world's most threatened biodiversity hotspots due to dense smallholder agriculture, high levels of land and resource pressures, and habitat loss and conversion. Results of three separate household surveys conducted in the vicinity of Kibale National Park during the late 2000s indicate that farmers are concerned with variable precipitation. Many survey respondents reported that conditions are drier and rainfall timing is becoming less predictable. Analysis of daily rainfall data for the climate normal period 1981 to 2010 indicates that total rainfall both within and across seasons has not changed significantly, although the timing and transitions of seasons has been highly variable. Results of rainfall data analysis also indicate significant changes in the intra-seasonal rainfall distribution, including longer dry periods within rainy seasons, which may contribute to the perceived decrease in rainfall and can compromise food security. Our results highlight the need for fine-scale climate information to assist agro-ecological communities in developing effective adaptive management. PMID:22384244

Ecological adaptation of diverse honey bee (Apis mellifera) populations.

PubMed

Parker, Robert; Melathopoulos, Andony P; White, Rick; Pernal, Stephen F; Guarna, M Marta; Foster, Leonard J

2010-06-15

Honey bees are complex eusocial insects that provide a critical contribution to human agricultural food production. Their natural migration has selected for traits that increase fitness within geographical areas, but in parallel their domestication has selected for traits that enhance productivity and survival under local conditions. Elucidating the biochemical mechanisms of these local adaptive processes is a key goal of evolutionary biology. Proteomics provides tools unique among the major 'omics disciplines for identifying the mechanisms employed by an organism in adapting to environmental challenges. Through proteome profiling of adult honey bee midgut from geographically dispersed, domesticated populations combined with multiple parallel statistical treatments, the data presented here suggest some of the major cellular processes involved in adapting to different climates. These findings provide insight into the molecular underpinnings that may confer an advantage to honey bee populations. Significantly, the major energy-producing pathways of the mitochondria, the organelle most closely involved in heat production, were consistently higher in bees that had adapted to colder climates. In opposition, up-regulation of protein metabolism capacity, from biosynthesis to degradation, had been selected for in bees from warmer climates. Overall, our results present a proteomic interpretation of expression polymorphisms between honey bee ecotypes and provide insight into molecular aspects of local adaptation or selection with consequences for honey bee management and breeding. The implications of our findings extend beyond apiculture as they underscore the need to consider the interdependence of animal populations and their agro-ecological context.

Enhancing Legume Ecosystem Services through an Understanding of Plant–Pollinator Interplay

PubMed Central

Suso, María J.; Bebeli, Penelope J.; Christmann, Stefanie; Mateus, Célia; Negri, Valeria; Pinheiro de Carvalho, Miguel A. A.; Torricelli, Renzo; Veloso, Maria M.

2016-01-01

Legumes are bee-pollinated, but to a different extent. The importance of the plant–pollinator interplay (PPI), in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: (1) optimal productivity, based on an efficient use of pollinators, and (2) biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the “pest control service” and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: (a) Farming with Alternative Pollinators and (b) Crop Design System. PMID:27047514

A comparative analysis to quantify the biogeochemical and biogeophysical cooling effects on climate of a white mustard cover crop

NASA Astrophysics Data System (ADS)

Ferlicoq, Morgan; Ceschia, Eric; Brut, Aurore; Tallec, Tiphaine; Carrer, Dominique; Pique, Gaetan; Ferroni, Nicole

2017-04-01

During the COP21, agriculture was recognised as a strategic sector and an opportunity to strengthen climate mitigation. In particular, the "4 per 1000" initiative relies upon solutions that refer to agro-ecology, conservation agriculture, … that could lead to increase carbon storage. Among those agro-ecology practices, including cover crops during fallow periods is considered as a fundamental agronomic lever for storing carbon. However, if biogeochemical benefits of cover-crops (CC) have already been addressed, their biogeophysical effects on climate have never been quantified and compared to biogeochemical effects. This comparative study (CC vs. bare soil), quantified and compared biogeochemical (including carbon storage) and biophysical effects (albedo and energy partitioning effect) of CC on climate. An experimental campaign was performed in 2013 in Southwest France, during the fallow period following a winter-wheat crop (and before a maize). The experimental plot was divided in two: the northern part was maintained in bare soil (BS) while white-mustard (WM) was grown during 3-months on the southern part. On each subplot, continuous measurements of CO2, latent and sensible fluxes (by eddy covariance) and solar radiation were acquired. Also, N2O emissions were measured by means of automatic chambers on each subplots. Moreover, by using a Life-Cycle-Analysis approach, each component of the greenhouse gas budget (GHGB) was quantified for each subplot, including emissions associated to field operations (FO). To quantify the albedo induced radiative forcing (RFα) caused by the white-mustard, the bare soil subplot was used as a reference state (IPCC, 2007). Finally, the net radiative forcing for each subplot was calculated as the sum of biogeochemical and biogeophysical (albedo effect) radiative forcing. The white-mustard allowed a net CO2 fixation of 63 g C-eq.m-2, corresponding to 20% of the net annual CO2 flux that year (-332 g C-eq.m-2). Through the WM seeds

Spatial-temporal variability in GHG fluxes and their functional interpretation in RusFluxNet

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Meshalkina, Julia; Sarzhanov, Dmitriy; Mazirov, Ilia; Yaroslavtsev, Alex; Komarova, Tatiana; Tikhonova, Maria

2016-04-01

different meso- or micro-relief forms, natural or man-made succession studies, topsoil texture or organic matter state, subsoil or perched groundwater features. Zonal, seasonal and functional subdividing the monitoring data allows essentially increase the regression links between GHG fluxes and air or soil temperature and moisture (to 0.75-0.87) that is very important for their modeling and prediction. In taiga and mix-forest zones usually there is stronger effect on GHG fluxes by air temperature than soil one due to comparatively thin (from 3 till 10 cm) layer of principal soil organic and/or humus-accumulative horizons with maximum biological activity that usually determines the total rate of GHG soil fluxes. Unfavorable seasonal conditions (dry season or low temperature) determine essential (in 1.5-2 times) decreasing not only in soil GHG fluxes but in level of their spatial variability, intraseasonal and daily dynamics too. These trends are most obvious in case of more open and sensitive to the external factors ecosystems, for example in case of industrial area lawns or at the first stages of the windthrow or fallow-forest successions. Understanding the principal regional and land-use-determined regularities of spatial and temporal changes in ecosystem and soil GHG fluxes help better modeling them in the process of spatial intra- and extrapolations, seasonal and interseasonal predictions, taking into attention basic and current principal ecological factors limiting GHG fluxes and balances. Their introduction in the ecological or agroecological models and land-use decision support systems allows improve the quality of environmental/agroecological monitoring and control not only for GHG emission but also for soil organic matter conservation, manure and nitrogen fertilizer application that is often crucially important for sustainable rural development and profitable farming.

Soil cover patterns and SOC dynamics impacts on the soil processes, land management and ecosystem services in Central Region of Russia

NASA Astrophysics Data System (ADS)

Vasenev, Ivan; Chernikov, Vladimir; Yashin, Ivan; Geraskin, Mikhail; Morev, Dmitriy

2014-05-01

In the Central Region of Russia (CRR) the soil cover patterns usually play the very important role in the soil forming and degradation processes (SFP & SDP) potential and current rates, soil organic carbon (SOC) dynamics and pools, greenhouse gases (GHG) emissions and soluble SOC fluxes that we need take into attention for better assessment of the natural and especially man-changed ecosystems' services and for best land-use practices development. Central Region of Russia is the biggest one in RF according to its population and role in the economy. CRR is characterized by high spatial variability of soil cover due to as original landscape heterogeneity as complicated history of land-use practices during last 700 years. Our long-term researches include the wide zonal-provincial set of representative ecosystems and soil cover patterns with different types and history of land-use (forest, meadow-steppe and agricultural ones) from middle-taiga to steppe zones with different level of continentality. The carried out more than 30-years region- and local-scale researches of representative natural and rural landscapes in Tver', Yaroslavl', Kaluga, Moscow, Vladimir, Saransk (Mordovia), Kursk, Orel, Tambov, Voronezh and Saratov oblasts give us the interregional multi-factorial matrix of elementary soil cover patterns (ESCP) with different soil forming and degradation processes rates and soil organic carbon dynamics due to regionally specific soil-geomorphologic features, environmental and dominated microclimate conditions, land-use current practices and history. The validation and ranging of the limiting factors of SFP and SDP develop¬ment, soil carbon dynamics and sequestration potential, ecosystem (agroecosystem) principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of SOC structure analysis, regional and local GIS, soil spatial patterns detail

Level and determinants of food insecurity in East and West Gojjam zones of Amhara Region, Ethiopia: a community based comparative cross-sectional study.

PubMed

Motbainor, Achenef; Worku, Alemayehu; Kumie, Abera

2016-06-11

.643), household monthly income quartiles, 1(st) (AOR = 2.756, 95 % CI: 1.902, 3.993), and 2(nd) (AOR =1.897, 95 % CI: 1.299, 2.775) were the significant socio-demographic determinants in east Gojjam zone. Illiterate mothers (AOR = 1.388, 95 % CI: 1.011, 1.905), household monthly income quartiles, 1(st) (AOR = 3.110232, 95 % CI: 2.366, 4.415), 2(nd) (AOR =2.618, 95 % CI: 1.892, 3.622) and 3(rd) (AOR = 2.177, 95 % CI: 1.6911, 2.803) were the significant socio-demographic predictors in west Gojjam zone. Rural residential area (AOR = 3.201, 95 % CI: 1.832, 5.594) and (AOR = 2.425, 95 % CI: 1.79, 3.272), highland agro-ecology (AOR = 2.193, 95 % CI: 1.348, 3.569 and AOR = 3.669, 95 % CI: 2.442, 5.513) and lack of livestock (AOR = 1.553, 95 % CI: 1.160, 2.078 and AOR = 1.568 95 % CI: 1.183, 2.080) were significant environmental predictors in east and west Gojjam zones respectively. Food insecurity is highly prevalent in both study areas; however, there are different predictor factors. Intervention strategies should give emphasis to women's education, diversified income generating opportunities, and for each agro-ecological zone, mixed agriculture strategy.

Participatory data collection and monitoring of agricultural pest dynamics for climate-resilient coffee production using Tiko'n, a generic tool to develop agroecological food web models

NASA Astrophysics Data System (ADS)

Rojas, M.; Malard, J. J.; Adamowski, J. F.; Tuy, H.

2016-12-01

Climate variability impacts agricultural processes through many mechanisms. For example, the proliferation of pests and diseases increases with warmer climate and alternated wind patterns, as longer growing seasons allow pest species to complete more reproductive cycles and changes in the weather patterns alter the stages and rates of development of pests and pathogens. Several studies suggest that enhancing plant diversity and complexity in farming systems, such as in agroforestry systems, reduces the vulnerability of farms to extreme climatic events. On the other hand, other authors have argued that vegetation diversity does not necessarily reduce the incidence of pests and diseases, highlighting the importance of understanding how, where and when it is recommendable to diversify vegetation to improve pest and disease control, and emphasising the need for tools to develop, monitor and evaluate agroecosystems. In order to understand how biodiversity can enhance ecosystem services provided by the agroecosystem in the context of climatic variability, it is important to develop comprehensive models that include the role of trophic chains in the regulation of pests, which can be achieved by integrating crop models with pest-predator models, also known as agroecosystem network (AEN) models. Here we present a methodology for the participatory data collection and monitoring necessary for running Tiko'n, an AEN model that can also be coupled to a crop model such as DSSAT. This methodology aims to combine the local and practical knowledge of farmers with the scientific knowledge of entomologists and agronomists, allowing for the simplification of complex ecological networks of plant and insect interactions. This also increases the acceptability, credibility, and comprehension of the model by farmers, allowing them to understand their relationship with the local agroecosystem and their potential to use key agroecosystem principles such as functional diversity to mitigate climate variability impacts. Preliminary results of a study currently being conducted in a coffee agroforestry system in El Quebracho, Guatemala, will be presented, where the data was directly collected by farmers during eight consecutive months. Finally, future recommendations from lessons learnt during this study will be discussed.

C principal pools and fluxes in the field agroecosystems of Juriev-Polskiy Opolie

NASA Astrophysics Data System (ADS)

Atenbekov, Ramiz; Yashin, Ivan; Vasenev, Ivan

2017-04-01

There are results of 7-year (2010-2016) investigation of the Podzols and Podzoluvisols genesis, dynamics and soil organic carbon (SOC) pools in the representative agrolandscapes of the Yuryev-Polish plain (Yaroslavl region) with estimated environmental risks, including topsoil CO2 emission and the water-soluble organic substances (WSOS) profile and lateral fluxes in conditions of different land-use practice and microclimate conditions. A set of regional stationary plots has been investigated in 5 soil-ecological catenas with different level of erosion and hydromorphic processes. Soil organic matter is poorly fixed to the mineral matrix and has high migration ability, as shown by the sorption lysimeter and model experiments with weak solutions of oxalic acid and water. The total content of soil organic carbon varies in the range of 1.4% to 2.8% in topsoil of the investigated arable Podzols and Podzoluvisols. SOC fractional-group average composition indicates the presence of 37% of fulvic acids and 41% of gumins. The most available for soil microorganisms, enhancing CO2 emission, principal water-soluble organic substances accumulate in the topsoil A1 horizon, whereas the eluvial horizon E serves as a transit barrier to their profile migration and layer of active lateral migration. Modern climate and land-use changes play important role in the spatial-temporal variability of dominant soil GHG fluxes in these landscapes that determines the rising interest in the agroecological monitoring here to develop basic elements of the climate-smart farming systems with sustainable grass, winter wheat and barley production.

Inter- and intraspecific variation in leaf economic traits in wheat and maize

PubMed Central

Hale, Christine E; Cerabolini, Bruno E L; Cornelissen, Johannes H C; Craine, Joseph; Gough, William A; Kattge, Jens; Tirona, Cairan K F

2018-01-01

Abstract Leaf Economics Spectrum (LES) trait variation underpins multiple agroecological processes and many prominent crop yield models. While there are numerous independent studies assessing trait variation in crops, to date there have been no comprehensive assessments of intraspecific trait variation (ITV) in LES traits for wheat and maize: the world’s most widespread crops. Using trait databases and peer-reviewed literature, we compiled over 700 records of specific leaf area (SLA), maximum photosynthetic rates (Amax) and leaf nitrogen (N) concentrations, for wheat and maize. We evaluated intraspecific LES trait variation, and intraspecific trait–environment relationships. While wheat and maize occupy the upper 90th percentile of LES trait values observed across a global species pool, ITV ranged widely across the LES in wheat and maize. Fertilization treatments had strong impacts on leaf N, while plant developmental stage (here standardized as the number of days since planting) had strong impacts on Amax; days since planting, N fertilization and irrigation all influenced SLA. When controlling for these factors, intraspecific responses to temperature and precipitation explained 39.4 and 43.7 % of the variation in Amax and SLA, respectively, but only 5.4 % of the variation in leaf N. Despite a long history of domestication in these species, ITV in wheat and maize among and within cultivars remains large. Intraspecific trait variation is a critical consideration to refine regional to global models of agroecosystem structure, function and food security. Considerable opportunities and benefits exist for consolidating a crop trait database for a wider range of domesticated plant species. PMID:29484152

Is Bhutan destined for 100% organic? Assessing the economy-wide effects of a large-scale conversion policy.

PubMed

Feuerbacher, Arndt; Luckmann, Jonas; Boysen, Ole; Zikeli, Sabine; Grethe, Harald

2018-01-01

Organic agriculture (OA) is considered a strategy to make agriculture more sustainable. Bhutan has embraced the ambitious goal of becoming the world's first 100% organic nation. By analysing recent on-farm data in Bhutan, we found organic crop yields on average to be 24% lower than conventional yields. Based on these yield gaps, we assess the effects of the 100% organic conversion policy by employing an economy-wide computable general equilibrium (CGE) model with detailed representation of Bhutan's agricultural sector incorporating agroecological zones, crop nutrients, and field operations. Despite a low dependency on agrochemicals from the onset of this initiative, we find a considerable reduction in Bhutan's GDP, substantial welfare losses, particularly for non-agricultural households, and adverse impacts on food security. The yield gap is the main driver for a strong decline in domestic agricultural production, which is largely compensated by increased food imports, resulting in a weakening of the country's cereal self-sufficiency. Current organic by default farming practices in Bhutan are still underdeveloped and do not apply the systems approach of organic farming as defined in the IFOAM organic farming standards. This is reflected in the strong decline of nitrogen (N) availability to crops in our simulation and bears potential for increased yields in OA. Improvement of soil-fertility practices, e.g., the adoption of N-fixing crops, improved animal husbandry systems with increased provision of animal manure and access to markets with price premium for organic products could help to lower the economic cost of the large-scale conversion.

Thermodynamics of Cadmium Sorption on Different Soils of West Bengal, India

PubMed Central

Paul, Ranjit Kumar; Das, D. K.; Boruah, Romesh K.; Sonar, Indira

2014-01-01

A sorption study was conducted on different soils collected from five agroecological zones of West Bengal, India, to understand the soil environmental behavior and fate of cadmium. For this purpose batch adsorption experiments were carried out at the native soil pH and at three different temperatures (25°C, 35°C, and 45°C). The adsorption data fitted by a linear least squares technique to the different sorption isotherms. Most data obtained give the good fit to both Freundlich and modified Langmuir isotherms, but they are not consistent with the linear Langmuir adsorption model. Thermodynamic parameters, namely, thermodynamics equilibrium constant at a particular temperature T  (K T 0), Gibbs free energy at a particular temperature T  (ΔG T 0), and change of enthalpy (ΔH 0) and change of entropy at temperature T  (ΔS T 0), were also determined by applying sorption value and concentrations of Cd in equilibrium solution within the temperature range. The thermodynamic parameters revealed that Cd sorption increases as the values of K T 0, ΔG T 0, ΔH 0, and ΔS T 0 were increased on reaction temperatures. The spontaneous sorption reaction can be concluded due to high values of ΔG T 0. The positive values of ΔH 0 indicated that the Cd sorption is an endothermic one. Under these present conditions, the soil and its components possibly supply a number of sites having different adsorption energies for cadmium sorption. PMID:24683322

Climate Mitigation Versus Agriculture in the Tropics

NASA Astrophysics Data System (ADS)

McAfee, K.

2011-12-01

Significant new drivers of land-use change in the tropics are market-based strategies for climate-change mitigation and biodiversity conservation. These strategies are based on the putative monetary values of new commodities: genetic resources and ecosystem services, especially carbon sequestration services by forests. Payments for Ecosystem Services projects are expanding in Latin America, Asia, and some parts of Africa, promising a 'triple-win' for nature, the private sector, and the poor. Analysis of Mexico's national PES program and review of a growing body of PES case studies, however, reveal a pattern of conflict between poverty alleviation and other social goals, on the one hand, and the market-efficiency criteria that frame many PES projects, on the other hand. This poses a warning for more ambitious, global schemes based on similar principles, such as Reduced Emissions from Deforestation and Degradation (REDD). Additionally, transnational trade in carbon offsets, seen as a source of finance for PES and for REDD, puts climate policy on a collision course with agriculture, particularly given the context of closing land frontiers and international 'land-grabbing' claims on land for food-export plantations. Because market-based PES and REDD tend to target small- and medium-scale farmers, they are likely to constrain agriculture for domestic needs in regions where food security is already weak. Land-use governance based on conservation-by-commercialization can be compared to alternative approaches that link greening, food production, and social equity in a more integrated way, by combining scientific and local ecological and agroecological knowledge with strategies for rural revitalization and development.

Budgeting of major nutrients and the mitigation options for nutrient mining in semi-arid tropical agro-ecosystem of Tamil Nadu, India using NUTMON model.

PubMed

Surendran, U; Rama Subramoniam, S; Raja, P; Kumar, V; Murugappan, V

2016-04-01

Mining of nutrients from soil is a major problem in developing countries causing soil degradation and threaten long-term food production. The present study attempts to apply NUTrient MONitoring (NUTMON) model for carrying out nutrient budgeting to assess the stocks and flows of nitrogen (N), phosphorus (P), and potassium (K) in defined geographical unit based on the inputs, viz., mineral fertilizers, manures, atmospheric deposition, and sedimentation, and outputs, viz., harvested crop produces, residues, leaching, denitrification, and erosion losses. The study area covers Coimbatore and Erode Districts, which are potential agricultural areas in western agro-ecological zone of Tamil Nadu, India. The calculated nutrient balances for both the districts at district scale, using NUTMON methodology, were negative for nitrogen (N -3.3 and -10.1 kg ha(-1)) and potassium (K -58.6 and -9.8 kg ha(-1)) and positive for phosphorus (P +14.5 and 20.5 kg ha(-1)). Soil nutrient pool has to adjust the negative balance of N and K; there will be an expected mining of nutrient from the soil reserve. A strategy was attempted for deriving the fertilizer recommendation using Decision Support System for Integrated Fertilizer Recommendation (DSSIFER) to offset the mining in selected farms. The results showed that when DSSIFER recommended fertilizers are applied to crops, the nutrient balance was positive. NUTMON-Toolbox with DSSIFER would serve the purpose on enhancing soil fertility, productivity, and sustainability. The management options to mitigate nutrient mining with an integrated system approach are also discussed.

Mapping H5N1 highly pathogenic avian influenza risk in Southeast Asia

PubMed Central

Gilbert, Marius; Xiao, Xiangming; Pfeiffer, Dirk U.; Epprecht, M.; Boles, Stephen; Czarnecki, Christina; Chaitaweesub, Prasit; Kalpravidh, Wantanee; Minh, Phan Q.; Otte, M. J.; Martin, Vincent; Slingenbergh, Jan

2008-01-01

The highly pathogenic avian influenza (HPAI) H5N1 virus that emerged in southern China in the mid-1990s has in recent years evolved into the first HPAI panzootic. In many countries where the virus was detected, the virus was successfully controlled, whereas other countries face periodic reoccurrence despite significant control efforts. A central question is to understand the factors favoring the continuing reoccurrence of the virus. The abundance of domestic ducks, in particular free-grazing ducks feeding in intensive rice cropping areas, has been identified as one such risk factor based on separate studies carried out in Thailand and Vietnam. In addition, recent extensive progress was made in the spatial prediction of rice cropping intensity obtained through satellite imagery processing. This article analyses the statistical association between the recorded HPAI H5N1 virus presence and a set of five key environmental variables comprising elevation, human population, chicken numbers, duck numbers, and rice cropping intensity for three synchronous epidemic waves in Thailand and Vietnam. A consistent pattern emerges suggesting risk to be associated with duck abundance, human population, and rice cropping intensity in contrast to a relatively low association with chicken numbers. A statistical risk model based on the second epidemic wave data in Thailand is found to maintain its predictive power when extrapolated to Vietnam, which supports its application to other countries with similar agro-ecological conditions such as Laos or Cambodia. The model's potential application to mapping HPAI H5N1 disease risk in Indonesia is discussed. PMID:18362346

Farmers' perceptions of and adaptation strategies to climate change and their determinants; the case of Punjab province, Pakistan

NASA Astrophysics Data System (ADS)

Abid, M.; Scheffran, J.; Schneider, U. A.; Ashfaq, M.

2014-10-01

Climate change is a global environmental threat to all economic sectors, particularly the agricultural sector. Pakistan is one of the negatively affected countries from climate change due to its high exposure to extreme events and low adaptive capacity. In Pakistan, farmers are the primary stakeholders in agriculture and are more at risk due to climate vulnerability. Based on farm household data of 450 households collected from three districts in three agro-ecological zones in Punjab province of Pakistan, this study examined how farmers perceive climate change and how they adapt their farming in response to perceived changes in climate. The results demonstrate that awareness to climate change persists in the area, and farm households make adjustments to adapt their agriculture in response to climatic change. Overall 58% of the farm households adapted their farming to climate change. Changing crop varieties, changing planting dates, plantation of trees and changing fertilizer were the main adaptation methods implemented by farm households in the study area. Results from the binary logistic model revealed that education, farm experience, household size, land area, tenancy status, ownership of tube-well, access to market information, information on weather forecasting and extension all influence the farmers' choice of adaptation measures. Results also indicate that adaptation to climate change is constrained by several factors such as lack of information; lack of money; resource constraint and shortage of irrigation water in the study area. Findings of the study suggest the need of greater investment in farmer education and improved institutional setup for climate change adaptation to improve farmers' wellbeing.

Modelling the distribution of domestic ducks in Monsoon Asia

USGS Publications Warehouse

Van Bockel, Thomas P.; Prosser, Diann; Franceschini, Gianluca; Biradar, Chandra; Wint, William; Robinson, Tim; Gilbert, Marius

2011-01-01

Domestic ducks are considered to be an important reservoir of highly pathogenic avian influenza (HPAI), as shown by a number of geospatial studies in which they have been identified as a significant risk factor associated with disease presence. Despite their importance in HPAI epidemiology, their large-scale distribution in Monsoon Asia is poorly understood. In this study, we created a spatial database of domestic duck census data in Asia and used it to train statistical distribution models for domestic duck distributions at a spatial resolution of 1km. The method was based on a modelling framework used by the Food and Agriculture Organisation to produce the Gridded Livestock of the World (GLW) database, and relies on stratified regression models between domestic duck densities and a set of agro-ecological explanatory variables. We evaluated different ways of stratifying the analysis and of combining the prediction to optimize the goodness of fit of the predictions. We found that domestic duck density could be predicted with reasonable accuracy (mean RMSE and correlation coefficient between log-transformed observed and predicted densities being 0.58 and 0.80, respectively), using a stratification based on livestock production systems. We tested the use of artificially degraded data on duck distributions in Thailand and Vietnam as training data, and compared the modelled outputs with the original high-resolution data. This showed, for these two countries at least, that these approaches could be used to accurately disaggregate provincial level (administrative level 1) statistical data to provide high resolution model distributions.

Abnormally high digestive enzyme activity and gene expression explain the contemporary evolution of a Diabrotica biotype able to feed on soybeans

PubMed Central

Curzi, Matías J; Zavala, Jorge A; Spencer, Joseph L; Seufferheld, Manfredo J

2012-01-01

Western corn rootworm (Diabrotica virgifera) (WCR) depends on the continuous availability of corn. Broad adoption of annual crop rotation between corn (Zea mays) and nonhost soybean (Glycine max) exploited WCR biology to provide excellent WCR control, but this practice dramatically reduced landscape heterogeneity in East-central Illinois and imposed intense selection pressure. This selection resulted in behavioral changes and “rotation-resistant” (RR) WCR adults. Although soybeans are well defended against Coleopteran insects by cysteine protease inhibitors, RR-WCR feed on soybean foliage and remain long enough to deposit eggs that will hatch the following spring and larvae will feed on roots of planted corn. Other than documenting changes in insect mobility and egg laying behavior, 15 years of research have failed to identify any diagnostic differences between wild-type (WT)- and RR-WCR or a mechanism that allows for prolonged RR-WCR feeding and survival in soybean fields. We documented differences in behavior, physiology, digestive protease activity (threefold to fourfold increases), and protease gene expression in the gut of RR-WCR adults. Our data suggest that higher constitutive activity levels of cathepsin L are part of the mechanism that enables populations of WCR to circumvent soybean defenses, and thus, crop rotation. These new insights into the mechanism of WCR tolerance of soybean herbivory transcend the issue of RR-WCR diagnostics and management to link changes in insect gut proteolytic activity and behavior with landscape heterogeneity. The RR-WCR illustrates how agro-ecological factors can affect the evolution of insects in human-altered ecosystems. PMID:22957201

From population viability analysis to coviability of farmland biodiversity and agriculture.

PubMed

Mouysset, L; Doyen, L; Jiguet, F

2014-02-01

Substantial declines in farmland biodiversity have been reported in Europe for several decades. Agricultural changes have been identified as a main driver of these declines. Although different agrienvironmental schemes have been implemented, their positive effect on biodiversity is relatively unknown. This raises the question as to how to reconcile farming production and biodiversity conservation to operationalize a sustainable and multifunctional agriculture. We devised a bioeconomic model and conducted an analysis based on coviability of farmland biodiversity and agriculture. The coviability approach extended population viability analyses by including bioeconomic risk. Our model coupled stochastic dynamics of both biodiversity and farming land-uses selected at the microlevel with public policies at the macrolevel on the basis of financial incentives (taxes or subsidies) for land uses. The coviability approach made it possible for us to evaluate bioeconomic risks of these public incentives through the probability of satisfying a mix of biodiversity and economic constraints over time. We calibrated the model and applied it to a community of 34 common birds in metropolitan France at the small agricultural regions scale. We identified different public policies and scenarios with tolerable (0-0%) agroecological risk and modeled their outcomes up to 2050. Budgetary, economic, and ecological (based on Farmland Bird Index) constraints were essential to understanding the set of viable public policies. Our results suggest that some combinations of taxes on cereals and subsidies on grasslands could be relevant to develop a multifunctional agriculture. Moreover, the flexibility and multicriteria viewpoint underlying the coviability approach may help in the implementation of adaptive management. © 2013 Society for Conservation Biology.

Diagnosis of nutrient imbalances with vector analysis in agroforestry systems.

PubMed

Isaac, Marney E; Kimaro, Anthony A

2011-01-01

Agricultural intensification has had unintended environmental consequences, including increased nutrient leaching and surface runoff and other agrarian-derived pollutants. Improved diagnosis of on-farm nutrient dynamics will have the advantage of increasing yields and will diminish financial and environmental costs. To achieve this, a management support system that allows for site-specific rapid evaluation of nutrient production imbalances and subsequent management prescriptions is needed for agroecological design. Vector diagnosis, a bivariate model to depict changes in yield and nutritional response simultaneously in a single graph, facilitates identification of nutritional status such as growth dilution, deficiency, sufficiency, luxury uptake, and toxicity. Quantitative data from cocoa agroforestry systems and pigeonpea intercropping trials in Ghana and Tanzania, respectively, were re-evaluated with vector analysis. Relative to monoculture, biomass increase in cocoa ( L.) under shade (35-80%) was accompanied by a 17 to 25% decline in P concentration, the most limiting nutrient on this site. Similarly, increasing biomass with declining P concentrations was noted for pigeonpea [ (L). Millsp.] in response to soil moisture availability under intercropping. Although vector analysis depicted nutrient responses, the current vector model does not consider non-nutrient resource effects on growth, such as ameliorated light and soil moisture, which were particularly active in these systems. We revisit and develop vector analysis into a framework for diagnosing nutrient and non-nutrient interactions in agroforestry systems. Such a diagnostic technique advances management decision-making by increasing nutrient precision and reducing environmental issues associated with agrarian-derived soil contamination. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

"Candidatus anaplasma camelii" in one-humped camels (Camelus dromedarius) in Morocco: a novel and emerging anaplasma species?

PubMed

Ait Lbacha, Hicham; Zouagui, Zaid; Alali, Said; Rhalem, Abdelkbir; Petit, Elisabeth; Ducrotoy, Marie Julie; Boulouis, Henri-Jean; Maillard, Renaud

2017-02-05

There has been a growing interest in camel anaplasmosis due to its recent emergence in this reservoir species and concerns for its zoonotic potential. The epidemiology of anaplasmosis in camels therefore remains poorly understood mostly because camels belong to marginalised poor and often transhumant populations whose interests are largely neglected. Most studies of anaplasmosis in camels have relied on microscopy and serology for diagnosis and only three studies, undertaken in Tunisia, Saudia Arabia and China, have used molecular diagnostics. The present work characterises Anaplasmataceae strains circulating in the Camelus dromedarius reservoir in Morocco using PCR. Camels (n = 106) were randomly sampled from 6 regions representing different agro-ecological areas in southern Morocco. Whole blood was collected and screened using PCR methods targeting the gene groEL. Anaplasmataceae strains were characterised by sequence analysis of the gene groEL. A total of 39.62% (42/106) camels screened were positive for Anaplasmataceae spp. GenBank BLAST analysis of five positive sequenced samples revealed that all strains were 100% identical to "Candidatus Anaplasma camelii". Phylogenetic investigation and genetic characterisation of the aligned segment (650 bp) of the gene groEL confirmed high similarity with A. platys. This study demonstrates the circulation of a previously unidentified species of the genus Anaplasma in Morocco which is genetically close to the agent causing canine anaplasmosis but whose main reservoir is thought to be Camelus dromedarius. This study is not a clinical trial and therefore a trial registration number does not apply.

Influence of student-designed experiments with fast plants on their understanding of plants and of scientific inquiry

NASA Astrophysics Data System (ADS)

Akey, Ann Kosek

2000-10-01

This dissertation investigates the influence of student designed experiments with Fast Plants in an undergraduate agroecology course on the students' conceptual understanding of plant life cycles and on their procedural understanding of scientific experimentation. It also considers students' perspectives on the value of these experiences. Data sources included semi-structured interviews with students and the instructor, a written task, course evaluations, and observations of class meetings. Students came into the course having strong practical experience with plants from their agricultural backgrounds. Students did not always connect aspects of plant biology that they studied in class, particularly respiration and photosynthesis, to plant growth requirements. The instructor was able to bridge the gap between some practical knowledge and textbook knowledge with experiences other than the Fast Plant project. Most students held an incomplete picture of plant reproduction that was complicated by differences between agricultural and scientific vocabulary. There is need for teaching approaches that help students tie together their knowledge of plants into a cohesive framework. Experiences that help students draw on their background knowledge related to plants, and which give students the opportunity to examine and discuss their ideas, may help students make more meaningful connections. The Fast Plant project, a positive experience for most students, was seen by these undergraduate students as being more helpful in learning about scientific experimentation than about plants. The process of designing and carrying out their own experiments gave students insight into experimentation, provoked their curiosity, and resulted in a sense of ownership and accomplishment.

Organic vs. organic - soil arthropods as bioindicators of ecological sustainability in greenhouse system experiment under Mediterranean conditions.

PubMed

Madzaric, Suzana; Ceglie, F G; Depalo, L; Al Bitar, L; Mimiola, G; Tittarelli, F; Burgio, G

2017-11-23

Organic greenhouse (OGH) production is characterized by different systems and agricultural practices with diverse environmental impact. Soil arthropods are widely used as bioindicators of ecological sustainability in open field studies, while there is a lack of research on organic production for protected systems. This study assessed the soil arthropod abundance and diversity over a 2-year crop rotation in three systems of OGH production in the Mediterranean. The systems under assessment differed in soil fertility management: SUBST - a simplified system of organic production, based on an input substitution approach (use of guano and organic liquid fertilizers), AGROCOM - soil fertility mainly based on compost application and agroecological services crops (ASC) cultivation (tailored use of cover crops) as part of crop rotation, and AGROMAN - animal manure and ASC cultivation as part of crop rotation. Monitoring of soil fauna was performed by using pitfall traps and seven taxa were considered: Carabidae, Staphylinidae, Araneae, Opiliones, Isopoda, Myriapoda, and Collembola. Results demonstrated high potential of ASC cultivation as a technique for beneficial soil arthropod conservation in OGH conditions. SUBST system was dominated by Collembola in all crops, while AGROMAN and AGROCOM had more balanced relative abundance of Isopoda, Staphylinidae, and Aranea. Opiliones and Myriapoda were more affected by season, while Carabidae were poorly represented in the whole monitoring period. Despite the fact that all three production systems are in accordance with the European Union regulation on organic farming, findings of this study displayed significant differences among them and confirmed the suitability of soil arthropods as bioindicators in protected systems of organic farming.

Inter- and intraspecific variation in leaf economic traits in wheat and maize.

PubMed

Martin, Adam R; Hale, Christine E; Cerabolini, Bruno E L; Cornelissen, Johannes H C; Craine, Joseph; Gough, William A; Kattge, Jens; Tirona, Cairan K F

2018-02-01

Leaf Economics Spectrum (LES) trait variation underpins multiple agroecological processes and many prominent crop yield models. While there are numerous independent studies assessing trait variation in crops, to date there have been no comprehensive assessments of intraspecific trait variation (ITV) in LES traits for wheat and maize: the world's most widespread crops. Using trait databases and peer-reviewed literature, we compiled over 700 records of specific leaf area (SLA), maximum photosynthetic rates ( A max ) and leaf nitrogen (N) concentrations, for wheat and maize. We evaluated intraspecific LES trait variation, and intraspecific trait-environment relationships. While wheat and maize occupy the upper 90th percentile of LES trait values observed across a global species pool, ITV ranged widely across the LES in wheat and maize. Fertilization treatments had strong impacts on leaf N, while plant developmental stage (here standardized as the number of days since planting) had strong impacts on A max ; days since planting, N fertilization and irrigation all influenced SLA. When controlling for these factors, intraspecific responses to temperature and precipitation explained 39.4 and 43.7 % of the variation in A max and SLA, respectively, but only 5.4 % of the variation in leaf N. Despite a long history of domestication in these species, ITV in wheat and maize among and within cultivars remains large. Intraspecific trait variation is a critical consideration to refine regional to global models of agroecosystem structure, function and food security. Considerable opportunities and benefits exist for consolidating a crop trait database for a wider range of domesticated plant species.

Validity of food consumption indicators in the Lao context: moving toward cross-cultural standardization.

PubMed

Baumann, Soo Mee; Webb, Patrick; Zeller, Manfred

2013-03-01

Cross-cultural validity of food security indicators is commonly presumed without questioning the suitability of generic indicators in different geographic settings. However, ethnic differences in the perception of and reporting on, food insecurity, as well as variations in consumption patterns, may limit the comparability of results. Although research on correction factors for standardization of food security indicators is in process, so far no universal indicator has been identified. The current paper considers the ability of the Food Consumption Score (FCS) developed by the World Food Programme in southern Africa in 1996 to meet the requirement of local cultural validity in a Laotian context. The analysis is based on research that seeks to identify options for correcting possible biases linked to cultural disparities. Based on the results of a household survey conducted in different agroecological zones of Laos in 2009, the FCS was validated against a benchmark of calorie consumption. Changing the thresholds and excluding small amounts of food items consumed were tested as options to correct for biases caused by cultural disparities. The FCS in its original form underestimates the food insecurity level in the surveyed villages. However, the closeness of fit of the FCS to the benchmark classification improves when small amounts of food items are excluded from the assessment. Further research in different cultural settings is required to generate more insight into the extent to which universal thresholds can be applied to dietary diversity indicators with or without locally determined correction factors such as the exclusion of small amounts of food items.

Salinity and High Temperature Tolerance in Mungbean [Vigna radiata (L.) Wilczek] from a Physiological Perspective

PubMed Central

HanumanthaRao, Bindumadhava; Nair, Ramakrishnan M.; Nayyar, Harsh

2016-01-01

Biotic and abiotic constraints seriously affect the productivity of agriculture worldwide. The broadly recognized benefits of legumes in cropping systems—biological nitrogen fixation, improving soil fertility and broadening cereal-based agro-ecologies, are desirable now more than ever. Legume production is affected by hostile environments, especially soil salinity and high temperatures (HTs). Among legumes, mungbean has acceptable intrinsic tolerance mechanisms, but many agro-physiological characteristics of the Vigna species remain to be explored. Mungbean has a distinct advantage of being short-duration and can grow in wide range of soils and environments (as mono or relay legume). This review focuses on salinity and HT stresses on mungbean grown as a fallow crop (mungbean-rice-wheat to replace fallow-rice-wheat) and/or a relay crop in cereal cropping systems. Salinity tolerance comprises multifaceted responses at the molecular, physiological and plant canopy levels. In HTs, adaptation of physiological and biochemical processes gradually may lead to improvement of heat tolerance in plants. At the field level, managing or manipulating cultural practices can mitigate adverse effects of salinity and HT. Greater understanding of physiological and biochemical mechanisms regulating these two stresses will contribute to an evolving profile of the genes, proteins, and metabolites responsible for mungbean survival. We focus on abiotic stresses in legumes in general and mungbean in particular, and highlight gaps that need to be bridged through future mungbean research. Recent findings largely from physiological and biochemical fronts are examined, along with a few agronomic and farm-based management strategies to mitigate stress under field conditions. PMID:27446183

A comprehensive assessment of arsenic in commonly consumed foodstuffs to evaluate the potential health risk in Bangladesh.

PubMed

Ahmed, Md Kawser; Shaheen, Nazma; Islam, Md Saiful; Habibullah-Al-Mamun, Md; Islam, Saiful; Islam, Md Monirul; Kundu, Goutam Kumar; Bhattacharjee, Lalita

2016-02-15

Arsenic (As), particularly of its inorganic form (iAs) is highly toxic, and its presence in food composites is a matter of concern for the public health safety, specifically in Bangladesh which is regarded as the most arsenic affected country throughout the world. This study was carried out to investigate the levels of As in the composite samples of commonly consumed foodstuffs collected from 30 different agro-ecological zones for the first time in Bangladesh. Most of the individual food composites contain a considerable amount of As which was, as a whole, in the range of 0.077-1.5mg/kg fw which was lower than those reported from Spain, EU, France, Korea, whereas higher than those of Mexico, Chile, Japan, Cambodia, Hong Kong, Serbia, respectively. Cereals, vegetables, milk, and fish contribute about 90% to the daily intake of inorganic arsenic. Human health risk of dietary iAs was assessed separately for both the rural and urban adults. The estimated daily dietary intakes (EDI) of iAs for the exposed rural (3.5) and urban residents (3.2 μg/kg-BW/day) clearly exceeded the previous provisional tolerable daily intake (PTDI) value of 2.1 μg/kg-BW/day, recommended by the World Health Organization (WHO). From the health point of view, this study concluded that both the rural and urban residents of Bangladesh are exposed to carcinogenic and non-carcinogenic risks who consume As-contaminated water and foodstuffs. Copyright © 2015 Elsevier B.V. All rights reserved.

The xanthine oxidase activity in different of secondary transformed peat-moorsh soils

NASA Astrophysics Data System (ADS)

Styła, Katarzyna; Wojciech Szajdak, Lech

2010-05-01

The investigations were carried out on the transect of peatland 4.5 km long, located in the Agroecological Landscape Park host D. Chlapowski in Turew (40 km South-West of Poznań, West Polish Lowland). The sites investigation were located along Wyskoć ditch. The following material was taken from four chosen sites marked as Zbęchy, Bridge, Shelterbelt and Hirudo in two layers: acrotelm (0-50 cm) and catotelm (50-100 cm). The object of this study was to characterize the biochemical properties by the determination of the xanthine oxidase activity in two layers (acrotelm and catotelm) of the four different peat-moorsh soils used as meadow. The xanthine oxidase activity was determined spectrophotometrically by measuring uric acid formation at λmax=290 nm with xanthine as substrate. In peat-moorsh soil the highest activities of xanthine oxidasewas observed in the Shelterbelt and whereas the lowest - in Zbęchy, Bridge and Hirudo. Activities of this enzyme in peat-moorsh soil ranged from 5.96 to 19.51 μmol h-1g d.m soil. Increased activities of xanthine oxidase have been recorded on the depth 50-100 cm - catotelm (from 11.71 to 19.51 μmol h-1g d.m soil) in comparison with the depth 0-50 cm - acrotelm (from 5.96 to 14.64 μmol h-1g d.m soil). This work was supported by a grant No. N N305 3204 36 founded by Polish Ministry of Education.

A study on sheep farming practices in relation to future production strategies in Bensa district of Southern Ethiopia.

PubMed

Kenfo, Hizkel; Mekasha, Yoseph; Tadesse, Yosef

2018-04-01

The study was carried out in Bensa district of Sidama zone, Southern Ethiopia. Agro-ecologically, the study sites were classified into highland and mid-altitude. The objective of the study was to identify sheep farming practices in relation to future production strategies in the study area. A total of 128 households from four kebeles (lower administrative structure) were selected purposively based on sheep population and production potential and accessibility. Data was collected through semi-structured questionnaire, focus group discussions, and key informants. The result showed that most of the household heads were male (92.75%) and mixed crop-livestock system was the dominant production system. Among the livestock species, sheep accounted for the largest proportion across the two agro ecologies and the average sheep flock size/household was 4.6 ± 0.33 and 22 4.3 ± 0.213 in highland and in mid-altitude, respectively. The primary reason of keeping sheep was for cash income and saving across the two agro ecologies. The major feed resources for sheep during the wet and dry seasons were natural pasture and crop residues respectively across the two agro ecologies. Feed shortages, disease, parasite prevalence, and market were the major sheep production constraints in highland while feed shortage, genotype, disease, parasite prevalence, and market in mid-altitude. It can be concluded that for enhancing future production from sheep in the area, emphasis is to be given on feed availability, disease management, breeding policy, and marketing strategies.

Regional Approaches to Climate Change for Inland Pacific Northwest Cereal Production Systems

NASA Astrophysics Data System (ADS)

Eigenbrode, S. D.; Abatzoglou, J. T.; Burke, I. C.; Capalbo, S.; Gessler, P.; Huggins, D. R.; Johnson-Maynard, J.; Kruger, C.; Lamb, B. K.; Machado, S.; Mote, P.; Painter, K.; Pan, W.; Petrie, S.; Paulitz, T. C.; Stockle, C.; Walden, V. P.; Wulfhorst, J. D.; Wolf, K. J.

2011-12-01

The long-term environmental and economic sustainability of agriculture in the Inland Pacific Northwest (northern Idaho, north central Oregon, and eastern Washington) depends upon improving agricultural management, technology, and policy to enable adaptation to climate change and to help realize agriculture's potential to contribute to climate change mitigation. To address this challenge, three land-grant institutions (Oregon State University, the University of Idaho and Washington State University) (OSU, UI, WSU) and USDA Agricultural Research Service (ARS) units are partners in a collaborative project - Regional Approaches to Climate Change for Pacific Northwest Agriculture (REACCH-PNA). The overarching goal of REACCH is to enhance the sustainability of Inland Pacific Northwest (IPNW) cereal production systems under ongoing and projected climate change while contributing to climate change mitigation. Supporting goals include: - Develop and implement sustainable agricultural practices for cereal production within existing and projected agroecological zones throughout the region as climate changes, - Contribute to climate change mitigation through improved fertilizer, fuel, and pesticide use efficiency, increased sequestration of soil carbon, and reduced greenhouse gas (GHG) emissions consistent with the 2030 targets set by the USDA National Institute for Food and Agriculture (NIFA), - Work closely with stakeholders and policymakers to promote science-based agricultural approaches to climate change adaptation and mitigation, - Increase the number of scientists, educators, and extension professionals with the skills and knowledge to address climate change and its interactions with agriculture. In this poster, we provide an overview of the specific goals of this project and activities that are underway since its inception in spring of 2011.

The "sowing of concrete": Peri-urban smallholder perceptions of rural-urban land change in the Central Peruvian Andes.

PubMed

Haller, Andreas

2014-05-01

Policy makers concerned with the peri-urban interface find their greatest challenges in the rapid urban growth of developing mountain regions, since limitations caused by relief and altitude often lead to an increased competition between rural and urban land use at the valley floors. In this context, little attention has been paid to the affected agriculturalists' perceptions of peri-urban growth-important information required for the realization of sustainable land use planning. How is the process of rural-urban land change perceived and assessed by peri-urban smallholder communities? Which are the major difficulties to be overcome? By what means are the affected people reacting and how are these adaptation strategies linked with the ongoing landscape transformations of the hinterland? By using the example of Huancayo Metropolitano, an emerging Peruvian mountain city, it is shown that rural-urban land change is intensively discussed within peri-urban smallholder groups. Although urbanization also leads to infrastructure investments by public institutions-an advantage perceived throughout the study area-the negative impacts of rural-urban land use change prevail. The perceptions' analysis reveals that the decrease of fertile and irrigated agricultural land at the quechua valley floor is especially considered to threaten subsistence, food and income security. In order to compensate the loss of production capacities, many smallholders try to expand or intensify their land use at the suni altitudinal belt: an agro-ecological zone characterized by steep and nonirrigated slopes that can actually not be used for the year-round production of crops previously cultivated at the quechua zone.

Effects of Land Use Change on C-N cycling: Microbes Matter.

NASA Astrophysics Data System (ADS)

Hofmockel, K.

2012-12-01

Large swaths of the terrestrial landscape have been altered by human actions on Earth's biophysical systems, resulting in the homogenization of Earth's biota, while simultaneously increasing greenhouse gases and reactive nitrogen (N). This is especially poignant in grasslands that have been largely replaced by managed agricultural systems with substantial N inputs, or by unmanaged grasslands that are dominated by exotic species. Impacted ecosystems may be important for global C models, because they comprise a major portion of the global land area, terrestrial NPP and the world's soil C stocks. This research investigates how anthropogenic changes in plant community composition and agricultural management systems influence the composition and function of microbial communities that mediate key aspects of belowground C and N cycling and storage. Data from agroecology and grassland climate change experiments are used to illustrate how microbial responses can have important implications for large scale coupling of C and N cycles. In this study exotic plant species significantly decreased root inputs, causing shifts in microbial community composition, including both specific taxa and functional guilds of bacteria. By contrast, climate change (precipitation manipulation) caused functional responses (increased carbon and phosphorus cycling) that were not detected in the microbial community composition. Mycorrhizal fungi in managed systems were responsive to both root biomass and nitrogen inputs, significantly altering hydrolytic enzyme activity and aggregate turnover. Collectively small-scale processes can alter the ecosystem biogeochemical cycles. Together theses results suggest that linking microbial communities to coupled C-N cycles may have important implications for terrestrial C cycling feedbacks that are an integral part of the anthropocene era.

A review on prevalence, control measure, and tolerance of Tanzania Shorthorn Zebu cattle to East Coast fever in Tanzania.

PubMed

Laisser, E L K; Chenyambuga, S W; Karimuribo, E D; Msalya, G; Kipanyula, M J; Mwilawa, A J; Mdegela, R H; Kusiluka, L J M

2017-04-01

In Tanzania, control of East Coast fever (ECF) has predominantly relied on tick control using acaricides and chemotherapy, little on ECF vaccination, and very little on dissemination regarding animal immunization. In this paper, the prevalence, control measure, and tolerance of Tanzania Shorthorn Zebu (TSHZ) cattle to ECF are reviewed. In addition, the opportunities available for reducing the use of acaricides for the benefit of the farmers in terms of reduction of costs of purchasing acaricides and environmental pollution are described. The tick distribution and epidemiological factors for ECF such as the agro-ecological zones (AEZ), livestock production systems (LPS), strain, and age of the animals are also described. These factors influence the epidemiology of ECF and the distribution of TSHZ strains in different geographic locations of Tanzania. We have further showed that there is a tendency of farmers to select among the strains of TSHZ for animals which can tolerate ticks and ECF and crossbreed them with their local strains with the aim of benefiting from the inherent characteristics of the most tolerant strains. Generally, many strains of TSHZ cattle are tolerant to tick infestation and ECF infection and can be bred to respond to the needs of the people. In this review paper, we recommend that in future, ECF epidemiological studies should account for factors such as livestock production system, agro-climate, breed of animal, tick control strategy, and the dynamic interactions between them. In conclusion, we have demonstrated that an integrated control method involving use of acaricides, immunization, and ECF-tolerant/-resistant animals is required.

Green Revolution research saved an estimated 18 to 27 million hectares from being brought into agricultural production

PubMed Central

Stevenson, James R.; Villoria, Nelson; Byerlee, Derek; Kelley, Timothy; Maredia, Mywish

2013-01-01

New estimates of the impacts of germplasm improvement in the major staple crops between 1965 and 2004 on global land-cover change are presented, based on simulations carried out using a global economic model (Global Trade Analysis Project Agro-Ecological Zone), a multicommodity, multiregional computable general equilibrium model linked to a global spatially explicit database on land use. We estimate the impact of removing the gains in cereal productivity attributed to the widespread adoption of improved varieties in developing countries. Here, several different effects—higher yields, lower prices, higher land rents, and trade effects—have been incorporated in a single model of the impact of Green Revolution research (and subsequent advances in yields from crop germplasm improvement) on land-cover change. Our results generally support the Borlaug hypothesis that increases in cereal yields as a result of widespread adoption of improved crop germplasm have saved natural ecosystems from being converted to agriculture. However, this relationship is complex, and the net effect is of a much smaller magnitude than Borlaug proposed. We estimate that the total crop area in 2004 would have been between 17.9 and 26.7 million hectares larger in a world that had not benefited from crop germplasm improvement since 1965. Of these hectares, 12.0–17.7 million would have been in developing countries, displacing pastures and resulting in an estimated 2 million hectares of additional deforestation. However, the negative impacts of higher food prices on poverty and hunger under this scenario would likely have dwarfed the welfare effects of agricultural expansion. PMID:23671086

Complex agro-ecosystems for food security in a changing climate

PubMed Central

Khumairoh, Uma; Groot, Jeroen CJ; Lantinga, Egbert A

2012-01-01

Attempts to increase food crop yields by intensifying agricultural systems using high inputs of nonrenewable resources and chemicals frequently lead to de-gradation of natural resources, whereas most technological innovations are not accessible for smallholders that represent the majority of farmers world wide. Alternatively, cocultures consisting of assemblages of plant and animal species can support ecological processes of nutrient cycling and pest control, which may lead to increasing yields and declining susceptibility to extreme weather conditions with increasing complexity of the systems. Here we show that enhancing the complexity of a rice production system by adding combinations of compost, azolla, ducks, and fish resulted in strongly increased grain yields and revenues in a season with extremely adverse weather conditions on East Java, Indonesia. We found that azolla, duck, and fish increased plant nutrient content, tillering and leaf area expansion, and strongly reduced the density of six different pests. In the most complex system comprising all components the highest grain yield was obtained. The net revenues of this system from sales of rice grain, fish, and ducks, after correction for extra costs, were 114% higher than rice cultivation with only compost as fertilizer. These results provide more insight in the agro-ecological processes and demonstrate how complex agricultural systems can contribute to food security in a changing climate. If smallholders can be trained to manage these systems and are supported for initial investments by credits, their livelihoods can be improved while producing in an ecologically benign way. PMID:22957173

Emergy evaluation of the contribution of irrigation water, and its utilization, in three agricultural systems in China

NASA Astrophysics Data System (ADS)

Chen, Dan; Luo, Zhaohui; Webber, Michael; Chen, Jing; Wang, Weiguang

2014-09-01

Emergy theory and method are used to evaluate the contribution of irrigation water, and the process of its utilization, in three agricultural systems. The agricultural systems evaluated in this study were rice, wheat, and oilseed rape productions in an irrigation pumping district of China. A corresponding framework for emergy evaluation and sensitivity analysis methods was proposed. Two new indices, the fraction of irrigation water ( FIW), and the irrigation intensity of agriculture ( IIA), were developed to depict the contribution of irrigation water. The calculated FIW indicated that irrigation water used for the rice production system (34.7%) contributed more than irrigation water used for wheat (5.3%) and oilseed rape (11.2%) production systems in a typical dry year. The wheat production with an IIA of 19.0 had the highest net benefit from irrigation compared to the rice (2.9) and oilseed rape (8.9) productions. The transformities of the systems' products represented different energy efficiencies for rice (2.50E + 05 sej·J-1), wheat (1.66E + 05 sej·J-1) and oilseed rape (2.14E + 05 sej·J-1) production systems. According to several emergy indices, of the three systems evaluated, the rice system had the greatest level of sustainability. However, all of them were less sustainable than the ecological agricultural systems. A sensitivity analysis showed that the emergy inputs of irrigation water and nitrogenous fertilizer were the highest sensitivity factors influencing the emergy ratios. Best Management Practices, and other agroecological strategies, could be implemented to make further improvements in the sustainability of the three systems.

Ecological risk assessment of ecosystem services in the Taihu Lake Basin of China from 1985 to 2020.

PubMed

Xu, Xibao; Yang, Guishan; Tan, Yan; Zhuang, Qianlai; Li, Hengpeng; Wan, Rongrong; Su, Weizhong; Zhang, Jian

2016-06-01

There are tremendous theoretical, methodological and policy challenges in evaluating the impact of land-use change on the degradation of ecosystem services (ES) at the regional scale. This study addresses these challenges by developing an interdisciplinary methodology based on the Procedure for Ecological Tiered Assessment of Risk (PETAR). This novel methodology integrates ecological models with a land-use change model. This study quantifies the multi-dimensional degradation risks of ES in the Taihu Lake Basin (TLB) of China from 1985 to 2020. Four key ES related to water purification, water quantity adjustment, carbon sequestration and grain production are selected. The study employs models of Denitrification-Decomposition (DNDC), Soil-Water-Atmosphere-Plant (SWAP), Biome-BGC and Agro-ecological Zoning (AEZ) for assimilations. Land-use changes by 2020 were projected using a geographically weighted multinomial logit-cellular automata (GWML-CA) model. The results show that rapid land-use change has posed a great degradation risk of ES in the region in 1985-2020. Slightly less than two-thirds of the basin experienced degradation of ES over the 1985-2010 period, and about 12% of the basin will continue to experience degradation until 2020. Hot spots with severe deterioration in 2010-2020 are projected to be centered around some small and less developed cities in the region. Regulating accelerated urban sprawl and population growth, reinforcing current environmental programs, and establishing monitoring systems for observing dynamics of regional ES are suggested as practical counter-measures. Copyright © 2015 Elsevier B.V. All rights reserved.

A Pilot Study in Cameroon to Understand Safe Uses of Pesticides in Agriculture, Risk Factors for Farmers’ Exposure and Management of Accidental Cases

PubMed Central

Pouokam, Guy Bertrand; Lemnyuy Album, William; Ndikontar, Alice S.; SIDATT, Mohamed El Hady

2017-01-01

Chemical pesticides are widely used in Cameroon for agricultural production. In 2015, more than 600 pesticide products were approved for use in various foodstuffs. Much misuse of these chemicals by farmers has been documented in rural and urban settings. This pilot study aims to contribute to the improvement of the health of the population and the environmental preservation by identifying pesticide-poisoning cases, the most incriminated products and critical risk factors of exposure. Questionnaires were administered to pesticide vendors, farmers and health personnel, and observations made on farmers’ practices at their work places. From July to September 2016, 24 villages from five sites, representing the most important agricultural production areas of the five agro-ecological zones of Cameroon, were visited. In total, 519 people were interviewed: 412 farmers, 69 pesticide vendors and 38 health personnel. A total of 180 pesticide formulations out of 610 registered in 2015 were said to be used by farmers. In the 38 health centers visited, 56 cases of pesticide poisonings and intoxications were reported between 2011 and 2016. Paraquat-, glyphosate-, cypermethrin- and metalaxyl-formulated pesticides were the most incriminated. In total, 78% of poisoning cases were accidental, 12% suicide attempts, 4% criminal. Entry of pesticide products from neighboring countries needs to be better regulated, and the quality of pesticides sold on the market should be monitored periodically. Empty pesticide containers should be recuperated from smallholder farmers. Authorities should set up a harmonized pesticide-poisoning management procedure, and create a toxico-vigilance system for surveillance cases and preventive actions. PMID:29104250

What Does It Cost to Improve Household Diets in Nepal? Using the Cost of the Diet Method to Model Lowest Cost Dietary Changes.

PubMed

Biehl, Erin; Klemm, Rolf D W; Manohar, Swetha; Webb, Patrick; Gauchan, Devendra; West, Keith P

2016-07-03

In Nepal, limited availability and affordability of nutritious foods contribute to malnutrition. To identify nutrient deficiencies in commonly consumed diets and model lowest cost changes that could improve diet quality in 3 agroecological zones of Nepal. In August to September 2014, we collected market price and women's food frequency data from 3 representative villages in Nepal's mountains (Mahat Gaun, Jumla, n = 181 households), hills (Sitapur, Arghakhanchi, n = 166), and terai (Saigaun, Banke, n = 232) and verified local diets during women's group discussions. Using the Cost of the Diet method, we compared models of the most nutritious version of a commonly consumed diet given locally available foods ("common diet") with the cheapest possible diet meeting nutrient requirements, including foods not currently available ("optimal diet"). The household common diet lacks sufficient vitamin B12, riboflavin, and calcium in the mountains; B6, B12, calcium, and iron in the hills; vitamin A, calcium, and iron in the terai. Adding fish to the mountain and hill diets and increasing dark green leafy vegetable consumption in all zones yielded nutritional adequacy. Optimal diets are more expensive than the common diet in the mountains and hills but less expensive in the terai. The modeled lowest cost diet commonly eaten in 3 Nepalese communities lacks key nutrients. Policies and interventions that increase market availability and consumption of vitamin B12- and calcium-rich fish and dark green leafy vegetables could improve local diets, particularly in the mountains and hills. © The Author(s) 2016.

Identifying risk factors of highly pathogenic avian influenza (H5N1 subtype) in Indonesia.

PubMed

Loth, Leo; Gilbert, Marius; Wu, Jianmei; Czarnecki, Christina; Hidayat, Muhammad; Xiao, Xiangming

2011-10-01

Highly pathogenic avian influenza (HPAI), subtype H5N1, was first officially reported in Indonesia in 2004. Since then the disease has spread and is now endemic in large parts of the country. This study investigated the statistical relationship between a set of risk factors and the presence or absence of HPAI in Indonesia during 2006 and 2007. HPAI was evaluated through participatory disease surveillance (PDS) in backyard village chickens (the study population), and risk factors included descriptors of people and poultry distribution (separating chickens, ducks and production sectors), poultry movement patterns and agro-ecological conditions. The study showed that the risk factors "elevation", "human population density" and "rice cropping" were significant in accounting for the spatial variation of the PDS-defined HPAI cases. These findings were consistent with earlier studies in Thailand and Vietnam. In addition "commercial poultry population", and two indicators of market locations and transport; "human settlements" and "road length", were identified as significant risk factors in the models. In contrast to several previous studies carried out in Southeast Asia, domestic backyard ducks were not found to be a significant risk factor in Indonesia. The study used surrogate estimates of market locations and marketing chains and further work should focus on the actual location of the live bird markets, and on the flow of live poultry and poultry products between them, so that patterns of possible transmission, and regions of particular risk could be better inferred. Copyright © 2011 Elsevier B.V. All rights reserved.

The “sowing of concrete”: Peri-urban smallholder perceptions of rural–urban land change in the Central Peruvian Andes☆

PubMed Central

Haller, Andreas

2014-01-01

Policy makers concerned with the peri-urban interface find their greatest challenges in the rapid urban growth of developing mountain regions, since limitations caused by relief and altitude often lead to an increased competition between rural and urban land use at the valley floors. In this context, little attention has been paid to the affected agriculturalists’ perceptions of peri-urban growth—important information required for the realization of sustainable land use planning. How is the process of rural–urban land change perceived and assessed by peri-urban smallholder communities? Which are the major difficulties to be overcome? By what means are the affected people reacting and how are these adaptation strategies linked with the ongoing landscape transformations of the hinterland? By using the example of Huancayo Metropolitano, an emerging Peruvian mountain city, it is shown that rural–urban land change is intensively discussed within peri-urban smallholder groups. Although urbanization also leads to infrastructure investments by public institutions—an advantage perceived throughout the study area—the negative impacts of rural–urban land use change prevail. The perceptions’ analysis reveals that the decrease of fertile and irrigated agricultural land at the quechua valley floor is especially considered to threaten subsistence, food and income security. In order to compensate the loss of production capacities, many smallholders try to expand or intensify their land use at the suni altitudinal belt: an agro-ecological zone characterized by steep and nonirrigated slopes that can actually not be used for the year-round production of crops previously cultivated at the quechua zone. PMID:25844006

Yield Gap, Indigenous Nutrient Supply and Nutrient Use Efficiency for Maize in China.

PubMed

Xu, Xinpeng; Liu, Xiaoyan; He, Ping; Johnston, Adrian M; Zhao, Shicheng; Qiu, Shaojun; Zhou, Wei

2015-01-01

Great achievements have been attained in agricultural production of China, while there are still many difficulties and challenges ahead that call for put more efforts to overcome to guarantee food security and protect environment simultaneously. Analyzing yield gap and nutrient use efficiency will help develop and inform agricultural policies and strategies to increase grain yield. On-farm datasets from 2001 to 2012 with 1,971 field experiments for maize (Zea mays L.) were collected in four maize agro-ecological regions of China, and the optimal management (OPT), farmers' practice (FP), a series of nutrient omission treatments were used to analyze yield gap, nutrient use efficiency and indigenous nutrient supply by adopting meta-analysis and ANOVA analysis. Across all sites, the average yield gap between OPT and FP was 0.7 t ha-1, the yield response to nitrogen (N), phosphorus (P), and potassium (K) were 1.8, 1.0, and 1.2 t ha-1, respectively. The soil indigenous nutrient supply of N, P, and K averaged 139.9, 33.7, and 127.5 kg ha-1, respectively. As compared to FP, the average recovery efficiency (RE) of N, P, and K with OPT increased by percentage point of 12.2, 5.5, and 6.5, respectively. This study indicated that there would be considerable potential to further improve yield and nutrient use efficiency in China, and will help develop and inform agricultural policies and strategies, while some management measures such as soil, plant and nutrient are necessary and integrate with advanced knowledge and technologies.

Ecological intensification of cereal production systems: yield potential, soil quality, and precision agriculture.

PubMed

Cassman, K G

1999-05-25

Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply. Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation. Meeting future food demand while minimizing expansion of cultivated area primarily will depend on continued intensification of these same four systems. The manner in which further intensification is achieved, however, will differ markedly from the past because the exploitable gap between average farm yields and genetic yield potential is closing. At present, the rate of increase in yield potential is much less than the expected increase in demand. Hence, average farm yields must reach 70-80% of the yield potential ceiling within 30 years in each of these major cereal systems. Achieving consistent production at these high levels without causing environmental damage requires improvements in soil quality and precise management of all production factors in time and space. The scope of the scientific challenge related to these objectives is discussed. It is concluded that major scientific breakthroughs must occur in basic plant physiology, ecophysiology, agroecology, and soil science to achieve the ecological intensification that is needed to meet the expected increase in food demand.

Yield Gap, Indigenous Nutrient Supply and Nutrient Use Efficiency for Maize in China

PubMed Central

Xu, Xinpeng; Liu, Xiaoyan; He, Ping; Johnston, Adrian M.; Zhao, Shicheng; Qiu, Shaojun; Zhou, Wei

2015-01-01

Great achievements have been attained in agricultural production of China, while there are still many difficulties and challenges ahead that call for put more efforts to overcome to guarantee food security and protect environment simultaneously. Analyzing yield gap and nutrient use efficiency will help develop and inform agricultural policies and strategies to increase grain yield. On-farm datasets from 2001 to 2012 with 1,971 field experiments for maize (Zea mays L.) were collected in four maize agro-ecological regions of China, and the optimal management (OPT), farmers’ practice (FP), a series of nutrient omission treatments were used to analyze yield gap, nutrient use efficiency and indigenous nutrient supply by adopting meta-analysis and ANOVA analysis. Across all sites, the average yield gap between OPT and FP was 0.7 t ha-1, the yield response to nitrogen (N), phosphorus (P), and potassium (K) were 1.8, 1.0, and 1.2 t ha-1, respectively. The soil indigenous nutrient supply of N, P, and K averaged 139.9, 33.7, and 127.5 kg ha-1, respectively. As compared to FP, the average recovery efficiency (RE) of N, P, and K with OPT increased by percentage point of 12.2, 5.5, and 6.5, respectively. This study indicated that there would be considerable potential to further improve yield and nutrient use efficiency in China, and will help develop and inform agricultural policies and strategies, while some management measures such as soil, plant and nutrient are necessary and integrate with advanced knowledge and technologies. PMID:26484543

Effects of atmospheric deposition nitrogen flux and its composition on soil solution chemistry from a red soil farmland, southeast China.

PubMed

Cui, Jian; Zhou, Jing; Peng, Ying; Chan, Andrew; Mao, Jingdong

2015-12-01

A detailed study on the solution chemistry of red soil in South China is presented. Data are collected from two simulated column-leaching experiments with an improved setup to evaluate the effects of atmospheric N deposition (ADN) composition and ADN flux on agricultural soil acidification using a (15)N tracer technique and an in situ soil solution sampler. The results show that solution pH values decline regardless of the increase of the NH4(+)/NO3(-) ratio in the ADN composition or ADN flux, while exchangeable Al(3+), Ca(2+), Mg(2+), and K(+) concentrations increase at different soil depths (20, 40, and 60 cm). Compared with the control, ADN (60 kg per ha per year N, NH4(+)/NO3(-) ratio of 2 : 1) decreases solution pH values, increases solution concentrations of NO3(-)-N, Al(3+), Ca(2+) and Mg(2+) at the middle and lower soil depths, and promotes their removal. NH4(+)-N was not detected in red soil solutions of all the three soil layers, which might be attributed to effects of nitrification, absorption and fixation in farmland red soil. Some of the NO3(-)-N concentrations at 40-60 cm soil depth exceed the safe drinking level of 10 mg L(-1), especially when the ADN flux is beyond 60 kg ha(-1) N. These features are critical for understanding the ADN agro-ecological effects, and for future assessment of ecological critical loads of ADN in red soil farmlands.

Is Bhutan destined for 100% organic? Assessing the economy-wide effects of a large-scale conversion policy

PubMed Central

Luckmann, Jonas; Boysen, Ole; Zikeli, Sabine; Grethe, Harald

2018-01-01

Organic agriculture (OA) is considered a strategy to make agriculture more sustainable. Bhutan has embraced the ambitious goal of becoming the world’s first 100% organic nation. By analysing recent on-farm data in Bhutan, we found organic crop yields on average to be 24% lower than conventional yields. Based on these yield gaps, we assess the effects of the 100% organic conversion policy by employing an economy-wide computable general equilibrium (CGE) model with detailed representation of Bhutan’s agricultural sector incorporating agroecological zones, crop nutrients, and field operations. Despite a low dependency on agrochemicals from the onset of this initiative, we find a considerable reduction in Bhutan’s GDP, substantial welfare losses, particularly for non-agricultural households, and adverse impacts on food security. The yield gap is the main driver for a strong decline in domestic agricultural production, which is largely compensated by increased food imports, resulting in a weakening of the country’s cereal self-sufficiency. Current organic by default farming practices in Bhutan are still underdeveloped and do not apply the systems approach of organic farming as defined in the IFOAM organic farming standards. This is reflected in the strong decline of nitrogen (N) availability to crops in our simulation and bears potential for increased yields in OA. Improvement of soil-fertility practices, e.g., the adoption of N-fixing crops, improved animal husbandry systems with increased provision of animal manure and access to markets with price premium for organic products could help to lower the economic cost of the large-scale conversion. PMID:29897989

[Epidemiology of caprine and ovine brucellosis in Formosa province, Argentina].

PubMed

Russo, Ana M; Mancebo, Orlando A; Monzón, Carlos M; Gait, Juan J; Casco, Rubén D; Torioni de Echaide, Susana M

2016-01-01

An epidemiological study of brucellosis was carried out in 516 goats and mixed flocks (goat/sheep) from the three agro-ecological regions of Formosa province, Argentina. Serum samples from a total of 25401 goats and 2453 sheeps were analyzed using buffered plate agglutination test (BPAT) and complement fixation test (CFT). Bacteriological and PCR analyses on milk samples from goats in three flocks with a history of brucellosis and recent abortions were also performed. Brucellosis was detected in four of the nine departments of the province with an overall prevalence of 2% and an intra-flock prevalence ranging between 1% and 40%. The proportion of infected flocks was 3.6%, 12% and 36% for the eastern, central and western regions, respectively. Brucella melitensis bv. 1 was isolated efrom goats for the first time in the province. The expected fragments of 827bp from the omp2ab gene (Brucella spp.) and 731bp from the insert IS711 (B. melitensis) were amplified by PCR. Detection of antibodies by BPAT and FCT in sheep cohabiting with goats suggests that infections could have been caused by B. melitensis, posing an additional risk to public health. Control and eradication programs for brucellosis should consider mixed flocks as a single epidemiological unit. The results indicate that brucellosis by B. melitensis bv1 is highly endemic in the central and western regions of Formosa province. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Irrigated Agriculture in Morocco: An Agent-Based Model of Adaptation and Decision Making Amid Increasingly Frequent Drought Events

NASA Astrophysics Data System (ADS)

Norton, M.

2015-12-01

In the past 100 years, Morocco has undertaken a heavy investment in developing water infrastructure that has led to a dramatic expansion of irrigated agriculture. Irrigated agriculture is the primary user of water in many arid countries, often accounting for 80-90% of total water usage. Irrigation is adopted by farmers not only because it leads to increased production, but also because it improves resilience to an uncertain climate. However, the Mediterranean region as a whole has also seen an increase in the frequency and severity of drought events. These droughts have had a dramatic impact on farmer livelihoods and have led to a number of coping strategies, including the adoption or disadoption of irrigation. In this study, we use a record of the annual extent of irrigated agriculture in Morocco to model the effect of drought on the extent of irrigated agriculture. Using an agent-based socioeconomic model, we seek to answer the following questions: 1) Do farmers expand irrigated agriculture in response to droughts? 2) Do drought events entail the removal of perennial crops like orchards? 3) Can we detect the retreat of irrigated agriculture in the more fragile watersheds of Morocco? Understanding the determinants of irrigated crop expansion and contractions will help us understand how agro-ecological systems transition from 20th century paradigms of expansion of water supply to a 21st century paradigm of water use efficiency. The answers will become important as countries learn how to manage water in new climate regimes characterized by less reliable and available precipitation.

Green Revolution research saved an estimated 18 to 27 million hectares from being brought into agricultural production.

PubMed

Stevenson, James R; Villoria, Nelson; Byerlee, Derek; Kelley, Timothy; Maredia, Mywish

2013-05-21

New estimates of the impacts of germplasm improvement in the major staple crops between 1965 and 2004 on global land-cover change are presented, based on simulations carried out using a global economic model (Global Trade Analysis Project Agro-Ecological Zone), a multicommodity, multiregional computable general equilibrium model linked to a global spatially explicit database on land use. We estimate the impact of removing the gains in cereal productivity attributed to the widespread adoption of improved varieties in developing countries. Here, several different effects--higher yields, lower prices, higher land rents, and trade effects--have been incorporated in a single model of the impact of Green Revolution research (and subsequent advances in yields from crop germplasm improvement) on land-cover change. Our results generally support the Borlaug hypothesis that increases in cereal yields as a result of widespread adoption of improved crop germplasm have saved natural ecosystems from being converted to agriculture. However, this relationship is complex, and the net effect is of a much smaller magnitude than Borlaug proposed. We estimate that the total crop area in 2004 would have been between 17.9 and 26.7 million hectares larger in a world that had not benefited from crop germplasm improvement since 1965. Of these hectares, 12.0-17.7 million would have been in developing countries, displacing pastures and resulting in an estimated 2 million hectares of additional deforestation. However, the negative impacts of higher food prices on poverty and hunger under this scenario would likely have dwarfed the welfare effects of agricultural expansion.

Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments

PubMed Central

Yang, Ji; Li, Wen-Rong; Lv, Feng-Hua; He, San-Gang; Tian, Shi-Lin; Peng, Wei-Feng; Sun, Ya-Wei; Zhao, Yong-Xin; Tu, Xiao-Long; Zhang, Min; Xie, Xing-Long; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Wang, Feng; Liu, Guang-Jian; Lu, Hong-Feng; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua; Liu, Ming-Jun

2016-01-01

Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8–9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change. PMID:27401233

Adaptations to Climate-Mediated Selective Pressures in Sheep

PubMed Central

Lv, Feng-Hua; Agha, Saif; Kantanen, Juha; Colli, Licia; Stucki, Sylvie; Kijas, James W.; Joost, Stéphane; Li, Meng-Hua; Ajmone Marsan, Paolo

2014-01-01

Following domestication, sheep (Ovis aries) have become essential farmed animals across the world through adaptation to a diverse range of environments and varied production systems. Climate-mediated selective pressure has shaped phenotypic variation and has left genetic “footprints” in the genome of breeds raised in different agroecological zones. Unlike numerous studies that have searched for evidence of selection using only population genetics data, here, we conducted an integrated coanalysis of environmental data with single nucleotide polymorphism (SNP) variation. By examining 49,034 SNPs from 32 old, autochthonous sheep breeds that are adapted to a spectrum of different regional climates, we identified 230 SNPs with evidence for selection that is likely due to climate-mediated pressure. Among them, 189 (82%) showed significant correlation (P ≤ 0.05) between allele frequency and climatic variables in a larger set of native populations from a worldwide range of geographic areas and climates. Gene ontology analysis of genes colocated with significant SNPs identified 17 candidates related to GTPase regulator and peptide receptor activities in the biological processes of energy metabolism and endocrine and autoimmune regulation. We also observed high linkage disequilibrium and significant extended haplotype homozygosity for the core haplotype TBC1D12-CH1 of TBC1D12. The global frequency distribution of the core haplotype and allele OAR22_18929579-A showed an apparent geographic pattern and significant (P ≤ 0.05) correlations with climatic variation. Our results imply that adaptations to local climates have shaped the spatial distribution of some variants that are candidates to underpin adaptive variation in sheep. PMID:25249477

Identifying risk factors of highly pathogenic avian influenza (H5N1 subtype) in Indonesia

PubMed Central

Leo, Loth; Marius, Gilbert; Jianmei, Wu; Christina, Czarnecki; Muhammad, Hidayat; Xiangming, Xiao

2016-01-01

Highly pathogenic avian influenza (HPAI), subtype H5N1, was first officially reported in Indonesia in 2004. Since then the disease has spread and is now endemic in large parts of the country. This study investigated the statistical relationship between a set of risk factors and the presence or absence of HPAI in Indonesia during 2006 and 2007. HPAI was evaluated through participatory disease surveillance (PDS) in backyard village chickens (the study population), and risk factors included descriptors of people and poultry distribution (separating chickens, ducks and production sectors), poultry movement patterns and agro-ecological conditions. The study showed that the risk factors “elevation”, “human population density” and “rice cropping” were significant in accounting for the spatial variation of the PDS-defined HPAI cases. These findings were consistent with earlier studies in Thailand and Vietnam. In addition “commercial poultry population”, and two indicators of market locations and transport; “human settlements” and “road length”, were identified as significant risk factors in the models. In contrast to several previous studies carried out in Southeast Asia, domestic backyard ducks were not found to be a significant risk factor in Indonesia. The study used surrogate estimates of market locations and marketing chains and further work should focus on the actual location of the live bird markets, and on the flow of live poultry and poultry products between them, so that patterns of possible transmission, and regions of particular risk could be better inferred. PMID:21813198

Practical problems in controlling H5N1 high pathogenicity avian influenza at village level in Vietnam and introduction of biosecurity measures.

PubMed

Cristalli, Alessandro; Capua, Ilaria

2007-03-01

After a consultancy mission funded by a nongovernmental organization (NGO), information was collected on the dynamics of avian influenza (AI) infection at the rural level in a Vietnamese province with several ongoing outbreaks. AI outbreaks are frequent at village level due to environmental, ecological, agroecological, physical, social, and cultural factors, the underlying factor being poor hygienic conditions. Viral circulation is facilitated by the interactions of the integrated aquaculture, animal raising, horticulture agroecosystem, which relies in the peculiar integration of aquaculture (ponding), animal activities, and horticulture and by the connections with the live-bird market system. The interactions of these factors determine the complex system in which wild birds interact with domestic birds and in which people are constantly exposed to sources of infection, leading to the association between poverty and AI infection in humans. This experience underlines that despite all efforts by the Vietnamese Government, international institutions, and the NGO sector, awareness of AI at the village level needs to be improved. In turn, the leading institutions and international donors funding projects of technical cooperation aimed at tackling AI in Vietnam should invest in a system based on a deep knowledge of the practical problems of village condition to address AI with an effective approach. On the basis of the data collected during the mission, particularly on rural and semi-intensive poultry rearing systems, proposals that encompass the application of an effective vaccination strategy including backyard flocks coupled with dissemination of relevant information on biosecurity measures have been developed for decision makers.

Genetic variation and population structure of maize inbred lines adapted to the mid-altitude sub-humid maize agro-ecology of Ethiopia using single nucleotide polymorphic (SNP) markers.

PubMed

Ertiro, Berhanu Tadesse; Semagn, Kassa; Das, Biswanath; Olsen, Michael; Labuschagne, Maryke; Worku, Mosisa; Wegary, Dagne; Azmach, Girum; Ogugo, Veronica; Keno, Tolera; Abebe, Beyene; Chibsa, Temesgen; Menkir, Abebe

2017-10-12

Molecular characterization is important for efficient utilization of germplasm and development of improved varieties. In the present study, we investigated the genetic purity, relatedness and population structure of 265 maize inbred lines from the Ethiopian Institute of Agricultural Research (EIAR), the International Maize and Wheat Improvement Centre (CIMMYT) and the International Institute of Tropical Agriculture (IITA) using 220,878 single nucleotide polymorphic (SNP) markers obtained using genotyping by sequencing (GBS). Only 22% of the inbred lines were considered pure with <5% heterogeneity, while the remaining 78% of the inbred lines had a heterogeneity ranging from 5.1 to 31.5%. Pairwise genetic distances among the 265 inbred lines varied from 0.011 to 0.345, with 89% of the pairs falling between 0.301 and 0.345. Only <1% of the pairs had a genetic distance lower than 0.200, which included 14 pairs of sister lines that were nearly identical. Relative kinship analysis showed that the kinship coefficients for 59% of the pairs of lines was close to zero, which agrees with the genetic distance estimates. Principal coordinate analysis, discriminant analysis of principal components (DAPC) and the model-based population structure analysis consistently suggested the presence of three groups, which generally agreed with pedigree information (genetic background). Although not distinct enough, the SNP markers showed some level of separation between the two CIMMYT heterotic groups A and B established based on pedigree and combining ability information. The high level of heterogeneity detected in most of the inbred lines suggested the requirement for purification or further inbreeding except those deliberately maintained at early inbreeding level. The genetic distance and relative kinship analysis clearly indicated the uniqueness of most of the inbred lines in the maize germplasm available for breeders in the mid-altitude maize breeding program of Ethiopia. Results from the present study facilitate the maize breeding work in Ethiopia and germplasm exchange among breeding programs in Africa. We suggest the incorporation of high density molecular marker information in future heterotic group assignments.

Can nanotechnology deliver the promised benefits without negatively impacting soil microbial life?

PubMed

Dimkpa, Christian O

2014-09-01

Nanotechnology exploits the enhanced reactivity of materials at the atomic scale to improve various applications for humankind. In agriculture, potential nanotechnology applications include crop protection and fertilization. However, such benefits could come with risks for the environment: non-target plants, plant-beneficial soil microbes and other life forms could be impacted if nanoparticles (nanomaterials) contaminate the environment. This review evaluates the impact of the major metallic nanoparticles (Ag, ZnO, CuO, CeO2 , TiO2 , and FeO-based nanoparticles) on soil microbes involved in agricultural processes. The current literature indicate that in addition to population and organismal-scale effects on microbes, other subtle impacts of nanoparticles are seen in the nitrogen cycle, soil enzyme activities, and processes involved in iron metabolism, phytohormone, and antibiotic production. These effects are negative or positive, the outcome being dependent on specific nanoparticles. Collectively, published results suggest that nanotechnology portends considerable, many negative, implications for soil microbes and, thus, agricultural processes that are microbially driven. Nonetheless, the potential of plant and soil microbial processes to mitigate the bioreactivity of nanoparticles also are observed. Whereas the roots of most terrestrial plants are associated with microbes, studies of nanoparticle interactions with plants and microbes are generally conducted separately. The few studies in actual microbe-plant systems found effects of nanoparticles on the functioning of arbuscular mycorrhizal fungi, nitrogen fixation, as well as on the production of microbial siderophores in the plant rhizosphere. It is suggested that a better understanding of the agro-ecological ramifications of nanoparticles would require more in-depth interactive studies in combined plant-microbe-nanoparticle systems. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reframing the land-sparing/land-sharing debate for biodiversity conservation.

PubMed

Kremen, Claire

2015-10-01

Conservation biologists are devoting an increasing amount of energy to debating whether land sparing (high-yielding agriculture on a small land footprint) or land sharing (low-yielding, wildlife-friendly agriculture on a larger land footprint) will promote better outcomes for local and global biodiversity. In turn, concerns are mounting about how to feed the world, given increasing demands for food. In this review, I evaluate the land-sparing/land-sharing framework--does the framework stimulate research and policy that can reconcile agricultural land use with biodiversity conservation, or is a revised framing needed? I review (1) the ecological evidence in favor of sparing versus sharing; (2) the evidence from land-use change studies that assesses whether a relationship exists between agricultural intensification and land sparing; and (3) how that relationship may be affected by socioeconomic and political factors. To address the trade-off between biodiversity conservation and food production, I then ask which forms of agricultural intensification can best feed the world now and in the future. On the basis of my review, I suggest that the dichotomy of the land-sparing/land-sharing framework limits the realm of future possibilities to two, largely undesirable, options for conservation. Both large, protected regions and favorable surrounding matrices are needed to promote biodiversity conservation; they work synergistically and are not mutually exclusive. A "both-and" framing of large protected areas surrounded by a wildlife-friendly matrix suggests different research priorities from the "either-or" framing of sparing versus sharing. Furthermore, wildlife-friendly farming methods such as agroecology may be best adapted to provide food for the world's hungry people. © 2015 New York Academy of Sciences.

Assessing the Potential and Limitations of Leveraging Food Sovereignty to Improve Human Health.

PubMed

Jones, Andrew D; Fink Shapiro, Lilly; Wilson, Mark L

2015-01-01

Food sovereignty has been defined as "the right of peoples to healthy and culturally appropriate food produced through ecologically sound and sustainable methods, and their right to define their own food and agriculture systems." Human health is an implied component of this definition through the principle of healthy food. In fact, improved human health is commonly cited as a benefit of transforming food production away from the dominant practices of industrial agriculture. Yet, does the use of "ecologically sound and sustainable methods" of food production necessarily translate into better human health outcomes? Does greater choice in defining an agricultural or food system create gains in health and well-being? We elucidate the conceptual linkages between food sovereignty and human health, critically examine the empirical evidence supporting or refuting these linkages, and identify research gaps and key priorities for the food sovereignty-human health research agenda. Five domains of food sovereignty are discussed including: (1) use of agroecological management practices for food production, (2) the localization of food production and consumption, (3) promotion of social justice and equity, (4) valuation of traditional knowledge, and (5) the transformation of economic and political institutions and structures to support self-determination. We find that although there are many plausible linkages between food sovereignty and human health, the empirical evidence in support of the hypothesis that increasing food sovereignty yields improvements to human health is weak. We propose that a concerted effort to generate new empirical evidence on the health implications of these domains of food sovereignty is urgently needed, and suggest areas of research that may be crucial for addressing the gaps in the evidence base.

Assessing the Potential and Limitations of Leveraging Food Sovereignty to Improve Human Health

PubMed Central

Jones, Andrew D.; Fink Shapiro, Lilly; Wilson, Mark L.

2015-01-01

Food sovereignty has been defined as “the right of peoples to healthy and culturally appropriate food produced through ecologically sound and sustainable methods, and their right to define their own food and agriculture systems.” Human health is an implied component of this definition through the principle of healthy food. In fact, improved human health is commonly cited as a benefit of transforming food production away from the dominant practices of industrial agriculture. Yet, does the use of “ecologically sound and sustainable methods” of food production necessarily translate into better human health outcomes? Does greater choice in defining an agricultural or food system create gains in health and well-being? We elucidate the conceptual linkages between food sovereignty and human health, critically examine the empirical evidence supporting or refuting these linkages, and identify research gaps and key priorities for the food sovereignty-human health research agenda. Five domains of food sovereignty are discussed including: (1) use of agroecological management practices for food production, (2) the localization of food production and consumption, (3) promotion of social justice and equity, (4) valuation of traditional knowledge, and (5) the transformation of economic and political institutions and structures to support self-determination. We find that although there are many plausible linkages between food sovereignty and human health, the empirical evidence in support of the hypothesis that increasing food sovereignty yields improvements to human health is weak. We propose that a concerted effort to generate new empirical evidence on the health implications of these domains of food sovereignty is urgently needed, and suggest areas of research that may be crucial for addressing the gaps in the evidence base. PMID:26636062

Agrogenic transformation of soil organic C in conditions of southern-taiga zone, European Russia

NASA Astrophysics Data System (ADS)

Yashin, Ivan; Vasenev, Ivan; Atenbekov, Ramiz

2017-04-01

The principal regional features of soil organic carbon (SOC) agrogenic transformation and water-soluble organic substances (WSOS) genesis and environmental functions have been investigated in the Podzols and Podzoluvisols of the representative natural and agro- ecosystems in the southern taiga subzone of the European part of Russia. Especial attention has been done to the role of SOC agrogenic degradation and WSOS with acidic and ligand properties in soil carbon dioxide emission. The long-term agroecological investigations run in the regional set of representative agrolandscape monitoring stations in the educational farm "Mikhailovskoye" (Podolsk district, Moscow region), Field experimental station and Forest experimental station (RTSAU campus, Moscow) and in the Central Forest biosphere reserve (Nelidovo district, Tver region). Field research methods include sorption lysimetry and radioactive tracers. The laboratory ones - chromatography and spectrophotometry. There were used activated charcoal brand "Carbolite", chemically purified quartz sand and barley plant residues (2-3 mm), totally labeled with 14C in the soil-horizontally distributed sorption columns. Obtained results became useful for quantitative assessment of the principal stages and processes in soil CO2 emission, including the water-soluble organic substances formation (3.0 g of SOC per 100 g of plant litter or 60-75 g of SOC per square meter of the organo-mineral horizon A0 per year) and CO2 emission. In the middle taiga ecosystem conditions (with relatively low soil biological activity) the highest emission of CO2 (83,0±4.1 % of the newly formed WSOS) was in case of arable Podzoluvisols, and lowest one (32,4±2,5%) - in their semihydromorphic versions.

Farmers' perceptions of and adaptation strategies to climate change and their determinants: the case of Punjab province, Pakistan

NASA Astrophysics Data System (ADS)

Abid, M.; Scheffran, J.; Schneider, U. A.; Ashfaq, M.

2015-05-01

Climate change is a global environmental threat to all economic sectors, particularly the agricultural sector. Pakistan is one of the countries negatively affected by climate change due to its high exposure to extreme events and low adaptive capacity. In Pakistan, farmers are the primary stakeholders in agriculture and are more at risk due to climate vulnerability. Based on farm household data from 450 households collected from three districts in three agroecological zones in the Punjab province of Pakistan, this study examines how farmers perceive climate change and how they adapt their farming in response to perceived changes in climate. The results demonstrate that awareness of climate change is widespread throughout the area, and farm households make adjustments to adapt their agriculture in response to climatic change. Overall 58% of the farm households adapted their farming to climate change. Changing crop varieties, changing planting dates, planting of shade trees and changing fertilizers were the main adaptation methods implemented by farm households in the study area. The results from the binary logistic model reveal that education, farm experience, household size, land area, tenancy status, ownership of a tube well, access to market information, information on weather forecasting and agricultural extension services all influence farmers' choices of adaptation measures. The results also indicate that adaptation to climate change is constrained by several factors such as lack of information, lack of money, resource constraints and shortage of irrigation water in the study area. Findings of the study suggest the need for greater investment in farmer education and improved institutional setup for climate change adaptation to improve farmers' wellbeing.

Water savings of redistributing global crop production

NASA Astrophysics Data System (ADS)

Davis, Kyle; Seveso, Antonio; Rulli, Maria Cristina; D'Odorico, Paolo

2016-04-01

Human demand for crop production is expected to increase substantially in the coming decades as a result of population growth, richer diets and biofuel use. For food production to keep pace, unprecedented amounts of resources - water, fertilizers, energy - will be required. This has led to calls for 'sustainable intensification' in which yields are increased on existing croplands while seeking to minimize impacts on water and other agricultural resources. Recent studies have quantified aspects of this, showing that there is a large potential to improve crop yields and increase harvest frequencies to better meet human demand. Though promising, both solutions would necessitate large additional inputs of water and fertilizer in order to be achieved under current technologies. However, the question of whether the current distribution of crops is, in fact, the best for realizing maximized production has not been considered to date. To this end, we ask: Is it possible to minimize water demand by simply growing crops where soil and climate conditions are best suited? Here we use maps of agro-ecological suitability - a measure of physical and chemical soil fertility - for 15 major food crops to identify differences between current crop distributions and where they can most suitably be planted. By redistributing crops across currently cultivated lands, we determine what distribution of crops would maintain current calorie production and agricultural value while minimizing the water demand of crop production. In doing this, our study provides a novel tool for policy makers and managers to integrate food security, environmental sustainability, and rural livelihoods by improving the use of freshwater resources without compromising crop calorie production or rural livelihoods.

Calorie increase and water savings of redistributing global crop production

NASA Astrophysics Data System (ADS)

Davis, K. F.; Seveso, A.; Rulli, M. C.; D'Odorico, P.

2015-12-01

Human demand for crop production is expected to increase substantially in the coming decades as a result of population growth, richer diets and biofuel use. In order for food production to keep pace, unprecedented amounts of resources - water, fertilizers, energy - will be required. This has led to calls for 'sustainable intensification' in which yields are increased on existing croplands while seeking to minimize impacts on water and other agricultural resources. Recent studies have quantified aspects of this, showing that there is a large potential to improve crop yields and increase harvest frequencies to better meet human demand. Though promising, both solutions would necessitate large additional inputs of water and fertilizer in order to be achieved under current technologies. However, the question of whether the current distribution of crops is, in fact, the best for realizing maximized production has not been considered to date. To this end, we ask: Is it possible to increase calorie production and minimize water demand by simply growing crops where soil and climate conditions are best suited? Here we use maps of agro-ecological suitability - a measure of physical and chemical soil fertility - for 15 major food crops to identify differences between current crop distributions and where they can most suitably be planted. By redistributing crops across currently cultivated lands, we determine the potential improvement in calorie production as well as the associated change in water demand. We also consider what distribution of crops would maintain current calorie production while minimizing crop water demand. In doing all of this, our study provides a novel tool for improving crop calorie production without necessarily increasing resource demands.

Women's empowerment in agriculture and child nutritional status in rural Nepal.

PubMed

Cunningham, Kenda; Ploubidis, George B; Menon, Purnima; Ruel, Marie; Kadiyala, Suneetha; Uauy, Ricardo; Ferguson, Elaine

2015-12-01

To examine the association between women's empowerment in agriculture and nutritional status among children under 2 years of age in rural Nepal. Cross-sectional survey of 4080 households conducted in 2012. Data collected included: child and maternal anthropometric measurements; child age and sex; maternal age, education, occupation and empowerment in agriculture; and household size, number of children, religion, caste and agro-ecological zone. Associations between the Women's Empowerment in Agriculture Index (WEAI)'s Five Domains of Empowerment (5DE) sub-index and its ten component indicators and child length-for-age Z-scores (LAZ) and weight-for-length Z-scores (WLZ) were estimated, using ordinary least-squares regression models, with and without adjustments for key child, maternal and household level covariates. Two hundred and forty rural communities across sixteen districts of Nepal. Children under 24 months of age and their mothers (n 1787). The overall WEAI 5DE was positively associated with LAZ (β=0·20, P=0·04). Three component indicators were also positively associated with LAZ: satisfaction with leisure time (β=0·27, P<0·01), access to and decisions regarding credit (β=0·20, P=0·02) and autonomy in production (β=0·10, P=0·04). No indicator of women's empowerment in agriculture was associated with WLZ. Women's empowerment in agriculture, as measured by the WEAI 5DE and three of its ten component indicators, was significantly associated with LAZ, highlighting the potential role of women's empowerment in improving child nutrition in Nepal. Additional studies are needed to determine whether interventions to improve women's empowerment will improve child nutrition.

Invited review: Learning from the future-A vision for dairy farms and cows in 2067.

PubMed

Britt, J H; Cushman, R A; Dechow, C D; Dobson, H; Humblot, P; Hutjens, M F; Jones, G A; Ruegg, P S; Sheldon, I M; Stevenson, J S

2018-05-01

The world's population will reach 10.4 billion in 2067, with 81% residing in Africa or Asia. Arable land available for food production will decrease to 0.15 ha per person. Temperature will increase in tropical and temperate zones, especially in the Northern Hemisphere, and this will push growing seasons and dairy farming away from arid areas and into more northern latitudes. Dairy consumption will increase because it provides essential nutrients more efficiently than many other agricultural systems. Dairy farming will become modernized in developing countries and milk production per cow will increase, doubling in countries with advanced dairying systems. Profitability of dairy farms will be the key to their sustainability. Genetic improvements will include emphasis on the coding genome and associated noncoding epigenome of cattle, and on microbiomes of dairy cattle and farmsteads. Farm sizes will increase and there will be greater lateral integration of housing and management of dairy cattle of different ages and production stages. Integrated sensors, robotics, and automation will replace much of the manual labor on farms. Managing the epigenome and microbiome will become part of routine herd management. Innovations in dairy facilities will improve the health of cows and permit expression of natural behaviors. Herds will be viewed as superorganisms, and studies of herds as observational units will lead to improvements in productivity, health, and well-being of dairy cattle, and improve the agroecology and sustainability of dairy farms. Dairy farmers in 2067 will meet the world's needs for essential nutrients by adopting technologies and practices that provide improved cow health and longevity, profitable dairy farms, and sustainable agriculture. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ongoing changes in migration phenology and winter residency at Bracken Bat Cave.

PubMed

Stepanian, Phillip M; Wainwright, Charlotte E

2018-02-14

Bats play an important role in agroecology and are effective bioindicators of environmental conditions, but little is known about their fundamental migration ecology, much less how these systems are responding to global change. Some of the world's largest bat populations occur during the summer in the south-central United States, when millions of pregnant females migrate from lower latitudes to give birth in communal maternity colonies. Despite a relatively large volume of research into these colonies, many fundamental questions regarding their abundance-including their intra- and interseasonal variability-remain unanswered, and even estimating the size of individual populations has been a long-running challenge. Overall, monitoring these bat populations at high temporal resolution (e.g., nightly) and across long time spans (e.g., decades) has been impossible. Here, we show 22 continuous years of nightly population counts at Bracken Cave, a large bat colony in south-central Texas, enabling the first climate-scale phenological analysis. Using quantitative radar monitoring, we found that spring migration and the summer reproductive cycle have advanced by approximately 2 weeks over the study period. Furthermore, we quantify the ongoing growth of a newly-established overwintering population that indicates a system-wide response to changing environmental conditions. Our observations reveal behavioral plasticity in bats' ability to adapt to changing resource availability, and provide the first long-term quantification of their response to a changing climate. As aerial insectivores, these changes in bat phenology and propensity for overwintering indicate probable shifts in prey availability, with clear implications for pest management across wider regional agrisystems. © 2018 John Wiley & Sons Ltd.

Future of forest gardens in the Uvan uplands of Sri Lanka

NASA Astrophysics Data System (ADS)

Nuberg, Ian K.; Evans, David G.; Senanayake, Ranil

1994-11-01

Forest gardens are traditional agroecosystems in the humid tropics that have evolved a forestlike structure and as such are commonly thought to be a good example of sustainable agriculture. While this may be true in the sense of soil protection and maintenance of biodiversity, they are not necessarily maintainable in the context of competing land use in the landscape. Such appears to be the case of forest gardens in the uplands of Uva Province of Sri Lanka. This paper reports an agroecological analysis of forest gardens and other forms of land use in Uva, and discusses how this understanding can be used to make use of the good properties of forest gardens. It shows that although they have very real environmental and social benefits, they are unable to satisfy the material needs of a rural population undergoing demographic and cultural changes. However, the alternative land-use systems, both private smallholder and state owned, have serious deficiencies with respect to long-term sustainability, and it is essential to develop appropriate alternatives. It should be possible to design a smallholder farming system that incorporates the high productivity of market gardens (i.e., the cultivation of seasonal crops such as vegetables) with, at least, the high stability and biophysical sustainability of the forest garden. Considerable work still needs to be done on the design of such a system as well as the agency for its development and promotion. The paper treats the forest gardens of Uva as a case study from which some general conclusions can be drawn with respect to the conscious development of forest garden systems elsewhere in the tropics.

Evaluation of the onset and length of growing season to define planting date—`a case study for Mali (West Africa)'

NASA Astrophysics Data System (ADS)

Akinseye, F. M.; Agele, S. O.; Traore, P. C. S.; Adam, M.; Whitbread, A. M.

2016-05-01

The agroecological zones (AEZ) of Mali fall within the semi-arid climate, the ability to determine efficiently or predict accurately the onset of growing season (OGS), and length of growing season (LGS) cannot be over-emphasized due to highly variable rainfall pattern and the dependence of smallholder farmers practising on rainfed farming agriculture. In this study, we determined the most suitable method for predicting the onset date of rainfall across AEZ that fitted with the planting windows of major cereal crops (maize, millet, and sorghum). Using long-term daily rainfall records from 22 meteorological stations spread across AEZ of Mali, four (4) known methods were applied to determine the onset dates of the rain. The mean onset dates were statistically compared with the farmer's planting window for the selected weather stations to determine the suitable dates of OGS and LGS. The hypothesis considered a time lag minimum of 7 days between the mean onset date and traditional farmer sowing dates for the crops. Then, the preferred method was used to estimate OGS based on early, normal and late dates respectively across the stations. Also, the estimated LGS according to each zone was evaluated using probability distribution chart with duration to maturity for varieties of the same crops. The results showed that Def_4 was found appropriate for Sahelian and Sudano-Sahelian zones; Def_3 satisfied the criteria and exhibited superior capacity into farmer's average planting date over Sudanian and Guinea Savannah zones. These results have an important application in cropping systems in order to prevent crop failure and ensure a better choice of crop variety according to LGS under climate variability and change being experienced across Mali.

Effect of crude plant extracts from some Oaxacan flora on two deleterious fungal phytopathogens and extract compatibility with a biofertilizer strain.

PubMed

Lira-De León, Karla I; Ramírez-Mares, Marco V; Sánchez-López, Vladimir; Ramírez-Lepe, Mario; Salas-Coronado, Raúl; Santos-Sánchez, Norma F; Valadez-Blanco, Rogelio; Hernández-Carlos, Beatriz

2014-01-01

The antimicrobial activity of 12 plant extracts was tested against the phytopathogens Alternaria alternata and Fusarium solani. In addition, the compatibility of the extracts toward Bacillus liqueniformis, a biofertilizer and a non-target microorganism, was assessed. Plants tested belong to the Euphorbiaceae, Asteraceae, Crassulaceae, Rubiaceae, Convolvulaceae, Verbenaceae, Orchidaceae, Nyctaginaceae, Boraginaceae, and Tiliaceae families and were collected in the State of Oaxaca. The antifungal activity of the plant extracts (50-100 mg/mL) against A. alternata and F. solani, was determined by measuring the mycelium radial growth and obtaining the minimum inhibitory concentration (MIC) of fungal growth. In addition, with the aim of finding plant extracts which are compatible with a B. licheniformis biofertilizer strain and to test the non-toxic nature of the treatments, the toxicity of the extracts toward this strain was evaluated using the agar diffusion method. Azoxystrobin (12 μg) and chloramphenicol (30 μg) were used as positive controls for the pathogens and for the non-target bacteria, respectively. Plant extracts inhibited fungal growth in the ranges of 0.76-56.17% against F. solani and 2.02-69.07% against A. alternata. The extracts of Acalypha subviscida, Ipomoea murucoides, Tournefortia densiflora and Lantana achyranthifolia showed MIC values between 5.77-12.5 mg/mL for at least one of the fungal species. The best treatment, Adenophyllum aurantium, exhibited a maximum inhibition for both F. solani (56.17%, MIC = 7.78 mg/mL) and A. alternata (68.64% MIC = 7.78 mg/mL), and resulted innocuous toward B. licheniformis. Therefore, this plant has an outstanding potential for the agroecological control of fungal phytopathogens in industrial crops.

Survival or productivity? Global synthesis of root and tuber production during drought

NASA Astrophysics Data System (ADS)

Daryanto, S.; Wang, L.; Jacinthe, P. A.

2016-12-01

According to FAO, there are six major root and tuber crops: potato, cassava, sweet potato, yam, taro, and yautia. Some root and tuber crops (e.g., sweet potato and cassava) are considered to be `drought-resistant', although quantitative evidence that support the premise was still lacking. Greater uncertainties exist on how drought effects co-vary with: 1) soil texture, 2) agro-ecological region, and 3) drought timing. To address these uncertainties, we collected literature data between 1980 and 2015 that reported monoculture root and tuber yield responses to drought under field conditions, and analyzed this large data set using meta-analysis techniques. Our results showed that the amount of water reduction was positively related with yield reduction, but the extent of the impact varied with root or tuber species and the phenological phase during which drought occurred. In contrast to common assumptions regarding drought resistance of certain root and tuber crops, we found that yield reduction was similar between potato and species thought to be `drought-resistant' such as cassava and sweet potato. Here we suggest that drought-resistance in cassava and sweet potato could be more related to survival rather than yield. All roots or tubers crops, however, experienced greater yield reduction when drought occurred during the tuberization period compared to during their vegetative phase. The effect of soil texture as well as region (and related climatic factors) on yield reduction and crop sensitivity were less obvious. Our study provides useful information that could inform agricultural planning, and influence the direction of research for improving the productivity and the resilience of these under-utilized crops in the drought-prone regions of the world.

Gravity and InSAR remote sensing of groundwater usage in the Sahel and Horn of Africa

NASA Astrophysics Data System (ADS)

Neely, W.; Borsa, A. A.; Burney, J. A.; Devlin, K.

2016-12-01

Changes in the Earth's climatic systems influence agro-ecological conditions on local, regional, and global scales. With the world's highest population growth rate, sub-Saharan Africa faces particularly acute concerns regarding food security and resource management. Historical sources of surface water for agricultural production may become less reliable and/or limited with increased climate variability, and African countries have already begun to depend on more stable sources of groundwater. Expected increases in groundwater usage pose questions about the sustainability of current agricultural practices, which require new sources of information to answer. Due to the logistics and costs to implement in situ networks to monitor regional water security, current remote sensing missions offer an affordable alternative. The Gravity Recovery and Climate Experiment (GRACE) has proven to be effective in quantifying changes in terrestrial water storage (TWS) at the regional scale using near-monthly gravity measurements from orbit. Using over a decade of measurements, we estimate TWS anomalies in Niger and Ethiopia. These anomalies offer a proxy for hydrological stressing, indicating potential targets for additional analysis. We use independent, but complementary, estimates of surface displacements from Interferometric Synthetic Aperture Radar (InSAR) to provide information on local groundwater withdrawal. Using data from ESA's Sentinel 1 mission and JAXA's Advanced Land Observing Satellite (ALOS) missions, we characterize the surface deformation over the past decade in regions of active groundwater pumping using the Small Baseline Subset (SBAS) technique. In particular, we investigate ties of ground motion to known agricultural/industrial land usage near Niamey, Niger and Eastern Oromia, Ethiopia to better understand how human activity affects available groundwater resources.

Mapping Potential Amplification and Transmission Hotspots for MERS-CoV, Kenya.

PubMed

Gikonyo, Stephen; Kimani, Tabitha; Matere, Joseph; Kimutai, Joshua; Kiambi, Stella G; Bitek, Austine O; Juma Ngeiywa, K J Z; Makonnen, Yilma J; Tripodi, Astrid; Morzaria, Subhash; Lubroth, Juan; Rugalema, Gabriel; Fasina, Folorunso Oludayo

2018-03-16

Dromedary camels have been implicated consistently as the source of Middle East respiratory syndrome coronavirus (MERS-CoV) human infections and attention to prevent and control it has focused on camels. To understanding the epidemiological role of camels in the transmission of MERS-CoV, we utilized an iterative empirical process in Geographic Information System (GIS) to identify and qualify potential hotspots for maintenance and circulation of MERS-CoV, and produced risk-based surveillance sites in Kenya. Data on camel population and distribution were used to develop camel density map, while camel farming system was defined using multi-factorial criteria including the agro-ecological zones (AEZs), production and marketing practices. Primary and secondary MERS-CoV seroprevalence data from specific sites were analyzed, and location-based prevalence matching with camel densities was conducted. High-risk convergence points (migration zones, trade routes, camel markets, slaughter slabs) were profiled and frequent cross-border camel movement mapped. Results showed that high camel-dense areas and interaction (markets and migration zones) were potential hotspot for transmission and spread. Cross-border contacts occurred with in-migrated herds at hotspot locations. AEZ differential did not influence risk distribution and plausible risk factors for spatial MERS-CoV hotspots were camel densities, previous cases of MERS-CoV, high seroprevalence and points of camel convergences. Although Kenyan camels are predisposed to MERS-CoV, no shedding is documented to date. These potential hotspots, determined using anthropogenic, system and trade characterizations should guide selection of sampling/surveillance sites, high-risk locations, critical areas for interventions and policy development in Kenya, as well as instigate further virological examination of camels.

Selection and characterization of Argentine isolates of Trichoderma harzianum for effective biocontrol of Septoria leaf blotch of wheat.

PubMed

Stocco, Marina C; Mónaco, Cecilia I; Abramoff, Cecilia; Lampugnani, Gladys; Salerno, Graciela; Kripelz, Natalia; Cordo, Cristina A; Consolo, Verónica F

2016-03-01

Species of the genus Trichoderma are economically important as biocontrol agents, serving as a potential alternative to chemical control. The applicability of Trichoderma isolates to different ecozones will depend on the behavior of the strains selected from each zone. The present study was undertaken to isolate biocontrol populations of Trichoderma spp. from the Argentine wheat regions and to select and characterize the best strains of Trichoderma harzianum by means of molecular techniques. A total of 84 out of the 240 strains of Trichoderma were able to reduce the disease severity of the leaf blotch of wheat. Thirty-seven strains were selected for the reduction equal to or greater than 50% of the severity, compared with the control. The percentage values of reduction of the pycnidial coverage ranged between 45 and 80%. The same last strains were confirmed as T. harzianum by polymerase chain reaction amplification of internal transcribed spacers, followed by sequencing. Inter-simple sequence repeat was used to examine the genetic variability among isolates. This resulted in a total of 132 bands. Further numerical analysis revealed 19 haplotypes, grouped in three clusters (I, II, III). Shared strains, with different geographical origins and isolated in different years, were observed within each cluster. The origin of the isolates and the genetic group were partially related. All isolates from Paraná were in cluster I, all isolates from Lobería were in cluster II, and all isolates from Pergamino and Santa Fe were in cluster III. Our results suggest that the 37 native strains of T. harzianum are important in biocontrol programs and could be advantageous for the preparation of biopesticides adapted to the agroecological conditions of wheat culture.

Assessing the vulnerability of traditional maize seed systems in Mexico to climate change.

PubMed

Bellon, Mauricio R; Hodson, David; Hellin, Jon

2011-08-16

Climate change is predicted to have major impacts on small-scale farmers in Mexico whose livelihoods depend on rain-fed maize. We examined the capacity of traditional maize seed systems to provide these farmers with appropriate genetic material under predicted agro-ecological conditions associated with climate change. We studied the structure and spatial scope of seed systems of 20 communities in four transects across an altitudinal gradient from 10-2,980 m above sea level in five states of eastern Mexico. Results indicate that 90% of all of the seed lots are obtained within 10 km of a community and 87% within an altitudinal range of ±50 m but with variation across four agro-climate environments: wet lowland, dry lowland, wet upper midlatitude, and highlands. Climate models suggest a drying and warming trend for the entire study area during the main maize season, leading to substantial shifts in the spatial distribution patterns of agro-climate environments. For all communities except those in the highlands, predicted future maize environments already are represented within the 10-km radial zones, indicating that in the future farmers will have easy access to adapted planting material. Farmers in the highlands are the most vulnerable and probably will need to acquire seed from outside their traditional geographical ranges. This change in seed sources probably will entail important information costs and the development of new seed and associated social networks, including improved linkages between traditional and formal seed systems and more effective and efficient seed-supply chains. The study has implications for analogous areas elsewhere in Mexico and around the world.

Assessing the vulnerability of traditional maize seed systems in Mexico to climate change

PubMed Central

Bellon, Mauricio R.; Hodson, David; Hellin, Jon

2011-01-01

Climate change is predicted to have major impacts on small-scale farmers in Mexico whose livelihoods depend on rain-fed maize. We examined the capacity of traditional maize seed systems to provide these farmers with appropriate genetic material under predicted agro-ecological conditions associated with climate change. We studied the structure and spatial scope of seed systems of 20 communities in four transects across an altitudinal gradient from 10–2,980 m above sea level in five states of eastern Mexico. Results indicate that 90% of all of the seed lots are obtained within 10 km of a community and 87% within an altitudinal range of ±50 m but with variation across four agro-climate environments: wet lowland, dry lowland, wet upper midlatitude, and highlands. Climate models suggest a drying and warming trend for the entire study area during the main maize season, leading to substantial shifts in the spatial distribution patterns of agro-climate environments. For all communities except those in the highlands, predicted future maize environments already are represented within the 10-km radial zones, indicating that in the future farmers will have easy access to adapted planting material. Farmers in the highlands are the most vulnerable and probably will need to acquire seed from outside their traditional geographical ranges. This change in seed sources probably will entail important information costs and the development of new seed and associated social networks, including improved linkages between traditional and formal seed systems and more effective and efficient seed-supply chains. The study has implications for analogous areas elsewhere in Mexico and around the world. PMID:21825131

Adaptation of rainfed agriculture to climatic variability in the Mixteca Alta Region of Oaxaca, Mexico

NASA Astrophysics Data System (ADS)

Rogé, P.; Friedman, A. R.; Astier, M.; Altieri, M.

2015-12-01

The traditional management systems of the Mixteca Alta Region of Oaxaca, Mexico offer historical lessons about resilience to climatic variability. We interviewed small farmers to inquire about the dynamics of abandonment and persistence of a traditional management systems. We interpret farmers' narratives from a perspective of general agroecological resilience. In addition, we facilitated workshops in small farmers described their adaptation to past climate challenges and identified 14 indicators that they subsequently used to evaluate the condition of their agroecosystems. The most recent years presented increasingly extreme climatic and socioeconomic hardships: increased temperatures, delayed rainy seasons, reduced capacity of soils to retain soil moisture, changing cultural norms, and reduced rural labor. Farmers reported that their cropping systems were changing for multiple reasons: more drought, later rainfall onset, decreased rural labor, and introduced labor-saving technologies. Examination of climate data found that farmers' climate narratives were largely consistent with the observational record. There have been increases in temperature and rainfall intensity, and an increase in rainfall seasonality that may be perceived as later rainfall onset. Farmers ranked landscape-scale indicators as more marginal than farmer management or soil quality indicators. From this analysis, farmers proposed strategies to improve the ability of their agroecosystems to cope with climatic variability. Notably, they recognized that social organizing and education are required for landscape-level indicators to be improved. Transformative change is required to develop novel cropping systems and complementary activities to agriculture that will allow for farming to be sustained in the face of these challenges. Climate change adaptation by small farmers involves much more than just a set of farming practices, but also community action to tackle collective problems.

A landscape ecology approach identifies important drivers of urban biodiversity.

PubMed

Turrini, Tabea; Knop, Eva

2015-04-01

Cities are growing rapidly worldwide, yet a mechanistic understanding of the impact of urbanization on biodiversity is lacking. We assessed the impact of urbanization on arthropod diversity (species richness and evenness) and abundance in a study of six cities and nearby intensively managed agricultural areas. Within the urban ecosystem, we disentangled the relative importance of two key landscape factors affecting biodiversity, namely the amount of vegetated area and patch isolation. To do so, we a priori selected sites that independently varied in the amount of vegetated area in the surrounding landscape at the 500-m scale and patch isolation at the 100-m scale, and we hold local patch characteristics constant. As indicator groups, we used bugs, beetles, leafhoppers, and spiders. Compared to intensively managed agricultural ecosystems, urban ecosystems supported a higher abundance of most indicator groups, a higher number of bug species, and a lower evenness of bug and beetle species. Within cities, a high amount of vegetated area increased species richness and abundance of most arthropod groups, whereas evenness showed no clear pattern. Patch isolation played only a limited role in urban ecosystems, which contrasts findings from agro-ecological studies. Our results show that urban areas can harbor a similar arthropod diversity and abundance compared to intensively managed agricultural ecosystems. Further, negative consequences of urbanization on arthropod diversity can be mitigated by providing sufficient vegetated space in the urban area, while patch connectivity is less important in an urban context. This highlights the need for applying a landscape ecological approach to understand the mechanisms shaping urban biodiversity and underlines the potential of appropriate urban planning for mitigating biodiversity loss. © 2015 John Wiley & Sons Ltd.

Developing mechanisms for estimating carbon footprint in farming systems

NASA Astrophysics Data System (ADS)

Anaya-Romero, María; Fernández Luque, José Enrique; Rodríguez Merino, Alejandro; José Moreno Delgado, Juan; Rodado, Concepción Mira; Romero Vicente, Rafael; Perez-Martin, Alfonso; Muñoz-Rojas, Miriam

2015-04-01

Sustainable land management is critical to avoid land degradation and to reclaim degraded land for its productive use and for reaping the benefits of crucial ecosystem services and protecting biodiversity. It also helps in mitigating and adapting to climate change. Land and its various uses are affected severely by climate change too (flooding, droughts, etc.). Existing tools and technologies for efficient land management need to be adapted and their application expanded. A large number of human livelihoods and ecosystems can benefit from these tools and techniques since these yield multiple benefits. Disseminating and scaling up the implementation of sustainable land management approaches will, however, need to be backed up by mobilizing strong political will and financial resources. The challenge is to provide an integral decision support tool that can establish relationships between soil carbon content, climate change and land use and management aspects that allow stakeholders to detect, cope with and intervene into land system change in a sustainable way. In order to achieve this goal an agro-ecological meta-model called CarboLAND will be calibrated in several plots located in Andalusia region, Southern Spain, under different scenarios of climate and agricultural use and management. The output will be the CLIMALAND e-platform, which will also include protocols in order to support stakeholders for an integrated ecosystem approach, taking into account biodiversity, hydrological and soil capability, socio-economic aspects, and regional and environmental policies. This tool will be made available at the European context for a regional level, providing user-friendly interfaces and a scientifically-technical platform for the assessment of sustainable land use and management.

Quantifying the thermal heat requirement of Brassica in assessing biophysical parameters under semi-arid microenvironments

NASA Astrophysics Data System (ADS)

Adak, Tarun; Chakravarty, N. V. K.

2010-07-01

Evaluation of the thermal heat requirement of Brassica spp. across agro-ecological regions is required in order to understand the further effects of climate change. Spatio-temporal changes in hydrothermal regimes are likely to affect the physiological growth pattern of the crop, which in turn will affect economic yields and crop quality. Such information is helpful in developing crop simulation models to describe the differential thermal regimes that prevail at different phenophases of the crop. Thus, the current lack of quantitative information on the thermal heat requirement of Brassica crops under debranched microenvironments prompted the present study, which set out to examine the response of biophysical parameters [leaf area index (LAI), dry biomass production, seed yield and oil content] to modified microenvironments. Following 2 years of field experiments on Typic Ustocrepts soils under semi-arid climatic conditions, it was concluded that the Brassica crop is significantly responsive to microenvironment modification. A highly significant and curvilinear relationship was observed between LAI and dry biomass production with accumulated heat units, with thermal accumulation explaining ≥80% of the variation in LAI and dry biomass production. It was further observed that the economic seed yield and oil content, which are a function of the prevailing weather conditions, were significantly responsive to the heat units accumulated from sowing to 50% physiological maturity. Linear regression analysis showed that growing degree days (GDD) could indicate 60-70% variation in seed yield and oil content, probably because of the significant response to differential thermal microenvironments. The present study illustrates the statistically strong and significant response of biophysical parameters of Brassica spp. to microenvironment modification in semi-arid regions of northern India.

[Comparing the ammonia volatilization characteristic of two typical paddy soil with total wheat straw returning in Taihu Lake region].

PubMed

Wang, Jun; Wang, De-Jian; Zhang, Gang; Wang, Yuan

2013-01-01

An experiment using monolith lysimeter was conducted to compare the characteristic of N loss by ammonia (NH3) volatilization between the gleyed paddy soil (G soil) and hydromorphic paddy soil (H soil) the Changshu National Agro-ecological Experimental Station of the Chinese Academy of Sciences(31 degrees 33' N, 123 degrees 38' E). Three treatments were designed for each soil type, i. e. control (no urea and straw applied), nitrogen solely and nitrogen plus wheat straw. Ammonia volatilization, flood water NH4(+) -N concentration, pH and top soil Eh were measured during the rice-growing season. Results showed that the NH3 volatilization flux and cumulative N losses by NH3 volatilization from G soil were significantly higher than those from H soil, the average cumulative N losses being about 41.8 kg x hm(-2) and 11.2 kg x hm(-2), or 15.2% and 3.8% of the fertilizer N, respectively. The average N loss by NH3 volatilization during the tillering stage was the highest among the three fertilization stages, accounting for 29.4% and 8.3% of the fertilizer N for G soil and H soil, respectively. Wheat straw returning significantly increased paddy filed NH3 volatilization losses. Comparing with the sole application of fertilizer-N, the cumulative N loss by NH3 volatilization of fertilizer-N in combination with wheat straw was increased by 19.8% and 20.6% for G soil and H soil, respectively. In addition, ammonia volatilization fluxes showed a positive relationship with the flood water NH4(+) -N concentration and pH for both soils, but the relationship with top soil Eh still needs further study.

Adaptations to climate-mediated selective pressures in sheep.

PubMed

Lv, Feng-Hua; Agha, Saif; Kantanen, Juha; Colli, Licia; Stucki, Sylvie; Kijas, James W; Joost, Stéphane; Li, Meng-Hua; Ajmone Marsan, Paolo

2014-12-01

Following domestication, sheep (Ovis aries) have become essential farmed animals across the world through adaptation to a diverse range of environments and varied production systems. Climate-mediated selective pressure has shaped phenotypic variation and has left genetic "footprints" in the genome of breeds raised in different agroecological zones. Unlike numerous studies that have searched for evidence of selection using only population genetics data, here, we conducted an integrated coanalysis of environmental data with single nucleotide polymorphism (SNP) variation. By examining 49,034 SNPs from 32 old, autochthonous sheep breeds that are adapted to a spectrum of different regional climates, we identified 230 SNPs with evidence for selection that is likely due to climate-mediated pressure. Among them, 189 (82%) showed significant correlation (P ≤ 0.05) between allele frequency and climatic variables in a larger set of native populations from a worldwide range of geographic areas and climates. Gene ontology analysis of genes colocated with significant SNPs identified 17 candidates related to GTPase regulator and peptide receptor activities in the biological processes of energy metabolism and endocrine and autoimmune regulation. We also observed high linkage disequilibrium and significant extended haplotype homozygosity for the core haplotype TBC1D12-CH1 of TBC1D12. The global frequency distribution of the core haplotype and allele OAR22_18929579-A showed an apparent geographic pattern and significant (P ≤ 0.05) correlations with climatic variation. Our results imply that adaptations to local climates have shaped the spatial distribution of some variants that are candidates to underpin adaptive variation in sheep. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments.

PubMed

Yang, Ji; Li, Wen-Rong; Lv, Feng-Hua; He, San-Gang; Tian, Shi-Lin; Peng, Wei-Feng; Sun, Ya-Wei; Zhao, Yong-Xin; Tu, Xiao-Long; Zhang, Min; Xie, Xing-Long; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Wang, Feng; Liu, Guang-Jian; Lu, Hong-Feng; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua; Liu, Ming-Jun

2016-10-01

Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8-9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Individual, household, and community level risk factors of stunting in children younger than 5 years: Findings from a national surveillance system in Nepal.

PubMed

Dorsey, Jamie L; Manohar, Swetha; Neupane, Sumanta; Shrestha, Binod; Klemm, Rolf D W; West, Keith P

2018-01-01

Despite substantial reductions in recent years in Nepal, stunting prevalence in children younger than 5 years remains high and represents a leading public health concern. To identify factors contributing to the stunting burden, we report multilevel risk factors associated with stunting in 4,853 children aged 6-59 months in a nationally and agroecologically representative random sample from the first year of the Policy and Science for Health, Agriculture, and Nutrition Community Studies, a community-based observational, mixed-panel study. Mixed effects logistic regressions controlling for multilevel clustering in the study design were used to examine the association of individual-, household-, and community-level factors associated with stunting. Stunting prevalence was 38% in our sample. After adjustment for potential confounding variables, maternal factors, including maternal height and education, were generally the strongest individual-level risk factors for stunting, adjusted odds ratio (AOR) = 2.52, 95% CI [1.96, 3.25], short (<145 cm) versus not short mothers; AOR = 2.09, 95% CI [1.48, 2.96], uneducated mothers versus secondary school graduates. Among the household- and community-level factors, household expenditure and community infrastructure (presence of paved roads, markets, or hospitals) were strongly, inversely associated with increased stunting risk, AOR = 1.68, 95% CI [1.27, 2.24], lowest versus highest household expenditure quintile; AOR = 2.38, 95% CI [1.36, 4.14], less developed (lacking paved roads, markets, or hospitals) versus more developed communities. Although most factors associated with stunting are not rapidly modifiable, areas for future research and possible interventions emerged. © 2017 John Wiley & Sons Ltd.

Farmers' perception on the importance of variegated grasshopper (Zonocerus variegatus (L.)) in the agricultural production systems of the humid forest zone of Southern Cameroon

PubMed Central

Kekeunou, Sévilor; Weise, Stephan; Messi, Jean; Tamò, Manuel

2006-01-01

Background Zonocerus variegatus (Linnaeus, 1758) (Orthoptera: Pyrgomorphidae) is known as an agricultural pest in West and Central Africa. However, its importance in the agricultural production system in Cameroon has not been investigated. The study assesses farmers' perception on the importance of Z. variegatus in the agricultural production systems of the humid forest zone of Southern Cameroon. Methods Research was carried out in 5 villages of each of three Agro-Ecological, Cultural and Demographic Blocks (AECD-Blocks) of the Forest Margin Benchmark Area (FMBA). In each village, a semi-structured survey was used; male and female groups of farmers were interviewed separately. Results Z. variegatus is present throughout the humid forest zone of Southern Cameroon, where it is ranked as the third most economically important insect pest of agriculture. In the farmers' opinion, Z. variegatus is a polyphagous insect with little impact on young perennial crops. The length of the pre-farming fallow does not affect Z. variegatus pest pressure in the following crops. The increased impact of the grasshopper observed today in the fields, compared to what existed 10 years ago is as a result of deforestation and increase in surface of herbaceous fallow. The damage caused by Z. variegatus is higher in fields adjacent to C. odorata and herbaceous fallows than in those adjacent to forests and shrubby fallows. The fight against this grasshopper is often done through physical methods carried out by hand, for human consumption. The farmers highlight low usage of the chemical methods and a total absence of biological and ecological methods. Conclusion Farmers' perception have contributed to understanding the status of Z. variegatus in the humid forest zone of Southern Cameroon. The results are in general similar to those obtained in other countries. PMID:16573815

Rates of return to sorghum and millet research investments: A meta-analysis.

PubMed

Zereyesus, Yacob A; Dalton, Timothy J

2017-01-01

Sorghum and millet grow in some of the most heterogeneous and austere agroecologies around the world. These crops are amongst the top five cereal sources of food and feed. Yet, few studies document the impact of sorghum and millet genetic enhancement. The Internal Rate of Return (ROR) is one of the most popular metrics used to measure the economic return on investment on agricultural research and development (R&D). This study conducted a meta-analysis of 59 sorghum and millet ROR estimates obtained from 25 sources published between 1958 and 2015. The average rate of return to sorghum and millet R&D investment is between 54-76 percent per year. All studies computed social rather than private RORs because the technologies were developed using public funds originating from host country National Agricultural Research Systems (NARS) and international organizations such as the INTSORMIL CRSP, ICRISAT and others. Nearly three quarter of the studies focused only on sorghum (72 percent) and around one tenth of the studies (8 percent) on millet. Regression models analyzed the determinants of variation in the reported RORs. Results show that ex-ante type and self-evaluated type of analyses are positively and significantly associated with the ROR estimates. Compared to estimates conducted by a university, results from international institutions and other mixed organizations provided significantly smaller estimates. Estimates conducted at national level also are significantly lower than those conducted at sub-national levels. The ROR is higher for studies conducted in the United States and for those conducted more recently. The study also reconstructed modified internal rate of return (MIRR) for a sub-sample of the reported RORs following recent methods from the literature. These results show that the MIRR estimates are significantly smaller than the reported ROR estimates. Both results indicate that investment in sorghum and millet research generates high social rates of

Improving nitrogen management via a regional management plan for Chinese rice production

NASA Astrophysics Data System (ADS)

Wu, Liang; Chen, Xinping; Cui, Zhenling; Wang, Guiliang; Zhang, Weifeng

2015-09-01

A lack of basic information on optimal nitrogen (N) management often results in over- or under-application of N fertilizer in small-scale intensive rice farming. Here, we present a new database of N input from a survey of 6611 small-scale rice farmers and rice yield in response to added N in 1177 experimental on-farm tests across eight agroecological subregions of China. This database enables us to evaluate N management by farmers and develop an optimal approach to regional N management. We also investigated grain yield, N application rate, and estimated greenhouse gas (GHG) emissions in comparison to N application and farming practices. Across all farmers, the average N application rate, weighted by the area of rice production in each subregion, was 210 kg ha-1 and ranged from 30 to 744 kg ha-1 across fields and from 131 to 316 kg ha-1 across regions. The regionally optimal N rate (RONR) determined from the experiments averaged 167 kg ha-1 and varied from 114 to 224 kg N ha-1 for the different regions. If these RONR were widely adopted in China, approximately 56% of farms would reduce their use of N fertilizer, and approximately 33% would increase their use of N fertilizer. As a result, grain yield would increase by 7.4% from 7.14 to 7.67 Mg ha-1, and the estimated GHG emissions would be reduced by 11.1% from 1390 to 1236 kg carbon dioxide (CO2) eq Mg-1 grain. These results suggest that to achieve the goals of improvement in regional yield and sustainable environmental development, regional N use should be optimized among N-poor and N-rich farms and regions in China.

Water sustainability assessment in Brazilian sugarcane expansion area

NASA Astrophysics Data System (ADS)

Scarpare, F. V.; Ruiz-Correa, S. T.; Hernandes, T. A.; Scanlon, B. R.; Picoli, M. C. A.; Bonomi, A.

2016-12-01

Due to the increasing demand for ethanol, sugarcane is expanding into Cerrado (Savannahs), where edaphoclimatic characteristics differ significantly from traditional areas in South-eastern Brazil. It is expected that the sugarcane will be irrigated in those areas to increase yields and ensure stable production. The main objective is to assess the sugarcane land occupation and its dynamics relating its occurrence with the potential and actual yields, the irrigation needs, the production costs, and the water footprint in Paranaíba watershed (222,593 km2 drainage area). The Agroecological Zone Model - FAO was used in order to provide essential data for yield and water requirement assessment. For sugarcane stalk yield estimation, several improvements have been made allowing this tool to assess different irrigation scenarios. In this study, full irrigation which aims to replace 100% of the water deficit until senescence period was considered. The sugarcane occupation and expansion was assessed through EVI approach from 2009/2010 to 2012/2013 crop seasons. It was possible to identify that most part of sugarcane occupation is concentrated in the central area, which presents less potential for yield gain through irrigation and significant water availability issues. With regard to the expansion, an increase of 54% of cane occupation (from 616,899 to 946,589 ha) was detected during the assessed period showing that the main dynamic occurred in central part towards west side and at less extent, to southeaster side. The irrigation management were responsible for increase, on average, 108% of yields while decreasing 42% of water footprints. Simulated yields combine with CanaSoft model estimated a 30% decline in production cost. Although several aspects such as land price and infrastructure must to be considered, in conclusion, the expansion dynamic agrees to the areas with greater yield gain potential through irrigation, lower sugarcane production costs and water footprint

The Impact of Region, Nitrogen Use Efficiency, and Grower Incentives on Greenhouse Gas Mitigation in Canola (Brassica napus) Production

NASA Astrophysics Data System (ADS)

Hammac, W. A.; Pan, W.; Koenig, R. T.; McCracken, V.

2012-12-01

The Environmental Protection Agency (EPA) has mandated through the second renewable fuel standard (RFS2) that biodiesel meet a minimum threshold requirement (50% reduction) for greenhouse gas (GHG) emission reduction compared to fossil diesel. This designation is determined by life cycle assessment (LCA) and carries with it potential for monetary incentives for biodiesel feedstock growers (Biomass Crop Assistance Program) and biodiesel processors (Renewable Identification Numbers). A national LCA was carried out for canola (Brassica napus) biodiesel feedstock by the EPA and it did meet the minimum threshold requirement. However, EPA's national LCA does not provide insight into regional variation in GHG mitigation. The authors propose for full GHG reduction potential of biofuels to be realized, LCA results must have regional specificity and should inform incentives for growers and processors on a regional basis. The objectives of this work were to determine (1) variation in biofuel feedstock production related GHG emissions between three agroecological zones (AEZs) in eastern Washington State (2) the impact of nitrogen use efficiency (NUE) on GHG mitigation potential for each AEZ and (3) the impact of incentives on adoption of oilseed production. Results from objective (1) revealed there is wide variability in range for GHG estimates both across and within AEZs based on variation in farming practices and environment. It is expected that results for objective (2) will show further GHG mitigation potential due to minimizing N use and therefore fertilizer transport and soil related GHG emission while potentially increasing biodiesel production per hectare. Regional based incentives may allow more timely achievement of goals for bio-based fuels production. Additionally, incentives may further increase GHG offsetting by promoting nitrogen conserving best management practices implementation. This research highlights the need for regional assessment/incentive based

Restoring monarch butterfly habitat in the Midwestern US: 'All hands on deck'

USGS Publications Warehouse

Thogmartin, Wayne E.; Lopez-Hoffman, Laura; Rohweder, Jason; Diffendorfer, James E.; Drum, Ryan G.; Semmens, Darius J.; Black, Scott; Caldwell, Iris; Cotter, Donita; Drobney, Pauline; Jackson, Laura L.; Gale, Michael; Helmers, Doug; Hilburger, Steven B.; Howard, Elizabeth; Oberhauser, Karen S.; Pleasants, John M.; Semmens, Brice X.; Taylor, Orley R.; Ward, Patrick; Weltzin, Jake F.; Wiederholt, Ruscena

2017-01-01

The eastern migratory population of monarch butterflies (Danaus plexippus plexippus) has declined by >80% within the last two decades. One possible cause of this decline is the loss of ≥1.3 billion stems of milkweed (Asclepias spp.), which monarchs require for reproduction. In an effort to restore monarchs to a population goal established by the US Fish and Wildlife Service and adopted by Mexico, Canada, and the US, we developed scenarios for amending the Midwestern US landscape with milkweed. Scenarios for milkweed restoration were developed for protected area grasslands, Conservation Reserve Program land, powerline, rail and roadside rights of way, urban/suburban lands, and land in agricultural production. Agricultural land was further divided into productive and marginal cropland. We elicited expert opinion as to the biological potential (in stems per acre) for lands in these individual sectors to support milkweed restoration and the likely adoption (probability) of management practices necessary for affecting restoration. Sixteen of 218 scenarios we developed for restoring milkweed to the Midwestern US were at levels (>1.3 billion new stems) necessary to reach the monarch population goal. One of these scenarios would convert all marginal agriculture to conserved status. The other 15 scenarios converted half of marginal agriculture (730 million stems), with remaining stems contributed by other societal sectors. Scenarios without substantive agricultural participation were insufficient for attaining the population goal. Agricultural lands are essential to reaching restoration targets because they occupy 77% of all potential monarch habitat. Barring fundamental changes to policy, innovative application of economic tools such as habitat exchanges may provide sufficient resources to tip the balance of the agro-ecological landscape toward a setting conducive to both robust agricultural production and reduced imperilment of the migratory monarch butterfly.

A land classification protocol for pollinator ecology research: An urbanization case study.

PubMed

Samuelson, Ash E; Leadbeater, Ellouise

2018-06-01

, including agroecological studies of pest control.

"Coca got us here and now it's our weakness:" Fusarium oxysporum and the political ecology of a drug war policy alternative in Bolivia.

PubMed

Pearson, Zoe

2016-07-01

A strain of Fusarium oxysporum fungus is killing coca plants in the Chapare coca growing region of Bolivia. Coca farmers are already constrained in the amount of coca they can grow under the government's community-based coca control approach, "social control." Coca leaf is the main ingredient in cocaine, but it is also a traditional medicine and food, is economically vital to household incomes, and is a political symbol of the current government administration. Bolivia's approach to coca control, now administered without any United States military intervention, is an innovative example of experimentation with drug policy reform. This paper is based on ethnographic research including semi-structured interviews and observation. Coca growers are worried about the dire economic, social, and political consequences of the fungus' appearance and spread since summer 2013. They have two explanations for its origins: First, that it was sent by the United States government, which in the past was developing a strain of F. oxysporum for use in the drug war; Second, and the explanation of scientists, is that the outbreak is caused by the overuse of agrochemicals and other intensive agricultural practices. More than a matter of agroecology, the practices identified in the second explanation must be understood in terms of the persistence of the international drug prohibition regime. Bolivia's social control approach is a successful alternative to violent eradication measures, however the country is constrained to uphold the fundamental principles of supply-side control in order to be a respected partner in global drug control. The supply-side logics restricting social control make intensive agriculture practices attractive, but may have contributed to the fungus' proliferation and its continued spread. The fungus draws attention to the challenges of policy reform, new collateral damages of drug control, and role environmental factors can play in drug control politics. Copyright �

Impacts on Water Management and Crop Production of Regional Cropping System Adaptation to Climate Change

NASA Astrophysics Data System (ADS)

Zhong, H.; Sun, L.; Tian, Z.; Liang, Z.; Fischer, G.

2014-12-01

China is one of the most populous and fast developing countries, also faces a great pressure on grain production and food security. Multi-cropping system is widely applied in China to fully utilize agro-climatic resources and increase land productivity. As the heat resource keep improving under climate warming, multi-cropping system will also shifting northward, and benefit crop production. But water shortage in North China Plain will constrain the adoption of new multi-cropping system. Effectiveness of multi-cropping system adaptation to climate change will greatly depend on future hydrological change and agriculture water management. So it is necessary to quantitatively express the water demand of different multi-cropping systems under climate change. In this paper, we proposed an integrated climate-cropping system-crops adaptation framework, and specifically focused on: 1) precipitation and hydrological change under future climate change in China; 2) the best multi-cropping system and correspondent crop rotation sequence, and water demand under future agro-climatic resources; 3) attainable crop production with water constraint; and 4) future water management. In order to obtain climate projection and precipitation distribution, global climate change scenario from HADCAM3 is downscaled with regional climate model (PRECIS), historical climate data (1960-1990) was interpolated from more than 700 meteorological observation stations. The regional Agro-ecological Zone (AEZ) model is applied to simulate the best multi-cropping system and crop rotation sequence under projected climate change scenario. Finally, we use the site process-based DSSAT model to estimate attainable crop production and the water deficiency. Our findings indicate that annual land productivity may increase and China can gain benefit from climate change if multi-cropping system would be adopted. This study provides a macro-scale view of agriculture adaptation, and gives suggestions to national

TEK and biodiversity management in agroforestry systems of different socio-ecological contexts of the Tehuacán Valley.

PubMed

Vallejo-Ramos, Mariana; Moreno-Calles, Ana I; Casas, Alejandro

2016-07-22

Transformation of natural ecosystems into intensive agriculture is a main factor causing biodiversity loss worldwide. Agroforestry systems (AFS) may maintain biodiversity, ecosystem benefits and human wellbeing, they have therefore high potential for concealing production and conservation. However, promotion of intensive agriculture and disparagement of TEK endanger their permanence. A high diversity of AFS still exist in the world and their potentialities vary with the socio-ecological contexts. We analysed AFS in tropical, temperate, and arid environments, of the Tehuacan Valley, Mexico, to investigate how their capacity varies to conserve biodiversity and role of TEK influencing differences in those contexts. We hypothesized that biodiversity in AFS is related to that of forests types associated and the vigour of TEK and management. We conducted studies in a matrix of environments and human cultures in the Tehuacán Valley. In addition, we reviewed, systematized and compared information from other regions of Mexico and the world with comparable socio-ecological contexts in order to explore possible general patterns. Our study found from 26 % to nearly 90 % of wild plants species richness conserved in AFS, the decreasing proportion mainly associated to pressures for intensifying agricultural production and abandoning traditional techniques. Native species richness preserved in AFS is influenced by richness existing in the associated forests, but the main driver is how people preserve benefits of components and functions of ecosystems. Elements of modern agricultural production may coexist with traditional management patterns, but imposition of modern models may break possible balances. TEK influences decisions on what and how modern techniques may be advantageous for preserving biodiversity, ecosystem integrity in AFS and people's wellbeing. TEK, agroecology and other sciences may interact for maintaining and improving traditional AFS to increase biodiversity

Tree spatial structure, host composition and resource availability influence mirid density or black pod prevalence in cacao agroforests in Cameroon.

PubMed

Gidoin, Cynthia; Babin, Régis; Bagny Beilhe, Leïla; Cilas, Christian; ten Hoopen, Gerben Martijn; Bieng, Marie Ange Ngo

2014-01-01

Combining crop plants with other plant species in agro-ecosystems is one way to enhance ecological pest and disease regulation mechanisms. Resource availability and microclimatic variation mechanisms affect processes related to pest and pathogen life cycles. These mechanisms are supported both by empirical research and by epidemiological models, yet their relative importance in a real complex agro-ecosystem is still not known. Our aim was thus to assess the independent effects and the relative importance of different variables related to resource availability and microclimatic variation that explain pest and disease occurrence at the plot scale in real complex agro-ecosystems. The study was conducted in cacao (Theobroma cacao) agroforests in Cameroon, where cocoa production is mainly impacted by the mirid bug, Sahlbergella singularis, and black pod disease, caused by Phytophthora megakarya. Vegetation composition and spatial structure, resource availability and pest and disease occurrence were characterized in 20 real agroforest plots. Hierarchical partitioning was used to identify the causal variables that explain mirid density and black pod prevalence. The results of this study show that cacao agroforests can be differentiated on the basis of vegetation composition and spatial structure. This original approach revealed that mirid density decreased when a minimum number of randomly distributed forest trees were present compared with the aggregated distribution of forest trees, or when forest tree density was low. Moreover, a decrease in mirid density was also related to decreased availability of sensitive tissue, independently of the effect of forest tree structure. Contrary to expectations, black pod prevalence decreased with increasing cacao tree abundance. By revealing the effects of vegetation composition and spatial structure on mirids and black pod, this study opens new perspectives for the joint agro-ecological management of cacao pests and diseases at the

Bitrophic and tritrophic effects of Bt Cry3A transgenic potato on beneficial, non-target, beetles.

PubMed

Ferry, Natalie; Mulligan, Evan A; Majerus, Michael E N; Gatehouse, Angharad M R

2007-12-01

Insect-resistant transgenic plants have been suggested to have unpredictable effects on the biodiversity of the agro-ecosystem, including potential effects on insect natural enemies, beneficial in control of crop pests. Whilst carnivorous as adults, many of these predators may also consume plant tissues, in particular plant pollen and nectar. Coleoptera are important in terms of agro-ecological research not only because of the large number of species in this order, but also because of their role as biological control agents. Thus any detrimental impact on this group of insects would be highly undesirable. The effects of potato expressing the coleopteran-specific Bacillus thuringiensis delta-endotoxin Cry3A (Bt Cry3A) on the ladybird beetle Harmonia axyridis and the carabid beetle Nebria brevicollis were investigated via the bitrophic interaction of the adult ladybird with potato flowers and the tritrophic interaction of the carabid consuming a non-target potato pest. Immunoassays confirmed accumulation of the transgene product in potato leaves and floral tissues (at levels of up to 0.01% (pollen) and 0.0285% (anthers) of total soluble protein). Despite H. axyridis and N. brevicollis belonging to the targeted insect order, no significant effects upon survival or overall body mass change of either beetle were observed. Furthermore, Bt Cry3A had no detrimental effects on reproductive fitness of either beetle species, either in terms of fecundity or subsequent egg viability. Behavioural analysis revealed no significant impact of Bt Cry3A on beetle activity or locomoter behaviour. Ligand blots indicate that this is due to either the absence of Bt-binding sites in brush border membrane vesicles (BBMV) isolated from Nebria brevicollis, or in the case of Harmonia axyridis, the binding did not functionally lead to behavioural or physical effects.

Sensitivity of crop cover to climate variability: insights from two Indian agro-ecoregions.

PubMed

Mondal, Pinki; Jain, Meha; DeFries, Ruth S; Galford, Gillian L; Small, Christopher

2015-01-15

Crop productivity in India varies greatly with inter-annual climate variability and is highly dependent on monsoon rainfall and temperature. The sensitivity of yields to future climate variability varies with crop type, access to irrigation and other biophysical and socio-economic factors. To better understand sensitivities to future climate, this study focuses on agro-ecological subregions in Central and Western India that span a range of crops, irrigation, biophysical conditions and socioeconomic characteristics. Climate variability is derived from remotely-sensed data products, Tropical Rainfall Measuring Mission (TRMM - precipitation) and Moderate Resolution Imaging Spectroradiometer (MODIS - temperature). We examined green-leaf phenologies as proxy for crop productivity using the MODIS Enhanced Vegetation Index (EVI) from 2000 to 2012. Using both monsoon and winter growing seasons, we assessed phenological sensitivity to inter-annual variability in precipitation and temperature patterns. Inter-annual EVI phenology anomalies ranged from -25% to 25%, with some highly anomalous values up to 200%. Monsoon crop phenology in the Central India site is highly sensitive to climate, especially the timing of the start and end of the monsoon and intensity of precipitation. In the Western India site, monsoon crop phenology is less sensitive to precipitation variability, yet shows considerable fluctuations in monsoon crop productivity across the years. Temperature is critically important for winter productivity across a range of crop and management types, such that irrigation might not provide a sufficient buffer against projected temperature increases. Better access to weather information and usage of climate-resilient crop types would play pivotal role in maintaining future productivity. Effective strategies to adapt to projected climate changes in the coming decades would also need to be tailored to regional biophysical and socio-economic conditions. Copyright © 2014

Implementing a Spinosad-Based Local Bait Station to Control Bactrocera cucurbitae (Diptera: Tephritidae) in High Rainfall Areas of Reunion Island

PubMed Central

Delpoux, Camille; Deguine, Jean-Philippe

2015-01-01

Three species of fruit flies cause serious damage to cucurbit crops on Reunion Island: Bactrocera cucurbitae (Diptera: Tephritidae) (Coquillett 1899), Dacus ciliatus (Loew 1901), and Dacus demmerezi (Bezzi 1917). To control them, a program of agroecological management of cucurbit flies has been implemented based on the application of Synéis-appât, especially spot sprays on corn borders. However, the high rainfall on Reunion Island limits the long-term efficiency of the bait; in addition, this method cannot be used for large chayote trellises, because corn borders cannot be planted around them. The aim of this study was to design a bait station adapted to prevailing conditions on Reunion Island. An ‘umbrella trap’ tested in Taiwan was used as a reference to compare its efficacy with our local bait station. Experiments were conducted in field cages on B. cucurbitae to test different characteristics of bait stations and to construct one using local materials. Results were validated in the field. The attractiveness of the bait station was related mainly to the color of the external surface, yellow being the most attractive color. The efficacy of the bait station with respect to fly mortality was found to be linked to the accessibility of the bait, and direct application of Synéis-appât on the bait station was found to be the most efficient. In the field, B. cucurbitae were more attracted to the local bait station than to the umbrella trap, while the two other fly species displayed equal attraction to both trap types. Our local bait station is a useful alternative to spot sprays of Synéis-appât and is now included in a local pest management program and is well accepted by farmers. PMID:25688089

Rates of return to sorghum and millet research investments: A meta-analysis

PubMed Central

2017-01-01

Sorghum and millet grow in some of the most heterogeneous and austere agroecologies around the world. These crops are amongst the top five cereal sources of food and feed. Yet, few studies document the impact of sorghum and millet genetic enhancement. The Internal Rate of Return (ROR) is one of the most popular metrics used to measure the economic return on investment on agricultural research and development (R&D). This study conducted a meta-analysis of 59 sorghum and millet ROR estimates obtained from 25 sources published between 1958 and 2015. The average rate of return to sorghum and millet R&D investment is between 54–76 percent per year. All studies computed social rather than private RORs because the technologies were developed using public funds originating from host country National Agricultural Research Systems (NARS) and international organizations such as the INTSORMIL CRSP, ICRISAT and others. Nearly three quarter of the studies focused only on sorghum (72 percent) and around one tenth of the studies (8 percent) on millet. Regression models analyzed the determinants of variation in the reported RORs. Results show that ex-ante type and self-evaluated type of analyses are positively and significantly associated with the ROR estimates. Compared to estimates conducted by a university, results from international institutions and other mixed organizations provided significantly smaller estimates. Estimates conducted at national level also are significantly lower than those conducted at sub-national levels. The ROR is higher for studies conducted in the United States and for those conducted more recently. The study also reconstructed modified internal rate of return (MIRR) for a sub-sample of the reported RORs following recent methods from the literature. These results show that the MIRR estimates are significantly smaller than the reported ROR estimates. Both results indicate that investment in sorghum and millet research generates high social rates of

Mites of sheep and goats in Oromia Zone of Amhara Region, North Eastern Ethiopia: species, prevalence and farmers awareness.

PubMed

Yasine, Ahmed; Kumsa, Bersissa; Hailu, Yacob; Ayana, Dinka

2015-05-24

Mites are one of the most common and widely distributed ectoparasites of small ruminants in Ethiopia, contributing to major hindrances in livestock productivity in the country. Despite of this fact, specific study was not conducted on mites of small ruminants in Ethiopia. Therefore, the present study was performed from October 2009 to May 2010 to determine the prevalence and species composition of mites in three agroecological zones in north eastern Ethiopia. In addition, a questionnaire survey on mites was conducted to assess the control practices and awareness of farmers in the study areas. Out of a total of 1280 sheep and 1264 goats examined, 97(7.6 %) of sheep and 174(13.8 %) goats were infested with one or more species of mites. In goats an overall prevalence of 10.3 % Sarcoptes, 2.8 % Demodex and 0.6 % Psoroptes were recorded whereas in sheep an overall prevalence of 3.5 % Sarcoptes, 2.1 % Demodex and 1.6 % Psoroptes were observed. Sarcoptes (P = 0.03; OR = 2.1) and Demodex (OR = 3.25; p = 0.004) were significantly more common in young than in adult sheep. Demodectic mange was significantly higher in young (4.1 %) compared to adult (2.3 %) goats (OR = 2.2; P = 0.02). Significantly higher (P < 0.01) overall prevalence of sarcoptic and demodectic mites in both sheep and goats with poor than with good body condition was recorded. Results of the questionnaire survey supported results of our cross-sectional study. This study demonstrates high prevalence of mange mites in sheep and goats of the study area. The study revealed that Sarcoptes is the predominant mite in both sheep and goats. Animal owners and veterinarians should consider mite control in small ruminants as part of the routine ectoparasite control in Ethiopia.

Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future

PubMed Central

2012-01-01

In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the

Sero-prevalence, risk factors and distribution of sheep and goat pox in Amhara Region, Ethiopia.

PubMed

Fentie, Tsegaw; Fenta, Nigusie; Leta, Samson; Molla, Wassie; Ayele, Birhanu; Teshome, Yechale; Nigatu, Seleshe; Assefa, Ashenafi

2017-12-11

Sheep pox and goat pox are contagious viral diseases of sheep and goats, respectively. The diseases result in substantial economic losses due to decreased milk and meat production, damage to hides and wool, and possible trade restriction. A study was undertaken in Amhara region of Ethiopia. A cross-sectional study design was used to estimate the sero-prevalence and identify associated risk factors, while retrospective study design was used to assess the temporal and spatial distribution of the disease. A total of 672 serum samples were collected from 30 Kebeles and tested using virus neutralization test. From a total of 672 sera tested, 104 (15.5%) were positive for sheep and goat pox virus antibody; from which 56 (17%) were sheep and 48 (14%) were goats. The diseases were prevalent in all study zones, the highest sero-prevalence was observed in South Gondar (20.9%) and the lowest in North Gondar and West Gojjam zones (11.9% each). From the potential risk factors considered (species, sex, age, agro-ecology and location); only sex and age were significantly associated (p < 0.05) with the diseases in multivariable logistic regression. Female and young animals were at higher risk than their counterparts. From January 2010 to December 2014, a total of 366 outbreaks, 12,822 cases and 1480 deaths due to SP and 182 outbreaks, 10,066 cases and 997 deaths due to GP were recorded in Amhara National Regional State. Both the serological and the outbreak data revealed that sheep and goat pox is one of the most prevalent and widespread diseases of sheep and goats in the study area. Hence, annual mass vaccination program must be implemented for economic and viable control of sheep and goat pox diseases in the Amhara region in particular and at a national level in general.

Soil fertility and the role of soils for food security in developing countries

NASA Astrophysics Data System (ADS)

Tittonell, Pablo

2015-04-01

Addressing current and future food security is not just a matter of producing more food globally. Agricultural productivity must increase where food is most needed, and where both rural and urban populations are expected to increase the fastest in the near future. This is the situation in most of sub-Saharan Africa and in several other regions of Latin America, Asia and the Pacific. There are some common denominators to these regions. In the first place, the inability of the majority of farmers to access and/or to afford agricultural inputs. Second, the severity with which climate change impacts on some of these regions. Third, the extent of soil degradation, which is estimated at 25% of the arable land in the world. And finally, the fact that some of these regions are hosting valuable biodiversity and/or delivering ecosystem services of global or regional importance, which often leads to competing claims between the local and international communities. It has been repeatedly shown that the technologies of industrial agriculture as practiced in developed regions are ineffective at sustaining soil productivity in the context of smallholder family agriculture. Restoring soil productivity and ecosystem functions in these contexts requires new ways of managing soil fertility. These include: (i) innovative forms of 'precision' agriculture that consider the diversity, heterogeneity and dynamics of smallholder farming systems; (ii) a systems approach to nutrient acquisition and management; (iii) agroecological strategies for the restoration of degraded soils and the maintenance of soil physical properties; and (iv) to capitalize on the recent and growing understanding on soil trophic networks to increase nutrient and water use efficiency. I will provide examples on advances in these fronts, and discuss the challenges ahead their broad implementation by farmers in developing regions.

Current situation and future prospects for beef production in Europe.

PubMed

Hocquette, Jean-Francois; Ellies-Oury, Marie-Pierre; Lherm, Michel; Pineau, Christele; Deblitz, Claus; Farmer, Linda

2018-05-24

The European Union (EU) is the world's third largest producer of beef. This contributes to the economy, rural development, social life, culture and gastronomy of Europe. The diversity of breeds, animal types (cows, bulls, steers, heifers) and farming systems (intensive, extensive on permanent or temporary pastures, mixed, breeders, feeders, etc) is a strength, and a weakness as the industry is often fragmented and poorly connected. There are also societal concerns regarding animal welfare and environmental issues, despite some positive environmental impacts of farming systems. The EU is amongst the most efficient for beef production as demonstrated by a relative low production of greenhouse gases. Due to regional differences in terms of climate, pasture availability, livestock practices and farms characteristics, productivity and incomes of beef producers vary widely across regions, being among the lowest of the agricultural systems. The beef industry is facing unprecedented challenges related to animal welfare, environmental impact, origin, authenticity, nutritional benefits and eating quality of beef. These may affect the whole industry, especially its farmers. It is therefore essential to bring the beef industry together to spread best practice and better exploit research in order to maintain and develop an economically viable and sustainable beef industry. Meeting consumers' expectations may be achieved by a better prediction of beef palatability using a modelling approach, such as in Australia. There is a need for accurate information and dissemination on the benefits and issues of beef for human health and for environmental impact. A better objective description of goods and services derived from livestock farming is also required. Putting into practice "agroecology" and organic farming principles are other potential avenues for the future. Different future scenarios can be written depending on the major driving forces, notably meat consumption, climate

DNA barcoding simplifies environmental risk assessment of genetically modified crops in biodiverse regions.

PubMed

Nzeduru, Chinyere V; Ronca, Sandra; Wilkinson, Mike J

2012-01-01

Transgenes encoding for insecticidal crystal (Cry) proteins from the soil-dwelling bacterium Bacillus Thuringiensis have been widely introduced into Genetically Modified (GM) crops to confer protection against insect pests. Concern that these transgenes may also harm beneficial or otherwise valued insects (so-called Non Target Organisms, NTOs) represents a major element of the Environmental Risk Assessments (ERAs) used by all countries prior to commercial release. Compiling a comprehensive list of potentially susceptible NTOs is therefore a necessary part of an ERA for any Cry toxin-containing GM crop. In partly-characterised and biodiverse countries, NTO identification is slowed by the need for taxonomic expertise and time to enable morphological identifications. This limitation represents a potentially serious barrier to timely adoption of GM technology in some developing countries. We consider Bt Cry1A cowpea (Vigna unguiculata) in Nigeria as an exemplar to demonstrate how COI barcoding can provide a simple and cost-effective means of addressing this problem. Over a period of eight weeks, we collected 163 insects from cowpea flowers across the agroecological and geographic range of the crop in Nigeria. These individuals included 32 Operational Taxonomic Units (OTUs) spanning four Orders and that could mostly be assigned to genus or species level. They included 12 Lepidopterans and two Coleopterans (both potentially sensitive to different groups of Cry proteins). Thus, barcode-assisted diagnoses were highly harmonised across groups (typically to genus or species level) and so were insensitive to expertise or knowledge gaps. Decisively, the entire study was completed within four months at a cost of less than 10,000 US$. The broader implications of the findings for food security and the capacity for safe adoption of GM technology are briefly explored.

Review: Animal health and sustainable global livestock systems.

PubMed

Perry, B D; Robinson, T P; Grace, D C

2018-04-10

This paper discusses the sustainability of livestock systems, emphasising bidirectional relations with animal health. We review conventional and contrarian thinking on sustainability and argue that in the most common approaches to understanding sustainability, health aspects have been under-examined. Literature review reveals deep concerns over the sustainability of livestock systems; we recognise that interventions are required to shift to more sustainable trajectories, and explore approaches to prioritising in different systems, focusing on interventions that lead to better health. A previously proposed three-tiered categorisation of 'hot spots', 'cold spots' and 'worried well' animal health trajectories provides a mental model that, by taking into consideration the different animal health status, animal health risks, service response needs and key drivers in each system, can help identify and implement interventions. Combining sustainability concepts with animal health trajectories allows for a richer analysis, and we apply this to three case studies drawn from North Africa and the Middle East; Bangladesh; and the Eastern Cape of South Africa. We conclude that the quest for sustainability of livestock production systems from the perspective of human and animal health is elusive and difficult to reconcile with the massive anticipated growth in demand for livestock products, mainly in low- and middle-income countries, as well as the aspirations of poor livestock keepers for better lives. Nevertheless, improving the health of livestock can contribute to health sustainability both through reducing negative health impacts of livestock and increasing efficiency of production. However, the choice of the most appropriate options must be under-pinned by an understanding of agro-ecology, economy and values. We argue that a new pillar of One Health should be added to the three traditional sustainability pillars of economics, society and environment when addressing

High soil and groundwater arsenic levels induce high body arsenic loads, health risk and potential anemia for inhabitants of northeastern Iran.

PubMed

Taheri, Masumeh; Mehrzad, Jalil; Mahmudy Gharaie, Mohamad Hosein; Afshari, Reza; Dadsetan, Ahmad; Hami, Shakiba

2016-04-01

Arsenic bioavailability in rock, soil and water resources is notoriously hazardous. Geogenic arsenic enters the body and adversely affects many biochemical processes in animals and humans, posing risk to public health. Chelpu is located in NE Iran, where realgar, orpiment and pyrite mineralization is the source of arsenic in the macroenvironment. Using cluster random sampling strategy eight rocks, 23 soils, 12 drinking water resources, 36 human urine and hair samples and 15 adult sheep urine and wool samples in several large-scale herds in the area were randomly taken for quantification of arsenic in rock/soil/water, wool/hair/urine. Arsenic levels in rock/soil/water and wool/hair/urine were measured using inductively coupled plasma spectroscopy and atomic absorption spectrophotometry, respectively. While arsenic levels in rocks, soils and water resources hazardously ranged 9.40-25,873.3 mg kg(-1), 7.10-1448.80 mg kg(-1) and 12-606 μg L(-1), respectively, arsenic concentrations in humans' hair and urine and sheep's wool and urine varied from 0.37-1.37 μg g(-1) and 9-271.4 μg L(-1) and 0.3-3.11 μg g(-1) and 29.1-1015 μg L(-1), respectively. Local sheep and human were widely sick and slightly anemic. Hematological examination of the inhabitants revealed that geogenic arsenic could harm blood cells, potentially resulting in many other hematoimmunological disorders including cancer. The findings warn widespread exposure of animals and human in this agroecologically and geopolitically important region (i.e., its proximity with Afghanistan, Pakistan and Turkmenistan) and give a clue on how arsenic could induce infectious and non-infectious diseases in highly exposed human/animals.

Barriers to Uptake of Climate-Smart Agriculture Practices at the Farm Level: A Case Study of Dano and Ouahigouya Farmers, Burkina Faso

NASA Astrophysics Data System (ADS)

Thomas, Y. B.

2016-12-01

Smallholder farmers in Burkina Faso, which are already bearing the brunt of climate vagaries, are among the most exposed to the risks associated to climate change. Supporting these farmers in adoption of climate-smart agriculture (CSA) practices would help to increase farm productivity and incomes, improve their resilience to climate risks, and mitigate climate change by reducing GHG emissions. CSA is neither a new agricultural system nor a set of practice, but is a new approach, a way to guide the needed changes of agricultural systems, given the necessity to jointly address food security and climate change. Integrating statistics and visualization analysis, this paper identifies and analyzes the key barriers to farmers' effective adoption of CSA practices in Dano and Ouahigouya areas, Burkina Faso. The data used in this study were collected, in May 2016, from 147 households in the two different agro-ecological zones; these data were supplemented by information from focus group discussion (FGD), interview with institutions, and direct observation. It come out from this study that a better adoption of CSA practices requires a strong understanding of barriers and mechanisms (appropriate policies, strategies and actions) that may facilitate these practices by all actors involved in the diffusion, transfer and implementation process. The study revealed that farmers' adoption was influenced by several factors. The inaccessibility of inputs, credit constraints, water shortage, uncertainty in market condition, and climate risk appeared to be among factors that hindered farmers' ability and willingness to adopt CSA practices. Therefore mechanisms (such as index based crop insurance and property and procedural rights frameworks) that protect farmers from these hazards and shocks could encourage them (especially, risk-averse farmers) to take on more risky and more technologies that have high potential to maximize their profit.

Application of system dynamics and participatory spatial group model building in animal health: A case study of East Coast Fever interventions in Lundazi and Monze districts of Zambia

PubMed Central

Skjerve, Eystein; Rich, Magda; Rich, Karl M.

2017-01-01

East Coast Fever (ECF) is the most economically important production disease among traditional beef cattle farmers in Zambia. Despite the disease control efforts by the government, donors, and farmers, ECF cases are increasing. Why does ECF oscillate over time? Can alternative approaches such as systems thinking contribute solutions to the complex ECF problem, avoid unintended consequences, and achieve sustainable results? To answer these research questions and inform the design and implementation of ECF interventions, we qualitatively investigated the influence of dynamic socio-economic, cultural, and ecological factors. We used system dynamics modelling to specify these dynamics qualitatively, and an innovative participatory framework called spatial group model building (SGMB). SGMB uses participatory geographical information system (GIS) concepts and techniques to capture the role of spatial phenomenon in the context of complex systems, allowing stakeholders to identify spatial phenomenon directly on physical maps and integrate such information in model development. Our SGMB process convened focus groups of beef value chain stakeholders in two distinct production systems. The focus groups helped to jointly construct a series of interrelated system dynamics models that described ECF in a broader systems context. Thus, a complementary objective of this study was to demonstrate the applicability of system dynamics modelling and SGMB in animal health. The SGMB process revealed policy leverage points in the beef cattle value chain that could be targeted to improve ECF control. For example, policies that develop sustainable and stable cattle markets and improve household income availability may have positive feedback effects on investment in animal health. The results obtained from a SGMB process also demonstrated that a “one-size-fits-all” approach may not be equally effective in policing ECF in different agro-ecological zones due to the complex interactions of

Epidemiology of East Coast fever (Theileria parva infection) in Kenya: past, present and the future.

PubMed

Gachohi, John; Skilton, Rob; Hansen, Frank; Ngumi, Priscilla; Kitala, Philip

2012-09-07

In this article, we review the epidemiology of East Coast fever (ECF), a tick-borne infection of cattle, in Kenya. The major factors associated with epidemiology of ECF include the agro-ecological zone (AEZ), livestock production system (LPS) and both animal breed and age. These factors appear to influence the epidemiology of ECF through structured gradients. We further show that the gradients are dynamically shaped by socio-demographic and environmental processes. For a vector-borne disease whose transmission depends on environmental characteristics that influence vector dynamics, a change in the environment implies a change in the epidemiology of the disease. The review recommends that future ECF epidemiological studies should account for these factors and the dynamic interactions between them. In Kenya, ECF control has previously relied predominantly on tick control using acaricides and chemotherapy while ECF immunization is steadily being disseminated. We highlight the contribution of ECF epidemiology and economics in the design of production system and/or geographical area-specific integrated control strategies based on both the dynamic epidemiological risk of the disease and economic impacts of control strategies. In all production systems (except marginal areas), economic analyses demonstrate that integrated control in which ECF immunization is always an important component, can play an important role in the overall control of the disease. Indeed, Kenya has recently approved ECF immunization in all production systems (except in marginal areas). If the infrastructure of the vaccine production and distribution can be heightened, large ECF endemic areas are expected to be endemically stable and the disease controlled. Finally, the review points the way for future research by identifying scenario analyses as a critical methodology on which to base future investigations on how both dynamic livestock management systems and patterns of land use influence the

Application of system dynamics and participatory spatial group model building in animal health: A case study of East Coast Fever interventions in Lundazi and Monze districts of Zambia.

PubMed

Mumba, Chisoni; Skjerve, Eystein; Rich, Magda; Rich, Karl M

2017-01-01

East Coast Fever (ECF) is the most economically important production disease among traditional beef cattle farmers in Zambia. Despite the disease control efforts by the government, donors, and farmers, ECF cases are increasing. Why does ECF oscillate over time? Can alternative approaches such as systems thinking contribute solutions to the complex ECF problem, avoid unintended consequences, and achieve sustainable results? To answer these research questions and inform the design and implementation of ECF interventions, we qualitatively investigated the influence of dynamic socio-economic, cultural, and ecological factors. We used system dynamics modelling to specify these dynamics qualitatively, and an innovative participatory framework called spatial group model building (SGMB). SGMB uses participatory geographical information system (GIS) concepts and techniques to capture the role of spatial phenomenon in the context of complex systems, allowing stakeholders to identify spatial phenomenon directly on physical maps and integrate such information in model development. Our SGMB process convened focus groups of beef value chain stakeholders in two distinct production systems. The focus groups helped to jointly construct a series of interrelated system dynamics models that described ECF in a broader systems context. Thus, a complementary objective of this study was to demonstrate the applicability of system dynamics modelling and SGMB in animal health. The SGMB process revealed policy leverage points in the beef cattle value chain that could be targeted to improve ECF control. For example, policies that develop sustainable and stable cattle markets and improve household income availability may have positive feedback effects on investment in animal health. The results obtained from a SGMB process also demonstrated that a "one-size-fits-all" approach may not be equally effective in policing ECF in different agro-ecological zones due to the complex interactions of socio

Tree Spatial Structure, Host Composition and Resource Availability Influence Mirid Density or Black Pod Prevalence in Cacao Agroforests in Cameroon

PubMed Central

Gidoin, Cynthia; Babin, Régis; Bagny Beilhe, Leïla; Cilas, Christian; ten Hoopen, Gerben Martijn; Bieng, Marie Ange Ngo

2014-01-01

Combining crop plants with other plant species in agro-ecosystems is one way to enhance ecological pest and disease regulation mechanisms. Resource availability and microclimatic variation mechanisms affect processes related to pest and pathogen life cycles. These mechanisms are supported both by empirical research and by epidemiological models, yet their relative importance in a real complex agro-ecosystem is still not known. Our aim was thus to assess the independent effects and the relative importance of different variables related to resource availability and microclimatic variation that explain pest and disease occurrence at the plot scale in real complex agro-ecosystems. The study was conducted in cacao (Theobroma cacao) agroforests in Cameroon, where cocoa production is mainly impacted by the mirid bug, Sahlbergella singularis, and black pod disease, caused by Phytophthora megakarya. Vegetation composition and spatial structure, resource availability and pest and disease occurrence were characterized in 20 real agroforest plots. Hierarchical partitioning was used to identify the causal variables that explain mirid density and black pod prevalence. The results of this study show that cacao agroforests can be differentiated on the basis of vegetation composition and spatial structure. This original approach revealed that mirid density decreased when a minimum number of randomly distributed forest trees were present compared with the aggregated distribution of forest trees, or when forest tree density was low. Moreover, a decrease in mirid density was also related to decreased availability of sensitive tissue, independently of the effect of forest tree structure. Contrary to expectations, black pod prevalence decreased with increasing cacao tree abundance. By revealing the effects of vegetation composition and spatial structure on mirids and black pod, this study opens new perspectives for the joint agro-ecological management of cacao pests and diseases at the

Influence of Environmental Conditions and Genetic Background of Arabica Coffee (C. arabica L) on Leaf Rust (Hemileia vastatrix) Pathogenesis

PubMed Central

Toniutti, Lucile; Breitler, Jean-Christophe; Etienne, Hervé; Campa, Claudine; Doulbeau, Sylvie; Urban, Laurent; Lambot, Charles; Pinilla, Juan-Carlos H.; Bertrand, Benoît

2017-01-01

Global warming is a major threat to agriculture worldwide. Between 2008 and 2013, some coffee producing countries in South and Central America suffered from severe epidemics of coffee leaf rust (CLR), resulting in high economic losses with social implications for coffee growers. The climatic events not only favored the development of the pathogen but also affected the physiological status of the coffee plant. The main objectives of the study were to evaluate how the physiological status of the coffee plant modified by different environmental conditions impact on the pathogenesis of CLR and to identify indicators of the physiological status able to predict rust incidence. Three rust susceptible genotypes (one inbred line and two hybrids) were grown in controlled conditions with a combination of thermal regime (TR), nitrogen and light intensity close to the field situation before being inoculated with the rust fungus Hemileia vastatrix. It has been demonstrated that a TR of 27-22°C resulted in 2000 times higher sporulation than with a TR of 23–18°C. It has been also shown that high light intensity combined with low nitrogen fertilization modified the CLR pathogenesis resulting in huge sporulation. CLR sporulation was significantly lower in the F1 hybrids than in the inbred line. The hybrid vigor may have reduced disease incidence. Among the many parameters studied, parameters related to photosystem II and photosynthetic electron transport chain components appeared as indicators of the physiological status of the coffee plant able to predict rust sporulation intensity. Taken together, these results show that CLR sporulation not only depends on the TR but also on the physiological status of the coffee plant, which itself depends on agronomic conditions. Our work suggests that vigorous varieties combined with a shaded system and appropriate nitrogen fertilization should be part of an agro-ecological approach to disease control. PMID:29234340

Gene flow in Prunus species in the context of novel trait risk assessment.

PubMed

Cici, S Zahra H; Van Acker, Rene C

2010-01-01

Prunus species are important commercial fruit (plums, apricot, peach and cherries), nut (almond) and ornamental trees cultivated broadly worldwide. This review compiles information from available literature on Prunus species in regard to gene flow and hybridization within this complex of species. The review serves as a resource for environmental risk assessment related to pollen mediated gene flow and the release of transgenic Prunus. It reveals that Prunus species, especially plums and cherries show high potential for transgene flow. A range of characteristics including; genetic diversity, genetic bridging capacity, inter- and intra-specific genetic compatibility, self sterility (in most species), high frequency of open pollination, insect assisted pollination, perennial nature, complex phenotypic architecture (canopy height, heterogeneous crown, number of flowers produced in an individual plant), tendency to escape from cultivation, and the existence of ornamental and road side Prunus species suggest that there is a tremendous and complicated ability for pollen mediated gene movement among Prunus species. Ploidy differences among Prunus species do not necessarily provide genetic segregation. The characteristics of Prunu s species highlight the complexity of maintaining coexistence between GM and non-GM Prunus if there were commercial production of GM Prunus species. The results of this review suggest that the commercialization of one GM Prunus species can create coexistence issues for commercial non-GM Prunus production. Despite advances in molecular markers and genetic analysis in agroecology, there remains limited information on the ecological diversity, metapopulation nature, population dynamics, and direct measures of gene flow among different subgenera represented in the Prunus genus. Robust environmental impact, biosafety and coexistence assessments for GM Prunus species will require better understanding of the mechanisms of gene flow and hybridization

Dominant viral pathologies in the extensive and semi-intensive animal breeding and their treatment mode in ethno veterinary medicine in Benin.

PubMed

Kpodékon, T M; Ogni, C A; Dassou, H; Dougnon, T J; Boko, C; Koutinhouin, G B; Goussanou, J S E; Akoegninou, A; Youssao, I

2015-12-01

This study aims to identify the dominant viral animal pathologies and to list the traditional recipes used by the breeders for their treatment. The method of data collection was based on a retrospective survey. Thus, 787 breeders and agro-breeders scattered in the eight agro-ecological areas of Benin were interviewed using semi-structured questionnaires. In total, 5 pathologies were reported by breeders. Among those pathologies, foot and mouth disease was reported by all of the breeders of the southern part of Borgou compared with the other areas (p<0.05) and treated by 25 species of medicinal plants. African swine fever was the main pathology reported (22.92%) (p<0.05) in the fishery areas which is controlled by 7 medicinal plants. Pseudorinderpest was more reported (33.78%) (p<0.05) in the cotton area of central Benin and treated by 8 medicinal plants. There is also Newcastle disease that was mostly reported in the Western Atacora and treated by 32 medicinal plants as well as fowl pox which was a more reported in the lands of the bar area and the low-pressure area about 34.48% and 36.17% proportions, respectively, and treated by eight medicinal plants. The breeders in Benin possess rich ethno veterinary knowledge on medicinal plants and their uses in the treatment of livestock. A total of 57 medicinal plants have been inventoried to fight against five major viral diseases as African swine fever, pseudorinderpest and foot and mouth disease. The common plants used to treat viral disease in general were Euphorbia unispina, Euphorbia poissonii, Lannea acida, and Mangifera indica. The most harvested organs on the plants reported in this survey were the barks, the leaves, and the whole plants. To better develop our indigenous resources, it would be important to expand this ethno-pharmacological investigation to other diseases category.

Managing Potato Biodiversity to Cope with Frost Risk in the High Andes: A Modeling Perspective

PubMed Central

Condori, Bruno; Hijmans, Robert J.; Ledent, Jean Francois; Quiroz, Roberto

2014-01-01

Austral summer frosts in the Andean highlands are ubiquitous throughout the crop cycle, causing yield losses. In spite of the existing warming trend, climate change models forecast high variability, including freezing temperatures. As the potato center of origin, the region has a rich biodiversity which includes a set of frost resistant genotypes. Four contrasting potato genotypes –representing genetic variability- were considered in the present study: two species of frost resistant native potatoes (the bitter Solanum juzepczukii, var. Luki, and the non-bitter Solanum ajanhuiri, var. Ajanhuiri) and two commercial frost susceptible genotypes (Solanum tuberosum ssp. tuberosum var. Alpha and Solanum tuberosum ssp. andigenum var. Gendarme). The objective of the study was to conduct a comparative growth analysis of four genotypes and modeling their agronomic response under frost events. It included assessing their performance under Andean contrasting agroecological conditions. Independent subsets of data from four field experiments were used to parameterize, calibrate and validate a potato growth model. The validated model was used to ascertain the importance of biodiversity, represented by the four genotypes tested, as constituents of germplasm mixtures in single plots used by local farmers, a coping strategy in the face of climate variability. Also scenarios with a frost routine incorporated in the model were constructed. Luki and Ajanhuiri were the most frost resistant varieties whereas Alpha was the most susceptible. Luki and Ajanhuiri, as monoculture, outperformed the yield obtained with the mixtures under severe frosts. These results highlight the role played by local frost tolerant varieties, and featured the management importance –e.g. clean seed, strategic watering- to attain the yields reported in our experiments. The mixtures of local and introduced potatoes can thus not only provide the products demanded by the markets but also reduce the impact of

Agronomic Challenges and Opportunities for Smallholder Terrace Agriculture in Developing Countries.

PubMed

Chapagain, Tejendra; Raizada, Manish N

2017-01-01

Improving land productivity is essential to meet increasing food and forage demands in hillside and mountain communities. Tens of millions of smallholder terrace farmers in Asia, Africa, and Latin America who earn $1-2 per day do not have access to peer-reviewed knowledge of best agronomic practices, though they have considerable traditional ecological knowledge. Terrace farmers also lack access to affordable farm tools and inputs required to increase crop yields. The objectives of this review are to highlight the agronomic challenges of terrace farming, and offer innovative, low-cost solutions to intensify terrace agriculture while improving local livelihoods. The article focuses on smallholder farmers in developing nations, with particular reference to Nepal. The challenges of terrace agriculture in these regions include lack of quality land area for agriculture, erosion and loss of soil fertility, low yield, poor access to agricultural inputs and services, lack of mechanization, labor shortages, poverty, and illiteracy. Agronomic strategies that could help address these concerns include intensification of terraces using agro-ecological approaches along with introduction of light-weight, low-cost, and purchasable tools and affordable inputs that enhance productivity and reduce female drudgery. To package, deliver, and share these technologies with remote hillside communities, effective scaling up models are required. One opportunity to enable distribution of these products could be to "piggy-back" onto pre-existing snackfood/cigarette/alcohol distribution networks that are prevalent even in the most remote mountainous regions of the world. Such strategies, practices, and tools could be supported by formalized government policies dedicated to the well-being of terrace farmers and ecosystems, to maintain resiliency at a time of alarming climate change. We hope this review will inform governments, non-governmental organizations, and the private sector to draw

Restoring monarch butterfly habitat in the Midwestern US: ‘all hands on deck’

NASA Astrophysics Data System (ADS)

Thogmartin, Wayne E.; López-Hoffman, Laura; Rohweder, Jason; Diffendorfer, Jay; Drum, Ryan; Semmens, Darius; Black, Scott; Caldwell, Iris; Cotter, Donita; Drobney, Pauline; Jackson, Laura L.; Gale, Michael; Helmers, Doug; Hilburger, Steve; Howard, Elizabeth; Oberhauser, Karen; Pleasants, John; Semmens, Brice; Taylor, Orley; Ward, Patrick; Weltzin, Jake F.; Wiederholt, Ruscena

2017-07-01

The eastern migratory population of monarch butterflies (Danaus plexippus plexippus) has declined by >80% within the last two decades. One possible cause of this decline is the loss of ≥1.3 billion stems of milkweed (Asclepias spp.), which monarchs require for reproduction. In an effort to restore monarchs to a population goal established by the US Fish and Wildlife Service and adopted by Mexico, Canada, and the US, we developed scenarios for amending the Midwestern US landscape with milkweed. Scenarios for milkweed restoration were developed for protected area grasslands, Conservation Reserve Program land, powerline, rail and roadside rights of way, urban/suburban lands, and land in agricultural production. Agricultural land was further divided into productive and marginal cropland. We elicited expert opinion as to the biological potential (in stems per acre) for lands in these individual sectors to support milkweed restoration and the likely adoption (probability) of management practices necessary for affecting restoration. Sixteen of 218 scenarios we developed for restoring milkweed to the Midwestern US were at levels (>1.3 billion new stems) necessary to reach the monarch population goal. One of these scenarios would convert all marginal agriculture to conserved status. The other 15 scenarios converted half of marginal agriculture (730 million stems), with remaining stems contributed by other societal sectors. Scenarios without substantive agricultural participation were insufficient for attaining the population goal. Agricultural lands are essential to reaching restoration targets because they occupy 77% of all potential monarch habitat. Barring fundamental changes to policy, innovative application of economic tools such as habitat exchanges may provide sufficient resources to tip the balance of the agro-ecological landscape toward a setting conducive to both robust agricultural production and reduced imperilment of the migratory monarch butterfly.

Transfer and transformation of soil iron and implications for hydrogeomorpholocial changes in Naoli River catchment, sanjiang plain, Northeast China

USGS Publications Warehouse

Ming, J.; Xianguo, L.; Hongqing, W.; Yuanchun, Z.; Haitao, W.

2011-01-01

Wetland soils are characterized by alternating redox process due to the fluctuation of waterlogged conditions. Iron is an important redox substance, and its transfer and transformation in the wetland ecosystem could be an effective indicator for the environment changes. In this paper, we selected the Naoli River catchment in the Sanjiang Plain, Northeast China as the study area to analyze the dynamics of transfer and transformation of soil iron, and the relationship between iron content change and environmental factors. The results show that the total and crystalline iron contents reach the peak in the depth of 60 cm in soil profile, while the amorphous iron content is higher in the topsoil. In the upper reaches, from the low to high landscape positions, the total and crystalline iron contents decrease from 62.98 g/kg to 41.61 g/kg, 22.82 g/kg to 10.53 g/kg respectively, while the amorphous iron content increases from 2.42 g/kg to 8.88 g/kg. Amorphous iron content has positive correlation with organic matter and soil water contents, while negative correlation with pH. Moreover, both the crystalline and amorphous iron contents present no correlation with total iron content, indicating that environmental factors play a more important role in the transfer and transformation of iron other than the content of the total iron. Different redoximorphic features were found along the soil profile due to the transfer and transformation of iron. E and B horizons of wetland soil in the study area have a matrix Chroma 2 or less, and all the soil types can meet the criteria of American hydric soil indicators except albic soil. ?? Science Press, Science Press, Northeast Institute of Geography and Agroecology, CAS and Springer-Verlag Berlin Heidelberg 2011.

Biostimulant Action of Protein Hydrolysates: Unraveling Their Effects on Plant Physiology and Microbiome

PubMed Central

Colla, Giuseppe; Hoagland, Lori; Ruzzi, Maurizio; Cardarelli, Mariateresa; Bonini, Paolo; Canaguier, Renaud; Rouphael, Youssef

2017-01-01

Plant-derived protein hydrolysates (PHs) have gained prominence as plant biostimulants because of their potential to increase the germination, productivity and quality of a wide range of horticultural and agronomic crops. Application of PHs can also alleviate the negative effects of abiotic plant stress due to salinity, drought and heavy metals. Recent studies aimed at uncovering the mechanisms regulating these beneficial effects indicate that PHs could be directly affecting plants by stimulating carbon and nitrogen metabolism, and interfering with hormonal activity. Indirect effects could also play a role as PHs could enhance nutrient availability in plant growth substrates, and increase nutrient uptake and nutrient-use efficiency in plants. Moreover, the beneficial effects of PHs also could be due to the stimulation of plant microbiomes. Plants are colonized by an abundant and diverse assortment of microbial taxa that can help plants acquire nutrients and water and withstand biotic and abiotic stress. The substrates provided by PHs, such as amino acids, could provide an ideal food source for these plant-associated microbes. Indeed, recent studies have provided evidence that plant microbiomes are modified by the application of PHs, supporting the hypothesis that PHs might be acting, at least in part, via changes in the composition and activity of these microbial communities. Application of PHs has great potential to meet the twin challenges of a feeding a growing population while minimizing agriculture’s impact on human health and the environment. However, to fully realize the potential of PHs, further studies are required to shed light on the mechanisms conferring the beneficial effects of these products, as well as identify product formulations and application methods that optimize benefits under a range of agro-ecological conditions. PMID:29312427

Agroforestry management in vineyards: effects on soil microbial communities

NASA Astrophysics Data System (ADS)

Montagne, Virginie; Nowak, Virginie; Guilland, Charles; Gontier, Laure; Dufourcq, Thierry; Guenser, Josépha; Grimaldi, Juliette; Bourgade, Emilie; Ranjard, Lionel

2017-04-01

Some vineyard practices (tillage, chemical weeding or pest management) are generally known to impact the environment with particular negative effects on the diversity and the abundance of soil microorganisms, and cause water and soil pollutions. In an agro-ecological context, innovative cropping systems have been developed to improve ecosystem services. Among them, agroforestry offers strategies of sustainable land management practices. It consists in intercropping trees with annual/perennial/fodder crop on the same plot but it is weakly referenced with grapevine. The present study assesses the effects of intercropped and neighbouring trees on the soil of three agroforestry vineyards, in south-western France regions. More precisely soils of the different plots were sampled and the impact of the distance to the tree or to the neighbouring trees (forest) on soil microbial community has been considered. Indigenous soil microbial communities were characterized by a metagenomic approach that consisted in extracting the molecular microbial biomass, then in calculating the soil fungi/bacteria ratio - obtained by qPCR - and then in characterizing the soil microbial diversity - through Illumina sequencing of 16S and 18S regions. Our results showed a significant difference between the soil of agroforestry vineyards and the soil sampled in the neighbouring forest in terms of microbial abundance and diversity. However, only structure and composition of bacterial community seem to be influenced by the implanted trees in the vine plots. In addition, the comparison of microbial co-occurrence networks between vine and forest plots as well as inside vine plots according to distance to the tree allow revealing a more sensitive impact of agroforestry practices. Altogether, the results we obtained build up the first references for concerning the soil of agroforestry vineyards which will be interpreted in terms of soil quality, functioning and sustainability.

Viral metagenomics of aphids present in bean and maize plots on mixed-use farms in Kenya reveals the presence of three dicistroviruses including a novel Big Sioux River virus-like dicistrovirus.

PubMed

Wamonje, Francis O; Michuki, George N; Braidwood, Luke A; Njuguna, Joyce N; Musembi Mutuku, J; Djikeng, Appolinaire; Harvey, Jagger J W; Carr, John P

2017-10-02

Aphids are major vectors of plant viruses. Common bean (Phaseolus vulgaris L.) and maize (Zea mays L.) are important crops that are vulnerable to aphid herbivory and aphid-transmitted viruses. In East and Central Africa, common bean is frequently intercropped by smallholder farmers to provide fixed nitrogen for cultivation of starch crops such as maize. We used a PCR-based technique to identify aphids prevalent in smallholder bean farms and next generation sequencing shotgun metagenomics to examine the diversity of viruses present in aphids and in maize leaf samples. Samples were collected from farms in Kenya in a range of agro-ecological zones. Cytochrome oxidase 1 (CO1) gene sequencing showed that Aphis fabae was the sole aphid species present in bean plots in the farms visited. Sequencing of total RNA from aphids using the Illumina platform detected three dicistroviruses. Maize leaf RNA was also analysed. Identification of Aphid lethal paralysis virus (ALPV), Rhopalosiphum padi virus (RhPV), and a novel Big Sioux River virus (BSRV)-like dicistrovirus in aphid and maize samples was confirmed using reverse transcription-polymerase chain reactions and sequencing of amplified DNA products. Phylogenetic, nucleotide and protein sequence analyses of eight ALPV genomes revealed evidence of intra-species recombination, with the data suggesting there may be two ALPV lineages. Analysis of BSRV-like virus genomic RNA sequences revealed features that are consistent with other dicistroviruses and that it is phylogenetically closely related to dicistroviruses of the genus Cripavirus. The discovery of ALPV and RhPV in aphids and maize further demonstrates the broad occurrence of these dicistroviruses. Dicistroviruses are remarkable in that they use plants as reservoirs that facilitate infection of their insect replicative hosts, such as aphids. This is the first report of these viruses being isolated from either organism. The BSRV-like sequences represent a potentially novel

Implementing a spinosad-based local bait station to control Bactrocera cucurbitae (Diptera: Tephritidae) in high rainfall areas of Reunion Island.

PubMed

Delpoux, Camille; Deguine, Jean-Philippe

2015-01-01

Three species of fruit flies cause serious damage to cucurbit crops on Reunion Island: Bactrocera cucurbitae (Diptera: Tephritidae) (Coquillett 1899), Dacus ciliatus (Loew 1901), and Dacus demmerezi (Bezzi 1917). To control them, a program of agroecological management of cucurbit flies has been implemented based on the application of Synéis-appât, especially spot sprays on corn borders. However, the high rainfall on Reunion Island limits the long-term efficiency of the bait; in addition, this method cannot be used for large chayote trellises, because corn borders cannot be planted around them. The aim of this study was to design a bait station adapted to prevailing conditions on Reunion Island. An 'umbrella trap' tested in Taiwan was used as a reference to compare its efficacy with our local bait station. Experiments were conducted in field cages on B. cucurbitae to test different characteristics of bait stations and to construct one using local materials. Results were validated in the field. The attractiveness of the bait station was related mainly to the color of the external surface, yellow being the most attractive color. The efficacy of the bait station with respect to fly mortality was found to be linked to the accessibility of the bait, and direct application of Synéis-appât on the bait station was found to be the most efficient. In the field, B. cucurbitae were more attracted to the local bait station than to the umbrella trap, while the two other fly species displayed equal attraction to both trap types. Our local bait station is a useful alternative to spot sprays of Synéis-appât and is now included in a local pest management program and is well accepted by farmers. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Water productivity mapping using Landsat 8 satellite together with weather stations

NASA Astrophysics Data System (ADS)

Franco, Renato A. M.; Hernandez, Fernando B. T.; de C. Teixeira, Antônio H.; Leivas, Janice Freitas; Coaguila, Daniel Noe; Neale, Christopher M.

2016-10-01

The use of remote sensing satellite in conjunction with models and meteorological data enable the mapping of biophysical properties of agroecosystems with satisfactory accuracy. The main goal of this research was to determine the spatial-temporal agro-ecological indicators of water productivity in watersheds with different types of land use and occupation, using Landsat 8 images, agro-meteorological stations and application of Monteith and SAFER (Simple Algorithm for Retrieving Evapotranspiration) models to estimate the production biomass (BIO) and the actual evapotranspiration (ET), respectively. Incident global solar radiation (RS ↓) is observed seasonality of radiation during the year. Higher RS ↓levels happen during the first and the last four months, when the Sun is around its zenith positions in the study region. During the natural dry period in the region, the RS↓ is lower because winter solstice time for the Southern Hemisphere, this condition it is verified the reducing in the values of ET and BIO. Average values of biophysical properties for the study period were 0.54, 0.16 and 301 K for Normalized Difference Vegetation Index, albedo and surface temperature, respectively. The highest value of BIO was 105 kg ha-1d-1 and occurred in July 2013. The lowest value was 15.9 kg ha-1d-1 and occurred in October 2014. ET showed a value of 1.65 mm d-1 in the rainy period and 0.64 during the dry period in the study area. The highest average ET occurred in the irrigated area (June 2014), with a value of 1.89 mm d-1 and a maximum of 2.46 mm d-1. WP average for the evaluated period was 3.06 Kg m-3, with the largest value of 4.91 Kg m-3 in June 2013 and a minimum value of 2.45 Kg m-3 in September 2013.

The food production and consumption balance in sub-Saharan Africa under different SSPs, from 2010 to 2050

NASA Astrophysics Data System (ADS)

Wada, Y.; Luan, Y.; Fischer, G.; Sun, L.; Shi, P.

2015-12-01

Forcing with the population growth and consequently increasing food requirement, food security in sub-Saharan Africa is one of the most emergent and challenging issues. The purposes of this work are 1) what's the future food requirement and their food security status in each sub-Saharan African countries? What is the distance from current and future food security status, corresponding to the food requirement, to the targeted food security status? 2) To what extent Sub-Saharan countries could meet their present and future food requirement, and whether they have potential to improve their food insecurity status on currently cultivated land? 3) Whether or, if there have, how the pressures on land resources from meeting the food requirements? To figure those questions out, we firstly use socio-economic pathways datasets, and historical food diet pattern classification to forecast the 2010-2050 food commodity and feed calories demand per country. A new food security indicator, which considered the influences of both the food energy and quality intake, was used to evaluate the food insecurity status and the distances to different targeted statuses of the specific country. The latest Global Agro-Ecological Zones (GAEZ) databases were used to estimate the current and future crop yield gap and crop potential production. For current to future scenario analysis, we considered population growth, dietary change, climate change, agricultural input level, and target food security status. Then the balance of food requirement with the current and potential crop production was analyzed for different scenarios. Land requirements were calculated for meeting those food requirements, and the pressures on land resources are evaluated. Our works are hoping to provide scientific-based evidences for policy recommendations for local government to tackle food insecurity problems in Sub-Saharan Africa.

Effect of crude plant extracts from some Oaxacan flora on two deleterious fungal phytopathogens and extract compatibility with a biofertilizer strain

PubMed Central

Lira-De León, Karla I.; Ramírez-Mares, Marco V.; Sánchez-López, Vladimir; Ramírez-Lepe, Mario; Salas-Coronado, Raúl; Santos-Sánchez, Norma F.; Valadez-Blanco, Rogelio; Hernández-Carlos, Beatriz

2014-01-01

The antimicrobial activity of 12 plant extracts was tested against the phytopathogens Alternaria alternata and Fusarium solani. In addition, the compatibility of the extracts toward Bacillus liqueniformis, a biofertilizer and a non-target microorganism, was assessed. Plants tested belong to the Euphorbiaceae, Asteraceae, Crassulaceae, Rubiaceae, Convolvulaceae, Verbenaceae, Orchidaceae, Nyctaginaceae, Boraginaceae, and Tiliaceae families and were collected in the State of Oaxaca. The antifungal activity of the plant extracts (50–100 mg/mL) against A. alternata and F. solani, was determined by measuring the mycelium radial growth and obtaining the minimum inhibitory concentration (MIC) of fungal growth. In addition, with the aim of finding plant extracts which are compatible with a B. licheniformis biofertilizer strain and to test the non-toxic nature of the treatments, the toxicity of the extracts toward this strain was evaluated using the agar diffusion method. Azoxystrobin (12 μg) and chloramphenicol (30 μg) were used as positive controls for the pathogens and for the non-target bacteria, respectively. Plant extracts inhibited fungal growth in the ranges of 0.76–56.17% against F. solani and 2.02–69.07% against A. alternata. The extracts of Acalypha subviscida, Ipomoea murucoides, Tournefortia densiflora and Lantana achyranthifolia showed MIC values between 5.77–12.5 mg/mL for at least one of the fungal species. The best treatment, Adenophyllum aurantium, exhibited a maximum inhibition for both F. solani (56.17%, MIC = 7.78 mg/mL) and A. alternata (68.64% MIC = 7.78 mg/mL), and resulted innocuous toward B. licheniformis. Therefore, this plant has an outstanding potential for the agroecological control of fungal phytopathogens in industrial crops. PMID:25147544

Patterns of species richness and diversity of insects associated with cucurbit fruits in the southern part of Cameroon.

PubMed

Mokam, Didi Gaëlle; Djiéto-Lordon, Champlain; Bilong Bilong, Charles-Félix

2014-01-01

Patterns of species diversity and community structure of insects associated with fruits of domesticated cucurbits were investigated from January 2009 to 2011 in three localities from two agroecological zones in the southern part of Cameroon. Rarefaction curves combined with nonparametric estimators of species richness were used to extrapolate species richness beyond our own data. Sampling efforts of over 92% were reached in each of the three study localities. Data collected revealed a total of 66 insect morphospecies belonging to 37 families and five orders, identified from a set of 57,510 insects. The orders Diptera (especially Tephritidae and Lonchaeidae) and Hymenoptera (mainly Braconidae and Eulophidae) were the most important, in terms of both abundance and species richness on the one hand, and effects on agronomic performance on the other. Values for both the species diversity (Shannon and Simpson) and the species richness indices (Margalef and Berger-Parker) calculated showed that the insect communities were species-rich but dominated, all to a similar extent, by five main species (including four fruit fly species and one parasitoid). Species abundance distributions in these communities ranged from the Zipf-Mandelbrot to Mandelbrot models. The communities are structured as tritrophic networks, including cucurbit fruits, fruit-feeding species (fruit flies) and carnivorous species (parasitoids). Within the guild of the parasitoids, about 30% of species, despite their low abundance, may potentially be of use in biological control of important pests. Our field data contribute in important ways to basic knowledge of biodiversity patterns in agrosystems and constitute baseline data for the planned implementation of biological control in Integrated Pest Management. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Convergent adaptations: bitter manioc cultivation systems in fertile anthropogenic dark earths and floodplain soils in Central Amazonia.

PubMed

Fraser, James Angus; Alves-Pereira, Alessandro; Junqueira, André Braga; Peroni, Nivaldo; Clement, Charles Roland

2012-01-01

Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for

Convergent Adaptations: Bitter Manioc Cultivation Systems in Fertile Anthropogenic Dark Earths and Floodplain Soils in Central Amazonia

PubMed Central

Fraser, James Angus; Alves-Pereira, Alessandro; Junqueira, André Braga; Peroni, Nivaldo; Clement, Charles Roland

2012-01-01

Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for

Dietary habits, food taboos, and perceptions towards weight gain during pregnancy in Arsi, rural central Ethiopia: a qualitative cross-sectional study.

PubMed

Zerfu, Taddese Alemu; Umeta, Melaku; Baye, Kaleab

2016-07-25

The nutritional status of women before and during pregnancy can be determined by maternal knowledge, attitudes, and perceptions towards certain foods. The present study aimed to explore maternal dietary habits, food taboos, and cultural beliefs that can affect nutrition during pregnancy in rural Arsi, central Ethiopia. A qualitative, cross-sectional study, involving 38 key informant in-depth interviews and eight focus group discussions, was conducted among purposefully selected pregnant women and their husbands, elderly people, community leaders, health workers, and agriculture office experts. Participants were selected purposefully from all the major agro-ecologic areas of the study site. Data was analyzed manually using the thematic framework analyses method. The pregnant women reported that they did not change the amount and type of foods consumed to take into account their increased nutritional need during pregnancy. The consumption of meat, fish, fruits, and some vegetables during pregnancy remained as low as the pre-pregnancy state, irrespective of the women's income and educational status. Although not practiced by all, a number of taboos related to the intake of certain food items and misconceptions that can adversely affect nutritional status during pregnancy were identified. The most common taboos were related to the consumption of green leafy vegetables, yogurt, cheese, sugar cane, and green pepper. However, the frequency and extent of the practice varied by maternal age, family composition, and literacy level. Older mothers, from rural villages, and those with no formal education were more likely to practice the taboos than younger and educated ones. Almost all of the participants disfavored weight gain during pregnancy in fear of obstetric complications associated with the delivery of a bigger infant. Misconceptions about weight gain during pregnancy and food taboos were widespread, particularly among older and illiterate rural communities. Thus

Agronomic Challenges and Opportunities for Smallholder Terrace Agriculture in Developing Countries

PubMed Central

Chapagain, Tejendra; Raizada, Manish N.

2017-01-01

Improving land productivity is essential to meet increasing food and forage demands in hillside and mountain communities. Tens of millions of smallholder terrace farmers in Asia, Africa, and Latin America who earn $1–2 per day do not have access to peer-reviewed knowledge of best agronomic practices, though they have considerable traditional ecological knowledge. Terrace farmers also lack access to affordable farm tools and inputs required to increase crop yields. The objectives of this review are to highlight the agronomic challenges of terrace farming, and offer innovative, low-cost solutions to intensify terrace agriculture while improving local livelihoods. The article focuses on smallholder farmers in developing nations, with particular reference to Nepal. The challenges of terrace agriculture in these regions include lack of quality land area for agriculture, erosion and loss of soil fertility, low yield, poor access to agricultural inputs and services, lack of mechanization, labor shortages, poverty, and illiteracy. Agronomic strategies that could help address these concerns include intensification of terraces using agro-ecological approaches along with introduction of light-weight, low-cost, and purchasable tools and affordable inputs that enhance productivity and reduce female drudgery. To package, deliver, and share these technologies with remote hillside communities, effective scaling up models are required. One opportunity to enable distribution of these products could be to “piggy-back” onto pre-existing snackfood/cigarette/alcohol distribution networks that are prevalent even in the most remote mountainous regions of the world. Such strategies, practices, and tools could be supported by formalized government policies dedicated to the well-being of terrace farmers and ecosystems, to maintain resiliency at a time of alarming climate change. We hope this review will inform governments, non-governmental organizations, and the private sector to draw

Minimum Dietary Diversity Scores for Women Indicate Micronutrient Adequacy and Food Insecurity Status in South African Towns

PubMed Central

2017-01-01

The lack of dietary diversity is a severe problem experienced by most poor households globally. In particular; women of reproductive age (WRA) are at high risk of inadequate intake of micronutrients resulting from diets dominated by starchy staples. The present study considered the diets, dietary diversity, and food security of women aged 15–49 years along the rural-urban continuum in three South African towns situated along an agro-ecological gradient. A 48 h dietary recall was conducted across two seasons with 554 women from rural, peri-urban, and urban locations of Richards Bay, Dundee, and Harrismith. Minimum Dietary Diversity for WRA (MDD-W) were calculated and a dichotomous indicator based on a set of ten food groups was used to determine if women had consumed at least five food groups the previous 48 h to achieve minimum dietary intake for women. The mean (±sd) MDD-W for Richards Bay (3.78 ± 0.07) was significantly higher than at Dundee (3.21 ± 0.08) and Harrismith (3.36 ± 0.07). Food security and MDD-W were significantly higher in urban locations than in peri-urban or rural ones. There was lower dependence on food purchasing in Richards Bay compared to Dundee and Harrismith. The majority of women in Richards Bay practiced subsistence agriculture, produced a surplus for sale, and collected wild foods which improved dietary intake and food security. The peri-urban populations had limited dietary intake and were more food insecure because of high levels of poverty, unemployment, and lack of land. Peri-urban dwellers are therefore more sensitive to changes in incomes and food prices because they lack safety nets to absorb income or price shocks as they purchase more, rather than growing their own food. This compromises dietary diversity as they have limited access to diverse foods. PMID:28788057

Using geomorphological variables to predict the spatial distribution of plant species in agricultural drainage networks.

PubMed

Rudi, Gabrielle; Bailly, Jean-Stéphane; Vinatier, Fabrice

2018-01-01

To optimize ecosystem services provided by agricultural drainage networks (ditches) in headwater catchments, we need to manage the spatial distribution of plant species living in these networks. Geomorphological variables have been shown to be important predictors of plant distribution in other ecosystems because they control the water regime, the sediment deposition rates and the sun exposure in the ditches. Whether such variables may be used to predict plant distribution in agricultural drainage networks is unknown. We collected presence and absence data for 10 herbaceous plant species in a subset of a network of drainage ditches (35 km long) within a Mediterranean agricultural catchment. We simulated their spatial distribution with GLM and Maxent model using geomorphological variables and distance to natural lands and roads. Models were validated using k-fold cross-validation. We then compared the mean Area Under the Curve (AUC) values obtained for each model and other metrics issued from the confusion matrices between observed and predicted variables. Based on the results of all metrics, the models were efficient at predicting the distribution of seven species out of ten, confirming the relevance of geomorphological variables and distance to natural lands and roads to explain the occurrence of plant species in this Mediterranean catchment. In particular, the importance of the landscape geomorphological variables, ie the importance of the geomorphological features encompassing a broad environment around the ditch, has been highlighted. This suggests that agro-ecological measures for managing ecosystem services provided by ditch plants should focus on the control of the hydrological and sedimentological connectivity at the catchment scale. For example, the density of the ditch network could be modified or the spatial distribution of vegetative filter strips used for sediment trapping could be optimized. In addition, the vegetative filter strips could constitute

Influence of Environmental Conditions and Genetic Background of Arabica Coffee (C. arabica L) on Leaf Rust (Hemileia vastatrix) Pathogenesis.

PubMed

Toniutti, Lucile; Breitler, Jean-Christophe; Etienne, Hervé; Campa, Claudine; Doulbeau, Sylvie; Urban, Laurent; Lambot, Charles; Pinilla, Juan-Carlos H; Bertrand, Benoît

2017-01-01

Global warming is a major threat to agriculture worldwide. Between 2008 and 2013, some coffee producing countries in South and Central America suffered from severe epidemics of coffee leaf rust (CLR), resulting in high economic losses with social implications for coffee growers. The climatic events not only favored the development of the pathogen but also affected the physiological status of the coffee plant. The main objectives of the study were to evaluate how the physiological status of the coffee plant modified by different environmental conditions impact on the pathogenesis of CLR and to identify indicators of the physiological status able to predict rust incidence. Three rust susceptible genotypes (one inbred line and two hybrids) were grown in controlled conditions with a combination of thermal regime (TR), nitrogen and light intensity close to the field situation before being inoculated with the rust fungus Hemileia vastatrix . It has been demonstrated that a TR of 27-22°C resulted in 2000 times higher sporulation than with a TR of 23-18°C. It has been also shown that high light intensity combined with low nitrogen fertilization modified the CLR pathogenesis resulting in huge sporulation. CLR sporulation was significantly lower in the F1 hybrids than in the inbred line. The hybrid vigor may have reduced disease incidence. Among the many parameters studied, parameters related to photosystem II and photosynthetic electron transport chain components appeared as indicators of the physiological status of the coffee plant able to predict rust sporulation intensity. Taken together, these results show that CLR sporulation not only depends on the TR but also on the physiological status of the coffee plant, which itself depends on agronomic conditions. Our work suggests that vigorous varieties combined with a shaded system and appropriate nitrogen fertilization should be part of an agro-ecological approach to disease control.

Managing potato biodiversity to cope with frost risk in the high Andes: a modeling perspective.

PubMed

Condori, Bruno; Hijmans, Robert J; Ledent, Jean Francois; Quiroz, Roberto

2014-01-01

Austral summer frosts in the Andean highlands are ubiquitous throughout the crop cycle, causing yield losses. In spite of the existing warming trend, climate change models forecast high variability, including freezing temperatures. As the potato center of origin, the region has a rich biodiversity which includes a set of frost resistant genotypes. Four contrasting potato genotypes--representing genetic variability--were considered in the present study: two species of frost resistant native potatoes (the bitter Solanum juzepczukii, var. Luki, and the non-bitter Solanum ajanhuiri, var. Ajanhuiri) and two commercial frost susceptible genotypes (Solanum tuberosum ssp. tuberosum var. Alpha and Solanum tuberosum ssp. andigenum var. Gendarme). The objective of the study was to conduct a comparative growth analysis of four genotypes and modeling their agronomic response under frost events. It included assessing their performance under Andean contrasting agroecological conditions. Independent subsets of data from four field experiments were used to parameterize, calibrate and validate a potato growth model. The validated model was used to ascertain the importance of biodiversity, represented by the four genotypes tested, as constituents of germplasm mixtures in single plots used by local farmers, a coping strategy in the face of climate variability. Also scenarios with a frost routine incorporated in the model were constructed. Luki and Ajanhuiri were the most frost resistant varieties whereas Alpha was the most susceptible. Luki and Ajanhuiri, as monoculture, outperformed the yield obtained with the mixtures under severe frosts. These results highlight the role played by local frost tolerant varieties, and featured the management importance--e.g. clean seed, strategic watering--to attain the yields reported in our experiments. The mixtures of local and introduced potatoes can thus not only provide the products demanded by the markets but also reduce the impact of frosts

Comparative Agronomic Performance and Reaction to Fusarium wilt of Lens culinaris × L. orientalis and L. culinaris × L. ervoides derivatives.

PubMed

Singh, Mohar; Rana, Jai C; Singh, Badal; Kumar, Sandeep; Saxena, Deep R; Saxena, Ashok; Rizvi, Aqeel H; Sarker, Ashutosh

2017-01-01

The development of transgressive phenotype in the segregating populations has been speculated to contribute to niche divergence of hybrid lineages, which occurs most frequently at larger genetic distances. Wild Lens species are considered to be more resistant against major biotic and abiotic stresses than that of the cultivated species. In the present study, we assessed the comparative agronomic performance of lentil ( Lens culinaris subsp. culinaris ) inter-sub-specific ( L. culinaris subsp. orientalis ) and interspecific ( L. ervoides ) derivatives, also discussed its probable basis of occurrence. The F 3 , F 4 , and F 5 inter sub-specific and interspecific populations of ILL8006 × ILWL62 and ILL10829 × ILWL30, respectively revealed a substantial range of variation for majority of agro-morphological traits as reflected by the range, mean and coefficient of variation. A high level of fruitful heterosis was also observed in F 3 and F 4 progeny for important traits of interest. Phenotypic coefficient of variation (PCV) was higher in magnitude than genotypic coefficient of variation (GCV) in all generations for several quantitative characters. The results showed high heritability estimates for majority of traits in conjunction with low to high genetic advance in F 3 and F 4 generations. Further, F 5 progeny of ILL10829 × ILWL30, manifested resistant disease reaction for fifteen recombinant inbred lines (RILs) against ( Fusarium oxysporum f. sp. lentis ( Vasd. Srin .) Gord.). The multilocation agronomic evaluation of both crosses showed better results for earliness, desirable seed yield and Fusarium wilt resistance under two agro-ecological regions of north-western India. These better performing recombinants of ILL8006 × ILWL62 and ILL10829 × ILWL30 can be advanced for further genetic improvement and developing high yielding disease resistant cultivars of lentil.

Comparative Agronomic Performance and Reaction to Fusarium wilt of Lens culinaris × L. orientalis and L. culinaris × L. ervoides derivatives

PubMed Central

Singh, Mohar; Rana, Jai C.; Singh, Badal; Kumar, Sandeep; Saxena, Deep R.; Saxena, Ashok; Rizvi, Aqeel H.; Sarker, Ashutosh

2017-01-01

The development of transgressive phenotype in the segregating populations has been speculated to contribute to niche divergence of hybrid lineages, which occurs most frequently at larger genetic distances. Wild Lens species are considered to be more resistant against major biotic and abiotic stresses than that of the cultivated species. In the present study, we assessed the comparative agronomic performance of lentil (Lens culinaris subsp. culinaris) inter-sub-specific (L. culinaris subsp. orientalis) and interspecific (L. ervoides) derivatives, also discussed its probable basis of occurrence. The F3, F4, and F5 inter sub-specific and interspecific populations of ILL8006 × ILWL62 and ILL10829 × ILWL30, respectively revealed a substantial range of variation for majority of agro-morphological traits as reflected by the range, mean and coefficient of variation. A high level of fruitful heterosis was also observed in F3 and F4 progeny for important traits of interest. Phenotypic coefficient of variation (PCV) was higher in magnitude than genotypic coefficient of variation (GCV) in all generations for several quantitative characters. The results showed high heritability estimates for majority of traits in conjunction with low to high genetic advance in F3 and F4 generations. Further, F5 progeny of ILL10829 × ILWL30, manifested resistant disease reaction for fifteen recombinant inbred lines (RILs) against (Fusarium oxysporum f. sp. lentis (Vasd. Srin.) Gord.). The multilocation agronomic evaluation of both crosses showed better results for earliness, desirable seed yield and Fusarium wilt resistance under two agro-ecological regions of north-western India. These better performing recombinants of ILL8006 × ILWL62 and ILL10829 × ILWL30 can be advanced for further genetic improvement and developing high yielding disease resistant cultivars of lentil. PMID:28751897

Soil-geographical and ecological tour in West-Russia: 20 years anniversary

NASA Astrophysics Data System (ADS)

Kuzyakov, Yakov

2013-04-01

Soil-geographical and agro-ecological tour in Russia celebrated in this summer its 20 years anniversary! More than 800 students, PhD students and researcher from Germany, Switzerland, Austria, Sweden and France participated at the tour since 1993. The majority of the participants were students studying soil science, geoecology, geography, agriculture and ecology. The tour is based on a classical Russian zonal approach: a cross-section of climatic zones starting from south taiga, through deciduous forest, forest steppe, steppe, dry steppe, to semi dessert and transition to the desert zone. In each zone the specifics of climate, vegetation, nutrient cycling, and of course soil genesis as well as soil use by forestry and agriculture are described. Half of the soil group units of WRB classification (2006) are presented on about 35 soil profile pits and are described with focus on pedogenic processes and soil forming factors. The following soil groups are described in details by horizons according to WRB soil classification (2006): Arenosols, Podzols, Albeluvisols Histosols, Gleysols, Luvisols, Phaeozems, Chernozems, Kastanozems, Calcisols, Vertisols, Leptosols, Fluvisols, Solonetzes, Solonchaks. In addition to natural conditions, large-scale experiments designing agricultural landscapes (stone steppe), biosphere reserves and conservation areas (Tula-Schneisen, Divnogor'je, Baskunchak), as well as collective agricultural farms (previously kolkhoz) are visited to evaluate the anthropogenic effects on ecosystems and especially on soils. The 2.5 weeks bus journey through many villages and small towns, visits of museums and historical monuments, introduction in the settlement development of different regions provide a broad presentation of Russian history, traditions, life style, and contemporary state. So, combination of very diverse educational part focused on soil and environmental conditions with anthropogenic impacts and local history as well as recent socioeconomic

Object-Based Land Use Classification of Agricultural Land by Coupling Multi-Temporal Spectral Characteristics and Phenological Events in Germany

NASA Astrophysics Data System (ADS)

Knoefel, Patrick; Loew, Fabian; Conrad, Christopher

2015-04-01

Crop maps based on classification of remotely sensed data are of increased attendance in agricultural management. This induces a more detailed knowledge about the reliability of such spatial information. However, classification of agricultural land use is often limited by high spectral similarities of the studied crop types. More, spatially and temporally varying agro-ecological conditions can introduce confusion in crop mapping. Classification errors in crop maps in turn may have influence on model outputs, like agricultural production monitoring. One major goal of the PhenoS project ("Phenological structuring to determine optimal acquisition dates for Sentinel-2 data for field crop classification"), is the detection of optimal phenological time windows for land cover classification purposes. Since many crop species are spectrally highly similar, accurate classification requires the right selection of satellite images for a certain classification task. In the course of one growing season, phenological phases exist where crops are separable with higher accuracies. For this purpose, coupling of multi-temporal spectral characteristics and phenological events is promising. The focus of this study is set on the separation of spectrally similar cereal crops like winter wheat, barley, and rye of two test sites in Germany called "Harz/Central German Lowland" and "Demmin". However, this study uses object based random forest (RF) classification to investigate the impact of image acquisition frequency and timing on crop classification uncertainty by permuting all possible combinations of available RapidEye time series recorded on the test sites between 2010 and 2014. The permutations were applied to different segmentation parameters. Then, classification uncertainty was assessed and analysed, based on the probabilistic soft-output from the RF algorithm at the per-field basis. From this soft output, entropy was calculated as a spatial measure of classification uncertainty

Using geomorphological variables to predict the spatial distribution of plant species in agricultural drainage networks

PubMed Central

Bailly, Jean-Stéphane; Vinatier, Fabrice

2018-01-01

To optimize ecosystem services provided by agricultural drainage networks (ditches) in headwater catchments, we need to manage the spatial distribution of plant species living in these networks. Geomorphological variables have been shown to be important predictors of plant distribution in other ecosystems because they control the water regime, the sediment deposition rates and the sun exposure in the ditches. Whether such variables may be used to predict plant distribution in agricultural drainage networks is unknown. We collected presence and absence data for 10 herbaceous plant species in a subset of a network of drainage ditches (35 km long) within a Mediterranean agricultural catchment. We simulated their spatial distribution with GLM and Maxent model using geomorphological variables and distance to natural lands and roads. Models were validated using k-fold cross-validation. We then compared the mean Area Under the Curve (AUC) values obtained for each model and other metrics issued from the confusion matrices between observed and predicted variables. Based on the results of all metrics, the models were efficient at predicting the distribution of seven species out of ten, confirming the relevance of geomorphological variables and distance to natural lands and roads to explain the occurrence of plant species in this Mediterranean catchment. In particular, the importance of the landscape geomorphological variables, ie the importance of the geomorphological features encompassing a broad environment around the ditch, has been highlighted. This suggests that agro-ecological measures for managing ecosystem services provided by ditch plants should focus on the control of the hydrological and sedimentological connectivity at the catchment scale. For example, the density of the ditch network could be modified or the spatial distribution of vegetative filter strips used for sediment trapping could be optimized. In addition, the vegetative filter strips could constitute

Genetic diversity and trait genomic prediction in a pea diversity panel.

PubMed

Burstin, Judith; Salloignon, Pauline; Chabert-Martinello, Marianne; Magnin-Robert, Jean-Bernard; Siol, Mathieu; Jacquin, Françoise; Chauveau, Aurélie; Pont, Caroline; Aubert, Grégoire; Delaitre, Catherine; Truntzer, Caroline; Duc, Gérard

2015-02-21

Pea (Pisum sativum L.), a major pulse crop grown for its protein-rich seeds, is an important component of agroecological cropping systems in diverse regions of the world. New breeding challenges imposed by global climate change and new regulations urge pea breeders to undertake more efficient methods of selection and better take advantage of the large genetic diversity present in the Pisum sativum genepool. Diversity studies conducted so far in pea used Simple Sequence Repeat (SSR) and Retrotransposon Based Insertion Polymorphism (RBIP) markers. Recently, SNP marker panels have been developed that will be useful for genetic diversity assessment and marker-assisted selection. A collection of diverse pea accessions, including landraces and cultivars of garden, field or fodder peas as well as wild peas was characterised at the molecular level using newly developed SNP markers, as well as SSR markers and RBIP markers. The three types of markers were used to describe the structure of the collection and revealed different pictures of the genetic diversity among the collection. SSR showed the fastest rate of evolution and RBIP the slowest rate of evolution, pointing to their contrasted mode of evolution. SNP markers were then used to predict phenotypes -the date of flowering (BegFlo), the number of seeds per plant (Nseed) and thousand seed weight (TSW)- that were recorded for the collection. Different statistical methods were tested including the LASSO (Least Absolute Shrinkage ans Selection Operator), PLS (Partial Least Squares), SPLS (Sparse Partial Least Squares), Bayes A, Bayes B and GBLUP (Genomic Best Linear Unbiased Prediction) methods and the structure of the collection was taken into account in the prediction. Despite a limited number of 331 markers used for prediction, TSW was reliably predicted. The development of marker assisted selection has not reached its full potential in pea until now. This paper shows that the high-throughput SNP arrays that are being

Characterization of the Genetic Diversity of Acid Lime (Citrus aurantifolia (Christm.) Swingle) Cultivars of Eastern Nepal Using Inter-Simple Sequence Repeat Markers.

PubMed

Munankarmi, Nabin Narayan; Rana, Neesha; Bhattarai, Tribikram; Shrestha, Ram Lal; Joshi, Bal Krishna; Baral, Bikash; Shrestha, Sangita

2018-06-12

Acid lime ( Citrus aurantifolia (Christm.) Swingle) is an important fruit crop, which has high commercial value and is cultivated in 60 out of the 77 districts representing all geographical landscapes of Nepal. A lack of improved high-yielding varieties, infestation with various diseases, and pests, as well as poor management practices might have contributed to its extremely reduced productivity, which necessitates a reliable understanding of genetic diversity in existing cultivars. Hereby, we aim to characterize the genetic diversity of acid lime cultivars cultivated at three different agro-ecological gradients of eastern Nepal, employing PCR-based inter-simple sequence repeat (ISSR) markers. Altogether, 21 polymorphic ISSR markers were used to assess the genetic diversity in 60 acid lime cultivars sampled from different geographical locations. Analysis of binary data matrix was performed on the basis of bands obtained, and principal coordinate analysis and phenogram construction were performed using different computer algorithms. ISSR profiling yielded 234 amplicons, of which 87.18% were polymorphic. The number of amplified fragments ranged from 7⁻18, with amplicon size ranging from ca. 250⁻3200 bp. The Numerical Taxonomy and Multivariate System (NTSYS)-based cluster analysis using the unweighted pair group method of arithmetic averages (UPGMA) algorithm and Dice similarity coefficient separated 60 cultivars into two major and three minor clusters. Genetic diversity analysis using Popgene ver. 1.32 revealed the highest percentage of polymorphic bands (PPB), Nei’s genetic diversity (H), and Shannon’s information index (I) for the Terai zone (PPB = 69.66%; H = 0.215; I = 0.325), and the lowest of all three for the high hill zone (PPB = 55.13%; H = 0.173; I = 0.262). Thus, our data indicate that the ISSR marker has been successfully employed for evaluating the genetic diversity of Nepalese acid lime cultivars and has furnished valuable information on

CERES–Maize Model for Determining the Optimum Planting Dates of Early Maturing Maize Varieties in Northern Nigeria

PubMed Central

Adnan, Adnan A.; Jibrin, Jibrin M.; Kamara, Alpha Y.; Abdulrahman, Bassam L.; Shaibu, Abdulwahab S.; Garba, Ismail I.

2017-01-01

Field trials were carried out in the Sudan Savannah of Nigeria to assess the usefulness of CERES–maize crop model as a decision support tool for optimizing maize production through manipulation of plant dates. The calibration experiments comprised of 20 maize varieties planted during the dry and rainy seasons of 2014 and 2015 at Bayero University Kano and Audu Bako College of Agriculture Dambatta. The trials for model evaluation were conducted in 16 different farmer fields across the Sudan (Bunkure and Garun—Mallam) and Northern Guinea (Tudun-Wada and Lere) Savannas using two of the calibrated varieties under four different sowing dates. The model accurately predicted grain yield, harvest index, and biomass of both varieties with low RMSE-values (below 5% of mean), high d-index (above 0.8), and high r-square (above 0.9) for the calibration trials. The time series data (tops weight, stem and leaf dry weights) were also predicted with high accuracy (% RMSEn above 70%, d-index above 0.88). Similar results were also observed for the evaluation trials, where all variables were simulated with high accuracies. Estimation efficiencies (EF)-values above 0.8 were observed for all the evaluation parameters. Seasonal and sensitivity analyses on Typic Plinthiustalfs and Plinthic Kanhaplustults in the Sudan and Northern Guinea Savannas were conducted. Results showed that planting extra early maize varieties in late July and early maize in mid-June leads to production of highest grain yields in the Sudan Savanna. In the Northern Guinea Savanna planting extra-early maize in mid-July and early maize in late July produced the highest grain yields. Delaying planting in both Agro-ecologies until mid-August leads to lower yields. Delaying planting to mid-August led to grain yield reduction of 39.2% for extra early maize and 74.4% for early maize in the Sudan Savanna. In the Northern Guinea Savanna however, delaying planting to mid-August resulted in yield reduction of 66.9 and 94