Science.gov

Sample records for agroecology

  1. Students Learning Agroecology: Phenomenon-Based Education for Responsible Action

    ERIC Educational Resources Information Center

    Ostergaard, Edvin; Lieblein, Geir; Breland, Tor Arvid; Francis, Charles

    2010-01-01

    Preparing students for a complex and dynamic future is a challenge for educators. This article explores three crucial issues related to agroecological education and learning: (1) the phenomenological foundation for learning agroecology in higher education; (2) the process of students' interactions with a wide range of various learners within and…

  2. Methodological difficulties of conducting agroecological studies from a statistical perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Statistical methods for analysing agroecological data might not be able to help agroecologists to solve all of the current problems concerning crop and animal husbandry, but such methods could well help agroecologists to assess, tackle, and resolve several agroecological issues in a more reliable an...

  3. New Concepts in Agroecology: A Service-Learning Course

    ERIC Educational Resources Information Center

    Jordan, Nicholas R.; Andow, David A.; Mercer, Kristin L.

    2005-01-01

    We describe our pedagogical approaches and experiences with a novel course in agroecology (one semester, three credit-hours, for graduate students and upper level undergraduates). Our course responds to recent proposals that agroecology expand its disciplinary focus to include human factors as well as ecological factors, thus taking a more…

  4. Agroecology Education: Action-Oriented Learning and Research

    ERIC Educational Resources Information Center

    Lieblein, Geir; Breland, Tor Arvid; Francis, Charles; Ostergaard, Edvin

    2012-01-01

    Purpose: This article examines and evaluates the potential contributions from action learning and action research with stakeholders to higher education in agriculture and food systems. Design/Methodology/Approach: The research is based on our experiences over the past two decades of running PhD courses and an MSc degree programme in Agroecology in…

  5. Crop pathogen emergence and evolution in agro-ecological landscapes

    PubMed Central

    Papaïx, Julien; Burdon, Jeremy J; Zhan, Jiasui; Thrall, Peter H

    2015-01-01

    Remnant areas hosting natural vegetation in agricultural landscapes can impact the disease epidemiology and evolutionary dynamics of crop pathogens. However, the potential consequences for crop diseases of the composition, the spatial configuration and the persistence time of the agro-ecological interface – the area where crops and remnant vegetation are in contact – have been poorly studied. Here, we develop a demographic–genetic simulation model to study how the spatial and temporal distribution of remnant wild vegetation patches embedded in an agricultural landscape can drive the emergence of a crop pathogen and its subsequent specialization on the crop host. We found that landscape structures that promoted larger pathogen populations on the wild host facilitated the emergence of a crop pathogen, but such landscape structures also reduced the potential for the pathogen population to adapt to the crop. In addition, the evolutionary trajectory of the pathogen population was determined by interactions between the factors describing the landscape structure and those describing the pathogen life histories. Our study contributes to a better understanding of how the shift of land-use patterns in agricultural landscapes might influence crop diseases to provide predictive tools to evaluate management practices. PMID:25926883

  6. Crop pathogen emergence and evolution in agro-ecological landscapes.

    PubMed

    Papaïx, Julien; Burdon, Jeremy J; Zhan, Jiasui; Thrall, Peter H

    2015-04-01

    Remnant areas hosting natural vegetation in agricultural landscapes can impact the disease epidemiology and evolutionary dynamics of crop pathogens. However, the potential consequences for crop diseases of the composition, the spatial configuration and the persistence time of the agro-ecological interface - the area where crops and remnant vegetation are in contact - have been poorly studied. Here, we develop a demographic-genetic simulation model to study how the spatial and temporal distribution of remnant wild vegetation patches embedded in an agricultural landscape can drive the emergence of a crop pathogen and its subsequent specialization on the crop host. We found that landscape structures that promoted larger pathogen populations on the wild host facilitated the emergence of a crop pathogen, but such landscape structures also reduced the potential for the pathogen population to adapt to the crop. In addition, the evolutionary trajectory of the pathogen population was determined by interactions between the factors describing the landscape structure and those describing the pathogen life histories. Our study contributes to a better understanding of how the shift of land-use patterns in agricultural landscapes might influence crop diseases to provide predictive tools to evaluate management practices. PMID:25926883

  7. 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. PMID:22073627

  8. Agroecological zones and the assessment of crop production potential

    PubMed Central

    Sivakumar, M. V. K.; Valentin, C.

    1997-01-01

    The rapidly growing world population puts considerable pressure on the scarce natural resources, and there is an urgent need to develop more efficient and sustainable agricultural production systems to feed the growing population. This should be based on an initial assessment of the physical and biological potential of natural resources, which can vary greatly. The agroecological zonation (AEZ) approach presents a useful preliminary evaluation of this potential, and ensures that representation is maintained at an appropriate biogeographic scale for regional sustainable development planning. The principal AEZs of the world, as described by the Technical Advisory Committee of the Consultative Group on International Agricultural Research, are presented along with their extent and characteristics. Net primary productivity of terrestrial vegetation can be assessed from weather data, and it varies from 1 t dry matter ha-1 yr-1 in high latitude zones and dry regions to 29 t ha-1 yr-1 in tropical wet regions, depending on the climatic conditions. To assess the crop production potential, length of the growing period zones, a concept introduced by the UN Food and Agriculture Organization, is very useful as it describes an area within which rainfall and temperature conditions are suitable for crop growth for a given number of days in the year. These data, combined with the information on soils and known requirements of different food crops, can be used to assess the potential crop productivity. Some perspectives on AEZs and crop production potential are presented by describing the manner in which production potential can be integrated with present constraints. Efforts to intensify production should place emphasis on methods appropriate to the socio-economic conditions in a given AEZ, and on promotion of conservation-effective and sustainable production systems to meet the food, fodder and fuel needs for the future.

  9. Current anthropogenic pressures on agro-ecological protected coastal wetlands.

    PubMed

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

    2015-01-15

    Coastal wetlands are areas that suffer from great pressure. Much of it is due to the rapid development of the surrounding artificial landscapes, where socio-economic factors lead to alterations in the nearby environment, affecting the quality of natural and agricultural systems. This work analyses interconnections among landscapes under the hypothesis that urban-artificial impacts could be detected on soils and waters of an agro-ecological protected area, L'Albufera de Valencia Natural Park, located in the vicinity of the City of Valencia, Spain. The methodological framework developed addresses two types of anthropogenic pressure: (1) direct, due to artificialisation of soil covers that cause soil sealing, and (2) indirect, which are related to water flows coming from urban populations through sewage and irrigation systems and which, ultimately, will be identified by the presence of emerging pharmaceutical contaminants in waters of the protected area. For 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, was applied. To determine presence of emerging contaminants, 21 water samples within the Natural Park were analysed applying liquid chromatography tandem mass spectrometry for the detection of 17 pharmaceutical compounds. Results showed that both processes are present in the Natural Park, with a clear geographical pattern. Soil sealing and presence 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 artificial ones (soil sealing). PMID:25042415

  10. How to measure the agroecological performance of farming in order to assist with the transition process.

    PubMed

    Trabelsi, Meriam; Mandart, Elisabeth; Le Grusse, Philippe; Bord, Jean-Paul

    2016-01-01

    The use of plant protection products enables farmers to maximize economic performance and yields, but in return, the environment and human health can be greatly affected because of their toxicity. There are currently strong calls for farmers to reduce the use of these toxic products for the preservation of the environment and the human health, and it has become urgent to invest in more sustainable models that help reduce these risks. One possible solution is the transition toward agroecological production systems. These new systems must be beneficial economically, socially, and environmentally in terms of human health. There are many tools available, based on a range of indicators, for assessing the sustainability of agricultural systems on conventional farm holdings. These methods are little suitable to agroecological farms and do not measure the performance of agroecological transition farms. In this article, we therefore develop a model for the strategic definition, guidance, and assistance for a transition to agroecological practices, capable of assessing performance of this transition and simulating the consequences of possible changes. This model was built by coupling (i) a decision-support tool and a technico-economic simulator with (ii) a conceptual model built from the dynamics of agroecological practices. This tool is currently being tested in the framework of a Compte d'Affectation Spéciale pour le Développement Agricole et Rural (CASDAR) project (CASDAR: project launched in 2013 by the French Ministry of Agriculture, Food and Forestry, on the theme "collective mobilisation for agroecology," http://agriculture.gouv.fr/Appel-a-projets-CASDAR ) using data from farms, most of which are engaged in agroenvironmental process and reducing plant protection treatments since 2008. PMID:26527345

  11. Salvadora persica agro-ecological suitability for oil production in Argentine dryland salinity.

    PubMed

    Falasca, Silvia; Pitta-Alvarez, Sandra; del Fresno, Carolina Miranda

    2015-12-15

    One of the major causes of crop stress is soil or water salinity. Thus, selection of the best species for cultivation in semiarid and arid climates is fundamental. Salvadora persica is an evergreen perennial halophyte that can grow under extreme conditions, from very dry environments to highly saline soils. Based on international bibliography, the authors outlined an agro-ecological zoning model to determine the potential cultivation zones for S. persica in Argentina. This model may be applied to any part of the world, using the agro-ecological limits presented in this work. All the maps were developed by the implementation of a geographic information system (GIS) that can be updated by the further incorporation of complementary information, with the consequent improvement of the original database. The overlap of the agroclimatic suitability map on the drylands' saline soils and the drylands' alkaline soils maps, determined the agro-ecological zoning. Since some areas in the agro-ecological zoning can overlap with land that is already assigned for other uses, protected areas, current land use/cover of the different zones, and urban areas maps were incorporated into the GIS and subtracted by a mask. This resulted in the delimitation of "potential cultivation zoning", thus avoiding possible conflicts surrounding the use of land and making the agro-ecological zonation more efficient. There is a broad agro-ecological zone for cultivation of S. persica that extends from Northern Argentina to approximately 41° South latitude, under dry-subhumid to semiarid climates. Lands classified with different degrees of suitability in the potential cultivation zoning could be used for production of this species for energy purposes on lands that are either unsuitable for food production or currently assigned for other purposes. This paper represents pioneering work since there are no previous studies concerning the introduction of S. persica in Argentina. PMID:26348151

  12. 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

  13. 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,…

  14. Behavioral Changes Based on a Course in Agroecology: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Harms, Kristyn; King, James; Francis, Charles

    2009-01-01

    This study evaluated and described student perceptions of a course in agroecology to determine if participants experienced changed perceptions and behaviors resulting from the Agroecosystems Analysis course. A triangulation validating quantitative data mixed methods approach included a written survey comprised of both quantitative and open-ended…

  15. 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...

  16. IT-based soil quality evaluation for agroecologically smart land-use planning in RF conditions

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan

    2016-04-01

    Activated in the first decades of XXI century global climate, economy and farming changes sharply actualized novel IT-based approaches in soil quality evaluation to address modern agricultural issues with agroecologically smart land-use planning. Despite global projected climate changes will affect a general decline of crop yields (IPCC 2014), RF boreal and subboreal regions will benefit from predicted and already particularly verified temperature warming and increased precipitation (Valentini, Vasenev, 2015) due to essential increasing of growing season length and mild climate conditions favorable for most prospective crops and best available agrotechnologies. However, the essential spatial heterogeneity is mutual feature for most natural and man-changed soils at the Central European region of Russia which is one of the biggest «food baskets» in RF. In these conditions potentially favorable climate circumstances will increase not only soil fertility and workability features but also their dynamics and spatial variability that determine crucial issues of IT-based soil quality evaluation systems development and agroecologically smart farming planning. Developed and verified within the LAMP project (RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) regionally adapted DSS (ACORD-R - RF #2012612944) gives effective informational and methodological support for smart farming agroecological optimization in global climate and farming changes challenges. Information basis for agroecologically smart land-use planning consists of crops and agrotechnologies requirements, regional and local systems of agroecological zoning, local landscape and soil cover patterns, land quality and degradation risk assessments, current and previous farming practices results, agroclimatic predictions and production agroecological models, environmental limitations and planned profitability, fertilizing efficiency DSS ACORD-R. Smart land-use practice refers to sustainable balance

  17. IT-based soil quality evaluation for agroecologically smart land-use planning in RF conditions

    NASA Astrophysics Data System (ADS)

    Vasenev, Ivan

    2016-04-01

    Activated in the first decades of XXI century global climate, economy and farming changes sharply actualized novel IT-based approaches in soil quality evaluation to address modern agricultural issues with agroecologically smart land-use planning. Despite global projected climate changes will affect a general decline of crop yields (IPCC 2014), RF boreal and subboreal regions will benefit from predicted and already particularly verified temperature warming and increased precipitation (Valentini, Vasenev, 2015) due to essential increasing of growing season length and mild climate conditions favorable for most prospective crops and best available agrotechnologies. However, the essential spatial heterogeneity is mutual feature for most natural and man-changed soils at the Central European region of Russia which is one of the biggest «food baskets» in RF. In these conditions potentially favorable climate circumstances will increase not only soil fertility and workability features but also their dynamics and spatial variability that determine crucial issues of IT-based soil quality evaluation systems development and agroecologically smart farming planning. Developed and verified within the LAMP project (RF Governmental projects #11.G34.31.0079 and #14.120.14.4266) regionally adapted DSS (ACORD-R - RF #2012612944) gives effective informational and methodological support for smart farming agroecological optimization in global climate and farming changes challenges. Information basis for agroecologically smart land-use planning consists of crops and agrotechnologies requirements, regional and local systems of agroecological zoning, local landscape and soil cover patterns, land quality and degradation risk assessments, current and previous farming practices results, agroclimatic predictions and production agroecological models, environmental limitations and planned profitability, fertilizing efficiency DSS ACORD-R. Smart land-use practice refers to sustainable balance

  18. Biodiversity and agro-ecology in field margins.

    PubMed

    De Cauwer, B; Reheul, D; Nijs, I; Milbau, A

    2005-01-01

    This multidisciplinary study investigates agro-ecological functions (nature conservation, agriculture, environment) and implications of newly created, mown sown and unsown field margin strips installed on ex-arable land to increase biodiversity. From conservational concern, the development of species rich field margin strips was not strongly affected by the installed type of margin strip since species diversity converged over time, whether strips were sown or not. Convergence between unsown and sown margin strips occurred also in terms of species composition: unsown and sown strips became similar over time. Mowing without removal of cuttings significantly reduced species richness, yielded more grassy margin strips and delayed similarity in species composition between sown and unsown margin strips. Species richness on the longer term was not significantly affected by light regime nor by disturbance despite significant temporary effects shortly after the disturbance event. On the contrary vegetation composition in terms of importance of functional groups changed after disturbance: the share of spontaneous species within functional groups increased resulting in higher similarity between the sown and unsown vegetation. Furthermore risk of invasion was highest in the disturbed unsown community on the unshaded side of a tree lane. A positive effect of botanical diversity on insect number and diversity was found. However the effects of botanical diversity on insect number was mediated by light regime. At high light availability differences between plant communities were more pronounced compared to low light availablilty. The abundance of some insect families was dependent on the vegetation composition. Furthermore light availability significantly influenced insect diversity as well as the spatial distribution of families. From agricultural concern, installing margin strips by sowing a species mixture and a mowing regime with removal of cuttings are good practices to

  19. [Qingshishan watershed agro-ecology information system and its application with the support of Geographic Information System (GIS)].

    PubMed

    Lu, J; Wang, Z

    2000-10-01

    Geographic Information System(GIS) is applied to establish Qingshishan Watershed Agro-Ecology Information System (QWAEIS), QWAEIS integrates spatial information such as land use, soil, water and topography with basic information such as population, climate and agricultural production. The watershed agro-ecology information was effectively analyzed and managed by QWAEIS, land suitable classes were evaluated by QWAEIS and the land evaluation result are given, QWAEIS also can support watershed planning with its spatial information. PMID:11767525

  20. Towards an agroecological assessment of dairy systems: proposal for a set of criteria suited to mountain farming.

    PubMed

    Botreau, R; Farruggia, A; Martin, B; Pomiès, D; Dumont, B

    2014-08-01

    Ruminant production systems have been facing the sustainability challenge, namely, how to maintain or even increase production while reducing their environmental footprint, and improving social acceptability. One currently discussed option is to encourage farmers to follow agroecological principles, that is, to take advantage of ecological processes to reduce inputs and farm wastes, while preserving natural resources, and using this diversity to increase system resilience. However, these principles need to be made more practical. Here, we present the procedure undertaken for the collaborative construction of an agroecological diagnostic grid for dairy systems with a focus on the mountain farming relying on the use of semi-natural grasslands. This diagnosis will necessarily rely on a multicriteria evaluation as agroecology is based on a series of complementary principles. It requires defining a set of criteria, based on practices to be recommended, that should be complied with to ensure agroecological production. We present how such agroecological criteria were identified and organized to form the architecture of an evaluation model. As a basis for this work, we used five agroecological principles already proposed for animal production systems. A group of five experts of mountain production systems and of their multicriteria evaluation was selected, with a second round of consultation with five additional experts. They first split up each principle into three to four generic sub-principles. For each principle, they listed three to eight categories of state variables on which the fulfilment of the principle should have a positive impact (e.g. main health disorders for the integrated health management principle). State variables are specific for a given production, for example, dairy farms. Crossing principles with state variables enabled experts to build five matrices, with 75 cells relevant for dairy systems. In each cell, criteria are specific to the local context

  1. 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.

  2. 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…

  3. The long-term agroecological research (LTAR) experiment in Iowa: Organic resilience in soil quality and profitability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Long-Term Agroecological Research (LTAR) experiment, at the Iowa State University Neely-Kinyon Farm in Greenfield, Iowa, was established in 1998 to compare the agronomic, ecological, and economic performance of conventional and organic cropping systems. The certified organic systems are designed...

  4. A CASE STUDY OF LAND DEGRADATION LINKING BIOPHYSICAL AND SOCIOECONOMIC ASPECTS OF AGROECOLOGICAL PRODUCTION SYSTEMS IN SOUTHERN HONDURAS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dahlem Desertification Protocol (DDP) was developed to analyze interrelationships within coupled human-environment systems. In this study, we apply the DDP to humid systems through an evaluation of an innovative agroecological production system in the mountains of southern Honduras, where season...

  5. The long-term agroecological research (LTAR) experiment supports organic yields, soil quality, and economic performance in Iowa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Long-Term Agroecological Research (LTAR) experiment, at the Iowa State University Neely-Kinyon Farm in Greenfield, Iowa, was established in 1998 to compare the agronomic, ecological and economic performance of conventional and organic cropping systems. The main goals of the project are to evalua...

  6. Agroecology and sustainable food systems: Participatory research to improve food security among HIV-affected households in northern Malawi.

    PubMed

    Nyantakyi-Frimpong, Hanson; Mambulu, Faith Nankasa; Bezner Kerr, Rachel; Luginaah, Isaac; Lupafya, Esther

    2016-09-01

    This article shares results from a long-term participatory agroecological research project in northern Malawi. Drawing upon a political ecology of health conceptual framework, the paper explores whether and how participatory agroecological farming can improve food security and nutrition among HIV-affected households. In-depth interviews were conducted with 27 farmers in HIV-affected households in the area near Ekwendeni Trading Centre in northern Malawi. The results show that participatory agroecological farming has a strong potential to meet the food, dietary, labour and income needs of HIV-affected households, whilst helping them to manage natural resources sustainably. As well, the findings reveal that place-based politics, especially gendered power imbalances, are imperative for understanding the human impacts of the HIV/AIDS epidemic. Overall, the study adds valuable insights into the literature on the human-environment dimensions of health. It demonstrates that the onset of disease can radically transform the social relations governing access to and control over resources (e.g., land, labour, and capital), and that these altered social relations in turn affect sustainable disease management. The conclusion highlights how the promotion of sustainable agroecology could help to partly address the socio-ecological challenges associated with HIV/AIDS. PMID:27475055

  7. Distribution and Toxigenicity of Aspergillus Species Isolated from Maize Kernels from Three Agro-ecological Zones in Nigeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize samples were collected during a survey in three agro-ecological zones in Nigeria to determine the distribution and aflatoxin-producing potential of members of Aspergillus section Flavi. Among Aspergillus, A. flavus was the most predominant and L-strains constituted > 90% of the species identi...

  8. 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

  9. 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

  10. 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. PMID:24821184

  11. 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.

  12. The effect of storage time and agroecological zone on mould incidence and aflatoxin contamination of maize from traders in Uganda.

    PubMed

    Kaaya, Archileo Natigo; Kyamuhangire, William

    2006-08-01

    A study to determine mould incidence and aflatoxin contamination of maize kernels was carried out among dealers (traders) in the three agroecological zones of Uganda. The maize kernels were categorized into those stored for two to six months or for more than six months to one year. Results indicate that the mean moisture content of the kernels was within the recommended safe storage levels of < or =15% but was significantly lower in the Highland maize kernels followed by the Mid-Altitude (dry) kernels while the Mid-Altitude (moist) kernels had the highest levels. Across the agroecological zones, Aspergillus, Fusarium, Penicillium and Rhizopus were the most predominant fungal genera identified and, among their species, A. niger had the highest incidence, followed by A. flavus, F. verticillioides, A. wentii, A. penicillioides and Rhizopus stolonifer. There were more aflatoxin positive samples from the Mid-Altitude (moist) zone (88%) followed by those samples from the Mid-Altitude (dry) zone (78%) while samples from the Highland zone (69%) were least contaminated. Aflatoxin levels increased with storage time such that maize samples from the Mid-Altitude (dry and moist) stored for more than six months had mean levels greater than the 20 ppb FDA/WHO regulatory limits. Aflatoxin B1 was the most predominant type and was found to contaminate maize kernels from all the three agroecological zones. These results indicate that maize consumers in Uganda are exposed to the danger of aflatoxin poisoning. Thus, there is the need for policy makers to establish and enforce maize quality standards and regulations related to moulds and aflatoxins across the agroecological zones to minimize health hazards related to consumption of contaminated kernels. PMID:16822572

  13. Relative Technical Efficiency of Cassava Farmers in the Three Agro-Ecological Zones of Edo State, Nigeria

    NASA Astrophysics Data System (ADS)

    Erhabor, P. O.; Emokaro, C. O.

    This study employed the use of the Stochastic Frontier Production Function in the comparative economic analysis of the relative technical efficiency of cassava farmers in the three agro-ecological zones of Edo State. A multi-stage random sampling technique was used to select 156 cassava farmers from the three agro-ecological zones of the State and the differences in the results obtained were discussed. The empirical estimates showed individual technical efficiency values that ranged from 23 to 95%, 43 to 97% and 52 to 98% with a mean of 72, 83 and 91%, for Edo South, Edo North and Edo Central agro-ecological zones, respectively. This shows that systemic differences in relative technical efficiency levels exist between the three zones and these differences were shown to be related to particular farmer`s characteristics. Non-physical factors that served as determinants of technical inefficiency in the three zones were, farmers level of education, age, farming experience and variety of planting materials used. Gender and family size were however, not found to be significant determinants of the technical inefficiency of cassava farmers in the State. Apart from this estimates serving as a guide to potential investors in the cassava industry in the State, the relative variations in technical efficiency is also an indication of the gaps that exist in the current production technologies employed by cassava farmers in the three agro-ecological zones of the State. The gaps should serve as intervention points for government and non-governmental agencies as well as other stakeholders in the emerging cassava industry in Nigeria.

  14. 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. PMID:26505637

  15. 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

  16. 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

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

    PubMed Central

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

    2010-01-01

    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. PMID:25567940

  18. Modeling the Agroecological Land Suitability for Coffea arabica L. in Central America

    NASA Astrophysics Data System (ADS)

    Lara, Leonel; Rasche, Livia; Schneider, Uwe

    2016-04-01

    Coffee production is an important income source for small farms in Central America, but climate change threatens the production. In order to develop efficient adaptation strategies, an assessment of local conditions and opportunities is essential. Lack or uncertainty of information are common challenges for such assessments. A tool to resolve these challenges is Bayesian network analysis. In this study, we developed ALECA, the first Bayesian network model to evaluate the agroecological land suitability for Coffea arabica L. A new set of suitability functions was created and subsequently used to populate the conditional probability tables of the variables. The variables include temperature, precipitation and dry season length for the climate, slope and aspect for the landform, and soil pH, cation exchange capacity and texture for the soil component. We validated ALECA by comparing a map of current coffee areas, and specific coffee areas with known suitability for coffee production in Central America to the suitability evaluations of the model; and proceeded to explore 1) the capabilities of the model to manage data uncertainty, and 2) the changes to suitability scores under climate change. The results showed that the area suitable for coffee production will decline in Central America under climate change, underlining the need for models like ALECA, which can be used to produce reliable land evaluations at local, national and regional scales under uncertainty.

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

    PubMed Central

    Perfecto, Ivette; Vandermeer, John

    2010-01-01

    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. PMID:20339080

  20. 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. PMID:21284238

  1. 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

  2. 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. PMID:26055891

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

    PubMed

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

    2010-06-01

    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. PMID:20585972

  4. 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.

  5. Persistence of Highly Pathogenic Avian Influenza H5N1 Virus Defined by Agro-Ecological Niche

    PubMed Central

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

    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. Electronic supplementary material The online version of this article (doi:10.1007/s10393-010-0324-z) contains supplementary material, which is available to authorized users. PMID:20585972

  6. “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

  7. 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

  8. Agro-ecological sustainability and land degradation potential in Nang Rong, Thailand

    NASA Astrophysics Data System (ADS)

    Welsh, William F.

    This dissertation examines specific aspects of the land use history of Nang Rong (1972 to 1997), Buriram Province, northeast Thailand, emphasizing the relationship between patterns of land use/land cover (LULC) and soils. The potential for land degradation---a reduction in the capability of soil to support plant growth (including crops) due to human actions---was assessed by comparison of multi-temporal LULC data to soil surveys, using the situational indicator approach. Resulting patterns of land degradation potential were then used to infer agro-ecological sustainability (the ability to obtain and maintain socio-economically viable crop yields given the prevailing biophysical milieu of a place) on the basis of likely changes to soil attributes associated with land use practices. Digital and analogue geographical analysis techniques were used to manipulate and process the image, map, and field data collected and compiled to represent the phenomena of interest. Geographical information science, earth systems science, landscape ecology, and political ecology form the theoretical context influencing the research design and the interpretation of results. The research was conducted in three distinct phases. First, Landsat imagery, cartographic, and field data were processed to produce LULC change trajectories (1972--1985--1997) for agriculturally-relevant classes (rice paddy, field crop, forest, savanna). Second, a composite soil crop suitability variable was created and compared to the LULC change trajectories to derive a map based on a qualitative Land Degradation Potential Index. Third, spatial pattern metric analysis was performed using the LULC data, stratified by composite soil suitability classes over time. The LULC change trajectories indicate that cropland was extended between 1972 and 1997 (net increase in area of 17.9%), through conversion of forest and savanna (net decreases of 9.8% and 8.1%, respectively). Rice paddy was the dominant LULC type in all

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

    PubMed Central

    Burdon, Jeremy J; Thrall, Peter H

    2008-01-01

    Abstract 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

  10. 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

  11. SEASONALITY AND TRANSMISSION OF SHIGA-TOXIGENIC ESCHERICHIA COLI INFECTIONS IN CATTLE: AGRO-ECOLOGICAL AND MOLECULAR EPIDEMIOLOGIC EVIDENCE OF A ROLE FOR PEST FLIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ecological or other basis for the strong observed summer prevalence peaks in Shiga-toxigenic Escherichia coli (STEC) O157 human and livestock infections and in meat and produce contamination remains unexplained and enigmatic. Using an agro-ecological approach to investigate livestock STEC season...

  12. Genetic Diversity of Cultivated Lentil (Lens culinaris Medik.) and Its Relation to the World's Agro-ecological Zones

    PubMed Central

    Khazaei, Hamid; Caron, Carolyn T.; Fedoruk, Michael; Diapari, Marwan; Vandenberg, Albert; Coyne, Clarice J.; McGee, Rebecca; Bett, Kirstin E.

    2016-01-01

    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 countries to estimate genetic diversity and genetic structure using 1194 polymorphic single nucleotide polymorphism (SNP) markers which span the lentil genome. Using principal coordinate analysis, population structure analysis and UPGMA cluster analysis, the accessions were categorized into three major groups that prominently reflected geographical origin (world's agro-ecological zones). The three clusters complemented the origins, pedigrees, and breeding histories of the germplasm. The three groups were (a) South Asia (sub-tropical savannah), (b) Mediterranean, and (c) northern temperate. Based on the results from this study, it is also clear that breeding programs still have considerable genetic diversity to mine within the cultivated lentil, as surveyed South Asian and Canadian germplasm revealed narrow genetic diversity. PMID:27507980

  13. Genetic Diversity of Cultivated Lentil (Lens culinaris Medik.) and Its Relation to the World's Agro-ecological Zones.

    PubMed

    Khazaei, Hamid; Caron, Carolyn T; Fedoruk, Michael; Diapari, Marwan; Vandenberg, Albert; Coyne, Clarice J; McGee, Rebecca; Bett, Kirstin E

    2016-01-01

    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 countries to estimate genetic diversity and genetic structure using 1194 polymorphic single nucleotide polymorphism (SNP) markers which span the lentil genome. Using principal coordinate analysis, population structure analysis and UPGMA cluster analysis, the accessions were categorized into three major groups that prominently reflected geographical origin (world's agro-ecological zones). The three clusters complemented the origins, pedigrees, and breeding histories of the germplasm. The three groups were (a) South Asia (sub-tropical savannah), (b) Mediterranean, and (c) northern temperate. Based on the results from this study, it is also clear that breeding programs still have considerable genetic diversity to mine within the cultivated lentil, as surveyed South Asian and Canadian germplasm revealed narrow genetic diversity. PMID:27507980

  14. 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

  15. 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

  16. 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. PMID:25767477

  17. The influence of storage practices on aflatoxin contamination in maize in four agroecological zones of Benin, west Africa.

    PubMed

    Hell; Cardwell; Setamou; Poehling

    2000-10-15

    Aflatoxin level in 300 farmers' stores in four agro-ecological zones in Benin, a west African coastal country, were determined over a period of 2 years. At sampling a questionnaire was used to evaluate maize storage practices. Farmers were asked what storage structure they used, their storage form, storage period, pest problems in storage and what was done against them. Beninese farmers often changed their storage structures during the storage period, transfering the maize from a drying or temporary store to a more durable one. Most of the farmers complained about insects damaging stored maize. Often, storage or cotton insecticides were utilized against these pests. Regression analysis identified those factors that were associated with increased or reduced aflatoxin.Maize samples in the southern Guinea and Sudan savannas were associated with higher aflatoxin levels and the forest/savanna mosaic was related to lower toxin levels. Factors associated with higher aflatoxin were: storage for 3-5 months, insect damage and use of Khaya senegalensis-bark or other local plants as storage protectants. Depending on the agroecological zone, storage structures that had a higher risk of aflatoxin development were the "Ago", the "Secco", the "Zingo" or storing under or on top of the roof of the house. Lower aflatoxin levels were related to the use of storage or cotton insecticides, mechanical means or smoke to protect against pests or cleaning of stores before loading them with the new harvest. Fewer aflatoxins were found when maize was stored in the "Ago" made from bamboo or when bags were used as secondary storage containers. PMID:10880814

  18. Assessment of aflatoxin contamination of maize, peanut meal and poultry feed mixtures from different agroecological zones in Cameroon.

    PubMed

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

    2013-05-01

    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

  19. 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

  20. 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

  1. Evaluation of climate change impacts and adaptation measures for maize cultivation in the western Uganda agro-ecological zone

    NASA Astrophysics Data System (ADS)

    Babel, M. S.; Turyatunga, E.

    2015-01-01

    In this study, we assessed the probable climate change impacts and the appropriate adaptation strategies for maize cultivation in the western Uganda agro-ecological zone. Detailed assessments were made using climate and crop models. The Statistical Downscaling Model (SDSM) v4.2 was used to downscale low resolution future climate data obtained from general circulation model HadCM3 for two SRES scenarios, A2 and B2. The CERES-Maize crop model of DSSAT v4.0.2.0 was used to simulate maize yield for the assessment of climate change impacts. In the western Uganda agro-ecological zone, the annual average temperature is expected to increase by between 0.69-2.46 and 0.66-1.78 °C under the A2 and B2 SRES scenarios, respectively, in the three future periods of 2020s, 2050s, and 2080s relative to the base period (1961-1990). Monthly average temperatures are expected to increase for most of the months but will slightly decrease for the month of November under both scenarios. The annual average rainfall is expected to decrease by between 4.7-16.4 and 4.7-11.8 % under the A2 and B2 scenarios, respectively, in the three future periods. Monthly average rainfall is expected to decrease for most of the months but will increase for the months of October, November, and December under both scenarios. Crop modeling results show that in the March-May crop season, maize yields will decrease by between 9.6-43.3 and 10.5-28.4 % under the A2 and B2 scenarios, respectively, relative to the base period in the three future periods. However, in the September-November crop season, maize yields are expected to increase by between 8.1-9.6 and 8.6-10.2 % under the A2 and B2 scenarios, respectively. Supplementary irrigation and shifting of planting dates are found to extenuate the impacts of future climate on maize yields. Irrigation application of 80 mm during the growing season in the March-May season is expected to increase maize yields by as high as 42.1 % under future climate, while planting 16

  2. 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.

  3. 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. PMID:24127024

  4. Toxigenic potential of Aspergillus species occurring on maize kernels from two agro-ecological zones in Kenya.

    PubMed

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

    2012-11-01

    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

  5. 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

  6. Serosurvey of peste des petits ruminants virus in small ruminants from different agro-ecological zones of Nigeria.

    PubMed

    Woma, Timothy Y; Ekong, Pius S; Bwala, Dauda G; Ibu, John O; Ta'ama, Louisa; Dyek, Dyek Y; Saleh, Ladi; Shamaki, David; Kalla, Demo J U; Bailey, Dalan; Kazeem, Haruna M; Quan, Melvyn

    2016-01-01

    Peste des petits ruminants, caused by the peste des petits ruminants virus (PPRV), is a highly contagious and economically important transboundary viral disease of domestic and wild small ruminants and a major hindrance to small-ruminant production in Nigeria. The seroprevalence and distribution of PPRV antibodies in small ruminants in rural households, farms, live animal markets and slaughter slabs across the six different agro-ecological zones of Nigeria were determined. A total of 4548 serum samples from 3489 goats and 1059 sheep were collected in 12 states. A PPRV competitive enzyme-linked immunosorbent assay was used to test the samples and the data analysed with R statistical software version 3.0.1. The study animals included all ages and both sexes. The overall prevalence estimate of sera positive for PPRV antibodies was 23.16% (n = 1018 positive samples per 4548 total samples, 95% confidence interval: 21.79% - 24.57%). There were significant differences in the seroprevalence between the states (p = 0.001). Taraba State had the highest seroprevalence of 29.51%, whilst the lowest seroprevalence of 14.52% was observed in Cross River State. There were no significant differences in the PPRV seroprevalence between male and female animals (p = 0.571), age (p = 0.323) and between species (p = 0.639). These data indicate the current seroprevalence to PPRV in the small-ruminant population in Nigeria. PMID:26974177

  7. Agroecological factors correlated to soil DNA concentrations of Rhizoctonia in dryland wheat production zones of Washington state, USA.

    PubMed

    Okubara, Patricia A; Schroeder, Kurtis L; Abatzoglou, John T; Paulitz, Timothy C

    2014-07-01

    The necrotrophic soilborne fungal pathogens Rhizoctonia solani AG8 and R. oryzae are principal causal agents of Rhizoctonia root rot and bare patch of wheat in dryland cropping systems of the Pacific Northwest. A 3-year survey of 33 parcels at 11 growers' sites and 60 trial plots at 12 Washington State University cereal variety test locations was undertaken to understand the distribution of these pathogens. Pathogen DNA concentrations in soils, quantified using real-time polymerase chain reaction, were correlated with precipitation, temperature maxima and minima, and soil texture factors in a pathogen-specific manner. Specifically, R. solani AG8 DNA concentration was negatively correlated with precipitation and not correlated with temperature minima, whereas R. oryzae concentration was correlated with temperature minima but not with precipitation. However, both pathogens were more abundant in soils with higher sand and lower clay content. Principal component analysis also indicated that unique groups of meteorological and soil factors were associated with each pathogen. Furthermore, tillage did not affect R. oryzae but affected R. solani AG8 at P = 0.06. Lower soil concentrations of R. solani AG8 but not R. oryzae occurred when the previously planted crop was a broadleaf (P < 0.05). Our findings showed that R. solani AG8 concentrations were consistent with the general distribution of bare patch symptoms, based on field observations and surveys of other pathogens, but was present at many sites in which bare patch symptoms were not evident. Management of Rhizoctonia root rot and bare patch should account for the likelihood that each pathogen is affected by a unique group of agroecological variables. PMID:24915426

  8. 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%.

  9. Effect of two agroecological management strategies on ant (Hymenoptera: Formicidae) diversity on coffee plantations in southwestern Colombia.

    PubMed

    Urrutia-Escobar, M X; Armbrecht, I

    2013-04-01

    Simplification of agroecosystems because of industrialization of agriculture may cause the loss of associated animal biodiversity of both vertebrates and invertebrates. To measure how the agricultural intensification on coffee plantations affects ant biodiversity, we intensively sampled ants in Caldono (Cauca, Colombia). We surveyed 15 sites classified into three management types: sun coffee plantations, shaded coffee plantations, and forest patches. Fifteen 50-m linear transects, each one consisting of 5 pitfall traps and 5 tuna baits, were set at each sampling location between December of 2009 and February of 2010. We collected 18,186 ants that represent 82 ant species, 34 genera, and 9 subfamilies of Formicidae (Hymenoptera: Formicidae). The management intensification index showed an increasing intensification gradient along the 15 sampling locations from forest patches to shaded coffee to sun coffee plantations. Shaded coffee plantations harbored the highest number of species (60), followed by forest (56) and sun coffee (33). Ant species composition and plant structure on shaded coffee plantations resembled the forest patches more than the sun coffee plantations. Forest and shaded coffee plantations had a more equitable distribution of ant species, whereas in sun coffee plantations, Linepithema neotropicum (Emery) and Ectatomma ruidum (Roger) typically outnumbered all other ant species. Evidence from functional groups indicated that specific habitat and feeding requirements exist among the species that are found together. Our results confirmed that intensification of agriculture negatively affects ant diversity, despite the fact that farms were located in a heterogeneous landscape, suggesting that agroecological management is a strong determinant in the conservation of wild fauna. PMID:23575008

  10. Prevalence of the gastro-intestinal parasites of domestic chicken Gallus domesticus Linnaeus, 1758 in Tunisia according to the agro-ecological zones.

    PubMed

    Ben Slimane, Badreddine

    2016-09-01

    Helminthosis is a very important disease affecting the poultry industry, especially the traditionally reared free ranging chickens. In Tunisia, the poultry production is considered as the most important source of protein in as much as chickens provide 53 % of animal protein production. The traditionally reared poultry farming system exposes chickens to many types of parasites, however, very little work has been done to establish the extend of helminth infection in Tunisia. The aim of this work is to investigate various aspects of helminth infections. A significant difference (p < 0.01) was found between the prevalence rates of helminth parasites in the different agro-ecological zones. The highest prevalence was observed in lowland areas of northern Tunisia (Siliana district). This suggests that agro-ecology has a major influence on the distribution of helminth parasites. Recovered nematodes included Heterakis spp. (100 %), Ascaridia galli (53.33 %) and Acuaria hamulosa (37 %). The principal cestode species encountered were Hymenolepis spp. (73.33 %) and Raillietina spp. (33.33 %). PMID:27605783

  11. 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

  12. 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

  13. 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

  14. 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. PMID:26560016

  15. 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. PMID:26567901

  16. Food Insecurity and Not Dietary Diversity Is a Predictor of Nutrition Status in Children within Semiarid Agro-Ecological Zones in Eastern Kenya

    PubMed Central

    Bukania, Zipporah N.; Mwangi, Moses; Karanja, Robert M.; Mutisya, Richard; Kombe, Yeri; Kaduka, Lydia U.

    2014-01-01

    Machakos and Makueni counties in Kenya are associated with historical land degradation, climate change, and food insecurity. Both counties lie in lower midland (LM) lower humidity to semiarid (LM4), and semiarid (LM5) agroecological zones (AEZ). We assessed food security, dietary diversity, and nutritional status of children and women. Materials and Methods. A total of 277 woman-child pairs aged 15–46 years and 6–36 months respectively, were recruited from farmer households. Food security and dietary diversity were assessed using standard tools. Weight and height, or length in children, were used for computation of nutritional status. Findings. No significant difference (P > 0.05) was observed in food security and dietary diversity score (DDS) between LM4 and LM5. Stunting, wasting, and underweight levels among children in LM4 and LM5 were comparable as were BMI scores among women. However, significant associations (P = 0.023) were found between severe food insecurity and nutritional status of children but not of their caregivers. Stunting was significantly higher in older children (>2 years) and among children whose caregivers were older. Conclusion. Differences in AEZ may not affect dietary diversity and nutritional status of farmer households. Consequently use of DDS may lead to underestimation of food insecurity in semiarid settings. PMID:25328691

  17. 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. PMID:26801158

  18. Clade-level Spatial Modelling of HPAI H5N1 Dynamics in the Mekong Region Reveals New Patterns and Associations with Agro-Ecological Factors.

    PubMed

    Artois, Jean; Newman, Scott H; Dhingra, Madhur S; Chaiban, Celia; Linard, Catherine; Cattoli, Giovanni; Monne, Isabella; Fusaro, Alice; Xenarios, Ioannis; Engler, Robin; Liechti, Robin; Kuznetsov, Dmitri; Pham, Thanh Long; Nguyen, Tung; Pham, Van Dong; Castellan, David; Von Dobschuetz, Sophie; Claes, Filip; Dauphin, Gwenaëlle; Inui, Ken; Gilbert, Marius

    2016-01-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus has been circulating in Asia since 2003 and diversified into several genetic lineages, or clades. Although the spatial distribution of its outbreaks was extensively studied, differences in clades were never previously taken into account. We developed models to quantify associations over time and space between different HPAI H5N1 viruses from clade 1, 2.3.4 and 2.3.2 and agro-ecological factors. We found that the distribution of clades in the Mekong region from 2004 to 2013 was strongly regionalised, defining specific epidemiological zones, or epizones. Clade 1 became entrenched in the Mekong Delta and was not supplanted by newer clades, in association with a relatively higher presence of domestic ducks. In contrast, two new clades were introduced (2.3.4 and 2.3.2) in northern Viet Nam and were associated with higher chicken density and more intensive chicken production systems. We suggest that differences in poultry production systems in these different epizones may explain these associations, along with differences in introduction pressure from neighbouring countries. The different distribution patterns found at the clade level would not be otherwise apparent through analysis treating all outbreaks equally, which requires improved linking of disease outbreak records and genetic sequence data. PMID:27453195

  19. 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. PMID:22868910

  20. Clade-level Spatial Modelling of HPAI H5N1 Dynamics in the Mekong Region Reveals New Patterns and Associations with Agro-Ecological Factors

    PubMed Central

    Artois, Jean; Newman, Scott H.; Dhingra, Madhur S.; Chaiban, Celia; Linard, Catherine; Cattoli, Giovanni; Monne, Isabella; Fusaro, Alice; Xenarios, Ioannis; Engler, Robin; Liechti, Robin; Kuznetsov, Dmitri; Pham, Thanh Long; Nguyen, Tung; Pham, Van Dong; Castellan, David; Von Dobschuetz, Sophie; Claes, Filip; Dauphin, Gwenaëlle; Inui, Ken; Gilbert, Marius

    2016-01-01

    The highly pathogenic avian influenza (HPAI) H5N1 virus has been circulating in Asia since 2003 and diversified into several genetic lineages, or clades. Although the spatial distribution of its outbreaks was extensively studied, differences in clades were never previously taken into account. We developed models to quantify associations over time and space between different HPAI H5N1 viruses from clade 1, 2.3.4 and 2.3.2 and agro-ecological factors. We found that the distribution of clades in the Mekong region from 2004 to 2013 was strongly regionalised, defining specific epidemiological zones, or epizones. Clade 1 became entrenched in the Mekong Delta and was not supplanted by newer clades, in association with a relatively higher presence of domestic ducks. In contrast, two new clades were introduced (2.3.4 and 2.3.2) in northern Viet Nam and were associated with higher chicken density and more intensive chicken production systems. We suggest that differences in poultry production systems in these different epizones may explain these associations, along with differences in introduction pressure from neighbouring countries. The different distribution patterns found at the clade level would not be otherwise apparent through analysis treating all outbreaks equally, which requires improved linking of disease outbreak records and genetic sequence data. PMID:27453195

  1. Agro-Ecological Analysis for the EU Water Framework Directive: An Applied Case Study for the River Contract of the Seveso Basin (Italy)

    NASA Astrophysics Data System (ADS)

    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.

  2. Differences in the epidemiology of theileriosis on smallholder dairy farms in contrasting agro-ecological and grazing strata of highland Kenya.

    PubMed Central

    Gitau, G. K.; McDermott, J. J.; Katende, J. M.; O'Callaghan, C. J.; Brown, R. N.; Perry, B. D.

    2000-01-01

    A prospective cohort study was conducted in five purposively-sampled agro-ecological zone (AEZ)-grazing system strata in Murang'a District, Kenya, between March 1995 and June 1996. The study strata were selected based on a preliminary characterization study to represent the widest range of risks to East Coast fever (ECF) in the District and included zero-grazing and open-grazing farms. In total, 225 calves from 188 smallholder farms were examined from birth to 6 months of age and visited within the first 2 weeks of life and thereafter at bi-weekly intervals for up to 14 visits. The purpose of the study was to characterize the differences in epidemiology (risks of infection, morbidity and mortality) and potential control of ECF between the selected strata. Evidence of Theileria parva infection was assessed by increased antibody levels as measured in an indirect ELISA assay by the percent positivity (PP) of serum samples relative to a strong positive reference serum. Sero-conversion risks of T. parva were highest in the open-grazing strata. Antibody prevalence in adult cattle and ECF morbidity and mortality risks were also highest in open-grazing strata. While different, all five AEZ-grazing strata were considered to be endemically unstable for ECF. East Coast fever challenge was low in all zero-grazing strata and this challenge is likely to remain low due to continuing intensification of smallholder farming in the central highlands. In the open-grazing strata, there was higher challenge and a greater impact of ECF. PMID:10813159

  3. The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: the effect of agro-ecological zone, grazing management and age of cattle.

    PubMed

    Rubaire-Akiiki, C; Okello-Onen, J; Nasinyama, G W; Vaarst, M; Kabagambe, E K; Mwayi, W; Musunga, D; Wandukwa, W

    2004-01-01

    Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60%) was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50%) were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified. PMID:15861224

  4. 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

  5. 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

  6. 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

  7. Bats initiate vital agroecological interactions in corn.

    PubMed

    Maine, Josiah J; Boyles, Justin G

    2015-10-01

    In agroecosystems worldwide, bats are voracious predators of crop pests and may provide services to farmers worth billions of U.S. dollars. However, such valuations make untested assumptions about the ecological effect of bats in agroecosystems. Specifically, estimates of the value of pest suppression services assume bats consume sufficient numbers of crop pests to affect impact pest reproduction and subsequent damage to crops. Corn is an essential crop for farmers, and is grown on more than 150 million hectares worldwide. Using large exclosures in corn fields, we show that bats exert sufficient pressure on crop pests to suppress larval densities and damage in this cosmopolitan crop. In addition, we show that bats suppress pest-associated fungal growth and mycotoxin in corn. We estimate the suppression of herbivory by insectivorous bats is worth more than 1 billion USD globally on this crop alone, and bats may further benefit farmers by indirectly suppressing pest-associated fungal growth and toxic compounds on corn. Bats face a variety of threats globally, but their relevance as predators of insects in ubiquitous corn-dominated landscapes underlines the economic and ecological importance of conserving biodiversity. PMID:26371304

  8. Agroecology of corn production in Tlaxcala, Mexico

    SciTech Connect

    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 more 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.

  9. Bats initiate vital agroecological interactions in corn

    PubMed Central

    Maine, Josiah J.; Boyles, Justin G.

    2015-01-01

    In agroecosystems worldwide, bats are voracious predators of crop pests and may provide services to farmers worth billions of U.S. dollars. However, such valuations make untested assumptions about the ecological effect of bats in agroecosystems. Specifically, estimates of the value of pest suppression services assume bats consume sufficient numbers of crop pests to affect impact pest reproduction and subsequent damage to crops. Corn is an essential crop for farmers, and is grown on more than 150 million hectares worldwide. Using large exclosures in corn fields, we show that bats exert sufficient pressure on crop pests to suppress larval densities and damage in this cosmopolitan crop. In addition, we show that bats suppress pest-associated fungal growth and mycotoxin in corn. We estimate the suppression of herbivory by insectivorous bats is worth more than 1 billion USD globally on this crop alone, and bats may further benefit farmers by indirectly suppressing pest-associated fungal growth and toxic compounds on corn. Bats face a variety of threats globally, but their relevance as predators of insects in ubiquitous corn-dominated landscapes underlines the economic and ecological importance of conserving biodiversity. PMID:26371304

  10. 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

  11. 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…

  12. 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. PMID:20697748

  13. 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. PMID:25326612

  14. Agroecology: Implications for plant response to climate change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  15. The risks associated with wastewater reuse and xenobiotics in the agroecological environment.

    PubMed

    Fatta-Kassinos, D; Kalavrouziotis, I K; Koukoulakis, P H; Vasquez, M I

    2011-09-01

    Treated wastewater reuse for irrigation, landscape and surface or groundwater replenishment purposes is being widely implemented. Although the reuse practice is accompanied by a number of benefits relating to the enhancement of water balances and soil nutrition by the nutrients existing in the treated effluents, a number of unanswered questions are still related to this practice. Besides the lack of knowledge in respect to possible elemental interactions that may influence the accumulation of heavy metals and other elements in the soil and the subsequent uptake by plants and crops, during the last several years, the technological progress in respect to analytical chromatographic methods has enabled the identification and quantitation of a number of organic xenobiotic compounds in treated wastewater. Therefore it is now known that the effluents' remaining organic matter most usually expressed as Chemical Oxygen Demand consists of a number of biorecalcitrant organic xenobiotic compounds including potential endocrine disrupting compounds (EDCs), pharmaceuticals, etc. It is also widely accepted that the currently applied treatment processes for urban wastewater abatement fail to completely remove such contaminants and this lead to their subsequent release in the terrestrial and aquatic environment through disposal and reuse applications. The number of studies focusing on the analysis and the toxicological assessment of such compounds in the environment is constantly increasing the aim being to bridge the various knowledge gaps associated with these issues. The existing knowledge in respect to the relevant existing legislation framework, the types of elements and chemicals of concern, the uptake of xenobiotic pollutants and also that of other neglected chemical elements along with their potential environmental interactions constitute the focus of the present review paper. The review addresses the problems that might be related to the repeated treated wastewater release in the environment for reuse applications in respect to the wastewater residual load in heavy metals, accumulating in soil and plants and especially in their edible parts, in xenobiotic compounds, including EDCs, pharmaceuticals and personal care products, drugs' metabolites, illicit drugs, transformation products, and also genes resistant to antibiotics. PMID:20435343

  16. 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 appealing…

  17. Genomic prediction models for grain yield of spring bread wheat in diverse agro-ecological zones

    PubMed Central

    Saint Pierre, C.; Burgueño, J.; Crossa, J.; Fuentes Dávila, G.; Figueroa López, P.; Solís Moya, E.; Ireta Moreno, J.; Hernández Muela, V. M.; Zamora Villa, V. M.; Vikram, P.; Mathews, K.; Sansaloni, C.; Sehgal, D.; Jarquin, D.; Wenzl, P.; Singh, Sukhwinder

    2016-01-01

    Genomic and pedigree predictions for grain yield and agronomic traits were carried out using high density molecular data on a set of 803 spring wheat lines that were evaluated in 5 sites characterized by several environmental co-variables. Seven statistical models were tested using two random cross-validations schemes. Two other prediction problems were studied, namely predicting the lines’ performance at one site with another (pairwise-site) and at untested sites (leave-one-site-out). Grain yield ranged from 3.7 to 9.0 t ha−1 across sites. The best predictability was observed when genotypic and pedigree data were included in the models and their interaction with sites and the environmental co-variables. The leave-one-site-out increased average prediction accuracy over pairwise-site for all the traits, specifically from 0.27 to 0.36 for grain yield. Days to anthesis, maturity, and plant height predictions had high heritability and gave the highest accuracy for prediction models. Genomic and pedigree models coupled with environmental co-variables gave high prediction accuracy due to high genetic correlation between sites. This study provides an example of model prediction considering climate data along-with genomic and pedigree information. Such comprehensive models can be used to achieve rapid enhancement of wheat yield enhancement in current and future climate change scenario. PMID:27311707

  18. 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…

  19. 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. PMID:24069068

  20. Agro-ecological drivers of rural out-migration to the Maya Biosphere Reserve, Guatemala

    NASA Astrophysics Data System (ADS)

    López-Carr, David

    2012-12-01

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

  1. [Diversity of Coccinellidae (Coleoptera) using aromatic plants (Apiaceae) as survival and reproduction sites in agroecological system].

    PubMed

    Lixa, Alice T; Campos, Juliana M; Resende, André L S; Silva, Joice C; Almeida, Maxwell M T B; Aguiar-Menezes, Elen L

    2010-01-01

    Studies show that Apiaceae may provide concentrated vital resources for predator insects, stimulating their abundance, diversity and persistence in agricultural systems, thereby increasing their efficiency as biological control agents. Among the predatory insects, Coccinellidae (Coleoptera) on many different species both as larvae and adults, complementing their diet with pollen and/or nectar. This study aimed to determine the diversity and relative abundance of Coccinellidae species visiting plants of Anethum graveolens (dill), Coriandrum sativum (coriander) and Foeniculum vulgare (sweet fennel) (all Apiaceae), particularly in their blooming seasons, and to evaluate the potential of these aromatic species for providing the resources for survivorship and reproduction of coccinelids. Coccinellids were collected by removal of samplings from September to October, 2007. Besides one unidentified species of Chilocorinae, five species of Coccinellinae were collected: Coleomegilla maculata DeGeer, Coleomegilla quadrifasciata (Schönherr), Cycloneda sanguinea (L.), Eriopis connexa (Germar) and Hippodamia convergens Guérin-Meneville. Dill provided a significant increase in the abundance of coccinellids as compared to coriander and sweet fennel. These aromatic species were used by coccinellids as survival and reproduction sites, providing food resources (pollen and/or prey), shelter for larvae, pupae and adults, and mating and oviposition sites as well. PMID:20676507

  2. Genomic prediction models for grain yield of spring bread wheat in diverse agro-ecological zones.

    PubMed

    Saint Pierre, C; Burgueño, J; Crossa, J; Fuentes Dávila, G; Figueroa López, P; Solís Moya, E; Ireta Moreno, J; Hernández Muela, V M; Zamora Villa, V M; Vikram, P; Mathews, K; Sansaloni, C; Sehgal, D; Jarquin, D; Wenzl, P; Singh, Sukhwinder

    2016-01-01

    Genomic and pedigree predictions for grain yield and agronomic traits were carried out using high density molecular data on a set of 803 spring wheat lines that were evaluated in 5 sites characterized by several environmental co-variables. Seven statistical models were tested using two random cross-validations schemes. Two other prediction problems were studied, namely predicting the lines' performance at one site with another (pairwise-site) and at untested sites (leave-one-site-out). Grain yield ranged from 3.7 to 9.0 t ha(-1) across sites. The best predictability was observed when genotypic and pedigree data were included in the models and their interaction with sites and the environmental co-variables. The leave-one-site-out increased average prediction accuracy over pairwise-site for all the traits, specifically from 0.27 to 0.36 for grain yield. Days to anthesis, maturity, and plant height predictions had high heritability and gave the highest accuracy for prediction models. Genomic and pedigree models coupled with environmental co-variables gave high prediction accuracy due to high genetic correlation between sites. This study provides an example of model prediction considering climate data along-with genomic and pedigree information. Such comprehensive models can be used to achieve rapid enhancement of wheat yield enhancement in current and future climate change scenario. PMID:27311707

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. Current knowledge and future research perspectives on cassava (Manihot esculenta Crantz) chemical defenses: An agroecological view.

    PubMed

    Pinto-Zevallos, Delia M; Pareja, Martín; Ambrogi, Bianca G

    2016-10-01

    Cassava (Manihot esculenta Crantz) is one of the most important staple crops worldwide. It constitutes the major source of carbohydrates for millions of low-income people living in rural areas, as well as a cash crop for smallholders in tropical and sub-tropical regions. The Food and Agriculture Organization of the United Nations predicts that cassava plantations will increase and production systems will intensify in the future, highlighting the need for developing strategies that improve the sustainability of production. Plant chemical defenses hold the potential for developing pest management strategies, as these plant traits can influence the behavior and performance of both pests and beneficial arthropods. Cassava plants are well-defended and produce a number of compounds involved in direct defense, such as cyanogenic glycosides, flavonoid glycosides, and hydroxycoumarins. In addition, volatile organic compounds induced upon herbivory and the secretion of extrafloral nectar act as indirect defense against herbivores by recruiting natural enemies. Here, cassava chemical defenses against pest arthropods are reviewed, with the aim of identifying gaps in our knowledge and areas of research that deserve further investigation for developing sound pest control strategies to improve sustainable production of this crop, and how these defenses can be used to benefit other crops. Cyanogenic content in cassava is also highly toxic to humans, and can cause irreversible health problems even at sub-lethal doses when consumed over prolonged periods. Therefore, the promotion of chemical defense in this crop should not aggravate these problems, and must be accompanied with the education on processing methods that reduce human exposure to cyanide. PMID:27316676

  5. Agroecological factors correlated to Rhizoctonia spp. in dryland wheat production zones of Washington state, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The necrotrophic soilborne fungal pathogens Rhizoctonia solani AG8 and R. oryzae are principal causal agents of Rhizoctonia root rot of wheat in dryland cropping systems of the Pacific Northwest (PNW). A three-year survey of 33 parcels at eleven growers’ sites and 22 plots at twelve Washington State...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Adaptation of the Training and Visit Extension System to Changing Socio-Cultural and Agro-Ecological Conditions.

    ERIC Educational Resources Information Center

    Blum, Abraham; Isaak, Michel

    1990-01-01

    A study examined adaptations made prior to or during the adoption of the Training and Visit (T&V) extension system. This system was developed in Turkey, based on the Israeli experience of the developer, and was further refined in India. It was later adopted by many countries in Southeast Asia, Africa, and other parts of the world. Experience…

  8. Diagnosis of heavy metal contamination in agro-ecology of Gujranwala, Pakistan using cattle egret (Bubulcus ibis) as bioindicator.

    PubMed

    Bostan, Nazish; Ashraf, Muhammad; Mumtaz, Abdul S; Ahmad, Iftikhar

    2007-03-01

    The present study investigated the status of heavy metals: Lead (Pb), Cadmium (Cd), Chromium (Cr), Cobolt (Co), Silver (Ag) and Nickle (Ni) residues in egg, regurgitate and sediment samples collected from two colonies of cattle egret (Bubulcus ibis) during the breeding seasons between April and August in 2004 and 2005. The mean concentration of heavy metals in eggs and regurgitates was found higher compared to the maximum residue limit (mrl) standards prescribed by Environmental Protection Agency (EPA). A further comparison was made with a similar study conducted in China. High concentrations of heavy metals have contributed to the altered breeding behaviour of the bird species studied. Based on these findings we suggested a regular monitoring of the spread of these pollutants as these have not yet reached to the sediments. PMID:17115270

  9. Agro-ecological modelling for monitoring rice productions: contribution of field experiment and multi-temporal EO data

    NASA Astrophysics Data System (ADS)

    Boschetti, M.; Confalonieri, R.; Stroppiana, D.; Bocchi, S.; Brivio, P. A.

    2005-10-01

    Crop growth and production can be simulated by models for the whole canopy as a function of intercepted radiation, water availability, air temperature and nitrogen availability. Simulation models supply quantitative outputs starting from quantitative inputs and they need quite complex databases to run simulations. In practice, the more complex and physically based these tools are, the more inputs are required for their application. In most cases such data are not available. This is the reason why, for large scale evaluations, simplified models are often applied and satellite data are used as input. In particular, multi-temporal Earth Observation data represent a valid tool to define crop phenological stages and derive temporal and spatial variability of vegetation biophysical parameters, such as the Leaf Area Index (LAI). In 2003 and 2004 two intensive field campaigns were conducted over different areas of the Italian Rice Belt, Northern Italy, with the objective of collecting data for growth model calibration. Field spectroradiometer measurements and LAI estimation, retrieved by LAI2000, have been used to study the best Vegetation Index (VI) for rice growth monitoring. VI vs LAI relationship has been scaled up to MODIS data to produce LAI map for the entire growing season and the key phenological rice events have been detected by multitemporal MODIS analysis. Preliminary results of rice production estimation using a Light Use efficiency model that ingests spatially distributed phenological information are presented. Comparison with CropSyst model phenological parameters are provided and the contribution of multi-temporal EO data for regional crop monitoring is discussed.

  10. 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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. 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.

  13. 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

  14. 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.…

  15. 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. PMID:22897885

  16. A comprehensive study to explore differences in mycotoxin patterns from agro-ecological regions through maize, peanut, and cassava products: a case study, Cameroon.

    PubMed

    Ediage, Emmanuel Njumbe; Hell, Kerstin; De Saeger, Sarah

    2014-05-21

    A total of 420 samples were collected from agrarian households. Whereas 51% (215/420) of the samples were contaminated with one or more toxins, the contamination rates for maize, peanut, and cassava products were 74, 62, and 24%, respectively. The fumonisins (20-5412 μg/kg), aflatoxin B1 (6-645 μg/kg), roquefortine C (1-181 μg/kg), and deoxynivalenol (27-3842 μg/kg) were the most prevalent contaminants in maize. For peanut samples, aflatoxin B1 (6-125 μg/kg) and ochratoxin A (0.3-12 μg/kg) were the main contaminants, whereas aflatoxin B1 (6-194 μg/kg) and penicillic acid (25-184 μg/kg) were detected in the cassava products. Exposures calculated through maize intake for fumonisin B1 and aflatoxin B1 were several-fold higher (2-5 for fumonisin B1 and 10(4)-10(5) for aflatoxin B1) than the health-based guidance values of 2 μg/kg bw/day and 0.15 ng/kg bw/day, respectively. The study design constitutes a good model that can be implemented in other sub-Saharan African countries. PMID:24796244

  17. 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

    2015-01-01

    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. PMID:26782461

  18. Effects of season and agro-ecological zone on the microbial quality of raw milk along the various levels of the value chain in Uganda.

    PubMed

    Grimaud, Patrice; Sserunjogi, Mohamed; Wesuta, Milton; Grillet, Nelly; Kato, Moses; Faye, Bernard

    2009-08-01

    Dairy production in Uganda is pasture-based and traditional Ankole cattle make up 80% of the cattle herd, reared in both pastoral and agro-pastoral ecological zones. Regardless of the zone, milk quality is lowest in production basin during the dry season when ambient temperatures are highest and water is scarce. Poor hygiene and quality management contributed to the deterioration of raw milk quality during its storage and delivery to the final consumer, and concealed the seasonal effect when milk reached urban consumption areas. Poor milk quality is a challenge for the Ugandan Dairy Development Authorities who wish to make the milk value chain safe. This study provides baseline information for the implementation of an HACCP-based system to ensure the hygienic quality of milk from the farm to the market place. PMID:19016339

  19. Species Composition, Distribution, and Seasonal Abundance of Liriomyza Leafminers (Diptera: Agromyzidae) Under Different Vegetable Production Systems and Agroecological Zones in Kenya.

    PubMed

    Foba, C N; Salifu, D; Lagat, Z O; Gitonga, L M; Akutse, K S; Fiaboe, K K M

    2015-04-01

    A longitudinal study to identify the species of Liriomyza leafminer, their distribution, relative abundance, and seasonal variation, including their host range, was conducted in vegetable fields at three altitudes in Kenya from November 2011 to November 2012. Three main species were identified: Liriomyza huidobrensis (Blanchard), Liriomyza sativae Blanchard, and Liriomyza trifolii (Burgess), of which L. huidobrensis was the most abundant across all altitudes irrespective of the cropping season and accounting for over 90% of the total Liriomyza specimens collected. Liriomyza species were collected from all infested incubated leaves of 20 crops surveyed belonging to seven families: Fabaceae, Solanaceae, Cucurbitaceae, Malvaceae, Brassicaceae, Amaranthaceae, and Amaryllidaceae. However, more than 87.5% of the Liriomyza species were obtained from only four of these crops: Pisum sativum L., Phaseolus vulgaris L., Solanum lycopersicum L., and Solanum tuberosum, thereby demonstrating that Fabaceae and Solonaceae crops are the most important hosts with regard to Liriomyza species richness and relative abundance. L. huidobrensis had the widest host range (20 crops), followed by L. sativae (18 crops) and L. trifolii (12 crops). Although L. trifolii has been considered the dominant Liriomyza leafminer in Kenya, this study suggests that this may not be the case anymore, as L. huidobrensis dominates at all altitudes. PMID:26313175

  20. 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. PMID:21669880

  1. Agro-ecological features of the introduction and spread of the highly pathogenic avian influenza (HPAI) H5N1 in northern Nigeria.

    PubMed

    Cecchi, Giuliano; Ilemobade, Albert; Le Brun, Yvon; Hogerwerf, Lenny; Slingenbergh, Jan

    2008-11-01

    Nigeria was the first African country to report highly pathogenic avian influenza (HPAI) H5N1 virus outbreaks in February 2006 and has since been the most severely hit country in sub-Saharan Africa. A retrospective survey carried out towards the end of 2007, coupled with follow-up spatial analysis, support the notion that the H5N1 virus may have spread from rural areas of northern Nigeria near wetlands frequented by palaearctic migratory birds. Possibly, this could have happened already during November to December 2005, one or two months prior to the first officially reported outbreak in a commercial poultry farm (Kaduna state). It is plausible that backyard poultry played a more important role in the H5N1 propagation than thought previously. Farming landscapes with significant numbers of domestic ducks may have helped to bridge the geographical and ecological gap between the waterfowl in the wetlands and the densely populated poultry rich states in north-central Nigeria, where the virus had more sizeable, visible impact. PMID:19021104

  2. Several problems on a rational structure for agricultural production and the agro-ecology of the Tai region of Tiangsu province

    SciTech Connect

    Ma Xiangyong

    1983-08-01

    This article presents a method of determining whether the output value structure, the soil structure, and the labor force structure are relatively balanced in an agricultural region of a Chinese province. Topics covered include several rational agricultural production structures for different types of soil, and several problems in setting up a rational agricultural production structure. A rational agricultural production structure is a consequence of the integrated development of farming, forestry, animal husbandry, sideline occupations, fisheries, and industry. The Tai Region has nine distinct types of soil. It is indicated that the level of grain production directly bears on the size and speed of development of economic diversification. Tables are presented on the output value structure of several representative communes and brigades, and soil nutrient content.

  3. Pacific Northwest (U.S.) In: Conversion to Sustainable Agriculture: Principles, Processes, and Practices. Stephen R. Gliessman, Martha Rosemeyer, and Sean Swezey (Editors). CRC Press Advances in Agroecology Series

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture represents a critical land use throughout the Pacific Northwest (PNW). It makes important contributions to the region’s economy, the nation’s food supply and to regional ecosystem services including air, water, and soil quality. As in many other regions of the U.S., adverse environmental...

  4. Estimating potential yield of wheat production in China based on cross-scale data-model fusion

    NASA Astrophysics Data System (ADS)

    Tian, Zhan; Zhong, Honglin; Shi, Runhe; Sun, Laixiang; Fischer, Günther; Liang, Zhuoran

    2012-12-01

    The response of the agro-ecological system to the environment includes the response of individual crop's physiologic process and the adaption of the crop community to the environment. Observation and simulation at the single scale level cannot fully explain the above process. It is necessary to develop cross-scale agro-ecological models and study the interaction of agro-ecological processes across different scales. In this research, two typical agroecological models, the Decision Support System for Agrotechnology Transfer (DSSAT) model and the Agroecological Zone (AEZ) model, are employed, and a framework for effective cross-scale data-model fusion is proposed and illustrated. The national observed data from 36 different agricultural observation stations and historical weather stations (1962-1999) are employed to estimate average crop productivity. Comparison of the two models' estimations are consistent, which would indicate the possibility ofcross-scale crop model fusion.

  5. 7 CFR 600.1 - General.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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, forestry, engineering, geology, hydrology, wetlands science, cultural resources, and economics. NRCS...

  6. 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, forestry, engineering, geology, hydrology, wetlands science, cultural resources, and economics. NRCS...

  7. Estimation of rhizome composition and overwintering ability in perennial Sorghum spp. using near-infrared spectroscopy (NIRS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperately-adapted perennial sorghum feedstocks have recently begun to receive increasing interest as candidate energy crops, producing significant biomass and contributing agroecological benefits including increased soil organic carbon, reduced soil erosion, reduced input requirements, and higher ...

  8. 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. PMID:24871266

  9. Wheat landraces: A mini review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Cotton and its interaction with cotton morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. PHOSPHORUS ACQUISITION AND USE: CRITICAL ADAPTATIONS BY PLANTS FOR SECURING A NONRENEWABLE RESOURCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The world is on the brink of a new agriculture, one that involves the marriage of plant biology and agroecology under the umbrella of biotechnology and germplasm improvement. Although P fertilizers will continue to play a major role in intensive agriculture, depletion of natural resources, loss of b...

  12. 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…

  13. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  15. Carbon, nutrient and energy budgets in the LTAR in Iowa: 10-year comparison

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Long-Term Agroecological Research (LTAR) site was established in 1998 on the Neely-Kinyon Research Farm near Greenfield, Iowa to evaluate agronomic and economic outcomes of certified organic and conventional grain-based cropping systems. The site was certified organic in 2000. This study evaluat...

  16. PREDICTING SPATIAL VARIATION OF CROP YIELD ACROSS A LANDSCAPE USING AGGREGATED ENVIRONMENTAL DATA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop yield variability is an important attribute of agroecological systems. For decision-makers to make informed choices, it is necessary to understand spatial distribution of yield variability across landscapes. Spatial patterns of yield variability are associated with underlying environmental vari...

  17. Bulk genetic characterization of Ghanaian maize landraces using microsatellite markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays) was first introduced into Ghana over 5 centuries ago and remains the most important cereal staple, grown in all agro-ecologies across the country. Yield from farmers’ fields are low, which is attributed in part to farmer’s preferences and/or reliance on local landraces for cultivati...

  18. Genetic diversity and structure of Phakopsora pachyrhizi infecting soybean in Nigeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  19. 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…

  20. Code modernization and modularization of APEX and SWAT watershed simulation models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 -...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  3. 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…

  4. Spatial Distribution of Soil Carbon in Pastures with Cow-Calf Operation: Effects of Slope Aspect and Slope Position

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The forests of the world have been the focus of most of the research on terrestrial C sequestration while other parts of the agro-ecological systems like pastures or grasslands have received less research attention. Broad knowledge of cattle movement in pasture situations is critical to understandin...

  5. Pathogenic variation of Phakopsora pachyrhizi in Nigeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean rust (Phakopsora pachyrhizi) is endemic to soybean growing areas in Nigeria. To determine the pathogenic variation, infected leaves were collected from 85 locations in the Derived Savanna, Southern Guinea Savanna, Northern Guinea Savanna and Mid-Altitude agroecological zones. A total of 116 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. 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…

  8. Soil Quality Change in Long-Term Organic Crop Rotations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Long-Term Agroecological Research (LTAR) site was established in 1998 on the Neely-Kinyon Research Farm near Greenfield, Iowa to evaluate agronomic and economic outcomes of certified organic and conventional grain-based cropping systems. The site was certified organic in 2000. This study evaluat...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. A global spectral library to characterize the world's soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. A global spectroscopic library to characterize the world's soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Assessment of Biomass Resources from Marginal Lands in APEC Economies

    SciTech Connect

    Milbrandt, A.; Overend, R. P.

    2009-08-01

    The goal of this study is to examine the marginal lands in Asia-Pacific Economic Cooperation (APEC) economies and evaluate their biomass productivity potential. Twelve categories of marginal lands are identified using the Global Agro-Ecological Zones system of the United Nations Food and Agriculture Organization.

  13. 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. PMID:21969578

  14. Investigating rural poverty and marginality in Burkina Faso using remote sensing-based products

    NASA Astrophysics Data System (ADS)

    Imran, M.; Stein, A.; Zurita-Milla, R.

    2014-02-01

    Poverty at the national and sub-national level is commonly mapped on the basis of household surveys. Typical poverty metrics like the head count index are not able to identify its underlaying factors, particularly in rural economies based on subsistence agriculture. This paper relates agro-ecological marginality identified from regional and global datasets including remote sensing products like the normalized difference vegetation index (NDVI) and rainfall to rural agricultural production and food consumption in Burkina Faso. The objective is to analyze poverty patterns and to generate a fine resolution poverty map at the national scale. We compose a new indicator from a range of welfare indicators quantified from Georeferenced household surveys, indicating a spatially varying set of welfare and poverty states of rural communities. Next, a local spatial regression is used to relate each welfare and poverty state to the agro-ecological marginality. Our results show strong spatial dependency of welfare and poverty states over agro-ecological marginality in heterogeneous regions, indicating that environmental factors affect living conditions in rural communities. The agro-ecological stress and related marginality vary locally between rural communities within each region. About 58% variance in the welfare indicator is explained by the factors of rural agricultural production and 42% is explained by the factor of food consumption. We found that the spatially explicit approach based on multi-temporal remote sensing products effectively summarizes information on poverty and facilitates further interpretation of the newly developed welfare indicator. The proposed method was validated with poverty incidence obtained from national surveys.

  15. Global food security: challenges and policies.

    PubMed

    Rosegrant, Mark W; Cline, Sarah A

    2003-12-12

    Global food security will remain a worldwide concern for the next 50 years and beyond. Recently, crop yield has fallen in many areas because of declining investments in research and infrastructure, as well as increasing water scarcity. Climate change and HIV/AIDS are also crucial factors affecting food security in many regions. Although agroecological approaches offer some promise for improving yields, food security in developing countries could be substantially improved by increased investment and policy reforms. PMID:14671289

  16. Productivity of Angora goats in the communal rangelands of Molimo-Nthuse area in Lesotho.

    PubMed

    Ng'ambi, J W; Norris, D; Matebesi, P A; Khitsane, L

    2006-01-01

    Production parameters were determined for kidding, offtake and mortality rates, and milk production and composition of Angora goats in two communal agro-ecological zones, Mountains and Lowlands, of Molimo-nthuse area in Lesotho. True incidence rates and risk rates as used in dynamic populations were used to calculate the different production parameters. A completely randomized design was used to compare the differences between the two agro-ecological zones. Angora goats in the two agro-ecological zones produced milk similarly (p > 0.05) in amounts and composition. There were no significant (p > 0.05) differences in annual kidding, mortality and offtake rates between Angora goats kept in the Lowlands and those in the Mountains. However, high mortality rates and mortality risk rates were observed in both zones. Thus, the risk rates that suckling Angora goats would die within their first 6 months after birth were 28% and 34% for the Mountains and Lowlands, respectively. It is suggested that future emphasis should be on reducing kid mortality through better herding of the goats and improvement of pre- and post-partum nutrition of the doe in this communal livestock farming system. PMID:17265776

  17. Local post-harvest practices associated with aflatoxin and fumonisin contamination of maize in three agro ecological zones of Tanzania.

    PubMed

    Kamala, Analice; Kimanya, Martin; Haesaert, Geert; Tiisekwa, Bendantuguka; Madege, Richard; Degraeve, Szanne; Cyprian, Cypriana; De Meulenaer, Bruno

    2016-01-01

    A survey was undertaken of a total of 120 farmers, 40 from each of the three studied agro-ecological zones of Tanzania, to determine local post-harvest management practices associated with aflatoxin (AF) and fumonisin (FB) contamination of maize. Data on practices (collected using a structured questionnaire) and maize samples were obtained from each of the 120 farmers. FB and AF contamination in the samples were analysed by HPLC. A total of 45% and 85% of maize samples were positive for AF and FB respectively, with levels ranging from 0.1 to 269 μg kg(-1) for AF and from 49 to 18 273 μg kg(-1) for FBs. Significant differences in contamination level were observed among the three agro-ecological zones. Farmers in the three agro-ecological zones practised similar practices in varying degrees. Drying, sorting and protecting maize against insect infestation are practices that showed significant association with AF or FB contamination of maize. Drying maize on mat/raised platform, sorting (damaged, discoloured and moulded grains) and application of synthetic insecticides during storage are practices that were associated with less contamination of maize with AF and FB. The results can be used to advise on effective post-harvest strategies for prevention of AF and FB contamination of maize in rural Tanzania. PMID:26795400

  18. Replacement of corn in the diet of broiler chickens using foxtail millet produced by 2 different cultivation strategies.

    PubMed

    Goodarzi Boroojeni, F; Samie, A H; Edriss, M A; Khorvash, M; Sadeghi, G; Van Kessel, A; Zentek, J

    2011-12-01

    Foxtail millet is well-suited to climatic conditions in semi-arid tropic regions where it is cultivated using both agro-ecologic and conventional cultivation practices. This study evaluated the nutritional value, digestibility, and physiological effects of agro-ecologic and conventionally cultivated foxtail millet in comparison with corn. Chemical and TME(n) analysis of foxtail millet cultivated conventionally and agro-ecologically indicated similar nutritional value. In total, 432 eight-day-old Ross 308 broiler chicks, using a 2 × 3 factorial arrangement, were randomly assigned to 4 replicate pens for each of 6 isonitrogenous and isoenergetic diets. Experimental diets were formulated by replacing corn with conventional or agro-ecologic millet at 3 levels (33, 66, or 100% of corn replacement). Body weight at 21 and 42 d of age was higher (P < 0.05) at 100% millet inclusion versus the lower inclusion levels. At 42 d of age, feed intake and feed conversion ratios were also improved (P < 0.05) at the 100% millet inclusion level. Similarly, the apparent ileal digestibility of CP increased (P < 0.05) for 100% millet diets. There were no differences in ileal digestibility of nutrients between millet growth conditions. Millet inclusion level significantly affected small intestinal morphology such that crypt depth was lowest (P < 0.05) in the 100% inclusion group for duodenum, jejunum, and ileum at 28 d of age, and for duodenum and ileum at 42 d of age. The villus crypt ratio was also highest (P < 0.05) in the 100% millet inclusion group for jejunum and ileum at 28 d of age, and duodenum, jejunum, and ileum at 42 d of age. Millet growth condition did not markedly affect small intestinal morphology. Serum antibody responses to Gumboro and Newcastle diseases were not affected by millet inclusion level or growth condition. In conclusion, foxtail millet could be considered as an alternate cereal for inclusion in the diet of broiler chickens. Broiler chicken performance and

  19. 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

  20. Biomass estimation to support pasture management in Niger

    NASA Astrophysics Data System (ADS)

    Schucknecht, A.; Meroni, M.; Kayitakire, F.; Rembold, F.; Boureima, A.

    2015-04-01

    Livestock plays a central economic role in Niger, but it is highly vulnerable due to the high inter-annual variability of rain and hence pasture production. This study aims to develop an approach for mapping pasture biomass production to support activities of the Niger Ministry of Livestock for effective pasture management. Our approach utilises the observed spatiotemporal variability of biomass production to build a predictive model based on ground and remote sensing data for the period 1998-2012. Measured biomass (63 sites) at the end of the growing season was used for the model parameterisation. The seasonal cumulative Fraction of Absorbed Photosynthetically Active Radiation (CFAPAR), calculated from 10-day image composites of SPOT-VEGETATION FAPAR, was computed as a phenology-tuned proxy of biomass production. A linear regression model was tested aggregating field data at different levels (global, department, agro-ecological zone, and intersection of agro-ecological and department units) and subjected to a cross validation (cv) by leaving one full year out. An increased complexity (i.e. spatial detail) of the model increased the estimation performances indicating the potential relevance of additional and spatially heterogeneous agro-ecological characteristics for the relationship between herbaceous biomass at the end of the season and CFAPAR. The model using the department aggregation yielded the best trade-off between model complexity and predictive power (R2 = 0.55, R2cv = 0.48). The proposed approach can be used to timely produce maps of estimated biomass at the end of the growing season before ground point measurements are made available.

  1. Agave biotechnology: an overview.

    PubMed

    Nava-Cruz, Naivy Y; Medina-Morales, Miguel A; Martinez, José L; Rodriguez, R; Aguilar, Cristóbal N

    2015-01-01

    Agaves are plants of importance both in Mexican culture and economy and in other Latin-American countries. Mexico is reported to be the place of Agave origin, where today, scientists are looking for different industrial applications without compromising its sustainability and preserving the environment. To make it possible, a deep knowledge of all aspects involved in production process, agro-ecological management and plant biochemistry and physiology is required. Agave biotechnology research has been focusing on bio-fuels, beverages, foods, fibers, saponins among others. In this review, we present the advances and challenges of Agave biotechnology. PMID:25058832

  2. 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.

  3. Stronger management needed to protect agricultural environment

    SciTech Connect

    Cai Shikui

    1983-01-01

    This article examines environmental issues and management in developed agricultural areas of China. Agricultural environmental management is defined as the adoption of countermeasures by applying the theories and methods of environmental science and management science and abiding by economic laws and ecological laws to prevent pollution of the agricultural environment and destruction of the agro-ecology by man; to coordinate the relationship between the development of agricultural production and the protection of the agricultural environment and to satisfy increasing demands for agricultural by-products. Topics considered include the basis for developing agricultural environmental management, the present condition of the agricultural environment in China, and several management proposals.

  4. Environmental distribution and genetic diversity of vegetative compatibility groups determine biocontrol strategies to mitigate aflatoxin contamination of maize by Aspergillus flavus.

    PubMed

    Atehnkeng, Joseph; Donner, Matthias; Ojiambo, Peter S; Ikotun, Babatunde; Augusto, Joao; Cotty, Peter J; Bandyopadhyay, Ranajit

    2016-01-01

    Maize infected by aflatoxin-producing Aspergillus flavus may become contaminated with aflatoxins, and as a result, threaten human health, food security and farmers' income in developing countries where maize is a staple. Environmental distribution and genetic diversity of A. flavus can influence the effectiveness of atoxigenic isolates in mitigating aflatoxin contamination. However, such information has not been used to facilitate selection and deployment of atoxigenic isolates. A total of 35 isolates of A. flavus isolated from maize samples collected from three agro-ecological zones of Nigeria were used in this study. Ecophysiological characteristics, distribution and genetic diversity of the isolates were determined to identify vegetative compatibility groups (VCGs). The generated data were used to inform selection and deployment of native atoxigenic isolates to mitigate aflatoxin contamination in maize. In co-inoculation with toxigenic isolates, atoxigenic isolates reduced aflatoxin contamination in grain by > 96%. A total of 25 VCGs were inferred from the collected isolates based on complementation tests involving nitrate non-utilizing (nit(-)) mutants. To determine genetic diversity and distribution of VCGs across agro-ecological zones, 832 nit(-) mutants from 52 locations in 11 administrative districts were paired with one self-complementary nitrate auxotroph tester-pair for each VCG. Atoxigenic VCGs accounted for 81.1% of the 153 positive complementations recorded. Genetic diversity of VCGs was highest in the derived savannah agro-ecological zone (H = 2.61) compared with the southern Guinea savannah (H = 1.90) and northern Guinea savannah (H = 0.94) zones. Genetic richness (H = 2.60) and evenness (E5  = 0.96) of VCGs were high across all agro-ecological zones. Ten VCGs (40%) had members restricted to the original location of isolation, whereas 15 VCGs (60%) had members located between the original source of isolation and a distance

  5. 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. PMID:24790810

  6. Sub-regional dimensions of agricultural and environmental nitrogen: the case of Asia.

    PubMed

    Syers, John Keith

    2005-09-01

    Asia embraces a wide range of cropping environments, largely related to the diversity of climate. To meet the high food requirements of a very large population (some 59% of the earth's total) large inputs of mineral N fertilizer are required (44.2 Tg N x yr(-1) in the mid 1990 s). However, because of the low (20%-50%) overall efficiency of use of fertilizer N, sometimes coupled with heavy use in intensively-farmed areas (for example in parts of China), losses of fertilizer N from agricultural land are expected to be high. Part of the N lost is thought to cause pollution of the atmosphere and water resources. A sub-regional approach, based on the FAO Agroecological Zone (AEZ) concept, has the potential to provide meaningful assessments of the agricultural and environmental dimensions of N. The AEZ concept can also provide the rationale for locating Sub-regional Centers of the International Nitrogen Initiative (INI) by basing the considerations, as far as practicable, on agroecological conditions. PMID:20549430

  7. Sub-regional dimensions of agricultural and environmental nitrogen: the case of Asia.

    PubMed

    Syers, John Keith

    2005-12-01

    Asia embraces a wide range of cropping environments, largely related to the diversity of climate. To meet the high food requirements of a very large population (some 59% of the earth's total) large inputs of mineral N fertilizer are required (44.2 Tg N x yr(-1) in the mid 1990s). However, because of the low (20%-50%) overall efficiency of use of fertilizer N, sometimes coupled with heavy use in intensively-farmed areas (for example in parts of China), losses of fertilizer N from agricultural land are expected to be high. Part of the N lost is thought to cause pollution of the atmosphere and water resources. A sub-regional approach, based on the FAO Agroecological Zone (AEZ) concept, has the potential to provide meaningful assessments of the agricultural and environmental dimensions of N. The AEZ concept can also provide the rationale for locating Sub-regional Centers of the International Nitrogen Initiative (INI) by basing the considerations, as far as practicable, on agroecological conditions. PMID:16512197

  8. First detection of Paenibacillus larvae the causative agent of American Foulbrood in a Ugandan honeybee colony.

    PubMed

    Chemurot, Moses; Brunain, Marleen; Akol, Anne M; Descamps, Tine; de Graaf, Dirk C

    2016-01-01

    Paenibacillus larvae is a highly contagious and often lethal widely distributed pathogen of honeybees, Apis mellifera but has not been reported in eastern Africa to date. We investigated the presence of P. larvae in the eastern and western highland agro-ecological zones of Uganda by collecting brood and honey samples from 67 honeybee colonies in two sampling occasions and cultivated them for P. larvae. Also, 8 honeys imported and locally retailed in Uganda were sampled and cultivated for P. larvae. Our aim was to establish the presence and distribution of P. larvae in honeybee populations in the two highland agro-ecological zones of Uganda and to determine if honeys that were locally retailed contained this lethal pathogen. One honeybee colony without clinical symptoms for P. larvae in an apiary located in a protected area of the western highlands of Uganda was found positive for P. larvae. The strain of this P. larvae was genotyped and found to be ERIC I. In order to compare its virulence with P. larvae reference strains, in vitro infection experiments were conducted with carniolan honeybee larvae from the research laboratory at Ghent University, Belgium. The results show that the virulence of the P. larvae strain found in Uganda was at least equally high. The epidemiological implication of the presence of P. larvae in a protected area is discussed. PMID:27468390

  9. 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

  10. 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.

  11. Study of gastro-intestinal helminths of scavenging chickens in four rural districts of Amhara region, Ethiopia.

    PubMed

    Eshetu, Y; Mulualem, E; Ibrahim, H; Berhanu, A; Aberra, K

    2001-12-01

    A total of 267 rural scavenging chickens were examined from October 1998 to August 1999 in four woredas (districts) of the Amhara Region, Ethiopia. Of these chickens, 243 (91.01%) were found to harbour one to nine different helminth parasites and 24 (8.99%) were free of helminth parasites. A significant difference (P < 0.01) was found between the prevalence rates of helminth parasites in the different agro-ecological zones; the highest prevalence was observed in the lowland areas. This suggests that agro-ecology has a major influence on the distribution of helminth parasites. Nematodes recovered included Heterakis gallinarum (17.28%), Subulura brumpti (17.60%), Ascaridia galli (35.58%), Cheilospirura hamulosa (0.75%) and Dyspharynx spiralis (2.62%). The principal cestode species encountered were Raillietina echinobothrida (25.84%), Raillietina tetragona (45.69%), Raillietina cesticillus (5.62%), Amoebotaenia sphenoides (40.45%), Davainea proglottina (1.12%) and Choanotaenia infundibulum (4.49%). PMID:11732422

  12. 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.

  13. 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

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

    PubMed Central

    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. PMID:26175463

  15. Nutritional values of available ruminant feed resources in smallholder dairy farms in Rwanda.

    PubMed

    Mutimura, Mupenzi; Ebong, Cyprian; Rao, Idupulapati Madhusudana; Nsahlai, Ignatius Verla

    2015-08-01

    Smallholder dairy farmers in Rwanda use diversity of resources to cope with endemic feed shortages. However, there is inadequate real farm data to support farmer decisions on choices of options. The main objective of this study was to evaluate nutritional quality of feed types that farmers use in different agro-ecological zones of Rwanda. Samples of feed types were collected from 90 randomly selected households in the low- and mid-high-altitude zones of Rwanda and analysed for proximate composition, contents of metabolisable energy (ME), organic matter digestibility (OMD) and neutral detergent fibre digestibility (NDFd). Rumen fermentation characteristics and efficiency of energy utilisation were examined by determining partitioning factor (PF). Results showed that only five out of 24 feed types were common in both districts. Chemical composition, OMD, ME, NDFd and PF of these feed types differed significantly (P < 0.05) in their nutritional attributes. This suggests that a common feed composition table can be used as a component of the decision support tool for rational feed resource development and utilisation in the smallholder farms in the selected agro-ecologies of Rwanda. PMID:25921293

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

    DOE PAGESBeta

    Preston, Benjamin L.; King, Anthony Wayne; Mei, Rui; Nair, Sujithkumar Surendran

    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

  17. 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. PMID:25958175

  18. 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. PMID:22436287

  19. 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

  20. A geographic information system on the potential distribution and abundance of Fasciola hepatica and F. gigantica in east Africa based on Food and Agriculture Organization databases.

    PubMed

    Malone, J B; Gommes, R; Hansen, J; Yilma, J M; Slingenberg, J; Snijders, F; Nachtergaele, F; Ataman, E

    1998-07-31

    An adaptation of a previously developed climate forecast computer model and digital agroecologic database resources available from FAO for developing countries were used to develop a geographic information system risk assessment model for fasciolosis in East Africa, a region where both F. hepatica and F. gigantica occur as a cause of major economic losses in livestock. Regional F. hepatica and F. gigantica forecast index maps were created. Results were compared to environmental data parameters, known life cycle micro-environment requirements and to available Fasciola prevalence survey data and distribution patterns reported in the literature for each species (F. hepatica above 1200 m elevation, F. gigantica below 1800 m, both at 1200-1800 m). The greatest risk, for both species, occurred in areas of extended high annual rainfall associated with high soil moisture and surplus water, with risk diminishing in areas of shorter wet season and/or lower temperatures. Arid areas were generally unsuitable (except where irrigation, water bodies or floods occur) due to soil moisture deficit and/or, in the case of F. hepatica, high average annual mean temperature >23 degrees C. Regions in the highlands of Ethiopia and Kenya were identified as unsuitable for F. gigantica due to inadequate thermal regime, below the 600 growing degree days required for completion of the life cycle in a single year. The combined forecast index (F. hepatica+F. gigantica) was significantly correlated to prevalence data available for 260 of the 1220 agroecologic crop production system zones (CPSZ) and to average monthly normalized difference vegetation index (NDVI) values derived from the advanced very high resolution radiometer (AVHRR) sensor on board the NOAA polar-orbiting satellites. For use in Fasciola control programs, results indicate that monthly forecast parameters, developed in a GIS with digital agroecologic zone databases and monthly climate databases, can be used to define the

  1. 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

  2. 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. PMID:23201602

  3. A multivariate analysis for evaluating the environmental and economical aspects of agroecosystem sustainability in central Italy.

    PubMed

    Di Felice, Vincenzo; Mancinelli, Roberto; Proulx, Raphaël; Campiglia, Enio

    2012-05-15

    Over the past century farming activity has intensified worldwide, characterized by an increasing dependence on external inputs and on land conversion. Although the intensification of agriculture has increased productivity, the sustainability of agroecosystems has also been compromised. The objective of this study is to build multivariate relationships between farm structural characteristics and farm performance to highlight the relative costs and benefits of four main farming systems in Central Italy: organic, conventional, mixed and non-mixed farms. Results show that the relationship between cropping diversity and agroecological sustainability is associated to a mixed versus non-mixed farm management dichotomy, not to organic or conventional farming practices. The presence of livestock appears to have played an important role as an economic lever for diversifying the farm cropping system. PMID:22265812

  4. Survival of phosphate-solubilizing bacteria against DNA damaging agents.

    PubMed

    Shrivastava, Manoj; Rajpurohit, Yogendra S; Misra, Hari S; D'Souza, S F

    2010-10-01

    Phosphate-solubilizing bacteria (PSBs) were isolated from different plant rhizosphere soils of various agroecological regions of India. These isolates showed synthesis of pyrroloquinoline quinone (PQQ), production of gluconic acid, and release of phosphorus from insoluble tricalcium phosphate. The bacterial isolates synthesizing PQQ also showed higher tolerance to ultraviolet C radiation and mitomycin C as compared to Escherichia coli but were less tolerant than Deinococcus radiodurans. Unlike E. coli, PSB isolates showed higher tolerance to DNA damage when grown in the absence of inorganic phosphate. Higher tolerance to ultraviolet C radiation and oxidative stress in these PSBs grown under PQQ synthesis inducible conditions, namely phosphate starvation, might suggest the possible additional role of this redox cofactor in the survival of these isolates under extreme abiotic stress conditions. PMID:20962905

  5. Blowback: new formal perspectives on agriculturally driven pathogen evolution and spread.

    PubMed

    Wallace, R; Wallace, R G

    2015-07-01

    By their diversity in time, space, and mode, traditional and conservation agricultures can create barriers limiting pathogen evolution and spread analogous to a sterilizing temperature. Large-scale monocropping and confined animal feeding-lot operations remove such barriers, resulting, above agroecologically specific thresholds, in the development and wide propagation of novel disease strains. We apply a newly developed class of necessary-conditions statistical models of evolutionary process, first using the theory on an evolutionarily stable viral pathogen vulnerable to vaccine treatment: post-World War II poliomyelitis emerged in the UK and USA from sudden widespread adoption of automobile ownership and usage. We then examine an evolutionarily variable pathogen, swine influenza in North America. The model suggests epidemiological blowback from globalizing intensive husbandry and the raising and shipping of monoculture livestock across increasing expanses, is likely to be far more consequential, driving viral selection for greater virulence and lowered response to biomedical intervention. PMID:26050716

  6. 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. PMID:26121947

  7. 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

  8. 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. PMID:24555109

  9. 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. PMID:26221807

  10. Perception of volcanic eruption as agent of change on Merapi volcano, Central Java

    NASA Astrophysics Data System (ADS)

    Dove, Michael R.

    2008-05-01

    Events like volcanic eruptions challenge equilibrium models of nature. This is a study of the perceptions of eruptions as agents of change, taking Mt. Merapi in Central Java as a case study. Villagers living on Merapi have developed a system of religious belief, and a system of agro-ecological practices, that 'domesticates' the volcanic hazard. The villagers view eruptions as agents of change, often change for the good. The Indonesian government, on the other hand, technologizes and exoticizes the volcanic hazard, and conceptually and materially separates it from the realm of civil society. The state focuses its attention exclusively on intermittent moments of heightened volcanic activity, whereas the villagers focus their attention on the much longer interim periods when there is little or no such activity. This case study shows that not just the perception of risk, but the very concept of risk itself can vary. The cultural production of such concepts co-evolves with natural patterns of perturbation.

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

    PubMed

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

    2015-06-01

    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. PMID:25955310

  12. 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. PMID:26221795

  13. 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

  14. Amino acid profiles and digestible indispensable amino acid scores of proteins from the prioritized key foods in Bangladesh.

    PubMed

    Shaheen, Nazma; Islam, Saiful; Munmun, Sarah; Mohiduzzaman, Md; Longvah, Thingnganing

    2016-12-15

    Concentrations of standard amino acids were determined in the composite samples (representing 30 agro-ecological zones of Bangladesh) of six prioritized key dietary protein sources: Oryza sativa (rice), Triticum aestivum (wheat flour), Lens culinaris (lentils), Pangusius pangusius (pangas), Labeo rohita (rohu) and Oreochromis mossambicus (tilapia). Digestible indispensable amino acid scores (DIAAS) was calculated using published data on amino acids' digestibility to evaluate the protein quality of these foods. Indispensable amino acid (IAA) contents (mg IAA/g protein), found to be highest in pangas (430) and lowest in wheat (336), of all these analyzed foods exceeded the FAO recommended daily allowance (277mg IAA/g protein) and contributed on average 40% to total amino acid contents. Untruncated DIAAS values ranged from 51% (lysine) in wheat to 106% (histidine) in pangas and distinguished pangas, rohu, and tilapia containing 'excellent quality' protein (DIAAS>100%) with potential to complement lower quality protein of cereals, fruits, and vegetables. PMID:27451158

  15. Induced Resistance in Solanum lycopersicum by Algal Elicitor Extracted from Sargassum fusiforme

    PubMed Central

    Sbaihat, Layth; Takeyama, Keiko; Koga, Takeharu; Takemoto, Daigo; Kawakita, Kazuhito

    2015-01-01

    Tomato (Solanum lycopersicum) production relies heavily on the use of chemical pesticides, which is undesired by health- and environment-concerned consumers. Environment-friendly methods of controlling tomato diseases include agroecological practices, organic fungicides, and biological control. Plants' resistance against pathogens is induced by applying agents called elicitors to the plants and would lead to disease prevention or reduced severity. We investigated the ability of a novel elicitor extracted from the brown sea algae (Sargassum fusiforme) to elicit induced resistance in tomato. The studied elicitor induced hypersensitive cell death and O2− production in tomato tissues. It significantly reduced severities of late blight, grey mold, and powdery mildew of tomato. Taken together, our novel elicitor has not shown any direct antifungal activity against the studied pathogens, concluding that it is an elicitor of induced resistance. PMID:25802893

  16. Reduction Potato s hydric soil erosion using space technology

    NASA Astrophysics Data System (ADS)

    Guyot, E.; Rios, V.; Zelaya, D.; Rios, E.; Lepen, F.; Padilla, P.; Soria, F.

    The potato's crop has an econ omic importance in Tucuman's agricultural PBI (Gross Product Income) because its rank is fourth(4°). Production's potato area is a breakable agro system; its geographic location is in Pedemonte's agro-ecological region so is essential to handle hydric erosion. Therefore, the aim of this work is improve crop's potato irrigation management through satellite information merge with farm's practices. The space technology consented to obtain Digital Model Soil using both unique differential and dual frequency GPS signals and total station. The irrigation practices were carried out due to irrigation management (FAO) and satellite imagine software (ENVI). Preliminary results of this experience allowed to follow the crop's growing through multitemporal study; reprogramming farm's irrigation practices intended for manage reduction hydric erosion and heighten economically its productivity for the next period

  17. 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. PMID:25813508

  18. Analyses of Twelve New Whole Genome Sequences of Cassava Brown Streak Viruses and Ugandan Cassava Brown Streak Viruses from East Africa: Diversity, Supercomputing and Evidence for Further Speciation.

    PubMed

    Ndunguru, Joseph; Sseruwagi, Peter; Tairo, Fred; Stomeo, Francesca; Maina, Solomon; Djikeng, Appolinaire; Djinkeng, Appolinaire; Kehoe, Monica; Boykin, Laura M

    2015-01-01

    Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are frequently found infecting cassava, one of sub-Saharan Africa's most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families without their primary food source, for an entire year. Twelve new whole genomes, including seven of CBSV and five of UCBSV were uncovered in this research, doubling the genomic sequences available in the public domain for these viruses. These new sequences disprove the assumption that the viruses are limited by agro-ecological zones, show that current diagnostic primers are insufficient to provide confident diagnosis of these viruses and give rise to the possibility that there may be as many as four distinct species of virus. Utilizing NGS sequencing technologies and proper phylogenetic practices will rapidly increase the solution to sustainable cassava production. PMID:26439260

  19. Analyses of Twelve New Whole Genome Sequences of Cassava Brown Streak Viruses and Ugandan Cassava Brown Streak Viruses from East Africa: Diversity, Supercomputing and Evidence for Further Speciation

    PubMed Central

    Ndunguru, Joseph; Sseruwagi, Peter; Tairo, Fred; Stomeo, Francesca; Maina, Solomon; Djinkeng, Appolinaire; Kehoe, Monica; Boykin, Laura M.

    2015-01-01

    Cassava brown streak disease is caused by two devastating viruses, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are frequently found infecting cassava, one of sub-Saharan Africa’s most important staple food crops. Each year these viruses cause losses of up to $100 million USD and can leave entire families without their primary food source, for an entire year. Twelve new whole genomes, including seven of CBSV and five of UCBSV were uncovered in this research, doubling the genomic sequences available in the public domain for these viruses. These new sequences disprove the assumption that the viruses are limited by agro-ecological zones, show that current diagnostic primers are insufficient to provide confident diagnosis of these viruses and give rise to the possibility that there may be as many as four distinct species of virus. Utilizing NGS sequencing technologies and proper phylogenetic practices will rapidly increase the solution to sustainable cassava production. PMID:26439260

  20. 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. PMID:12781758

  1. The African Millennium Villages

    PubMed Central

    Sanchez, Pedro; Palm, Cheryl; Sachs, Jeffrey; Denning, Glenn; Flor, Rafael; Harawa, Rebbie; Jama, Bashir; Kiflemariam, Tsegazeab; Konecky, Bronwen; Kozar, Raffaela; Lelerai, Eliud; Malik, Alia; Modi, Vijay; Mutuo, Patrick; Niang, Amadou; Okoth, Herine; Place, Frank; Sachs, Sonia Ehrlich; Said, Amir; Siriri, David; Teklehaimanot, Awash; Wang, Karen; Wangila, Justine; Zamba, Colleen

    2007-01-01

    We describe the concept, strategy, and initial results of the Millennium Villages Project and implications regarding sustainability and scalability. Our underlying hypothesis is that the interacting crises of agriculture, health, and infrastructure in rural Africa can be overcome through targeted public-sector investments to raise rural productivity and, thereby, to increased private-sector saving and investments. This is carried out by empowering impoverished communities with science-based interventions. Seventy-eight Millennium Villages have been initiated in 12 sites in 10 African countries, each representing a major agroecological zone. In early results, the research villages in Kenya, Ethiopia, and Malawi have reduced malaria prevalence, met caloric requirements, generated crop surpluses, enabled school feeding programs, and provided cash earnings for farm families. PMID:17942701

  2. Mange mite infestation in small ruminants in Ethiopia: Systematic review and meta-analysis.

    PubMed

    Asmare, Kassahun; Abebe, Rahmeto; Sheferaw, Desie; Krontveit, Randi I; Barbara, Wieland

    2016-03-15

    Mange mites are economically important ectoparasites of sheep and goats responsible for rejection or downgrading of skins in tanneries or leather industries in Ethiopia. The objective of this systematic review was to compute the pooled prevalence estimate and identify factors influencing mange mite prevalence in sheep and goats at national level based on the available research evidence. Articles on mange mite infestation of small ruminants in Ethiopia were searched in PubMed, Web of Science, Google scholar and African journals on-line. The review was based on 18 cross-sectional studies carried out between 2003 and 2015 in four administrative states of Ethiopia. Accordingly, the pooled prevalence estimate in a random effects meta-analysis was estimated to be 4.4% (95% CI 3.0, 6.3) although there were evidence of a substantial amount of between-study variance (I(2)=98.4%). In subgroup and multivariable meta-regression analyses, animal species, agro-ecology and administrative state were found to have significant effect on the prevalence estimate (P<0.05) and explained 32.87% of the explainable proportion of the heterogeneity noted between studies The prevalence was found to be higher in goats in lowland agro-ecology. Region wise the highest estimate was calculated for Amhara (6.4%) followed by Oromia (4.7%), Tigray (3.6%) and Southern Nations, Nationalities and People Region (SNNPR) (3.1%). Significant difference was noted between Amhara and SNNPR. The study further revealed that mites of the genus Sarcoptes, Demodex and Psoroptes are the most prevalent mites infesting small ruminants in Ethiopia. Valid studies were lacking from five regional states. As some of these regions are known for their large small ruminant population, further studies are warranted to produce better picture of the infestation at a national level. Meanwhile, the need for monitoring the ongoing control intervention is suggested. PMID:26872931

  3. 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.

  4. 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.

  5. 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

    2016-01-01

    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. PMID:27608505

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

    PubMed

    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. PMID:26092049

  7. 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

  8. 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.

  9. Serological survey of African horse sickness in selected districts of Jimma zone, Southwestern Ethiopia.

    PubMed

    Bitew, Molalegne; Andargie, Ashenafi; Bekele, Mihreteab; Jenberie, Shiferaw; Ayelet, Gelagay; Gelaye, Esayas

    2011-12-01

    A cross-sectional serological survey was undertaken in selected districts of different agro-ecology of Jimma zone (Dedo, Yebu, Seka, Serbo, and Jimma town) from November 2009 to February 2010 to determine the seroprevalence of African horse sickness virus and associated risk factors of the disease. Two hundred seventy-four equids (189 horses, 43 mules, and 47 donkeys) with a history of non-vaccination for at least 2 years were selected randomly from the above areas. Sera samples were collected and assayed for the presence of specific antibody against African horse sickness virus using blocking ELISA. An overall seroprevalence of 89 (32.5%) was found and it was 24 (51.1%) for donkeys, 13 (30.2%) for mules, and 52(28.3%) for horses. Seroprevalence was significantly (X(2) = 11.05, P < 0.05) different among the different species of equids. Seroprevalence was also significantly (X(2) = 11.43, P < 0.05) different among the different agro-ecological areas being higher in highlands 47 (40.5%) followed by midland 30 (34.5%) and lowland 12 (16.9%). Age and sex were not significantly (X(2) = 3.15, P > 0.05 and X(2) = 3.38, P > 0.05, respectively) associated with seroprevalence of AHSV. The present study showed that African horse sickness (AHS) is highly prevalent disease for the horses followed by mules and then donkeys in Jimma zone explained by lower seroconversion rate. Therefore, control strategy against AHS should target at high risk species of all age and sex in their locality in the initial stage for better containment of the disease. PMID:21465102

  10. 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. PMID:19937381

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

    PubMed

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

    2005-11-29

    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' X 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

  12. Eco-epidemiology of visceral leishmaniasis in Ethiopia.

    PubMed

    Gadisa, Endalamaw; Tsegaw, Teshome; Abera, Adugna; Elnaiem, Dia-Eldin; den Boer, Margriet; Aseffa, Abraham; Jorge, Alvar

    2015-01-01

    Visceral leishmaniasis (VL, Kala-azar) is one of the growing public health challenges in Ethiopia with over 3.2 million people at risk and estimated up to 4000 new cases per year. Historically, VL was known as the diseases of the lowlanders; in the lower and upper Kola agro-ecological zones of Ethiopia. The 2005-07 out breaks in highlands of Libo Kemkem and Fogera, in the Woina Degas, that affected thousands and claimed the life of hundreds misdiagnosed as drug resistance malaria marked that VL is no more the problem of the lowlanders. The Kola (lower and upper) and the Woina Dega are the most productive agroecological zones, supporting both the ongoing and planned expansions of large or small scale agriculture and/or agriculture based industries. Thus, the (re)emergence of VL is not only a public health and social problem but also have a direct implication on the country's economy and further development. Thus is high time for its control and/or elimination. Yet, the available data seem incomplete to plan for a cost-effective and efficient VL control strategy: there is a need to update data on vector behaviour in specific ecosystems and the roles of domestic animals need to be ascertained. The effectiveness and social acceptability of available vector control tools need be evaluated. There is a need for identifying animal reservoir(s), or establish the absence of zoonosis in Ethiopia. The planning of prevention of (re)emergence and spread of VL to areas adjacent to endemic foci need be supported with information from spatio-temporal mapping. In affected communities, available data showed that their knowledge about VL is generally very low. Thus, well designed studies to identify risk factors, as well as better tools for social mobilization with the understanding of their knowledge, aptitude and practice towards VL are necessary. PMID:26187584

  13. 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

  14. 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

  15. Impact of farm level adaptation to climate change on agricultural productivity and farmers' wellbeing: Empirical evidence from Pakistan

    NASA Astrophysics Data System (ADS)

    Abid, Muhammad; Scheffran, Jürgen

    2016-04-01

    Climate change is projected to adversely affect the agricultural sector and attached rural livelihoods, particularly in the developing countries. Hence adaptation to climate change is crucial to support agricultural productivity and rural livelihoods. The current study is based on comprehensive cross sectional data collected through 450 face-to-face interviews with farmers from three agro-ecological zones of Punjab province, Pakistan. This paper aims to examine the factors that influence the farmers' adaptation decisions and to assess the impact of farm level adaptation on crop productivity and farmers' wellbeing. The paper uses correlation analysis, binary logistic regression and propensity score matching techniques in order to explore the study objectives. The results of the study indicate that education, age, land holdings, farmer-to-farmer interaction, access to weather forecasting information and location in agro-ecological zone does have significant impact on farmers' decision to adapt to climate change. Major adaptation measures adopted by farmers were changing planting dates, changing cropping varieties, planting shaded trees and changing input-mix. Moreover the study found a positive and significant impact of adaptation on productivity of all major crops (wheat, sugarcane, maize and rice) and on farmers' wellbeing in term of farm income. Furthermore, the study also found that the extent of adaptation benefits increases with the number of adaptation measures. The findings of the study suggest to focus on farmers' education and easy access to climate-specific information for better adaptation at farm level and improved farm wellbeing. Key words: Climate change; Farm level adaptation; crop productivity; farmers' wellbeing; Pakistan

  16. 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

  17. 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. PMID:26464048

  18. Mycotoxigenic fungi and mycotoxins associated with stored maize from different regions of Lesotho.

    PubMed

    Mohale, Sejakhosi; Medina, Angel; Rodríguez, Alicia; Sulyok, Michael; Magan, Naresh

    2013-11-01

    Samples of stored maize from villages located in five different agroecological zones (southern lowlands, northern lowlands, Senqu river valley, foothills and mountains) of Lesotho were collected in 2009/10 and 2010/11 and assessed for contamination with toxigenic fungi. The water activity of all samples collected during the two seasons was <0.70. The total fungal populations of the maize from different regions in the two seasons was not significantly different (p > 0.05). Fusarium verticillioides, F. proliferatum and F. subglutinans predominated in different regions in both seasons based on molecular analyses. In the 2009/10 season, the isolates of these species all produced FB1, while in the 2010/11 season, very few produced FB1. A. flavus isolates (2009/10) were recovered from mountains and Senqu river valley samples while the 2010/11 isolates were predominantly from the foothills and northern lowlands. The mountain isolates of Aspergillus section Flavi produced the highest levels of AFB1 (20 mg kg(-1)). Aspergillus parasiticus was only isolated from the foothills, Senqu river valley and southern lowlands samples, and the AFB1 levels produced ranged from 'none detected' to 3.5 mg kg(-1). The Aspergillus ochraceous isolates were least frequently encountered in both seasons. In the 2009/10 season, the isolates from the northern lowlands produced ochratoxin A (OTA) in culture. No isolates of A. niger from different regions in both seasons produced any OTA. Multi-mycotoxin analyses of the maize samples were done for a range of mycotoxins. At least one sample from each region in both seasons was FB1-positive. FB1 levels for 2010/11 samples (7-936 μg kg(-1)) were higher than in the 2009/10 season (2-3 μg kg(-1)). In both seasons, the mountains registered the highest levels of FB1. Deoxynivalenol (DON) was recovered from all the samples analysed, with the highest mean contamination of 1,469 μg kg(-1) in samples from the northern lowlands. Moniliformin

  19. 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

  20. 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

  1. 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

  2. Impact of climate change and adaptation strategies on crop production in Nigeria

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    The vulnerability of agricultural to climate change is of particular interest to policy makers because the high social and economical importance of agriculture sector in Nigeria, which contributes approximately 40 percent to total GDP and support 70 percent of the population. It is necessary to investigate the potential climate change impacts in order to identify specific agricultural sectors and Agro-Ecological Zones that will be more vulnerable to changes in climatic conditions and implement and develop the most appropriate policies to cope with these changes. In this framework, this study aimed to assess the climate change impacts on Nigerian agricultural sector and to explore some of potential adaptation strategies for the most important crops in the food basket of the Country. The analysis was made using the DSSAT-CSM (Decision Support System for Agrotechnology Transfer - Cropping System Model) software, version 4.5. Crop simulation models included in DSSAT are tools that allows to simulate physiological process of crop growth, development and production, by combining genetic crop characteristics and environmental (soil and weather) conditions. In this analysis, for each selected crop, the models included into DSSAT-CSM software were ran, after a calibration phase, to evaluate climate change impacts on crop production. The climate data used for the analysis are derived by the Regional Circulation Model COSMO-CLM, from 1971 to 2065, at 8 km of spatial resolution. The RCM model output were "perturbed" with 10 Global Climate Models in order to have a wide variety of possible climate projections for impact analysis. Multiple combinations of soils and climate conditions, crop management and varieties were considered for each Agro-Ecological Zone of Nigeria. The climate impact assessment was made by comparing the yield obtained with the climate data for the present period and the yield obtainable under future changed climate conditions. The models ran by keeping

  3. Identifying crop specific signals for global agricultural monitoring based on the stability of daily multi-angular MODIS reflectance time series

    NASA Astrophysics Data System (ADS)

    Duveiller, G.; Lopez-Lozano, R.

    2013-12-01

    Global agricultural monitoring requires satellite Earth Observation systems that maximize the observation revisit frequency over the largest possible geographical coverage. Such compromise has thus far resulted in using a spatial resolution that is often coarser than desired. As a consequence, for many agricultural landscapes across the world, crop status can only be inferred from a mixed signal of the landscape (with a pixel size typically close to 1 km), composed of reflectance from neighbouring fields with potentially different crops, variable phenological behaviours and distinct management practices. MODIS has been providing, since 2000, a higher spatial resolution (~250m) that is closer to the size of individual fields in many agro-ecological landscapes. However, the challenge for operational crop specific monitoring remains to identify in time where a given crop has been sown during the current growing season. An innovative use of MODIS daily data is proposed for crop identification based on the stability of the multi-angular signal. MODIS is a whiskbroom sensor with a large swath. For any given place, consecutive MODIS observations are made with considerably different viewing angles according to the daily change in orbit. Consequently, the footprint of the observation varies considerably, thereby sampling the vicinity around the centre of the grid cell in which the time series is ultimately recorded in. If the consecutive observations that have sampled the vicinity provide similar NDVI values (for which BRDF effects are reduced), the resulting temporal signal is relatively stable. This stability indicated that the signal comes from a spatially homogeneous surface, such as a single large field covered by the same crop with similar agro-management practices. If the resulting temporal signal is noisy, it is probable that the consecutive daily observations have sampled different land uses, thus contaminating the signal. Such time series can therefore be

  4. 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

  5. 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

  6. Sero-positivity and associated risk factors for contagious bovine pleuropneumonia under two cattle production systems in North Central Nigeria.

    PubMed

    Alhaji, Nma Bida; Babalobi, Olutayo Olajide

    2016-02-01

    A cross-sectional survey of 765 cattle in 125 nomadic and 375 cattle in 125 sedentary herds was conducted to investigate prevalence and risk factors for contagious bovine pleuropneumonia (CBPP) in the two production systems of Niger State in North Central Nigeria, between January and August 2013. Data on herd characteristics were collected using structured questionnaires administered on herd owners. Serological analysis was conducted using competitive enzyme linked immunosorbent assay (c-ELISA) test. Descriptive, univariate, and multivariate statistical analyses were conducted with OpenEpi version 2.3.1 software. Statistical significance was held at P < 0.05. CBPP sero-prevalence in nomadic cattle was 16.2 % (confidence interval (CI) 13.7-19.0) and 9.6 % (CI 6.9-12.9) in sedentary cattle. The overall cattle-level sero-prevalence for two the cattle production systems was 14.0 % (CI 12.1-16.1). Age and agro-ecological zones were significantly (P < 0.001 and P < 0.001, respectively) associated with sero-positivity to Mmm in nomadic production. Agro-ecological zone C had the highest sero-prevalence (25.3 %, CI 20.2-31.0). No significant cattle factors were detected in sedentary production. Factors significantly associated with CBPP occurrence at herd-level were contacts with other herds during grazing (P < 0.001) and at watering points (P < 0.001). Others were introduction of new cattle into herd (P < 0.001), outbreaks of CBPP in an area (P < 0.001), socio-cultural factors of cattle gifts and dowry payment (P < 0.001), herd composition of keeping cattle and small ruminants together (P < 0.001), and long trekking during migrations (P = 0.0009). This study had shown the burden of CBPP in the two production systems. Sero-diagnosis and risk factor identification should be institutionalized as elements of epidemio-surveillance and control strategies for CBPP, especially in resource-poor pastoralists' settlements in Nigeria. PMID

  7. 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.

  8. `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.

  9. The compatibility of agricultural intensification in a global hotspot of smallholder agrobiodiversity (Bolivia).

    PubMed

    Zimmerer, Karl S

    2013-02-19

    Integrating the conservation of biodiversity by smallholder farmers with agricultural intensification is increasingly recognized as a leading priority of sustainability and food security amid global environmental and socioeconomic change. An international research project investigated the smallholder agrobiodiversity of maize (corn) in a global hotspot (Bolivia) undergoing significant intensification. Peach-based intensification was pronounced (300-400%) and prolonged (2000-2010) in study areas. Intensification and maize agrobiodiversity were found to co-occur within smallholder landscapes. Interactions of these field systems did not trigger land-change tipping points leading to landrace extirpation. By 2010 maize landraces in the study areas still demonstrated high levels of taxonomic and ecological biodiversity and contributed significantly to this crop's agrobiodiversity at national (31%) and hemispheric (3%) scales. Social and ecological resilience and in situ conservation of the maize agrobiodiversity by Bolivian smallholders was enabled through robust linkages to off-farm migration; resource access and asset capabilities among both traditional and nontraditional growers; landrace agroecology and food uses; and innovative knowledge and skills. The smallholders' resilience resulting from these linkages was integral to the conditional success of the in situ conservation of maize agrobiodiversity. Environment-development interactions both enabled smallholders' agrobiodiversity resilience and influenced the limits and vulnerability of agrobiodiversity. Scientific policy recommendations regarding land-use planning and sustainability analysis are targeted to specific Río+20 priorities for agrobiodiversity. PMID:23382215

  10. 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. PMID:22384244

  11. Spatial analysis to support geographic targeting of genotypes to environments

    PubMed Central

    Hyman, Glenn; Hodson, Dave; Jones, Peter

    2013-01-01

    Crop improvement efforts have benefited greatly from advances in available data, computing technology, and methods for targeting genotypes to environments. These advances support the analysis of genotype by environment interactions (GEI) to understand how well a genotype adapts to environmental conditions. This paper reviews the use of spatial analysis to support crop improvement research aimed at matching genotypes to their most appropriate environmental niches. Better data sets are now available on soils, weather and climate, elevation, vegetation, crop distribution, and local conditions where genotypes are tested in experimental trial sites. The improved data are now combined with spatial analysis methods to compare environmental conditions across sites, create agro-ecological region maps, and assess environment change. Climate, elevation, and vegetation data sets are now widely available, supporting analyses that were much more difficult even 5 or 10 years ago. While detailed soil data for many parts of the world remains difficult to acquire for crop improvement studies, new advances in digital soil mapping are likely to improve our capacity. Site analysis and matching and regional targeting methods have advanced in parallel to data and technology improvements. All these developments have increased our capacity to link genotype to phenotype and point to a vast potential to improve crop adaptation efforts. PMID:23515351

  12. 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. PMID:27478691

  13. Ecological intensification of cereal production systems: Yield potential, soil quality, and precision agriculture

    PubMed Central

    Cassman, Kenneth G.

    1999-01-01

    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. PMID:10339523

  14. Haplo-block structure of Southern African village chicken populations inferred using genome-wide SNP data.

    PubMed

    Khanyile, K S; Dzomba, E F; Muchadeyi, F C

    2015-01-01

    This study investigated the haplo-block structure, haplotype sharing, and diversity in extensively raised chicken populations of Southern Africa. Two hundred ninety village chickens from Malawi (N = 30), South Africa (N = 132), and Zimbabwe (N = 128) were included in the study, from which 649, 2104, and 2442 haplo-blocks were observed, respectively. The majority of haplo-blocks were smaller than 25 kb in size and only five blocks were more than 2000 kb in size. The low chromosomal coverage of haplo-blocks observed across the genome suggests that multiple recombination events fragmented the ancestral haplo-blocks into smaller sizes. Haplo-block sharing was observed between populations with 2325 haplo-blocks common between Zimbabwe and Malawi and 2689 between South Africa and Zimbabwe. Haplotype sharing allows transferability of genomic tools between these extensively raised chicken populations of Southern Africa. The unique haplo-blocks could have originated from isolated evolution taking place in specific agro-ecological zones. Quantitative trait loci analysis revealed that genes related to body composition were spanned by these haplo-blocks. Body composition traits are important for village chicken populations, which have to harness poor quality feed obtained from the environment to meet their maintenance and production needs. PMID:26505376

  15. [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. PMID:23189675

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

    PubMed

    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

  17. 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. PMID:21692537

  18. 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.

  19. [Emergy evaluation and dynamic measurement analysis of agro-ecosystems in Sichuan Province of Southwest China].

    PubMed

    Zhang, Ying-Cong; Du, Shou-Hu

    2012-03-01

    Agro-ecosystem is the most basic system for human beings survival, while the analysis of the structure and function of the system is the key to solve the problems of agro-ecological environment. In this paper, emergy theory and related economic measurement methods including data envelopment analysis, cointegration test, and error correction model were applied to quantitatively analyze the operation dynamics, environmental loading, operation efficiency, and input-output relation of the agro-ecosystems in Sichuan Province and its 21 cities in 1997-2009. In the study period, Sichuan Province was in the transition period from traditional agriculture to modern agriculture. The agricultural mechanization level of the Province improved constantly, resources utilization efficiency enhanced continually, overall structural dominant degree was better, but the over-reliance on economic emergy input caused the sustainability of the system weakened gradually. The development status of the agro-ecosystems in the Province varied among regions. Chengdu Plain and Western Sichuan Highland were either in overexploited or in underutilized, while the hilly areas were full of vitality and development potential, tended to be the important areas for the future development of Sichuan agriculture. Generally, the operation efficiency of the agro-ecosystems in the Province was relatively low, with the situation differed in different regions due to the lower technical efficiency or improper scale. There was a long-term equilibrium between the economic emergy indices and output emergy, but the short-term emergy input didn't reach the ideal output. PMID:22720632

  20. [Coupling analysis of agro-ecolomic system in gully area of Loess Plateau in 1949-2008: a case study in Changwu County of Shaanxi Province].

    PubMed

    Zhang, Jian-jun; Zhang, Xiao-ping; Wang, Ji-jun; Hao, Ming-de; Xu, Jin-peng

    2011-03-01

    Based on the analysis of the coercing and dynamic evolution relationships between agro-economic system and agro-ecological system, and by using modified entropy method, the weight of each evaluation index for the agro-ecolomic system in Changwu County of Shaanxi Province was determined, and, by employing coupling degree model, the coupling processes of agro-ecolomic system in the gullyarea of Loess Plateau were investigated. From 1949 to 2008, the agro-ecolomic system in the County experienced three stages of "traditional extensive agriculture", "agricultural mechanization", and "agricultural pre-modernization". In corresponding to the implement of national macro policies, the coupling degree of the agro-ecolomic system reached two peaks standing for utmost increasing phase and three valleys standing for coordinate development phase. Periods 1955-1961 and 1984-1992 were the utmost increasing phases of the coupling degree; periods 1962-1965 and 1981-1983 were the rapid transition periods responding to the national-wide policies controlling; while periods 1949-1954 and 1966-1980 were the low-level coordinated development phases. Since 1993, the system had been in the harmonious phase by a spiral development. At present, the system had a potential risk of changing from the harmonious phase to the utmost development phase. Appropriate agricultural policies and better external environment could promote the stable development of the agro-ecolomic system on a harmonious level; otherwise, a retrogressive system might be expected. PMID:21657035

  1. 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. PMID:26693586

  2. 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. PMID:25436456

  3. Bacterial Distribution in the Rhizosphere of Wild Barley under Contrasting Microclimates

    PubMed Central

    Timmusk, Salme; Paalme, Viiu; Pavlicek, Tomas; Bergquist, Jonas; Vangala, Ameraswar; Danilas, Triin; Nevo, Eviatar

    2011-01-01

    Background All plants in nature harbor a diverse community of rhizosphere bacteria which can affect the plant growth. Our samples are isolated from the rhizosphere of wild barley Hordeum spontaneum at the Evolution Canyon (‘EC’), Israel. The bacteria which have been living in close relationship with the plant root under the stressful conditions over millennia are likely to have developed strategies to alleviate plant stress. Methodology/Principal Findings We studied distribution of culturable bacteria in the rhizosphere of H. spontaneum and characterized the bacterial 1-aminocyclopropane-1-carboxylate deaminase (ACCd) production, biofilm production, phosphorus solubilization and halophilic behavior. We have shown that the H. spontaneum rhizosphere at the stressful South Facing Slope (SFS) harbors significantly higher population of ACCd producing biofilm forming phosphorus solubilizing osmotic stress tolerant bacteria. Conclusions/Significance The long-lived natural laboratory ‘EC’ facilitates the generation of theoretical testable and predictable models of biodiversity and genome evolution on the area of plant microbe interactions. It is likely that the bacteria isolated at the stressful SFS offer new opportunities for the biotechnological applications in our agro-ecological systems. PMID:21448272

  4. Simulating Regional Dynamic Vegetation and Water Resources with Coupled Biophysical and Hydrologic Models

    NASA Astrophysics Data System (ADS)

    Kendall, A. D.; Basso, B.; Hyndman, D. W.

    2010-12-01

    Climate change, population growth, biofuel production, and a host of other global forces are driving alterations of agricultural production worldwide, with little comprehensive understanding of the impacts these changes will have on water resources. While plot-scale soil-plant-water interactions have been intensively studied and simulated for decades, few tools are available to quantify watershed-to-basin scale impacts of shifting agricultural production systems. A recent class of fully-distributed models that simulate the complete terrestrial hydrologic cycle are well suited for fine-resolution, basin-scale studies. Here we present the first coupling of such a model, the Integrated Landscape Hydrology Model (ILHM), with a dynamic vegetation/crop growth model, the Systems Approach to Land Use Sustainability (SALUS) model. The coupled SALUS-ILHM code was first tested for a series of plots with both intensively monitored agricultural and natural land uses in Michigan. We then simulate a regional watershed in Michigan under current and statistically-downscaled forecast climate to demonstrate the capabilities of the coupled models and validate their performance. Model-predicted leaf area index (LAI) and agricultural yields are compared to remotely-sensed and county-aggregate statistics, respectively. Impacts of explicitly simulating vegetation and root growth on hydrologic model performance are presented. Preliminary climate change forecast scenarios indicate significant alterations to Michigan’s hydrologic and agroecological systems, including longer growing seasons, altered yields for current-generation crops, reduced seasonal snowpacks, and lower summer stream flows.

  5. 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. PMID:24163614

  6. 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. PMID:19680908

  7. '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. PMID:26092046

  8. 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.

  9. 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. PMID:26707856

  10. Complex agro-ecosystems for food security in a changing climate.

    PubMed

    Khumairoh, Uma; Groot, Jeroen Cj; Lantinga, Egbert A

    2012-07-01

    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