Science.gov

Sample records for agroecology

  1. Book review: Agroecology in action

    USDA-ARS?s Scientific Manuscript database

    Agroecology extends the boundaries of modern agriculture relying primarily on reductionistic scientific investigations of how plants and animals respond to and interact with the environment to a more holistic understanding between humans and nature to produce more sustainable agricultural systems th...

  2. 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…

  3. 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…

  4. 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…

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

    USDA-ARS?s Scientific Manuscript database

    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...

  6. 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…

  7. [Ecological monitoring in agro-ecological systems].

    PubMed

    Baĭkov, B D

    1983-01-01

    The fundamental principles of the ecologic monitoring in the antropogenic ecosystems are dealt with. Analyzed are the structure and function of the agroecologic systems, and, on the basis of the particular aspects established a concept is developed of the ecologic control at autoecologic and biocoenologic level. An analysis is likewise made of the ecologic sequelae resulting from the chemical war launched by the American aggressors in Vietnam and the specific trends therefrom in the substantiation of the ecologic monitoring. Stated is the necessity of profound investigations to establish the bioaccumulation of dioxine, a poisonous agent which was contained in herbicides and defoliants used in the war, and which was distinguished by exclusively high toxicity, producing teratogenic and cancerogenic effects and possessing high resistance in the environment.

  8. [Research progress and trend on grassland agroecology].

    PubMed

    Ren, Jizhou; Li, Xianglin; Hou, Fujiang

    2002-08-01

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

  9. Agroecological strategies for arthropod pest management in Brazil.

    PubMed

    Lemos, Felipe; Sarmento, Renato A; Teodoro, Adenir V; dos Santos, Gil R; do Nascimento, Ildon R

    2011-05-01

    There is a need to implement a new approach to pest control in which agroecological strategies are developed and adapted in a site-specific way to highly variable and diverse farm conditions typical of farms in tropical regions such as Brazil. It has become evident that the conventional agriculture based on high use of external inputs and oriented to maximize profits, has often been detrimental and unviable when considered from social and ecological perspectives. Pest problems, for example, are generally related to high input, single-crop agroecosystems. We discuss here agroecological strategies such as conservation biological control, use of natural pesticides and selectivity of synthetic and natural pesticides as a way to conserve and increase natural enemies' efficiency in Brazilian agroecosystems. In addition, we discuss some patents related to agroecological pest management.

  10. 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…

  11. 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…

  12. Lice infesting horses in three agroecological zones in central Oromia.

    PubMed

    Tafese, Adane; Jibat, Tariku; Aklilu, Nigatu; Zewdu, Hanna; Kumsa, Bersissa

    2014-12-01

    A cross-sectional study was conducted to determine the prevalence and species composition of lice infesting horses in three agroecological zones in seven different districts in central Oromia from November 2011 to April 2012. For this purpose, a total of 420 horses were thoroughly examined for presence of lice. Collected lice were identified to species level under a microscope. The study showed an overall prevalence of 28.8 % (121/420) lice infestation on horses. We identified two spp. of lice on horses namely, Bovicola (Werneckiella) equi and Haematopinus asini with an overall prevalence of 22.9 % (96/420) and 5.9 % (25/420), respectively. The overall prevalence of lice infestation on horses in districts was 48.3, 43.3, 33.3, 23.3, 21.7, 18.3 and 13.3 %, in Debre Brehan, Shashemene, Hawassa, Akaki, Adama, Modjo and Bishoftu, respectively. B. equi was encountered as the predominant species on horses in all districts. Higher overall prevalence of lice infestation was recorded in highland agroecology than mid and lowland agroecological zones. Similarly, our study revealed significantly higher overall prevalence of lice on saddle horses than on cart horses. In view of the findings of the present study two species of lice are responsible for health and welfare problems of horses in all the districts. Detailed epidemiological studies on the significance, prevalence and role of lice as vectors of zoonotic pathogens in different agroecological zones, breeds and management systems warrant urgent attention. Animal owners and veterinarians should consider lice control in horses as part of the ectoparasite control in other species of animals.

  13. Agroecology and the Sustainable Production of Food and ...

    EPA Pesticide Factsheets

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

  14. Agroecology and the Sustainable Production of Food and ...

    EPA Pesticide Factsheets

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

  15. 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.

  16. 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.

  17. 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). Copyright © 2014 Elsevier B.V. All rights reserved.

  18. 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.

  19. 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. Copyright © 2015 Elsevier

  20. 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

  1. Agroecology and healthy food systems in semi-humid tropical Africa: Participatory research with vulnerable farming households in Malawi.

    PubMed

    Nyantakyi-Frimpong, Hanson; Kangmennaang, Joseph; Bezner Kerr, Rachel; Luginaah, Isaac; Dakishoni, Laifolo; Lupafya, Esther; Shumba, Lizzie; Katundu, Mangani

    2017-11-01

    This paper assesses the relationship between agroecology, food security, and human health. Specifically, we ask if agroecology can lead to improved food security and human health among vulnerable smallholder farmers in semi-humid tropical Africa. The empirical evidence comes from a cross-sectional household survey (n=1000) in two districts in Malawi, a small country in semi-humid, tropical Africa. The survey consisted of 571 agroecology-adoption and 429 non-agroecology-adoption households. Ordered logistics regression and average treatment effects models were used to determine the effect of agroecology adoption on self-reported health. Our results show that agroecology-adoption households (OR=1.37, p=0.05) were more likely to report optimal health status, and the average treatment effect shows that adopters were 12% more likely to be in optimal health. Furthermore, being moderately food insecure (OR=0.59, p=0.05) and severely food insecure (OR=0.89, p=0.10) were associated with less likelihood of reporting optimal health status. The paper concludes that with the adoption of agroecology in the semi-humid tropics, it is possible for households to diversify their crops and diets, a condition that has strong implications for improved food security, good nutrition and human health. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. 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...

  3. 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...

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

    ERIC Educational Resources Information Center

    Diesel, Vivien; Miná Dias, Marcelo

    2016-01-01

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

  5. An Education in Gender and Agroecology in Brazil's Landless Rural Workers' Movement

    ERIC Educational Resources Information Center

    Schwendler, Sônia Fátima; Thompson, Lucia Amaranta

    2017-01-01

    This article explores the implications of a blended agroecology and gender education within "Brazil's Landless Rural Workers' Movement" (MST). The discussion is first situated within MST's struggle for land and for peasant families' livelihoods, generally, and under neoliberalism, specifically. Central to the struggle against…

  6. 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…

  7. 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,…

  8. 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…

  9. An Education in Gender and Agroecology in Brazil's Landless Rural Workers' Movement

    ERIC Educational Resources Information Center

    Schwendler, Sônia Fátima; Thompson, Lucia Amaranta

    2017-01-01

    This article explores the implications of a blended agroecology and gender education within "Brazil's Landless Rural Workers' Movement" (MST). The discussion is first situated within MST's struggle for land and for peasant families' livelihoods, generally, and under neoliberalism, specifically. Central to the struggle against…

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

    ERIC Educational Resources Information Center

    Diesel, Vivien; Miná Dias, Marcelo

    2016-01-01

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

  11. 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,…

  12. 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

  13. 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

  14. [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.

  15. Agroecology in the tropics: Achieving a balance between land use and preservation

    NASA Astrophysics Data System (ADS)

    Gliessman, Stephen R.

    1992-11-01

    Agroecology is the application of ecological concepts and principles to the design and management of sustainable agricultural systems. An agroecological approach to agriculture has special importance in the humid tropics where agricultural development and the preservation of tropical forests are most often in direct conflict. It is proposed that a more sustainable approach to development is needed, where agroecosystems depend on low external inputs, function more on the use of locally available and renewable resources, have benign impacts on the environment, and are based on the knowledge and culture of the local inhabitants. Examples of traditional agroecosystem management in Mesoamerica that can provide this basis are presented. The preservation of both biological and cultural diversity are integral to the long-term sustainable management of natural resources in the tropics.

  16. Agroecological bases for raising the productivity of degraded soils in Khorasan province of Iran

    NASA Astrophysics Data System (ADS)

    Rozhkov, V. A.; Nurberdiev, M.; Rangavar, A.

    2007-12-01

    Agroecological principles and approaches for the assessment of the soil water supply in Khorasan province of the Islamic Republic of Iran are suggested. The soil water supply is the crucial factor controlling the productivity of local pastures. The agroclimatic division of the province is suggested and the seasonal dynamics of the soil water and surface runoff on experimental plots are analyzed. Experimental materials that are used in semiempirical models and calculations of the potential productivity of pastures are discussed.

  17. Ectoparasites of sheep in three agro-ecological zones in central Oromia, Ethiopia.

    PubMed

    Kumsa, Bersissa; Beyecha, Kebede; Geloye, Mesula

    2012-10-23

    A cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central Oromia, Ethiopia, from October 2009 to April 2010. The study revealed that 637 (48.1%) of the 1325 sheep examined were infested with one or more ectoparasites. The ectoparasites identified were Bovicola ovis (27.2%), Melophagus ovinus (16.4%), Ctenocephalides sp. (2.3%), Linognathus africanus (1.2%), Linognathus ovillus (0.3%), Sarcoptes sp. (1.2%), Amblyomma variegatum (4.4%), Rhipicephalus evertsi evertsi (1.9%), Rhipicephalus pravus (1.9%), Rhipicephalus (Boophilus) decoloratus (1.1%), Rhipicephalus sanguineus (0.9%), Rhipicephalus praetextatus (1.1%) and Hyalomma truncatum (1.6%). Statistically significant difference was observed in prevalence of B. ovis amongst study agroecological zones: highland 36.6%, midland 20.9% and lowland 14.0%. Significantly higher prevalence was recorded in highland agroecological zone. A significantly (OR = 0.041, p < 0.001) higher prevalence of M. ovinus in the highland (31.7%) than in both the lowland (0%) and midland (1.9%) was observed. The risk of tick infestation in the lowland and midland was 9.883 times and 13.988 times higher than the risk in the highland, respectively. A significantly higher prevalence of Ctenocephalides species was encountered in both the lowland (OR = 4.738, p = 0.011) and midland (OR = 8.078, p = 0.000) than in the highland agro-ecological zone. However, a significant difference (p = 0.191) amongst agro-ecological zones was not found for the prevalence of Linognathus and Sarcoptes species. Statistically significant variation (p > 0.05) was never recorded in the prevalence of all the identified species of ectoparasites between male and female sheep hosts. However, a significantly (p = 0.006) higher prevalence of B. ovis was recorded between young and adult sheep. The risk of B. ovis infestation was 1.45 times higher in young than the

  18. A soil-specific agro-ecological strategy for sustainable production in Argentina farm fields

    NASA Astrophysics Data System (ADS)

    Zamora, Martin; Barbera, Agustin; Castro-Franco, Mauricio; Hansson, Alejandro; Domenech, Marisa

    2017-04-01

    The continuous increment of frequencies and doses of pesticides, glyphosate and fertilizers, the deterioration of the structure, biotic balance and fertility of soils and the ground water pollution are characteristics of the current Argentinian agricultural model. In this context, agro-ecological innovations are needed to develop a real sustainable agriculture, enhancing the food supply. Precision agriculture technologies can strengthen the expansion of agro-ecological farming in experimental farm fields. The aim of this study was to propose a soil-specific agro-ecological strategy for sustainable production at field scale focused on the use of soil sensors and digital soil mapping techniques. This strategy has been developed in 15 hectares transition agro-ecological farm field, located at Barrow Experimental Station (Lat:-38.322844, Lon:-60.25572) Argentina. The strategy included five steps: (i) to measure apparent electrical conductivity (ECa) and elevation within agro-ecological farm field; (ii) to apply a clustering method using MULTISPATI-PCA algorithm to delimitate three soil-specific zones (Z1, Z2 and Z3); (iii) to determine three soil sampling points by zone, using conditioned Latin hypercube method, in addition to elevation and ECa as auxiliary information; (iv) to collect soil samples at 2-10 cm depth in each point and to determine in laboratory: total organic carbon content (TOC), cation-exchange capacity (CEC), pH and phosphorus availability (P-Bray). In addition, soil bulk density (SBD) was measured at 0-20 cm depth. Finally, (v) according to each soil-specific zone, a management strategy was recommended. Important differences in soil properties among zones could suggest that the strategy developed was able to apply an agro ecological soil-specific practice management. pH and P-Bray were significantly (p<0.05) higher in Z1 than in Z2 and Z3. TOC did not show significant difference among zones, but it was higher in Z2. CEC was significantly (p<0

  19. 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

  20. Comparative nutrient composition of selected wild edible mushrooms from two agro-ecological zones, Uganda.

    PubMed

    Nakalembe, Immaculate; Kabasa, John David; Olila, Deogratias

    2015-01-01

    In Uganda, wild mushrooms are mainly collected during the rainy season and valued as a traditionally nutritious food by the rural poor. However, their nutritional attributes have not been adequately studied and documented. Comparative nutrient composition of five wild edible mushroom species was determined, namely: P. tenucuilus, T. tyleranus, T. clypeatus, V. speciosa and T. microcarpus of sub-humid and humid agro-ecological zones. Standard analytical techniques following the AOAC were used for proximate and mineral contents determinations. Vitamins determination followed the established standard protocols of the laboratories where the analyses were conducted. Combined use of nutrient concentration and scores were used to compare the level of the contents in the mushroom species. Significant differences (p < 0.05) in nutrient values were demonstrated between and among the mushroom species obtained from the two agro-ecological zones. On dry weight basis, all proximate compositions were high in mushroom species obtained from the humid zone with exception of the total carbohydrates and energy values. Irrespective of the source of the mushrooms, significant amounts were demonstrated in protein, dry matter, ash and total carbohydrates ranging between 11.56-27.42%, 82.34-99.76%, 10.79-16.87%, and 37.12-61.05%, respectively. In comparison with recommended dietary daily intakes, the K, P, Se, Mn, Cu and Fe contents were relatively high with low Ca, Mg, Zn and Na. Thiamin, folic acid, vitamin C, and niacin levels were high but below the recommended FAO references. Considering mushrooms from different agro-ecological zones, significant differences (p < 0.05) were observed in all mushroom species in P except in T. clypeatus, T. tyleranus, T. microcarpus and T. clypeatus in potassium, T. clypeatus and T. microcarpus in Mg. Mushrooms from humid agro-ecological zones had relatively high overall mineral and vitamin supply potential. In conclusion, consumption of these

  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. 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…

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

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

  7. Developing an Agro-Ecological Zoning Model for Tumbleweed (Salsola kali), as Energy Crop in Drylands of Argentina

    NASA Astrophysics Data System (ADS)

    Falasca, Silvia; Pitta-Alvarez, Sandra; Ulberich, Ana

    2016-12-01

    Salsola kali is considered extremely valuable as an energy crop worldwide because it adapts easily to environments with strong abiotic stresses (hydric, saline and alkaline) and produces large amounts of biomass in drylands. This species is categorized as an important weed in Argentina. The aim of this work was to design an agro-ecological zoning model for tumbleweed in Argentina, employing a Geography Information System. Based on the bioclimatic requirements for the species and the climatic data for Argentina (1981-2010 period), an agro-climatic suitability map was drawn. This map was superimposed on the saline and alkaline soil maps delineated by the Food and Agriculture Organization for dry climates, generating the agro-ecological zoning on a scale of 1 : 500 000. This zoning revealed very suitable and suitable cultivation areas on halomorphic soils. The potential growing areas extend from N of the Salta province (approximately 22° S) to the Santa Cruz province (50° S). The use of tumbleweed on halomorphic soils under semi-arid to arid conditions, for the dual purpose of forage use and source of lignocellulosic material for bioenergy, could improve agricultural productivity in these lands. Furthermore, it could also contribute to their environmental sustainability, since the species can be used to reclaim saline soils over the years. Based on international bibliography, the authors outlined an agro-ecological zoning model. This model may be applied to any part of the world, using the agro-ecological limits presented here.

  8. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Distribution and toxigenicity of Aspergillus species isolated from maize kernels from three agro-ecological zones in Nigeria.

    PubMed

    Atehnkeng, Joseph; Ojiambo, Peter S; Donner, Matthias; Ikotun, T; Sikora, Richard A; Cotty, Peter J; Bandyopadhyay, Ranajit

    2008-02-29

    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. The three agro-ecological zones were, Derived Savannah (DS) and Southern Guinea Savannah (SGS) in the humid south and North Guinea Savannah (NGS) in the drier north. Across agro-ecological zones, Aspergillus was the most predominant fungal genera identified followed by Fusarium with mean incidences of 70 and 24%, respectively. Among Aspergillus, A. flavus was the most predominant and L-strains constituted >90% of the species identified, while the frequency of the unnamed taxon S(BG) was <3%. The incidence of atoxigenic strains of A. flavus was higher in all the districts surveyed except in the Ogbomosho and Mokwa districts in DS and SGS zones, respectively, where frequency of toxigenic strains were significantly (P<0.05) higher than that of atoxigenic strains. The highest and lowest incidence of aflatoxin positive samples was recorded in the SGS (72%) and NGS (20%), respectively. Aflatoxin contamination in grain also followed a similar trend and the highest mean levels of B-aflatoxins were detected in maize samples obtained from Bida (612 ng g(-1)) and Mokwa (169 ng g(-1)) districts, respectively, in the SGS. Similarly, the highest concentrations of G-aflatoxins were detected in samples from Akwanga district in the SGS with a mean of 193 and 60 ng g(-1), respectively. When agro-ecological zones were compared, B-aflatoxins were significantly (P<0.05) higher in SGS than in NGS, and intermediate in maize samples from the DS agro-ecological zone.

  10. 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

  11. 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

  12. 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.

  13. [Energy value evaluation of dike-pond agro-ecological engineering modes].

    PubMed

    Lu, Hongfang; Peng, Shaolin; Lan, Shengfang; Chen, Feipeng

    2003-10-01

    In this paper, energy value analysis and new energy index for sustainable development (EISD) were used to evaluate three different dike-pond agro-ecological engineering modes in Sanshui city of Pearl River Delta in system and subsystem levels. The result showed that mode III was the best in its sustainable development ability. The EISD of mode III was 58.3% and 29.7% higher than that of modes I and II. With a higher economic benefit and higher environmental loading, the planting subsystem had the lowest sustainability. Although the economic benefit of stock raising subsystem was not high, its indirect benefit was higher. With a higher economic benefit and a lower environmental loading, fishing subsystem had the highest sustainability.

  14. 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.

  15. Depth distribution of glyphosate and organic matter after 5 years of agroecology transition compared with industrial agriculture

    NASA Astrophysics Data System (ADS)

    Aparicio, Virginia; Zamora, Martin; Barbera, Agustin; Castro Franco, Mauricio; Domenech, Marisa; De Geronimo, Eduardo; Costa, Jose Luis

    2017-04-01

    The industrial model of agriculture, defined here by its capital intensity and dependence on massive inputs like seeds, fertilizer, and pesticides, is reducing soil organic matter and increasing the inefficiency in agrochemical used. Ecological impacts of industrial agriculture include pollution by pesticides, soil organic matter loss and soil degradation, among many others, with the consequent human health risks. Many of the negative effects of industrial agriculture are remote from fields and farms. The impacts of industrial agriculture on the environment, public health, and rural communities make it an unsustainable way to grow our food over the long term. An alternative approach to the industrial agriculture is the agroecology which has shown promising success on the ground and is actually the only way to ensure that all people have access to sufficient, healthful food. Farming systems designed and managed according to ecological principles can meet the food needs of society while addressing these pressing environmental and social issues. Our concept of agroecological transition is based on increasing resource use efficiency (e.g. fertilizer, pesticides and water), recycling waste or byproducts of one subsystem in another and applying sound? agricultural practices or precision-agriculture technologies. The objective of this work was to compare two production systems: a) industrial agriculture, b) agroecological transition with respect to the impact on the glyphosate load and the organic matter content in the soil and its distribution in depth. The study sites were two field of 15 ha each located at Barrow Experimental Station (38°19´S, 60°15´W). Soil ECa mapping was carried out and the complete experimental area was divided in three ECa classes with similar soil characteristics. Therefore, soil sampling was carried out by zones, based on three ECa classes at each production systems. Soil samples were taken at 0-2, 2-5, 5-10, 10-20, 20-30 and 30-40 cm depth

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

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  17. Mineral composition of Tamarindus indica LINN (tamarind) pulp and seeds from different agro-ecological zones of Uganda.

    PubMed

    Okello, Jaspher; Okullo, John B L; Eilu, Gerald; Nyeko, Philip; Obua, Joseph

    2017-09-01

    Mineral composition of dry Tamarindus indica LINN pulp and seeds was evaluated on samples collected from three different agro-ecological zones of Uganda (Lake Victoria Crescent, and Eastern and West Nile). The objective of the study was to evaluate the mineral composition of T. indica pulp and seed samples from across Uganda's different agro-ecological zones and land use types. Separately grounded samples of T. indica pulp and seeds were analyzed for Zn, Fe, Mg, P, Na, K, and Ca. The univariate analysis of variance in the General Linear Model was used to compare differences in mineral composition. Treatment means were separated using Least Significant Difference (LSD) in Post Hoc Tests. The results showed that there were significant differences (p ≤ 0.005) in mineral composition levels of T. indica pulp and seed samples between the different agro-ecological zones with the exception of P and Na (for pulp). The T. indica pulp and seeds samples from the Lake Victoria Crescent zone and wild land use type had generally higher mineral levels than T. indica samples from other agro-ecological zones and different land use types. As mineral composition levels were generally higher in the seed than the pulp samples, consumption of T. indica seeds should be promoted. There is also need to conserve individual species both on-farm and in the wild population, but T. indica mineral concentrations (both pulp and seeds) were higher in the samples from the wild population, making them good for human and animal diets.

  18. 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.

  19. 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.

  20. Phylogenetic diversity and symbiotic functioning in mungbean (Vigna radiata L. Wilczek) bradyrhizobia from contrast agro-ecological regions of Nepal.

    PubMed

    Risal, Chandra Prasad; Djedidi, Salem; Dhakal, Dhruba; Ohkama-Ohtsu, Naoko; Sekimoto, Hitoshi; Yokoyama, Tadashi

    2012-02-01

    Nepal consists wide range of climatic and topographical variations. Here, we explored the phylogeny of native mungbean bradyrhizobia isolated from different agro-ecological regions of Nepal and accessed their nodulation and nitrogen fixation characteristics. Soil samples were collected from three agro-ecological regions with contrasting climate and topography. A local mungbean cultivar, Kalyan, was used as a trap plant. We characterized isolates based on the full nucleotide sequence of the 16S rRNA, ITS region, and nodA genes; and partial sequences of nodD1 and nifD genes. We found 50% of isolates phylogenetically related to B. yuanmingense, 13% to B. japonicum, 8% to B. elkanii, and 29% to novel phylogenetic origin. Results of the inoculation test suggested that expression of different symbiotic genes in isolates resulted in different degrees of symbiotic functioning. Our results indicate B. yuanmingense and novel strains are more efficient symbiotic partners than B. elkanii for the local mungbean cv. Kalyan. We also found most mungbean rhizobial genotypes were conserved across agro-ecological regions. All the strains from tropical Terai region belonged to B. yuanmingense or a novel lineage of B. yuanmingense, and dominance of B. japonicum related strains was observed in the Hill region. Higher genetic diversity of Bradyrhizobium strains was observed in temperate and sub-tropical region than in the tropical region. Copyright © 2011 Elsevier GmbH. All rights reserved.

  1. 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

  2. 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

  3. 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.

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

    PubMed

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

    2010-09-01

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

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

    PubMed

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

    2007-08-01

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

  6. Fungal isolates and metabolites in locally processed rice from five agro-ecological zones of Nigeria.

    PubMed

    Abdus-Salaam, Rofiat; Atanda, Olusegun; Fanelli, Francesca; Sulyok, Micheal; Cozzi, Giuseppe; Bavaro, Simona; Krska, Rudolf; Logrieco, Antonio F; Ezekiel, Chibundu N; Salami, Waheed A

    2016-12-01

    This study reports the distribution of fungal isolates and fungal metabolites that naturally contaminate locally processed rice from five agro-ecological zones of Nigeria. The fungal species were isolated by the dilution plate technique and identified by appropriate diagnostics, while metabolites were determined by a liquid chromatographic tandem mass spectrometric method. Aspergillus and Penicillium species were the predominant isolates found in the rice samples while Fusarium spp. were not isolated. The mean fungal count differed significantly (p < 0.05) across the zones and ranged from 9.98 × 10(2) cfu g(-1) in the Southern Guinea Savannah to 96.97 × 10(2) cfu g(-1) in the Derived Savannah. For 16 fungal metabolites, selected from 63 positively identified fungal metabolites based on their concentration and spread across the zones, an occurrence map was constructed. The Northern Guinea Savannah recorded the highest contamination of fungal metabolites while the Sudan Savannah zone recorded the least.

  7. 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

  8. Ectoparasites of small ruminants in three selected agro-ecological sites of Tigray Region, Ethiopia.

    PubMed

    Mulugeta, Y; Yacob, Hailu T; Ashenafi, Hagos

    2010-08-01

    A study on ectoparasites of small ruminants in three selected agro-ecological sites of Tigray Region, Ethiopia disclosed an overall prevalence of 55.5% and 58% in each examined 750 sheep and goats, respectively. In the sheep population, Melophagus ovinus (19.1%), tick infestations (16%), Damalinia ovis (15.3%), Linognathus africanus (11.5%), and Ctenocephalides felis (9%) were the major ectoparasites. The major ectoparasites identified in goats were tick infestations (29.7%), L. africanus (27.9%), Sarcoptes scabiei var. caprae (12.5%), C. felis (11.1%), and Demodex caprae (6.8%). In sheep, there was a statistically significant difference (P < 0.001) in the prevalence of Damalinia ovis, M. ovinus, L. africanus, and ticks between midland and highland. In goats, the risk of Sarcoptes scabiei var. caprae infestation in midland (odds ratio (OR) = 17.2, P < 0.001) and lowland (OR = 5.2, P < 0.001) was 17.2 times and 5.2 times, respectively, higher than the highland. Favorable climatic conditions, backward level of management, poor level of consciousness and awareness of farmers, and weak animal health extension services are believed to have contributed for widespread distribution and occurrences of ectoparasites. The growing threat of ectoparasites to small ruminant production and the tanning industry needs well-coordinated and urgent control intervention.

  9. 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

  10. Liriomyza Leafminer (Diptera: Agromyzidae) Parasitoid Complex in Different Agroecological Zones, Seasons, and Host Plants in Kenya.

    PubMed

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

    2016-04-01

    Liriomyza leafminers (Diptera: Agromyzidae) are severe pests of vegetables and ornamentals worldwide. Previous studies revealed low leafminer parasitism across different agroecological zones in Kenya. The present paper reports on the composition of leafminer parasitoids at different elevations, in different seasons, and on different host crops. Surveys were conducted monthly from January to November 2012, and nine parasitoid species were recovered. Total mean parasitism in the study sites was 31.23 ± 1.03% from a total of 20 different vegetable Liriomyza-infested crops belonging to seven families. Diglyphus isaea (Walker) (Hymenoptera: Eulophidae), Phaedrotoma scabriventris, a newly released parasitoid, and Opius dissitus Muesebeck (Hymenoptera: Braconidae) were the most abundant at all elevations, accounting for 67.3, 18.6, and 9.2% of total parasitoids, respectively. Elevation, season, and host crop significantly affected the parasitoid species present and their abundance. Diglyphus isaea was more abundant at the high- and mid-elevations at all seasons compared with the low-elevation, whereas the lower-elevation favored higher abundance of P. scabriventris and O. dissitus during the long rainy season compared with the high- and mid-elevations at all seasons. Of all the host crops surveyed, parasitoids were more abundant on tomato, local kidney bean, snow pea and French bean than other crops. The total parasitism rate observed in this study suggests a considerable improvement in leafminer parasitism compared with previous surveys in Kenya. The implications of these findings for leafminer management in vegetable and ornamental production in Kenya are discussed.

  11. 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.

  12. Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes: I-selection goals and criteria.

    PubMed

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

    2016-11-01

    Agroecology uses natural processes and local resources rather than chemical inputs to ensure production while limiting the environmental footprint of livestock and crop production systems. Selecting to achieve a maximization of target production criteria has long proved detrimental to fitness traits. However, since the 1990s, developments in animal breeding have also focussed on animal robustness by balancing production and functional traits within overall breeding goals. We discuss here how an agroecological perspective should further shift breeding goals towards functional traits rather than production traits. Breeding for robustness aims to promote individual adaptive capacities by considering diverse selection criteria which include reproduction, animal health and welfare, and adaptation to rough feed resources, a warm climate or fluctuating environmental conditions. It requires the consideration of genotype×environment interactions in the prediction of breeding values. Animal performance must be evaluated in low-input systems in order to select those animals that are adapted to limiting conditions, including feed and water availability, climate variations and diseases. Finally, we argue that there is no single agroecological animal type, but animals with a variety of profiles that can meet the expectations of agroecology. The standardization of both animals and breeding conditions indeed appears contradictory to the agroecological paradigm that calls for an adaptation of animals to local opportunities and constraints in weakly artificialized systems tied to their physical environment.

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

    PubMed Central

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

    2007-01-01

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

  14. 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.

  15. 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.

  16. Molecular diversity analysis of Rhizoctonia solani isolates infecting various pulse crops in different agro-ecological regions of India.

    PubMed

    Dubey, Sunil C; Tripathi, Aradhika; Upadhyay, B K

    2012-11-01

    Genetic diversity of 89 isolates of Rhizoctonia solani isolated from different pulse crops representing 21 states from 16 agro-ecological regions of India, 49 morphological, and 7 anastomosis groups (AGs) was analyzed using 12 universal rice primers (URPs), 22 random amplified polymorphic DNA (RAPD), and 23 inter-simple sequence repeats (ISSR) markers. Both URPs and RAPD markers provided 100 % polymorphism with the bands ranging from 0.1 to 5 kb in size, whereas ISSR markers gave 99.7 % polymorphism with the bands sizes ranging from 0.1 to 3 kb. The marker URP 38F followed by URP13R, URP25F, and URP30F, RAPD marker R1 followed by OPM6, A3 and OPA12 and ISSR3 followed by ISSR1, ISSR4, and ISSR20 produced the highest number of amplicons. R. solani isolates showed a high level of genetic diversity. Unweighted pair group method with an arithmetic average (UPGMA) analysis grouped the isolates into 7 major clusters at 35 % genetic similarity using the three sets of markers evaluated. In spite of using three different types of markers, about 95 % isolates shared common grouping patterns. The majority of the isolates representing various AGs were grouped together into different sub-clusters using all three types of markers. Molecular groups of the isolates did not correspond to agro-ecological regions or states and crops of the origin. An attempt was made for the first time in the present study to determine the genetic diversity of R. solani populations isolated from different pulse crops representing various AGs and agro-ecological regions.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  19. 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

  20. Agroecological management of a soil-dwelling orthopteran pest in vineyards.

    PubMed

    Nboyine, Jerry Asalma; Boyer, Stephane; Saville, David J; Wratten, Stephen David

    2016-11-28

    The efficacy of different combinations of undervine and inter-row treatments for managing a soil-dwelling orthopteran pest, weta (Hemiandrus sp.), in vineyards was investigated over 2 seasons. This insect damages vine buds, thus reducing subsequent grape yield. The undervine treatments comprised pea straw mulch, mussel shells, tick beans [Vicia faba Linn. var minor (Fab)], plastic sleeves on vine trunks (treated control) and control (no intervention), while inter-rows contained either the existing vegetation or tick beans. Treatments were arranged in a randomized complete block design with 10 replicates. Data were collected on weta densities, damage to beans and components of yield. The latter were numbers of bud laid down per vine, shoots per bud, clusters per shoot, grape bunches per vine, bunch weight and yield. The undervine treatments significantly affected all variables except the number of shoots per bud. In contrast, none of the variables was significantly affected by the inter-row treatments or their interaction with undervine treatments, apart from weta density. At the end of the experiment, weta density in the shell treatment was about 58% lower than in the control. As a result, there was about 39% significant yield increase in that treatment compared to the control. Although the undervine beans and sleeves treatments increased yield, there were no reductions in weta density. With undervine beans, the insect fed on the bean plants instead of vine buds. Thus, yield in that treatment was approximately 28% higher than in the control. These results demonstrate that simple agroecological management approaches can reduce above-ground damage by soil-dwelling insects.

  1. Diversity of Rhizoctonia solani associated with pulse crops in different agro-ecological regions of India.

    PubMed

    Dubey, Sunil C; Tripathi, Aradhika; Upadhyay, Balendu K; Deka, Utpal K

    2014-06-01

    Four hundred seventy Rhizoctonia solani isolates from different leguminous hosts originating from 16 agro-ecological regions of India covering 21 states and 72 districts were collected. The disease incidence caused by R. solani varied from 6.8 to 22.2 % in the areas surveyed. Deccan plateau and central highlands, hot sub-humid ecoregion followed by northern plain and central highlands and hot semi-arid ecoregion showed the highest disease incidence. R. solani isolates were highly variable in growth diameter, number, size and pattern of sclerotia formation as well as hyphal width. The isolates obtained from aerial part of the infected plants showing web blight symptoms produced sclerotia of 1-2 mm in size whereas, the isolates obtained from infected root of the plants showing wet root rot symptoms produced microsclerotia (<1 mm). Majority of R. solani isolates showed <8 μm hyphal diameter. Based on morphological characters the isolates were categorized into 49 groups. Seven anastomosis groups (AGs) were identified among the populations of R. solani associated with the pulse crops. The frequency (25.6 %) of AG3 was the highest followed by AG2-3 (20.9 %) and AG5 (17.4 %). The cropping sequence of rice/sorghum/wheat-chickpea/mungbean/urdbean/cowpea/ricebean influenced the dominance of AG1 (16.3 %). Phylogenetic analysis utilizing ITS-5.8S rDNA gene sequences indicated high level of genetic similarity among isolates representing different AGs, crops and regions. ITS groups did not correspond to the morphological characters. The sequence data from this article has been deposited with NCBI data libraries with JF701707 to JF701795 accession numbers.

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

    PubMed

    Burdon, Jeremy J; Thrall, Peter H

    2008-02-01

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

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

    PubMed

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

    2016-11-01

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

  4. “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

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

    PubMed

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

    2012-10-01

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

  6. 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

  7. 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

  8. 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

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

    PubMed

    Wielgosz, Benjamin; Kato, Edward; Ringler, Claudia

    2014-07-03

    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. 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. 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. 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 agricultural basis of malaria transmission is

  10. Agroecological and environmental factors influence Barley yellow dwarf viruses in grasslands in the US Pacific Northwest.

    PubMed

    Ingwell, Laura L; Lacroix, Christelle; Rhoades, Paul R; Karasev, Alexander V; Bosque-Pérez, Nilsa A

    2017-04-15

    Plant pathogens can play a role in the competitive interactions between plant species and have been understudied in native prairies, which are declining globally, and in Conservation Reserve Program (CRP) lands in the United States. Barley/Cereal yellow dwarf virus (B/CYDV) are among the most economically important disease-causing agents of small grain cereal crops, such as wheat, and are known to infect over 150 Poaceae species, including many of the grass species present in prairies and CRP lands. Field surveys of Poaceae species were conducted in endangered Palouse Prairie and CRP habitats of southeastern Washington and adjacent northern Idaho, USA from 2010 to 2012 to examine for the presence of B/CYDV among plant hosts and aphid vectors. Viral species were identified via cloning and sequencing. Landscape, soil and climate data were retrieved from USDA-NASS and USDA-NRCS databases. Analyses were conducted to examine effects of diverse agroecological and environmental factors on virus prevalence. A total of 2271 grass samples representing 30 species were collected; 28 of these were infected with BYDV in at least one location. BYDV infection was detected at every CRP and prairie remnant sampled, with an overall infection of 46%. BYDV-SGV and BYDV-PAV were the only two B/CYDV species encountered, with BYDV-SGV being more prevalent. Sampling time (season) and host plant identity were the main variables explaining variation in virus prevalence among sites. BYDV was more prevalent in perennial compared to annual grass species. Aphids were encountered only once suggesting non-colonizing aphids, potentially from neighboring cereal fields, are responsible for disease spread in these habitats. BYDV prevalence increased in sampled habitats as cereal crop cover increased within a 1-km radius of a habitat patch. Results demonstrate moderate to high and persistent prevalence of BYDV in an endangered grassland habitat. Species composition and susceptibility to pathogens

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

    PubMed Central

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

    2008-01-01

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

  12. Prevalence and species composition of ixodid ticks infesting horses in three agroecologies in central Oromia, Ethiopia.

    PubMed

    Kumsa, Bersissa; Tamrat, Habtamu; Tadesse, Getachew; Aklilu, Nigatu; Cassini, Rudi

    2012-01-01

    A cross-sectional study was conducted to determine the species composition and prevalence of ixodid ticks infesting horses in three agroecological zones in central Ethiopia. For this purpose, a total of 1,168 horses were examined for tick infestation. An overall prevalence of 39.04% of tick infestation on horses was recorded. A total of 917 adult ticks were collected from infested horses. Amblyomma, Boophilus, Rhipicephalus, and Hyalomma genera with the respective prevalence of 3.2%, 1.8%, 29.2%, and 4.7% were identified. In the study, Rhipicephalus evertsi evertsi was encountered with the highest prevalence (15.8%) whereas Amblyomma gemma was with lowest prevalence (1.5%). From the highland, Hyalomma marginatum rufipes (3.1%), Hyalomma truncatum (1.0%), and Boophilus decoloratus (0.3%) were identified. From the midland, R. evertsi evertsi (27.5%), Rhipicephalus pulchellus (18%), Amblyomma variegatum (3.6%), B. decoloratus (2.8%), H. marginatum rufipes (2.6%), H. truncatum (1.8%), and A. gemma (1.5%) were identified. R. evertsi evertsi, 107 (27.5%), was with the highest prevalence in the midland. From the lowland, R. pulchellus (22.3%), R. evertsi evertsi (20%), H. truncatum (3.6%), A. gemma (3.1%), B. decoloratus (2.3%), H. marginatum rufipes (2.1%), and A. variegatum (1.5%) were identified. In the lowland, R. pulchellus, 87 (22.3%), was the most abundant tick species. The overall prevalence of tick infestation on horses was significantly (P<0.05) higher both in the midland, 225 (57.8%), and the lowland, 214 (54.87%), than the highland, 17 (4.4%). This suggests that horses in midland and lowland are at higher risk of tick infestation than those horses in the highland. Further studies on the role of ticks in transmission of diseases to equines and the importance of horses as alternative hosts in different parts of Ethiopia are needed.

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

    PubMed

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

    2015-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  15. 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.

  16. 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

  17. Effects of introduced and indigenous viruses on native plants: exploring their disease causing potential at the agro-ecological interface.

    PubMed

    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 natural

  18. 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

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

    PubMed

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

    2017-01-01

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

  20. 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.

  1. 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.

  2. 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

  3. 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

    2013-04-29

    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.

  4. 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

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

    PubMed

    Revollo-Fernández, Daniel

    2016-04-01

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

  6. Impact of Agroecological Infrastructures on the Dynamics of Dysaphis plantaginea (Hemiptera: Aphididae) and Its Natural Enemies in Apple Orchards in Northwestern France.

    PubMed

    Albert, Laurence; Franck, Pierre; Gilles, Yann; Plantegenest, Manuel

    2017-06-01

    Apple orchard production is facing new environmental and societal challenges, resulting, in particular, in strong pressure to reduce pesticide use. Cider-apple production, for which the perfect visual aspect of fruits is not a marketability imperative, offers good opportunities to study production systems that are developing new agronomic strategies, which could be subsequently extended to all apple-production types. Agroecological infrastructures play an important role in providing shelter, food resources, or reproduction habitats to many arthropods. Consequently, setting-up agroecological infrastructures in the vicinity of or within orchards could increase natural enemy presence and thus improve the biological control of pests. In this study, we focused on Dysaphis plantaginea (Passerini), one of the major pests in apple orchards in Europe, which causes important economic production losses. During two years (2014 and 2015), we monitored the population dynamics of D. plantaginea, its natural enemies, and mutualistic ants in commercial production cider-apple orchards. The influences of the cider-apple cultivar, insecticide use, and distance to agroecological infrastructures (hedgerows and flower strips) were assessed. Our results suggest that flower strips favor an increase in natural enemy abundance in the vicinity of the orchards and could thus play an important role in the production system by improving the biological control of D. plantaginea. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. 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

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

    PubMed

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

    2017-01-01

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

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2017-01-20

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

  11. Fungal and bacterial metabolites of stored maize (Zea mays, L.) from five agro-ecological zones of Nigeria.

    PubMed

    Adetunji, Modupeade; Atanda, Olusegun; Ezekiel, Chibundu N; Sulyok, Michael; Warth, Benedikt; Beltrán, Eduardo; Krska, Rudolf; Obadina, Olusegun; Bakare, Adegoke; Chilaka, Cynthia A

    2014-05-01

    Seventy composite samples of maize grains stored in five agro-ecological zones (AEZs) of Nigeria where maize is predominantly produced were evaluated for the presence of microbial metabolites with the LC-MS/MS technique. The possible relationships between the storage structures and levels of mycotoxin contamination were also evaluated. Sixty-two fungal and four bacterial metabolites were extracted from the grains, 54 of which have not been documented for maize in Nigeria. Aflatoxin B1 and fumonisin B1 were quantified in 67.1 and 92.9% of the grains, while 64.1 and 57.1% exceeded the European Union Commission maximum acceptable limit (MAL) for aflatoxin B1 and fumonisins, respectively. The concentration of deoxynivalenol was, however, below the MAL with occurrence levels of 100 and 10% for its masked metabolite, deoxynivalenol glucoside. The bacterial metabolites had low concentrations and were not a source of concern. The storage structures significantly correlated positively or negatively (p < 0.01 and p < 0.05), respectively with the levels of grain contamination. Consumption of maize grains, a staple Nigerian diet, may therefore expose the population to mycotoxin contamination. There is need for an immediate action plan for mycotoxin mitigation in Nigeria, especially in the Derived Savannah zone, in view of the economic and public health importance of the toxins.

  12. 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

    2012-10-25

    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.

  13. 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

    2016-03-11

    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.

  14. 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

  15. 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.

  16. 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.

  17. Concurrent iron and zinc deficiencies in lactating mothers and their children 6-23 months of age in two agro-ecological zones of rural Ethiopia.

    PubMed

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

    2016-12-09

    The aim of this study is to examine the co-occurrences of low serum ferritin and zinc and anaemia among mothers and their children in two agro-ecological zones of rural Ethiopia. Data were collected from 162 lactating mothers and their breast fed children aged 6-23 months. The data were collected via a structured interview, anthropometric measurements, and blood tests for zinc, ferritin and anaemia. Correlation, Chi-square and multivariable analysis were used to determine the association between nutritional status of mothers and children, and agro-ecological zones. Low serum levels of iron and zinc, anaemia and iron deficiency anaemia were found in 44.4, 72.2, 52.5 and 29.6% of children and 19.8, 67.3, 21.8, 10.5% of mothers, respectively. There was a strong correlation between the micronutrient status of the mothers and the children for ferritin, zinc and anaemia (p < 0.005). Deficiency in both zinc and ferritin and one of the two was observed in 19.1, and 53.7% of the mothers and 32.7 and 46.3%, of their children, respectively. In the 24 h before the survey, 82.1% of mothers and 91.9% of their infants consumed foods that can decrease zinc bioavailability while only 2.5% of mothers and 3.7% of their infants consumed flesh foods. This study shows that micronutrient deficiencies were prevalent among lactating mothers and their children, with variation in prevalence across the agro-ecological zones. This finding calls for a need to design effective preventive public health nutrition programs to address both the mothers' and their children's needs.

  18. Heavy metal pollutants in selected organs of African giant rats from three agro-ecological zones of Nigeria: evidence for their role as an environmental specimen bank.

    PubMed

    Usende, Ifukibot Levi; Emikpe, Benjamin O; Olopade, James Olukayode

    2017-08-14

    An assessment of the concentration of heavy metals in the liver, brain, kidney, bone, and lungs of African giant rats (AGRs) from three agro-ecological zones of Nigeria having different industrial activities was carried out using atomic absorption spectrophotometer. Twenty adult AGRs from cities in mangrove/freshwater swamp, rainforest, and woodland/tall grass savanna agro-ecological zones of Nigeria were used for this study. AGRs were euthanized, carefully dissected, and the brains, liver, lungs, bone, and kidneys were harvested, digested, and analyzed for concentrations of vanadium (V), lead (Pb), cadmium (Cd), zinc (Zn), selenium (Se), copper (Cu), and iron (Fe). All data generated were evaluated for statistical significance using one-way ANOVA with Tukey's multiple post-test comparison. Results showed the major environmental heavy metal pollutants of the mangrove/freshwater swamp to be vanadium and selenium while those of woodland/tall grass savanna agro-ecological zones were lead, selenium, and zinc. The vanadium concentration was more than twofold higher in the observed tissues of AGR from the mangrove/freshwater swamp, and this may be related to increased exploitation of minerals and the activities of militants in pipeline vandalization in this zone. Interestingly, the highest concentration of this metal was seen in the lungs suggestive of a respiratory route of exposure. Among the potential adverse effects derived from exposure to metals, developmental toxicity is a serious risk. This type of investigation can assist in knowing the level of animal and human exposure to environmental pollutants both in highly industrialized and non-industrialized areas and is more ideal in environmental monitoring. This study therefore suggests AGR as model for ecotoxicological research and environmental specimen banks (ESBs) in this part of Africa.

  19. Community-based alternative breeding plans for indigenous sheep breeds in four agro-ecological zones of Ethiopia.

    PubMed

    Mirkena, T; Duguma, G; Willam, A; Wurzinger, M; Haile, A; Rischkowsky, B; Okeyo, A M; Tibbo, M; Solkner, J

    2012-06-01

    Based on the results of participatory approaches to define traits in the breeding objectives, four scenarios of ram selection and ram use were compared via deterministic modelling of breeding plans for community-based sheep breeding programmes in four diverse agro-ecological regions of Ethiopia. The regions (and production systems) were Afar (pastoral/agro-pastoral), Bonga and Horro (both mixed crop-livestock) and Menz (sheep-barley). The schemes or scenarios differed in terms of selection intensity and duration of ram use. The predicted genetic gains per year in yearling weight (kilograms) were comparable across the schemes but differed among the breeds and ranged from 0.399 to 0.440 in Afar, 0.813 to 0.894 in Bonga, 0.850 to 0.940 in Horro, and 0.616 to 0.699 in Menz. The genetic gains per year in number of lambs born per ewe bred ranged from 0.009 to 0.010 in both Bonga and Horro. The predicted genetic gain in the proportion of lambs weaned per ewe joined was nearly comparable in all breeds ranging from 0.008 to 0.011. The genetic gain per year in milk yield of Afar breed was in the order of 0.018 to 0.020 kg, while the genetic gain per generation for greasy fleece weight (kg) ranged from 0.016 to 0.024 in Menz. Generally, strong selection and shorter duration of ram use for breeding were the preferred options. The expected genetic gains are satisfactory but largely rely on accurate and continuous pedigree and performance recording. © 2011 Blackwell Verlag GmbH.

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

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  1. 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%.

  2. 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.

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

    PubMed

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

    2017-01-01

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

  4. 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

  5. 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 %).

  6. 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

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

    PubMed

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

    2016-01-01

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

  8. 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.

  9. 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.

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

    PubMed

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

    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.

  11. 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

  12. Interrelationships among seed yield, total protein and amino acid composition of ten quinoa (Chenopodium quinoa) cultivars from two different agroecological regions.

    PubMed

    Gonzalez, Juan A; Konishi, Yotaro; Bruno, Marcela; Valoy, Mariana; Prado, Fernando E

    2012-04-01

    Quinoa is a good source of protein and can be used as a nutritional ingredient in food products. This study analyses how much growing region and/or seasonal climate might affect grain yield and nutritional quality of quinoa seeds. Seeds of ten quinoa cultivars from the Andean highlands (Bolivia/Argentina site) and Argentinean Northwest (Encalilla site) were analysed for seed yield, protein content and amino acid composition. Grain yields of five cultivars growing at Encalilla were higher, and four were lower, compared with data from the Bolivia/Argentina site. Protein contents ranged from 91.5 to 155.3 and from 96.2 to 154.6 g kg(-1) dry mass for Encalilla and Bolivia/Argentina seeds respectively, while essential amino acid concentrations ranged from 179.9 to 357.2 and from 233.7 to 374.5 g kg(-1) protein respectively. Significant positive correlations were found between the content of essential amino acids and protein percentage. It appears that there are clear variations in seed yield, total protein content and amino acid composition among cultivars from the two sites. Essential amino acid composition was more affected than grain yield and protein level. The study revealed that both environmental and climatic factors influence the nutritional composition of quinoa cultivars growing in different agroecological regions. Copyright © 2011 Society of Chemical Industry.

  13. 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.

  14. 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.

  15. Changes in physical and biological soil quality indicators in a tropical crop system (Havana, Cuba) in response to different agroecological management practices.

    PubMed

    Izquierdo, I; Caravaca, F; Alguacil, M M; Roldán, A

    2003-11-01

    The objective of our study was to assess the response of physical (aggregate stability and bulk density) and biological (enzyme activities and microbial biomass) soil quality indicators to the adoption of agroecological management practices, such as the planting of forage species (forage area) and the rotation of local crops (polycrop area), carried out in a representative tropical pasture on an integrated livestock-crop farm. The pasture system was used as control (pasture area). In all three areas, the values of water-soluble C were higher in the rainy season compared to the dry season. Pasture and forage areas had the highest percentage of stable aggregates in the rainy season, while polycrops developed soils with less stable aggregates. Soil bulk density was lower in the pasture and forage areas than in the polycrop area. In the pasture area, the microbial biomass C values, dehydrogenase, urease, protease-BAA, acid phosphatase, and beta-glucosidase activities were higher than in the forage and polycrop areas, particularly in the dry season. The highest increase in the microbial biomass C in the rainy season, with respect to the dry season, was recorded in the pasture area (about 1.2-fold). In conclusion, the planting of forage species can be considered an effective practice for carrying out sustainable, integrated livestock-crop systems, due to its general maintenance of soil quality, while the adoption of polycrop rotations appears to be less favorable because it decreases soil quality.

  16. 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

    2016-07-25

    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.

  17. 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

  18. Variations between post- and pre-harvest seasons in stunting, wasting, and Infant and Young Child Feeding (IYCF) practices among children 6-23 months of age in lowland and midland agro-ecological zones of rural Ethiopia.

    PubMed

    Roba, Kedir Teji; O'Connor, Thomas Pacelli; Belachew, Tefera; O'Brien, Nora Mary

    2016-01-01

    Food availability and access are strongly affected by seasonality in Ethiopia. However, there are little data on seasonal variation in Infant and Young Child Feeding (IYCF) practices and malnutrition among 6-23 months old children in different agro-ecological zones of rural Ethiopia. Socio-demographic, anthropometry and IYCF indicators were assessed in post- and pre-harvest seasons among children aged 6-23 months of age randomly selected from rural villages of lowland and midland agro-ecological zones. Child stunting and underweight increased from prevalence of 39.8% and 26.9% in post-harvest to 46.0% and 31.8% in pre-harvest seasons, respectively. The biggest increase in prevalence of stunting and underweight between post- and pre-harvest seasons was noted in the midland zone. Wasting decreased from 11.6% post-harvest to 8.5% pre-harvest, with the biggest decline recorded in the lowland zone. Minimum meal frequency, minimum acceptable diet and poor dietary diversity increased considerably in pre-harvest compared to post-harvest season in the lowland zone. Feeding practices and maternal age were predictors of wasting, while women's dietary diversity and children age was predictor of child dietary diversity in both seasons. There is seasonal variation in malnutrition and IYCF practices among children 6-23 months of age with more pronounced effect in midland agro-ecological zone. A major contributing factor for child malnutrition may be poor feeding practices. Health information strategies focused on both IYCF practices and dietary diversity of mothers could be a sensible approach to reduce the burden of child malnutrition in rural Ethiopia.

  19. Variations between post- and pre-harvest seasons in stunting, wasting, and Infant and Young Child Feeding (IYCF) practices among children 6-23 months of age in lowland and midland agro-ecological zones of rural Ethiopia

    PubMed Central

    Roba, Kedir Teji; O’Connor, Thomas Pacelli; Belachew, Tefera; O’Brien, Nora Mary

    2016-01-01

    Introduction Food availability and access are strongly affected by seasonality in Ethiopia. However, there are little data on seasonal variation in Infant and Young Child Feeding (IYCF) practices and malnutrition among 6-23 months old children in different agro-ecological zones of rural Ethiopia. Methods Socio-demographic, anthropometry and IYCF indicators were assessed in post- and pre-harvest seasons among children aged 6–23 months of age randomly selected from rural villages of lowland and midland agro-ecological zones. Results Child stunting and underweight increased from prevalence of 39.8% and 26.9% in post-harvest to 46.0% and 31.8% in pre-harvest seasons, respectively. The biggest increase in prevalence of stunting and underweight between post- and pre-harvest seasons was noted in the midland zone. Wasting decreased from 11.6% post-harvest to 8.5% pre-harvest, with the biggest decline recorded in the lowland zone. Minimum meal frequency, minimum acceptable diet and poor dietary diversity increased considerably in pre-harvest compared to post-harvest season in the lowland zone. Feeding practices and maternal age were predictors of wasting, while women’s dietary diversity and children age was predictor of child dietary diversity in both seasons. Conclusion There is seasonal variation in malnutrition and IYCF practices among children 6-23 months of age with more pronounced effect in midland agro-ecological zone. A major contributing factor for child malnutrition may be poor feeding practices. Health information strategies focused on both IYCF practices and dietary diversity of mothers could be a sensible approach to reduce the burden of child malnutrition in rural Ethiopia. PMID:27795761

  20. Geographic distribution of non-clinical Theileria parva infection among indigenous cattle populations in contrasting agro-ecological zones of Uganda: implications for control strategies.

    PubMed

    Kabi, Fredrick; Masembe, Charles; Muwanika, Vincent; Kirunda, Halid; Negrini, Riccardo

    2014-09-01

    Non-clinical Theileria parva infection among indigenous cattle occurs upon recovery from primary disease during the first year of life. Continuous exposure to infection through contaminated tick infestations with absence of clinical disease gives rise to endemic stability. Endemic stable populations may become sources of infection if contaminated tick vectors are shared with susceptible exotic cattle. This study aimed at establishing a nationwide distribution of non-clinical T. parva infection among indigenous cattle populations to inform novel control strategies. The occurrence of non-clinical T. parva infection among apparently healthy 925 indigenous cattle from 209 herds spread out in 10 agro-ecological zones (AEZs) was determined using a nested PCR assay. The influence of AEZ, breed, sex, age and farmers' ranking of ECF importance were interrogated for influence of non-clinical parasite occurrence. The overall prevalence of non-clinical T. parva infection was 30% (278/925). A gradual increase of non-clinical T. parva infection was observed ranging from 17% (95% CI: 0.03-0.23) to 43% (95% CI: 0.3-0.55) in the North Eastern Savannah Grasslands (NESG) to the Western Highland Ranges (WHR) respectively. A similarly associated 18% (95% CI: 0.07-0.28) and 35% (95% CI: 0.3-0.39) non-clinical parasite prevalence was observed among the East African shorthorn Zebu (EASZ) and Ankole cattle respectively. Average herd level non-clinical T. parva prevalence was 28%, ranging from zero to 100%. The likelihood of non-clinical T. parva infection was 35.5% greater in the western highlands compared to the northeastern semi-arid AEZs. Non-clinical T. parva occurs countrywide, structured along patterns of AEZ and breed gradients. These findings may guide policy formulation, deployment of integrated control strategies and local cattle improvement programs.

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2000-04-01

    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.

  5. Serum trace mineral variations in Nili-Ravi buffaloes suffering with prepartum vaginal prolapse in two different agro-ecological zones of Punjab, Pakistan.

    PubMed

    Akhtar, M S; Lodhi, L A; Ahmad, I; Qureshi, Z I; Muhammad, G

    2012-04-15

    The present study was conducted during 2005 and 2006 on 200 Nili-Ravi buffaloes kept in two agroecological zones (irrigated [zone 1] and rain-fed [zone-2]) of Punjab, Pakistan, with the objective to determine the level of trace minerals (Cu, Fe, Zn, Se) in serum of the buffaloes suffering from vaginal prolapse and to compare them with their healthy counterparts. In each zone 50 buffaloes suffering from prepartum vaginal prolapse during their seventh month of gestation were identified through survey. Vaginal prolapse-affected buffaloes belonging to zone 1 were identified as group VPB1 (N = 50), whereas buffaloes belonging to zone 2 were recognized as VPB2 (N = 50). The buffaloes of control group in zone 1 and zone 2 were identified as NCB1 and NCB2, respectively. The blood samples in all four groups of buffaloes were collected three times, i.e., first when these animals were in the eighth month of gestation, second during the eighth to ninth month of gestation, and finally when these animals were in the ninth or later month of gestation. The mean serum copper concentrations in buffaloes of group VPB1 were significantly lower (P < 0.05) in comparison with NCB1 and NCB2, whereas there were nonsignificant differences (P > 0.05) in copper concentrations between VPB1 and VPB2. There was a significant difference (P < 0.05) of iron concentration in VPB1 compared with NCB1 and NCB2. Similarly, VPB2 also had significantly lower (P < 0.05) iron concentrations compared with NCB1 and NCB2. Serum zinc concentrations were significantly lower (P < 0.05) in animals of the VPB1 group when compared with NCB1 and NCB2. Similarly, lower zinc concentrations were observed in VPB2 in comparison with NCB1 and NCB2. There was significantly lower (P < 0.05) zinc concentration in affected buffaloes (VPB1 and VPB2) from the ninth month of gestation to term when compared with those in the eighth to ninth mo of gestation, and with those not yet in the eighth month of gestation. Serum selenium

  6. 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

  7. 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

  8. 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

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

    PubMed

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

    2006-08-17

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

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

    PubMed

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

    2017-04-19

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

  11. 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

  12. 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.

  13. Agroecological niches and thrips (Thysanoptera: Thripidae) dynamics

    Treesearch

    Michael E. Irwin

    1991-01-01

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

  14. Bats initiate vital agroecological interactions in corn.

    PubMed

    Maine, Josiah J; Boyles, Justin G

    2015-10-06

    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.

  15. 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

  16. 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…

  17. 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.

  18. Agroecology: Implications for plant response to climate change

    USDA-ARS?s Scientific Manuscript database

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

  19. 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.

  20. 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…

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

    PubMed Central

    López-Carr, David

    2013-01-01

    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

  2. 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…

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

    PubMed Central

    Palminha, A.; Melo, I. Q.; Pereira, J. M. C.

    2017-01-01

    The objective of this work is to develop a simple methodology for high resolution crop suitability analysis under current and future climate, easily applicable and useful in Least Developed Countries. The approach addresses both regional planning in the context of climate change projections and pre-emptive short-term rural extension interventions based on same-year agricultural season forecasts, while implemented with off-the-shelf resources. The developed tools are applied operationally in a case-study developed in three regions of Guinea-Bissau and the obtained results, as well as the advantages and limitations of methods applied, are discussed. In this paper we show how a simple approach can easily generate information on climate vulnerability and how it can be operationally used in rural extension services. PMID:28873392

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

    USDA-ARS?s Scientific Manuscript database

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

  5. Production constraints of smallholder pig farms in agro-ecological zones of Mpumalanga, South Africa.

    PubMed

    Munzhelele, Priscilla; Oguttu, James; Fasanmi, Olubunmi G; Fasina, Folorunso O

    2017-01-01

    South African pig sector is a contributor to the agricultural industry. A study was conducted to identify the production constraints and compare the management practices in smallholder pig farms in Mpumalanga, South Africa. A total of 220 selected smallholder pig farmers were interviewed. Smallholder pig farming was predominated by male (64 %), age above 50 years (54 %), black Africans (98.6 %), and three quarters of the smallholder farmers were poor to just below average. Majority (80 %) have no pig husbandry training, while only 33 % received assistance from government's Agricultural Department. In terms of stock, mixed breeds (89 %) from exotic pigs were mostly kept and majority (87 %) of the farmers kept ≤10 sows in their herds. Many farmers (75 %) engaged in risky behavior of buying auctioned-sourced boars, free-range boars, and untested boars from neighbors and relatives. Few (17 %) farmers practiced vaccination and only 10 % kept farm records. Majority of the responses on pre-weaning mortality (50 %) and post-weaning mortality (90 %) were within acceptable range of 1-10 and 1-5 % mortality rates, respectively. The lead causes of mortality were weak piglets and crushing (46 %), diarrhea (27 %), poor management knowledge (19 %), and malnutrition (16 %). Agricultural training and government incentives will facilitate improved productivity in smallholder pig farming.

  6. 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

    2016-06-17

    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.

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

    PubMed

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

    2017-01-01

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

  8. 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…

  9. 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…

  10. 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.

  11. 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

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

    PubMed

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

    2017-10-01

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

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

    USDA-ARS?s Scientific Manuscript database

    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...

  14. 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.

  15. 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…

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

    ERIC Educational Resources Information Center

    Moore, Sophie Sapp

    2017-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

  18. Choice of breeding stock, preference of production traits and culling criteria of village chickens among Zimbabwe agro-ecological zones.

    PubMed

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

    2009-03-01

    Free ranging chickens reared by smallholder farmers represent genetic diversity suited for particular environments and shaped by the socio-economic and cultural values of the farming systems. This study sought to investigate the existence of chicken strains and evaluate the breeding goals and strategies used by village chicken farmers in Zimbabwe. A semi-structured questionnaire was administered to 97, 56, 70, 104 and 37 households randomly selected from five agro-ecological-zones I-V, respectively. Fifteen chicken strains mostly defined by morphological traits were reported in the five eco-zones. Production criteria such as body size, and fertility were highly ranked (ranging from 1.3-2.6) by farmers across all the eco-zones, while cultural traits were the least preferred production traits. As a common breeding practice, farmers chose the type of hens and cocks to retain for breeding purposes and these randomly mixed and mated with others from community flocks. Chicken body size was ranked the major determinant in choosing breeding animals followed by mothering ability, and fertility. More households culled chickens associated with poor reproductive performance, poor growth rates and those intolerant to disease pathogens. The focus on many negatively correlated production traits and the absence of farmer records compromises breeding strategies in these production systems.

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

    PubMed

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

    2017-04-01

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

  20. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    PubMed Central

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

    2017-01-01

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

  4. 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

  5. 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

  6. 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.

  7. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

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

  9. 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.

  10. 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.

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

    PubMed

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

    2015-12-28

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

  12. Genetic diversity and population differentiation of traditional fonio millet (Digitaria spp.) landraces from different agro-ecological zones of West Africa.

    PubMed

    Adoukonou-Sagbadja, H; Wagner, C; Dansi, A; Ahlemeyer, J; Daïnou, O; Akpagana, K; Ordon, F; Friedt, W

    2007-11-01

    Fonio millets (Digitaria exilis Stapf, D. iburua Stapf) are valuable indigenous staple food crops in West Africa. In order to investigate the genetic diversity and population differentiation in these millets, a total of 122 accessions from five countries (Benin, Burkina Faso, Guinea, Mali and Togo) were analysed by Amplified Fragment Length Polymorphisms (AFLPs). Genetic distance-based UPGMA clustering and principal coordinate analysis revealed a clear-cut differentiation between the two species and a clustering of D. exilis accessions in three major genetic groups fitting to their geographical origins. Shannon's diversity index detected in D. iburua was low (H = 0.02). In D. exilis, the most widespread cultivated species, moderate levels of genetic diversity (Shannon's diversity H = 0.267; Nei's gene diversity H' = 0.355) were detected. This genetic diversity is unequally distributed with the essential part observed in the Upper Niger River basin while a very low diversity is present in the Atacora mountain zone. Analysis of molecular variance (AMOVA) revealed that a large part of the genetic variation resides among the genetic groups (70%) and the country of origin (56%), indicating a clear genetic differentiation within D. exilis. Influence of mating system (inbreeding or apomixis), agricultural selection and ecological adaptations as well as founding effects in the genetic make-up of the landraces were visible and seemed to jointly contribute to the genetic structure detected in this species. The genetic variability found between the analysed accessions was weakly correlated with their phenotypic attributes. However, the genetic groups identified differed significantly in their mean performance for some agro-morphologic traits. The results obtained are relevant for fonio millets breeding, conservation and management of their genetic resources in West Africa.

  13. 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.…

  14. 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.

  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.

  16. Participatory data collection and monitoring of agricultural pest dynamics for climate-resilient coffee production using Tiko'n, a generic tool to develop agroecological food web models

    NASA Astrophysics Data System (ADS)

    Rojas, M.; Malard, J. J.; Adamowski, J. F.; Tuy, H.

    2016-12-01

    Climate variability impacts agricultural processes through many mechanisms. For example, the proliferation of pests and diseases increases with warmer climate and alternated wind patterns, as longer growing seasons allow pest species to complete more reproductive cycles and changes in the weather patterns alter the stages and rates of development of pests and pathogens. Several studies suggest that enhancing plant diversity and complexity in farming systems, such as in agroforestry systems, reduces the vulnerability of farms to extreme climatic events. On the other hand, other authors have argued that vegetation diversity does not necessarily reduce the incidence of pests and diseases, highlighting the importance of understanding how, where and when it is recommendable to diversify vegetation to improve pest and disease control, and emphasising the need for tools to develop, monitor and evaluate agroecosystems. In order to understand how biodiversity can enhance ecosystem services provided by the agroecosystem in the context of climatic variability, it is important to develop comprehensive models that include the role of trophic chains in the regulation of pests, which can be achieved by integrating crop models with pest-predator models, also known as agroecosystem network (AEN) models. Here we present a methodology for the participatory data collection and monitoring necessary for running Tiko'n, an AEN model that can also be coupled to a crop model such as DSSAT. This methodology aims to combine the local and practical knowledge of farmers with the scientific knowledge of entomologists and agronomists, allowing for the simplification of complex ecological networks of plant and insect interactions. This also increases the acceptability, credibility, and comprehension of the model by farmers, allowing them to understand their relationship with the local agroecosystem and their potential to use key agroecosystem principles such as functional diversity to mitigate climate variability impacts. Preliminary results of a study currently being conducted in a coffee agroforestry system in El Quebracho, Guatemala, will be presented, where the data was directly collected by farmers during eight consecutive months. Finally, future recommendations from lessons learnt during this study will be discussed.

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

    SciTech Connect

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

    2016-11-01

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

  18. 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.…

  19. 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.

  20. 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.

  1. 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.

  2. 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

    USDA-ARS?s Scientific Manuscript database

    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...

  3. [Change in the socio-demographic profile of consumers of organic produce].

    PubMed

    Pereira, Maristela Costamilan; Müller, Cátia Regina; Rodrigues, Fernanda Souza Abduch; Moutinho, Angélica Bandeira Afonso; Rodrigues, Kelly Lameiro; Botelho, Fabiana Torma

    2015-09-01

    The scope of this study was to establish the socio-demographic profile, health status and the relationship with the consumption of organic produce among consumers who frequent different agroecological street markets in Pelotas in the state of Rio Grande do Sul. A questionnaire was given to the consumers of organic produce while shopping in the agroecological street markets. It was found that the consumers with lower education levels and lower income began to frequent the agroecological street markets more often and consume more organic foods. The consumers were concerned about their health and nutrition status with very few of them having a diagnosis of disease, there being different motivations influencing the purchase of organic food.

  4. 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.

  5. Wheat landraces: A mini review

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  7. 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…

  8. 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.

  9. Pathogenic variation of Phakopsora pachyrhizi in Nigeria

    USDA-ARS?s Scientific Manuscript database

    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 ...

  10. 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…

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  13. Pathogenic Variation of Phakopsora pachyrhizi Infecting Soybean in Nigeria

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  17. 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…

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  20. Assessing the value of transgenic crops.

    PubMed

    Lacey, Hugh

    2002-10-01

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

  1. A quest for ecologically based pest management systems

    NASA Astrophysics Data System (ADS)

    Altieri, M. A.; Martin, P. B.; Lewis, W. J.

    1983-01-01

    The article presents a holistic approach to studying and applying crop protection in agricultural systems A theoretical framework of integrated pest management (IPM) is presented that allows an understanding of pest population processes on a whole-agroecological-system basis The need for and emergence of holistic research on agroecosystems is discussed, as are the current trends in ecological theory and pest management

  2. 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…

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

    USDA-ARS?s Scientific Manuscript database

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

  4. 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…

  5. 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…

  6. 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…

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

    USDA-ARS?s Scientific Manuscript database

    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...

  8. Cotton and its interaction with cotton morphology

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  10. 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.

  11. 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.

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

    PubMed

    Liu, Dong; Zhang, Zhi-Qiang

    2014-03-24

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

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

    PubMed

    JOHNS

    1999-01-01

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

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

    PubMed

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

    2017-07-21

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

  15. 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.

  16. Dietary exposure to aflatoxin from maize and groundnut in young children from Benin and Togo, West Africa.

    PubMed

    Egal, S; Hounsa, A; Gong, Y Y; Turner, P C; Wild, C P; Hall, A J; Hell, K; Cardwell, K F

    2005-10-15

    Aflatoxins are a family of fungal toxins that are carcinogenic to man and cause immunosuppression, cancer and growth reduction in animals. We conducted a cross-sectional study among 480 children (age 9 months to 5 years) across 4 agro-ecological zones (SS, NGS, SGS and CS) in Benin and Togo to identify the effect of aflatoxin exposure on child growth and assess the pattern of exposure. Prior reports on this study [Gong, Y.Y.,Cardwell, K., Hounsa, A., Egal, S., Turner, Hall, A.J., Wild, C.P., 2002. Dietary aflatoxin exposure and impaired growth in young children from Benin and Togo: cross sectional study. British Medical Journal 325, 20-21, Gong, Y.Y., Egal, S., Hounsa, A., Turner, P.C., Hall, A.J., Cardwell, K., Wild, C.P., 2003. Determinants of aflatoxin exposure in young children from Benin and Togo, West Africa: the critical role of weaning and weaning foods. International Journal of Epidemiology, 32, 556-562] showed that aflatoxin exposure among these children is widespread (99%) and that growth faltering is associated with high blood aflatoxin-albumin adducts (AF-alb adducts), a measure of recent past exposure. The present report demonstrates that consumption of maize is an important source of aflatoxin exposure for the survey population. Higher AF-alb adducts were correlated with higher A. flavus (CFU) infestation of maize (p=0.006), higher aflatoxin contamination (ppb) of maize (p<0.0001) and higher consumption frequencies of maize (p=0.053). The likelihood of aflatoxin exposure from maize was particularly high in agro-ecological zones where the frequency of maize consumption (SGS and CS), the presence of aflatoxin in maize (SGS) or the presence of A. flavus on maize (NGS and SGS) was relatively high. Socio-economic background did not affect the presence of A. flavus and aflatoxin in maize, but better maternal education was associated with lower frequencies of maize consumption among children from the northernmost agro-ecological zone (SS) (p=0.001). The

  17. 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

  18. Phenolic content and ferric reducing-antioxidant power of cow's milk produced in different pasture-based production systems in southern Brazil.

    PubMed

    Kuhnen, Shirley; Moacyr, Juliana R; Mayer, Jaqueline K; Navarro, Bruno B; Trevisan, Rafael; Honorato, Luciana A; Maraschin, Marcelo; Pinheiro Machado Filho, Luiz C

    2014-12-01

    Phenolic compounds are widely present in forage. However, few studies have been carried out to investigate the presence of these compounds in animal products such as milk. In this study, the total phenolic content (TPC) and ferric reducing-antioxidant power (FRAP) of milk produced under agroecological and conventional management systems in southern Brazil were determined. Three systems were compared: (a) agroecological, with intensive rotational grazing, also known as Voisin grazing (ECO); (b) semi-intensive conventional (SIC); and (c) conventional grazing (CGR) (n = 8 per group). Pastures with distinct and more diverse botanical composition were observed on the ECO farms. Significantly (P < 0.05) lower amounts of TPC were found in agroecologically produced milk in autumn and summer and the CGR system showed the highest FRAP value (P < 0.05) for the samples collected in autumn. Positive correlations where found between the TPC and FRAP values obtained for the milk samples (0.198, P < 0.05), milk FRAP and forage TPC values (0.344, P < 0.05), and the TPC and FRAP values obtained for the forage (0.70, p < 0.01). PCA applied to the UV spectra dataset (200-350 nm) clearly distinguished the samples collected from the ECO system in the winter. Our results revealed that, under the conditions prevalent in southern Brazil, since the cows were allowed to graze in all of the systems, the TPC and antioxidant capacity of the milk samples showed minimal variation. However, since the forage TPC and FRAP values for the milk were correlated, TPC appears to be a promising variable for the purpose of monitoring forage prior to its selection aimed at enhancing the antioxidant activity of milk. © 2014 Society of Chemical Industry.

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

    PubMed

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

    2010-01-01

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

  20. 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.

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

    NASA Astrophysics Data System (ADS)

    Cano, Ramiro; Abián, Alberto; Mena, Elena

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

  2. Input management of production systems.

    PubMed

    Odum, E P

    1989-01-13

    Nonpoint sources of pollution, which are largely responsible for stressing regional and global life-supporting atmosphere, soil, and water, can only be reduced (and ultimately controlled) by input management that involves increasing the efficiency of production systems and reducing the inputs of environmentally damaging materials. Input management requires a major change, an about-face, in the approach to management of agriculture, power plants, and industries because the focus is on waste reduction and recycling rather than on waste disposal. For large-scale ecosystem-level situations a top-down hierarchical approach is suggested and illustrated by recent research in agroecology and landscape ecology.

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

    PubMed

    Boval, Maryline; Angeon, Valérie; Rudel, Tom

    2017-02-01

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

  4. Bovine trypanosomosis: changes in parasitemia and packed cell volume in dry and wet seasons at Gidami District, Oromia Regional State, western Ethiopia.

    PubMed

    Degneh, Efrem; Shibeshi, Workineh; Terefe, Getachew; Asres, Kaleab; Ashenafi, Hagos

    2017-09-11

    Animal trypanosomosis is one of the major disease problems affecting agricultural productivity in Ethiopia. The impact of the disease is believed to vary with season and agro-ecologies in line with fly vector distribution. A cross-sectional study on bovine trypanosomosis was conducted from November 2015 to June 2016, in seven selected villages of Gidami district, Oromia Regional State, western Ethiopia. A total of 930 blood samples were collected and subjected to parasitological and hematological analysis. The overall prevalence of bovine trypanosomosis was 14.1%. The seasonal prevalence shows 9.06% in early dry and 18.4% in early rainy seasons. Three trypanosome species, Trypanosoma congolense, Trypanosoma vivax and Trypanosoma brucei were identified in the examined animals. T. congolense followed by T. vivax were the predominant species (respectively 59.0 and 35.9% in early dry season and 62.0 and 22.8% in early rainy season). The prevalence of T. vivax remained similar in both early dry and early rainy seasons in both lowland and midland agroecologies whereas T. congolense was more dominant in the lowland area in both seasons compared to mid land study sites. The disease was more prevalent in lowland (23.9%) compared to midland (11.1%) during early rainy season (P < 0.001) whereas no significant difference was observed between the two agroecologies during early dry season (P = 0.165). Packed cell volume (PCV) was much lower in parasitemic animals than in aparasitemic cattle whereas the mean PCV value for parasitemic animals (20.36%; 95% CI 19.56 to 21.16) in early dry season was similar to values in early rainy season (20.46%, 95% CI 18.84 to 21.08%). A similar situation was noticed for animals in both low land and mid land study sites. Overall, the detection of trypanosomes in blood was significantly affected by agro-ecology, season and body condition of the animals. Special emphasis should be given to integrated trypanosomosis management in early rainy

  5. 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.

  6. 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.

  7. 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

  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.

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

    PubMed Central

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

    2016-01-01

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

  10. 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.

  11. Natural enemies of the maize cob borer, Mussidia nigrivenella (Lepidoptera: Pyralidae) in Benin, West Africa.

    PubMed

    Sétamou, M; Schulthess, F; Goergen, G; Poehling, H-M; Borgemeister, C

    2002-08-01

    Mussidia nigrivenella Ragonot is a pest of maize cobs in West Africa. It significantly reduces maize yields and grain quality, with quantitative losses of 2-25%at harvest, and up to 10-15% indirect losses due to an increase in storage pest infestation levels. Infestation by M. nigrivenella also significantly increased the susceptibility of maize to Aspergillus flavus infection and subsequent aflatoxin contamination. Surveys conducted in different agro-ecological zones of Benin on cultivated and wild host plants during 1994-1997 revealed one egg parasitoid, three larval parasitoids and one pupal parasitoid attacking M. nigrivenella. Egg parasitism was scarce on all host plants sampled and in all four agro-ecological zones. Parasitism by larval and pupal parasitoids was usually less than 10%, and varied with host plant species. Both larval and pupal parasitoids were rare or absent in cultivated maize fields. The solitary chalcidid pupal parasitoid, Antrocephalus crassipes Masi, was the predominant species, contributing approximately 53% of the observed mortality. Logistic regression analysis indicated that this parasitoid was more prevalent on fruits of Gardenia spp. (Rubiaceae) than on the other host plant species including maize used by M. nigrivenella, and was most abundant between February and September. The differences in parasitoid diversity and parasitism between Benin and other regions suggest that there are opportunities for biological control through introduction of exotic parasitoids or using the 'new association' approach, which uses natural enemies of closely related host species that occupy similar ecological niches to the target pest.

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

    SciTech Connect

    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 in 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.

  13. Insect fauna associated with Anacardium occidentale (Sapindales: Anacardiaceae) in Benin, West Africa.

    PubMed

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  15. 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

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

    PubMed

    Molento, Marcelo Beltrão

    2009-08-07

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

  17. Risk of Exposure to Multiple Mycotoxins from Maize-Based Complementary Foods in Tanzania.

    PubMed

    Kamala, Analice; Kimanya, Martin; Lachat, Carl; Jacxsens, Liesbeth; Haesaert, Geert; Kolsteren, Patrick; Ortiz, Johana; Tiisekwa, Bendantuguka; De Meulenaer, Bruno

    2017-08-23

    This study estimated exposure to multiple mycotoxins in 249 infants aged between 6 and 12 months in three agro-ecological zones of Tanzania. Maize-based complementary food intakes were estimated using two 24 h dietary recalls. Using @Risk software, probabilistic exposure assessment was conducted by modeling maize intake data (kg/kg body weight/day) with previously determined multiple mycotoxin (except for ochratoxin A (OTA) and zearalenone (ZEA), present in only a few samples) contamination data (μg/kg) in maize. Maize intakes ranged from 0.13 to 185 g/child/day (average = 59 ± 36 g/child/day). The estimated mean exposures were higher for aflatoxins (6-fold), fumonisins (3-fold), and deoxynivalenol (2-fold) than health-based guidance values of 0.017 ng/kg body weight/day, 2 μg/kg body weight/day, and 1 μg/kg body weight/day, respectively. The population at risk of exposures above the limits of health concern ranged from 12% for HT-2 toxin through 35% for deoxynivalenol to 100% for aflatoxins. The exposure varied among the agro-ecological zones. Strategies targeting multiple mycotoxins in maize are urgently needed to minimize exposures in Tanzania.

  18. Determination of seasonal rainfall variability, onset and cessation in semi-arid Tharaka district, Kenya

    NASA Astrophysics Data System (ADS)

    Recha, C. W.; Makokha, G. L.; Traore, P. S.; Shisanya, C.; Lodoun, T.; Sako, A.

    2012-05-01

    The study quantified rainfall variability for March-May (MAM) and October-December (OND) seasons in Tharaka district, Kenya. The parameters analysed were inter-annual variability of seasonal rainfall, onset and cessation using daily rainfall data in three agro-ecological zones' stations. Percentage mean cumulative method was used to determine onset and cessation, and seasonal variability was estimated using rainfall variability indices. Although both seasons are highly variable, OND has been persistently below mean over time while MAM shows high within-season variability. Despite the near uniformity in the mean onset and cessation dates, the former is highly variable on an inter-annual scale. The two rainfall seasons are inherently dissimilar and therefore require specific cropping in agro-ecological zone LM4 and LM4-5. It is possible that farmers in IL5 are missing an opportunity by under-utilising MAM rainfall. The results should be incorporated in implications of climate variability and vulnerability assessment in semi-arid Tharaka district.

  19. Establishing a regional nitrogen management approach to mitigate greenhouse gas emission intensity from intensive smallholder maize production.

    PubMed

    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.

  20. 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.

  1. 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

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  3. 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

  4. 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.

  5. Genetic diversity of Ehrlichia ruminantium in Amblyomma variegatum ticks and small ruminants in The Gambia determined by restriction fragment profile analysis.

    PubMed

    Faburay, Bonto; Jongejan, Frans; Taoufik, Amar; Ceesay, Ansumana; Geysen, Dirk

    2008-01-01

    Understanding genetic diversity of Ehrlichia ruminantium in host and vector populations is an important prerequisite to controlling heartwater by vaccination in traditional livestock systems in sub-Saharan Africa. We carried out a study in two phases: (i) evaluating the usefulness of the PCR-RFLP assay based on the map1 coding sequence of E. ruminantium as a discriminatory tool to characterise genetic diversity, (ii) applying the technique to field samples from Amblyomma variegatum ticks and small ruminants to characterise genotypic diversity of the organism in three main agroecological zones of The Gambia, Sudano-Guinean (SG), Western Sudano-Sahelian (WSS) and Eastern Sudano-Sahelian (ESS). Restriction fragment length polymorphisms were observed among different strains of E. ruminantium supporting the usefulness of the PCR-RFLP technique for studying genetic diversity of the organism. Restriction enzyme map1 profile analysis indicated the presence in The Gambia of multiple genotypes (at least 11) of E. ruminantium with sites in the WSS and SG zones showing comparatively high number of diverse genotypes. Profiles similar to the Kerr Seringe genotype (DQ333230) showed the highest distribution frequency, being present at sites in all three agroecological zones, thereby making the strain a suitable candidate for further characterisation in cross-protection studies. An additional three genotypes showed relatively high distribution frequency and were present in all three zones making them equally important for isolation and subsequent characterisation. The study demonstrated the occurrence of mixed infections with E. ruminantium genotypes in ruminants and ticks.

  6. Infestation and population dynamics of insects on stored cassava and yams chips in Benin, West Africa.

    PubMed

    Gnonlonfin, G J B; Hell, K; Siame, A B; Fandohan, P

    2008-12-01

    Natural insect infestation in cassava (Manihot esculenta Crantz subspecies esculenta) and yam (Dioscorea spp.) chips was evaluated during two consecutive storage seasons (2003-2004 and 2004-2005) in two agroecological zones of Benin (Northern Guinea Savanna [NGS] and Sudan Savanna [SS]). The insects infesting chips were collected, identified, and counted, they included Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), Cathartus quadricollis (Guerin) (Coleoptera: Silvanidae), Carpophilus dimidiatus (F.) (Coleoptera: Nitidulidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), and Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). P. truncatus and C. quadricollis were observed with a higher prevalence on cassava than on yam chips. During both seasons after 3 mo of storage, all (100%) cassava chip samples were infested with P. truncatus and C. quadricollis in both agroecological zones, whereas yam chips only showed lower infestation rates of 59.5 and 19.1% for P. truncatus and C. quadricollis, respectively, at the end of storage in 2003-2004. During the 2004-2005 season after 3 mo of storage infestation rate in yam chips was 66 and 24% in NGS and 100 and 0% in SS for P. truncatus and C. quadricollis, respectively, showing that insect infestation levels vary significantly with commodity, year, and fluctuate during the storage season.

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

    DOE PAGES

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

    2016-02-11

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

  8. 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.

  9. 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.

  10. 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%).

  11. 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

  12. Increased productivity of a cover crop mixture is not associated with enhanced agroecosystem services.

    PubMed

    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.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

  15. 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

  16. 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.

  17. 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

  18. 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.

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

    PubMed

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

    2015-04-01

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

  20. The effect of variety and location on cactus pear (Opuntia ficus-indica) fruit quality.

    PubMed

    de Wit, Maryna; Nel, Philip; Osthoff, Gernot; Labuschagne, Maryke T

    2010-06-01

    Little is known about the performance of South African cactus pear varieties in different agro-ecological regions. Effects of locality on internal quality parameters of available cactus pear varieties were examined. With only one exception, no significant differences among the mean replication values for the different parameters between the different locations were observed. The differences between mean values for most individual parameters at the three localities were highly significant. Highly significant differences between the mean values for the measured characteristics were observed, not only among the locations (except for the pulp glucose values), but also for the influences of genotype and interaction between locality and genotype. Significant variations existed between mean values of the different characteristics between localities. Genotype x environmental interactions were noted. It was concluded that Meyers is the most appropriate cultivar for economical purposes in South Africa.

  1. [Eco-fitness of county-level agricultural leading industry structure: assessment and development prediction].

    PubMed

    Wang, Liang; Zhu, Li-Qun; Zhang, Si-Wei; Zhang, Pei-Qi; Xu, Min-Lun; Bian, Xin-Min

    2012-11-01

    Based on the 'three critical points' theory of eco-fitness, and by using dynamic weighting and fitting methods, an assessment system for the eco-fitness of county-level agricultural leading industry structure was constructed, and, taking Zhangqiu of Shandong Province, East China as a case, the eco-fitness of county-level agricultural leading industry structure was assessed and predicted. Due to the limited agro-ecological resources, the comprehensive eco-fitness index of four kinds of agricultural leading industry in Zhangqiu presented an upward trend from 2005 to 2010, but a downward trend from 2011 to 2015. The eco-fitness indices of oil crops and fruits would be negative in 2015. The applied research in Zhangqiu confirmed the validity of the assessment system constructed for the eco-fitness of county-level agriculture leading industry structure and the rationality of the prediction model.

  2. 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.

  3. 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

  4. [Toxicity and apple production in southern Brazil].

    PubMed

    Klanovicz, Jó

    2010-03-01

    The article explores the links between the controversial apprehension of contaminated apples in southern Brazil in 1989 and the reactions of the apple industry to press reports on the use of pesticides in Brazilian orchards. The issue is framed within a broader analysis of the notions of toxicity and 'danger' surrounding the consumption of healthier food and the idea of 'food security,' notions that have begun taking hold in public and private life. It is argued that apple growers' responses to the problem can be better understood through a historical reading of the interactions between the biology of the apple tree, the agroecology of this monoculture, and the structures, actors, and discourses of the human and non-human groups in Brazil's apple-producing region.

  5. Reframing the Food-Biodiversity Challenge.

    PubMed

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

    2017-03-08

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

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

    PubMed

    Memmott, Jane

    2009-06-27

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

  7. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  9. 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

  10. 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

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

    PubMed

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

    2015-06-02

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

  12. Arthropod pest management in organic crops.

    PubMed

    Zehnder, Geoff; Gurr, Geoff M; Kühne, Stefan; Wade, Mark R; Wratten, Steve D; Wyss, Eric

    2007-01-01

    Burgeoning consumer interest in organically produced foods has made organic farming one of the fastest growing segments of agriculture. This growth has not been supported adequately by rigorous research to address challenges such as arthropod pest management. The research that has been conducted, however, is complemented by research in aspects of conventional agriculture that may have applicability in organic systems, as well as by research in underpinning fields such as applied ecology. This article synthesizes the available literature in relation to a conceptual model of arthropod pest management strategies suitable for organic systems. The present work uses the four phases of the model to review the strategies in an agroecological context and provides a synthesis of the factors that influence the success of each phase. Rather than constituting a fringe science, pest management research for organic systems draws on cutting edge science in fields such as landscape and chemical ecology and has a bright future.

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

    PubMed

    Rasul, Golam; Hussain, Abid

    2015-01-01

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

  14. 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.

  15. Anaplasma, Ehrlichia and rickettsial pathogens in ixodid ticks infesting cattle and sheep in western Oromia, Ethiopia.

    PubMed

    Teshale, Sori; Kumsa, Bersissa; Menandro, Maria Luisa; Cassini, Rudi; Martini, Marco

    2016-10-01

    Although ticks are widely distributed in all agro-ecological zones of Ethiopia, information on tick-borne pathogens is scarce. This study was conducted to determine the presence of Anaplasma spp., Ehrlichia spp., and Rickettsia spp. in Rhipicephalus evertsi and Rhipicephalus (Boophilus) decoloratus collected from cattle and sheep at Bako, western Oromia, Ethiopia, using polymerase chain reaction and sequencing. Anaplasma ovis and Anaplasma spp., Ehrlichia ruminantium and Ehrlichia spp. were detected in Rh. decoloratus, whereas only A. ovis was detected in Rh. evertsi. Both tick species were found to harbor DNA belonging to Rickettsia spp., and Rickettsia africae. Our findings highlight the risk of infection of animals and humans with these zoonotic tick-borne bacteria in Ethiopia.

  16. 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.

  17. [Effects of straw mulching on CO2 flux in wintry fallow paddy field].

    PubMed

    Yin, Chun-mei; Xie, Xiao-li; Wang, Kai-rong

    2008-01-01

    This paper studied the effects of straw mulching on the CO2 flux in a wintry fallow paddy field at Taoyuan Agro-ecological Station, Chinese Academy of Sciences. The results showed that the effects of straw mulching mainly exerted in two ways. First, it positively affected soil temperature, making the CO2 flux increased obviously. Straw mulching gave a net emission of 2.68 g CO2 x m(-2) x d(-1), while no mulching gave a net fixation of 1.99 g CO2 x m(-2) x d(-1), the difference between them being very significant (P < 0.01). Second, straw mulching decreased the biomass of weeds and the photosynthetically active radiation they absorbed, which in turn resulted in an increase of CO2 flux. Under straw mulching, the water content in surface soil layer (0-15 cm) increased by 9% or more, but no significant change was observed in CO2 flux.

  18. 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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Examining adaptations to water stress among farming households in Sri Lanka's dry zone.

    PubMed

    Williams, Nicholas E; Carrico, Amanda

    2017-09-01

    Climate change is increasing water scarcity in Sri Lanka. Whether these changes will undermine national-level food security depends upon the ability of the small-scale farmers that dominate rice production and the institutions that support them to overcome the challenges presented by changing water availability. Analyzing household survey data, this research identifies household, institutional, and agroecological factors that influence how water-stressed farmers are working to adapt to changing conditions and how the strategies they employ impact rice yields. Paralleling studies conducted elsewhere, we identified institutional factors as particularly relevant in farmer adaptation decisions. Notably, our research identified farmers' use of hybrid seed varietals as the only local climate adaptation strategy to positively correlate with farmers' rice yields. These findings provide insight into additional factors pertinent to successful agricultural adaptation and offer encouraging evidence for policies that promote plant breeding and distribution in Sri Lanka as a means to buffer the food system to climate change-exacerbated drought.

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

    NASA Astrophysics Data System (ADS)

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

    2017-04-01

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

  1. 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.

  2. 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

  3. Aflatoxins and ochratoxin A in maize of Punjab, Pakistan.

    PubMed

    Iram, Wajiha; Anjum, Tehmina; Abbas, Mateen; Khan, Abdul Muqeet

    2014-01-01

    Aflatoxin and ochratoxin levels were determined in maize samples collected from store houses of 15 districts belonging to three agro-ecological zones of Punjab, Pakistan. Toxins were extracted by Aflaochra immunoaffinity columns and analysed by high-performance liquid chromatography (HPLC). Mean moisture content of maize kernels was recorded above the safe storage level of 15%. Results indicated that aflatoxin B1 and B2 contamination was found in 97.3% and 78.9% of the collected samples, respectively. Aflatoxin G1, aflatoxin G2 and ochratoxin A were not detected in any sample. Among positive samples, 77.3% contained aflatoxin B1 and 28% aflatoxin B2, exceeding the legal limits as set by the European Union (EU) and the United States Food and Drug Administration (USFDA). It was concluded that a significant number of samples contained aflatoxin B1 and B2 above the legal limits.

  4. Functional traits in agriculture: agrobiodiversity and ecosystem services.

    PubMed

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

    2015-09-01

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

  5. 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

  6. 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

  7. Traditional ecological knowledge underlying herding decisions of pastoralists.

    PubMed

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

    2017-08-29

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

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

    PubMed

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

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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Genetic differentiation and diversity analysis of medicinal tree Syzygium cumini (Myrtaceae) from ecologically different regions of India.

    PubMed

    Khan, Suphiya; Vaishali; Sharma, Vinay

    2010-04-01

    This study represents the agro-ecological zone wise surveys of molecular variation of important medicinal tree Syzygium cumini Linn. (Jamun) which is native to India. It is used world wide in treatment of diabetes. Despite of its diverse medicinal properties no molecular data is available about the pattern of variation in its natural range. Populations of S. cumini in India are located in different habitats which differ from each other with regard to ecological factors. In this study, random amplified polymorphic DNA (RAPD) markers were used to detect inter and intra levels of genetic variations of sixteen S. cumini genotypes collected from three major agro-ecological zones of India. A total of 220 amplification products were scored of which 87.50 % were polymorphic. The level of polymorphism ranged from 47.69 % to 74.87 % polymorphic bands per population and was correlated with population size. Different measures of diversity: Shannon's index of phenotypic diversity (I) = 0.451 ± 0.230; Nei's genetic diversity (h) = 0.300 ± 0.172; effective number of alleles per locus (Ne) = 1.51 ± 0.347; total species diversity (Hsp) = 0.315 ± 0.031 and within population diversity (Hpop) = 0.158 ± 0.104 showed high genetic diversity at species level. Coefficient of genetic differentiation (Gst =0.498; Nm = 0.503) revealed significant genetic differentiation among the populations. Most of the genetic variations are contained among the populations. The results of cluster analysis and principal component analysis (PCA) give only little evidence for an ecotypic differentiation of S. cumini populations. Present genetic structure of population suggests ex situ conservation in seed banks in which seeds from at least five populations need to collected and conserved. Secondly, our study provides practical information to herbal drugs manufactures who use Jamun as a raw material.

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

    PubMed

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

    2017-01-01

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

  16. Applicability of near-infrared reflectance spectroscopy (NIRS) for determination of crude protein content in cowpea (Vigna unguiculata) leaves

    PubMed Central

    Towett, Erick K; Alex, Merle; Shepherd, Keith D; Polreich, Severin; Aynekulu, Ermias; Maass, Brigitte L

    2013-01-01

    There is uncertainty on how generally applicable near-infrared reflectance spectroscopy (NIRS) calibrations are across genotypes and environments, and this study tests how well a single calibration performs across a wide range of conditions. We also address the optimization of NIRS to perform the analysis of crude protein (CP) content in a variety of cowpea accessions (n = 561) representing genotypic variation as well as grown in a wide range of environmental conditions in Tanzania and Uganda. The samples were submitted to NIRS analysis and a predictive calibration model developed. A modified partial least-squares regression with cross-validation was used to evaluate the models and identify possible spectral outliers. Calibration statistics for CP suggests that NIRS can predict this parameter in a wide range of cowpea leaves from different agro-ecological zones of eastern Africa with high accuracy (R2cal = 0.93; standard error of cross-validation = 0.74). NIRS analysis improved when a calibration set was developed from samples selected to represent the range of spectral variability. We conclude from the present results that this technique is a good alternative to chemical analysis for the determination of CP contents in leaf samples from cowpea in the African context, as one of the main advantages of NIRS is the large number of compounds that can be measured at once in the same sample, thus substantially reducing the cost per analysis. The current model is applicable in predicting the CP content of young cowpea leaves for human nutrition from different agro-ecological zones and genetic materials, as cowpea leaves are one of the popular vegetables in the region. PMID:24804013

  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.

  18. 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.

  19. 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

  20. Satellite climatology and the environmental risk of Schistosoma mansoni in Ethiopia and east Africa.

    PubMed

    Malone, J B; Yilma, J M; McCarroll, J C; Erko, B; Mukaratirwa, S; Zhou, X

    2001-04-27

    Annual and seasonal composite maps prepared from the normalized difference vegetation index (NDVI) and earth surface maximum temperature (T(max)) satellite data from the archives of the Global land 1-km program of the United States Geological Survey (USGS) were studied for. their potential value, using geographic information system (GIS) methods, as surrogates of climate data in the development of environmental risk models for schistosomiasis in Ethiopia. Annual, wet season and dry season models were developed and iteratively analyzed for relationships with Schistosoma mansoni distribution and infection prevalence rates. Model-predicted endemic area overlays that best fit the distribution of sites with over 5% prevalence corresponded to values of NDVI 125-145 and T(max) 20-33 degrees C in the annual composite map, NDVI 125-145 and T(max) 18-29 degrees C for the wet season map, and NDVI 125-140 and T(max) 22-37 degrees C for the dry season map. The model-predicted endemic area was similar to that of a prior model developed using an independent agroecologic zone data set from the United Nations Food and Agriculture Organization (FAO). Results were consistent with field and laboratory data on the preferences and limits of tolerance of the S. mansoni-Biomphalaria pfeifferi system. Results suggest that Global 1-km NDVI and T(max), when used together, can be used as surrogate climate data for development of GIS risk assessment models for schistosomiasis. The model developed for Ethiopia based on global 1-km satellite data was extrapolated to a broader area of East Africa. When used with FAO agroecologic zone climate data limits of <27 degrees C for average annual mean temperature and annual moisture deficits (annual rain-annual potential evapotranspiration) of <-1300 mm, the model accurately represented the regional distribution of the S. mansoni-B. pfeifferi system in the East Africa extrapolation area.

  1. 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.

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

    PubMed

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Sluyter, Andrew

    1997-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

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

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

    PubMed Central

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

    2016-01-01

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

  7. Applicability of near-infrared reflectance spectroscopy (NIRS) for determination of crude protein content in cowpea (Vigna unguiculata) leaves.

    PubMed

    Towett, Erick K; Alex, Merle; Shepherd, Keith D; Polreich, Severin; Aynekulu, Ermias; Maass, Brigitte L

    2013-01-01

    There is uncertainty on how generally applicable near-infrared reflectance spectroscopy (NIRS) calibrations are across genotypes and environments, and this study tests how well a single calibration performs across a wide range of conditions. We also address the optimization of NIRS to perform the analysis of crude protein (CP) content in a variety of cowpea accessions (n = 561) representing genotypic variation as well as grown in a wide range of environmental conditions in Tanzania and Uganda. The samples were submitted to NIRS analysis and a predictive calibration model developed. A modified partial least-squares regression with cross-validation was used to evaluate the models and identify possible spectral outliers. Calibration statistics for CP suggests that NIRS can predict this parameter in a wide range of cowpea leaves from different agro-ecological zones of eastern Africa with high accuracy (R (2)cal = 0.93; standard error of cross-validation = 0.74). NIRS analysis improved when a calibration set was developed from samples selected to represent the range of spectral variability. We conclude from the present results that this technique is a good alternative to chemical analysis for the determination of CP contents in leaf samples from cowpea in the African context, as one of the main advantages of NIRS is the large number of compounds that can be measured at once in the same sample, thus substantially reducing the cost per analysis. The current model is applicable in predicting the CP content of young cowpea leaves for human nutrition from different agro-ecological zones and genetic materials, as cowpea leaves are one of the popular vegetables in the region.

  8. 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.

  9. Estimating crop yields by integrating the FAO Crop Specific Water Balance model with real-time satellite data and ground-based ancillary data

    NASA Astrophysics Data System (ADS)

    Reynolds, Curt Andrew

    The broad objective of this research was to develop a spatial model which provides both timely and quantitative regional maize yield estimates for real-time Early Warning Systems (EWS) by integrating satellite data with ground-based ancillary data. The Food and Agriculture Organization (FAO) Crop Specific Water Balance (CSWB) model was modified by using the real-time spatial data that include: dekad (ten-day) estimated rainfall (RFE) and Normalized Difference Vegetation Index (NDVI) composites derived from the METEOSAT and NOAA-AVHRR satellites, respectively; ground-based dekad potential evapo-transpiration (PET) data and seasonal estimated area-planted data provided by the Government of Kenya (GoK). A Geographical Information System (GIS) software was utilized to: drive the crop yield model; manage the spatial and temporal variability of the satellite images; interpolate between ground-based potential evapo-transpiration and rainfall measurements; and import ancillary data such as soil maps, administrative boundaries, etc. In addition, agro-ecological zones, length of growing season, and crop production functions, as defined by the FAO, were utilized to estimate quantitative maize yields. The GIS-based CSWB model was developed for three different resolutions: agro-ecological zone (AEZ) polygons; 7.6-kilometer pixels; and 1.1-kilometer pixels. The model was validated by comparing model production estimates from archived satellite and agro-meteorological data to historical district maize production reports from two Kenya government agencies, the Ministry of Agriculture (MoA) and the Department of Resource Surveys and Remote Sensing (DRSRS). For the AEZ analysis, comparison of model district maize production results and district maize production estimates from the MoA (1989-1997) and the DRSRS (1989-1993) revealed correlation coefficients of 0.94 and 0.93, respectively. The comparison for the 7.6-kilometer analysis showed correlation coefficients of 0.95 and 0

  10. 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

  11. 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

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

    PubMed

    Olango, Temesgen Magule; Tesfaye, Bizuayehu; Catellani, Marcello; Pè, Mario Enrico

    2014-05-08

    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. 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. 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 prepare 10 different dishes

  13. 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

  14. 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

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

    PubMed

    Segnon, Alcade C; Achigan-Dako, Enoch G

    2014-12-23

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

  16. 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.

  17. 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

  18. Sub-regional integration in Sudan: the key to food security and recovery.

    PubMed

    D'Silva, Brian; Tecosky, Olivia

    2007-03-01

    The signing of the Comprehensive Peace Agreement (CPA) in Sudan has created a new opportunity for peace. Approaches to food security must now be reoriented based on the agro-ecological diversity in Sudan. WFP is in a unique position to catalyse an approach to food security that meets immediate needs and contributes to long-term recovery, in collaboration with the Government of National Unity (GNU) and the Government of South Sudan (GOSS). Aggregate food production in Sudan has increased in the past decade. At sub-regional levels, however, many areas remain food insecure. Major research must be undertaken to identify optimum levels of food production and barriers to access to food at sub-regional levels as a first step towards linking deficit areas with areas of surplus. Initiatives must also be undertaken to facilitate increased integration between sub-regions. Increased sub-regional linkages could ensure more efficient delivery of food in the short term as well as recovery and economic growth in the long term.

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

    PubMed

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

    2017-01-03

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

  20. Rhizosphere effect on survival of Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in manure-amended soil during cabbage (Brassica oleracea) cultivation under tropical field conditions in Sub-Saharan Africa.

    PubMed

    Ongeng, Duncan; Muyanja, Charles; Ryckeboer, Jaak; Geeraerd, Annemie H; Springael, Dirk

    2011-09-15

    The effect of cabbage (Brassica oleracea) rhizosphere on survival of Escherichia coli O157:H7 and Salmonella Typhimurium in manure-amended soils under tropical field conditions was investigated in the Central Agro-Ecological Zone of Uganda. Three-week old cabbage seedlings were transplanted and cultivated for 120 days on manure-amended soil inoculated with 4 or 7 log CFU/g non-virulent E. coli O157:H7 and S. Typhimurium. Cabbage rhizosphere did not affect survival of the 4log CFU/g inocula in manure-amended soil and the two enteric bacteria were not detected on/in cabbage leaves at harvest. The 7 log CFU/g E. coli O157:H7 and S. Typhimurium survived in bulk soil for a maximum of 80 and 96 days, respectively, but the organisms remained culturable in cabbage rhizosphere up to the time of harvest. At 7 log CFU/g inoculum, E. coli O157:H7 and S. Typhimurium contamination on cabbage leaves occurred throughout the cultivation period. Leaf surface sterilisation with 1% AgNO(3) indicated that the organisms were present superficially and in protected locations on the leaves. These results demonstrate that under tropical field conditions, cabbage rhizosphere enhances the persistence of E. coli O157:H7 and S. Typhimurium in manure-amended soil at high inoculum density and is associated with long-term contamination of the leaves.

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

    PubMed Central

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

    2017-01-01

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

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

    PubMed Central

    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

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

    PubMed Central

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

    2016-01-01

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

  4. [Epidemiology of caprine and ovine brucellosis in Formosa province, Argentina].

    PubMed

    Russo, Ana M; Mancebo, Orlando A; Monzón, Carlos M; Gait, Juan J; Casco, Rubén D; Torioni de Echaide, Susana M

    2016-01-01

    An epidemiological study of brucellosis was carried out in 516 goats and mixed flocks (goat/sheep) from the three agro-ecological regions of Formosa province, Argentina. Serum samples from a total of 25401 goats and 2453 sheeps were analyzed using buffered plate agglutination test (BPAT) and complement fixation test (CFT). Bacteriological and PCR analyses on milk samples from goats in three flocks with a history of brucellosis and recent abortions were also performed. Brucellosis was detected in four of the nine departments of the province with an overall prevalence of 2% and an intra-flock prevalence ranging between 1% and 40%. The proportion of infected flocks was 3.6%, 12% and 36% for the eastern, central and western regions, respectively. Brucella melitensis bv. 1 was isolated efrom goats for the first time in the province. The expected fragments of 827bp from the omp2ab gene (Brucella spp.) and 731bp from the insert IS711 (B. melitensis) were amplified by PCR. Detection of antibodies by BPAT and FCT in sheep cohabiting with goats suggests that infections could have been caused by B. melitensis, posing an additional risk to public health. Control and eradication programs for brucellosis should consider mixed flocks as a single epidemiological unit. The results indicate that brucellosis by B. melitensis bv1 is highly endemic in the central and western regions of Formosa province.

  5. Social organization influences the exchange and species richness of medicinal plants in Amazonian homegardens

    PubMed Central

    2016-01-01

    Medicinal plants provide indigenous and peasant communities worldwide with means to meet their healthcare needs. Homegardens often act as medicine cabinets, providing easily accessible medicinal plants for household needs. Social structure and social exchanges have been proposed as factors influencing the species diversity that people maintain in their homegardens. Here, we assess the association between the exchange of medicinal knowledge and plant material and medicinal plant richness in homegardens. Using Tsimane’ Amazonian homegardens as a case study, we explore whether social organization shapes exchanges of medicinal plant knowledge and medicinal plant material. We also use network centrality measures to evaluate people’s location and performance in medicinal plant knowledge and plant material exchange networks. Our results suggest that social organization, specifically kinship and gender relations, influences medicinal plant exchange patterns significantly. Homegardens total and medicinal plant species richness are related to gardeners’ centrality in the networks, whereby people with greater centrality maintain greater plant richness. Thus, together with agroecological conditions, social relations among gardeners and the culturally specific social structure seem to be important determinants of plant richness in homegardens. Understanding which factors pattern general species diversity in tropical homegardens, and medicinal plant diversity in particular, can help policy makers, health providers, and local communities to understand better how to promote and preserve medicinal plants in situ. Biocultural approaches that are also gender sensitive offer a culturally appropriate means to reduce the global and local loss of both biological and cultural diversity. PMID:27668001

  6. Lentil (Lens culinaris Medik.) nodulates with genotypically and phenotypically diverse rhizobia in Ethiopian soils.

    PubMed

    Tena, Wondwosen; Wolde-Meskel, Endalkachew; Degefu, Tulu; Walley, Fran

    2017-01-01

    Forty-eight lentil-nodulating rhizobia were isolated from soil samples collected from diverse agro-ecological locations in Ethiopia, and characterized based on 76 phenotypic traits. Furthermore, 26 representative strains were selected and characterized using multilocus sequence analyses (MLSA) of core (16S rRNA, recA, atpD, glnII and gyrB) and symbiotic (nodA and nifH) genes. Numerical analysis of phenotypic characteristics showed that the 48 test strains fell into three major distinct clusters. The phylogenetic trees based on 16S rRNA genes showed that they belong to the Rhizobium genus. Our phylogenetic reconstruction based on combined gene trees (recA, atpD and glnII) supported three distinct sub-lineages (Clades I-III). While genospecies I and II could be classified with Rhizobium etli and Rhizobium leguminosarum, respectively, genospecies III, might be an unnamed genospecies within the genus Rhizobium. Phylogenetic reconstruction based on the symbiosis-related genes supported a single cluster, indicating differences in the evolutionary histories between chromosomal and symbiotic genes. Overall, these results confirmed the presence of a great diversity of lentil-nodulating Rhizobium species in Ethiopia, inviting further exploration. Moreover, the differences in symbiotic effectiveness of the test strains indicated the potential for selecting and using them as inoculants to improve the productivity of lentil in the country. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

    PubMed Central

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

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

    PubMed

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

    2012-06-01

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

  10. [Impact of chemical fertilizers application on soil ecological environment].

    PubMed

    Li, Dong-Po; Wu, Zhi-Jie

    2008-05-01

    China heads the list in the world's chemical fertilizers production and consumption. In 2006, the chemical fertilizers production in this country was 5304.8 x 10(4) t, being 14.2% higher than that in 2005. At present, its chemical nitrogen application rate is averagely more than 220 kg hm(-2), and phosphorous fertilizer application rate is more than 102 kg hm(-2) (P2O5) in single growing season. Some chemical fertilizers in use contain toxic by-components such as heavy metals, inorganic acids and organic pollutants, and thus, a long-term application of these chemical fertilizers can possibly induce the accumulation of these by-components in soil, resulting in the worsening of soil ecological environment, and making the heavy metals, nitrate, and other harmful components in agricultural products including vegetables, grains and fruits seriously surpassed the standards. In this paper, the causes, characteristics, and consequences of soil contamination via chemical fertilizers application were discussed, and some countermeasures for the mitigation of agro-ecological environmental pollution by chemical fertilizers were put forward.

  11. 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.

  12. 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.

  13. Analysis of population structure of Aspergillus flavus from peanut based on vegetative compatibility, geographic origin, mycotoxin and sclerotia production.

    PubMed

    Pildain, M Belén; Vaamonde, Graciela; Cabral, Daniel

    2004-05-15

    Isolates of Aspergillus flavus obtained from a new growing peanut region in Argentina (Formosa province) were examined for aflatoxin types B and G and cyclopiazonic acid (CPA) production. Sclerotia diameters and the number of sclerotia produced per square centimetre were also determined for each isolate. They were tested by vegetative compatibility group analysis to investigate their genetic relatedness and correlate the results with vegetative compatibility groups previously described from the major peanut-growing area (Córdoba province) in our country. Two isolates were considered atypical because they simultaneously produce aflatoxins B and G and CPA. A. flavus population from Formosa province was very diverse genetically. Vegetative compatibility groups (VCGs) formed by typical isolations of A. flavus were different among agroecological sites. Formosa isolates could not be grouped to any of the Córdoba VCGs, while that one of the VCGs that contain atypical isolates included strains from the two geographical regions. Each VCG included isolates of the same mycotoxin and sclerotia production pattern. The two regions analysed have different climatic conditions, soil type, crop sequence history and also are in different latitude. These parameters may reflect different geographic adaptation between isolates from both sites.

  14. Large-scale ecological networks do work in an ecologically complex biodiversity hotspot.

    PubMed

    Samways, Michael J; Pryke, James S

    2016-03-01

    Landscape-scale ecological networks (ENs) are interconnected conservation corridors of high-quality habitat used to mitigate the adverse effects of landscape fragmentation and to connect with protected areas. The effectiveness of ENs for biodiversity conservation and ecosystem function has been challenged. Here we show how an extensive system of ENs of remnant historic land was put in place at a large spatial scale (>0.5 million ha) in a plantation forestry context in a global biodiversity hotspot in southern Africa. These ENs can maintain indigenous and historic compositional and functional biodiversity, even in an area prone to the challenging effects of El Niño. Furthermore, ENs increase the effective size of local protected areas. Socio-ecological solutions and financial viability are also integrated as part of practical implementation of ENs. By adopting a retrospective analytical approach, biodiversity is maintained while also having productive forestry, making this a powerful agro-ecological approach on a large conservation-significant scale.

  15. A comprehensive assessment of arsenic in commonly consumed foodstuffs to evaluate the potential health risk in Bangladesh.

    PubMed

    Ahmed, Md Kawser; Shaheen, Nazma; Islam, Md Saiful; Habibullah-Al-Mamun, Md; Islam, Saiful; Islam, Md Monirul; Kundu, Goutam Kumar; Bhattacharjee, Lalita

    2016-02-15

    Arsenic (As), particularly of its inorganic form (iAs) is highly toxic, and its presence in food composites is a matter of concern for the public health safety, specifically in Bangladesh which is regarded as the most arsenic affected country throughout the world. This study was carried out to investigate the levels of As in the composite samples of commonly consumed foodstuffs collected from 30 different agro-ecological zones for the first time in Bangladesh. Most of the individual food composites contain a considerable amount of As which was, as a whole, in the range of 0.077-1.5mg/kg fw which was lower than those reported from Spain, EU, France, Korea, whereas higher than those of Mexico, Chile, Japan, Cambodia, Hong Kong, Serbia, respectively. Cereals, vegetables, milk, and fish contribute about 90% to the daily intake of inorganic arsenic. Human health risk of dietary iAs was assessed separately for both the rural and urban adults. The estimated daily dietary intakes (EDI) of iAs for the exposed rural (3.5) and urban residents (3.2 μg/kg-BW/day) clearly exceeded the previous provisional tolerable daily intake (PTDI) value of 2.1 μg/kg-BW/day, recommended by the World Health Organization (WHO). From the health point of view, this study concluded that both the rural and urban residents of Bangladesh are exposed to carcinogenic and non-carcinogenic risks who consume As-contaminated water and foodstuffs.

  16. Defining a breeding objective for Nile tilapia that takes into account the diversity of smallholder production systems.

    PubMed

    Omasaki, S K; van Arendonk, J A M; Kahi, A K; Komen, H

    2016-10-01

    In general, livestock and fish farming systems in developing countries tend to be highly diverse in terms of agro-ecological conditions and market orientation. There are no studies that have investigated if and how this diversity translates to varying preferences for breeding objective traits. This is particularly important for breeding programmes that are organized on a national level (e.g. government-supported nucleus breeding programmes). The aim of this study was to investigate whether Nile tilapia farmers with diverse production systems and economic constraints have different preferences for breeding objective traits. The second objective was to derive a consensus breeding goal, using weighted goal programming that could be used for a national breeding programme for Nile tilapia. A survey was conducted among 100 smallholder Nile tilapia farmers in Kenya to obtain preference values for traits of economic importance, by using multiple pairwise comparisons. Individual and group preference values were estimated using analytical hierarchy process. Low-income farmers preferred harvest weight, while medium- and high-income farmers preferred growth rate and survival. Grouping farmers according to market objective (fingerling production or fattening) showed that fingerling producers preferred growth rate and survival, while fattening farmers preferred harvest weight, height and thickness. Weighted goal programming was used to obtain consensus preference values, and these were used to derive desired gains for a breeding goal of a national breeding programme that takes into account the diversity of smallholder production systems.

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

    DOE PAGES

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

    2016-12-01

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

  18. Risk Assessment of Mycotoxins in Stored Maize Grains Consumed by Infants and Young Children in Nigeria.

    PubMed

    Adetunji, Modupeade C; Atanda, Olusegun O; Ezekiel, Chibundu N

    2017-07-10

    Maize is a major complimentary food for infants (0-4years) and young children (5-12years) in Nigeria. In this study, we assessed the risk of exposure of infants and young children (IYC) to some major mycotoxins in stored maize grains from five agro-ecological zones of Nigeria. The probable daily intake approach was employed to determine exposure to five mycotoxins while the margin of exposure (MOE) and population at risk of primary hepatocellular carcinoma approaches were used to characterize the risk of consuming aflatoxin contaminated maize. Infants and young children in the Derived Savannah zone are more exposed to aflatoxins, ochratoxins, and zearalenone while those in the Northern Guinea Savanna zone are mainly exposed to deoxynivalenol and fumonisins. The mean national MOE for infants and children were 0.12 and 0.3 respectively while the risk of developing primary liver cancer was estimated at 152.7 and 61.1 cancer/year/100,000 population of infants and children, respectively. Infants and young children consuming mycotoxin contaminated maize in Nigeria are therefore vulnerable to the adverse health effects. Mycotoxin contamination of maize is still a challenge in Nigeria; mitigation efforts should target the value chain and stricter tolerable limits should be enforced.

  19. [Variation characteristic in soil respiration of apple orchard and its biotic and abiotic influencing factors].

    PubMed

    Wang, Rui; Guo, Sheng-Li; Liu, Qing-Fang; Zhang, Yan-Jun; Jiang, Ji-Shao; Guo, Hui-Min; Li, Ru-Jian

    2014-05-01

    To evaluate the orchard variability of soil respiration and the response of soil respiration to its influencing factors is helpful for a deep understanding about the effects of converting cropland to apple orchard. A field experiment was conducted in the Changwu State Key Agro-Ecological Station. Soil respiration, soil temperature, soil moisture and roots biomasses were periodically measured in a mature apple orchard during 2011 and 2012. Soil respiration decreased as the distance from the trunk increased. The cumulative soil respiration in the 0.5 m-distance from the trunk was 20% and 31% higher than that in the 2 m-distance from the trunk, respectively in 2011 and 2012. The temperature sensitivity of soil respiration (Q10) was relatively lower in the 2 m-distance than that in the 0. 5 m-distance in both years. Soil temperature and soil moisture were slightly higher in the 2 m-distance, but there was no significant difference between the 2 m-distance and the 0. 5 m-distance. Soil respiration and soil temperature showed a significant exponential relationship, but there was no positive correlation between soil moisture and soil respiration. Soil temperature changes can explain seasonal variation of soil respiration well, but it could not explain its spatial variability. Root density was an important factor for the spatial variability of soil respiration and Q15. Variation of soil respiration coefficient was 23% -31%. Therefore, the distance from the trunk should be considered when estimating orchards soil respiration.

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

    PubMed

    Santosa, Edi; Lian, Chun Lan; Sugiyama, Nobuo; Misra, Raj Shekhar; Boonkorkaew, Patchareeya; Thanomchit, Kanokwan

    2017-01-01

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

  1. 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.

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

    SciTech Connect

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

    2016-12-01

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

  3. Ssr analysis for genetic structure and diversity determination of maize local populations from former Yugoslavia territories.

    PubMed

    Ignjatović-Micić, D; Drinić, S Mladenović; Nikolić, A; Lazić-Jancić, V

    2008-11-01

    A collection of 2178 local populations from ex-Yugoslavia territories is maintained in Maize Research Institute (MRI) gene bank. These populations were characterized mainly by morphological markers. In this work 21 local populations belonging to seven different agro-ecological groups have been subjected to SSR analysis using a DNA-pooling strategy. The objective of this work was to develop genetic fingerprints for characterization, identification and classification of the populations, as well as for estimation of their genetic diversity. Also, a DNA-pooling strategy was employed with the aim to certify if it could be applied for population analysis with SSR markers. Statistical analysis of 25 informative SSR primers revealing 224 alleles (bands) showed that the average within-population mean number of alleles was 2.55, the average values for total and within-population diversity were 0.784 and 0.502, respectively and G(ST) value was 0.360. Genetic distance values calculated using Modified Rogers' Distance were in the range from 0.35 to 0.60. The silver staining method of DNA used for bulked samples showed some weakness that could be overcome with a more sensitive staining method. Nevertheless, the results in this work indicate that the SSR analysis of bulks could be used for characterizing a large number of populations in gene banks.

  4. Fertilizer induced nitrous oxide emissions from Vertisols and Alfisols during sweet sorghum cultivation in the Indian semi-arid tropics.

    PubMed

    Ramu, Karri; Watanabe, Takeshi; Uchino, Hiroshi; Sahrawat, Kanwar L; Wani, Suhas P; Ito, Osamu

    2012-11-01

    Nitrous oxide (N(2)O) emissions from Vertisols and Alfisols during sweet sorghum cultivation in the Indian semi-arid tropics were determined using a closed chamber technique during the rainy season (June-October) of 2010. The study included two treatments, nitrogen (N) at a rate of 90 kg/ha and a control without N fertilizer application. The N(2)O emissions strongly coincided with N fertilization and rainfall events. The cumulative N(2)O-N emission from Alfisols was 1.81 N(2)O-N kg/ha for 90 N treatment and 0.15 N(2)O-N kg/ha for the 0 N treatment. Similarly, the N(2)O-N emission from Vertisols was 0.70 N(2)O-N kg/ha for 90 N treatment and 0.09 N(2)O-N kg/ha for the 0 N treatment. The mean N(2)O-N emission factor for fertilizer induced emissions from the Alfisols was 0.90% as compared to 0.32% for Vertisols. Our results suggest that the N(2)O emissions are dependent on the soil properties. Therefore, the monitoring of N(2)O emissions from different agro-ecological regions, having different soil types, rainfall characteristics, cropping systems and crop management practices are necessary to develop comprehensive and accurate green house gas inventories.

  5. '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.

  6. Epidemiological and evolutionary management of plant resistance: optimizing the deployment of cultivar mixtures in time and space in agricultural landscapes

    PubMed Central

    Fabre, Frédéric; Rousseau, Elsa; Mailleret, Ludovic; Moury, Benoît

    2015-01-01

    The management of genes conferring resistance to plant–pathogens should make it possible to control epidemics (epidemiological perspective) and preserve resistance durability (evolutionary perspective). Resistant and susceptible cultivars must be strategically associated according to the principles of cultivar mixture (within a season) and rotation (between seasons). We explored these questions by modeling the evolutionary and epidemiological processes shaping the dynamics of a pathogen population in a landscape composed of a seasonal cultivated compartment and a reservoir compartment hosting pathogen year-round. Optimal deployment strategies depended mostly on the molecular basis of plant–pathogen interactions and on the agro-ecological context before resistance deployment, particularly epidemic intensity and landscape connectivity. Mixtures were much more efficient in landscapes in which between-field infections and infections originating from the reservoir were more prevalent than within-field infections. Resistance genes requiring two mutations of the pathogen avirulence gene to be broken down, rather than one, were particularly useful when infections from the reservoir predominated. Combining mixture and rotation principles were better than the use of the same mixture each season as (i) they controlled epidemics more effectively in situations in which within-field infections or infections from the reservoir were frequent and (ii) they fulfilled the epidemiological and evolutionary perspectives. PMID:26640518

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

    PubMed Central

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

    2016-01-01

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

  8. Evolutionary and Ecological Dynamics of Transboundary Disease Caused by H5N1 Virus in Southeast Asia.

    PubMed

    Wei, K; Lin, Y; Xie, D

    2015-06-01

    Southeast Asia has been the breeding ground for many emerging diseases in the past decade, and it is in this region that new genetic variants of HPAI H5N1 viruses have been emerging. Cross-border movement of animals accelerates the spread of H5N1, and the changing environmental conditions also exert strong selective pressure on the viruses. The transboundary zoonotic diseases caused by H5N1 pose a serious and continual threat to global economy and public health. Here, we divided the H5N1 viruses isolated in Southeast Asia during 2003-2009 into four groups according to their phylogenetic relationships among HA gene sequences. Molecular evolution analysis suggests populations in expansion rather than a positive selection for group 2 and group 3, yet group 4 is under strong positive selection. Site 193 was found to be a potential glycosylation site and located in receptor-binding domain. Note that site 193 tends to appear in avian isolates instead of human strains. Population dynamics analysis reveals that the effective population size of infections in Southeast Asia has undergone three obvious increases, and the results are consistent with the epidemiological analysis. Ecological and phylogeographical analyses show that agro-ecological environments, migratory birds, domestic waterfowl, especially free-ranging ducks, are crucial in the occurrence, maintenance and spread of H5N1 virus. The epidemiological links between Indonesia and Suphanburi observed suggest that viruses in Indonesia were originated from multiple introductions.

  9. Avian Conservation Practices Strengthen Ecosystem Services in California Vineyards

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

    Okonya, Joshua Sikhu; Kroschel, Jürgen

    2015-01-01

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

  11. Fungal and bacterial metabolites associated with natural contamination of locally processed rice (Oryza sativa L.) in Nigeria.

    PubMed

    Rofiat, Abdus-Salaam; Fanelli, Francesca; Atanda, Olusegun; Sulyok, Michael; Cozzi, Giuseppe; Bavaro, Simona; Krska, Rudolf; Logrieco, Antonio F; Ezekiel, Chibundu N

    2015-01-01

    This study reports the fungal and bacterial metabolites associated with natural contamination of 38 composite samples of locally processed rice from five agro-ecological zones of Nigeria (AEZs). The samples were evaluated for the presence of microbial metabolites by LC-MS/MS. Among the identified metabolites, 63 fungal and 5 bacterial metabolites were measured at varying concentrations and occurrence levels. Fusarium toxins had the highest incidence of 79%, but occurred in low amounts with fumonisin B1 (FB1) having the highest percentage incidence of 39.5% and a mean of 18.5 µg/kg. Among the Aspergillus toxins, aflatoxins (AFs) occurred in 36.9% of the rice samples, with aflatoxin B1 (AFB1) having the highest occurrence level of 18.4% and a mean value of 5 µg/kg. About 12 metabolites had incidence levels > 50%, including beauvericin (BEA) and tryptophol, which had occurrence levels of 100%. Among the emerging toxins under evaluation by international organisations such as the European Food Safety Authority (EFSA) and the Food and Agriculture Organisation of the United Nations (FAO), citrinin, sterigmatocystin (STER) and beauvericin were detected with maximum values of 207, 125 and 131 μg/kg, respectively. This paper also reports the first documented evidence of the contamination of Nigerian rice by bacterial and Alternaria metabolites, nivalenol, kojic acid, STER, moniliformin, fusaric acid, fumonisin B3, citrinin, 3-nitropropionic acid, andrastin A, cytochalasins, emodin and physicon.

  12. Population Dynamics, Distribution, and Species Diversity of Fruit Flies on Cucurbits in Kashmir Valley, India

    PubMed Central

    Ganie, S. A.; Khan, Z. H.; Ahangar, R. A.; Bhat, H. A.; Hussain, Barkat

    2013-01-01

    Given the economic importance of cucurbits and the losses incurred by fruit fly infestation, the population dynamics of fruit flies in cucurbit crops and the influence of abiotic parameters, such as temperature, relative humidity, rainfall, and total sunshine hours per day on the fruit fly population were studied. The study was carried out at six locations; in district Srinagar the locations were Batmaloo, Shalimar, and Dal, while in district Budgam the locations were Chadoora, Narkara, and Bugam (Jammu and Kashmir, India). Various cucurbit crops, such as cucumber, bottle gourd, ridge gourd and bitter gourd, were selected for the study. With regard to locations, mean fruit fly population was highest (6.09, 4.55, 3.87, and 3.60 flies/trap/week) at Batamaloo and Chadoora (4.73, 3.93, 2.73, and 2.73 flies/trap/week) on cucumber, bottle gourd, ridge gourd, and bitter gourd, respectively. The population of fruit flies was significantly correlated with the minimum and maximum temperature. The maximum species diversity of fruit flies was 0.511, recorded in Chadoora. Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) was the most predominant species in both Srinagar and Budgam, followed by B. dorsalis (Hendel) and B. tau (Walker), while B. scutellaris (Bezzi) was found only in Chadoora. Results of the present investigation may be utilized in developing a sustainable pest management strategy in the agroecological system. PMID:23906383

  13. Population dynamics, distribution, and species diversity of fruit flies on cucurbits in Kashmir Valley, India.

    PubMed

    Ganie, S A; Khan, Z H; Ahangar, R A; Bhat, H A; Hussain, Barkat

    2013-01-01

    Given the economic importance of cucurbits and the losses incurred by fruit fly infestation, the population dynamics of fruit flies in cucurbit crops and the influence of abiotic parameters, such as temperature, relative humidity, rainfall, and total sunshine hours per day on the fruit fly population were studied. The study was carried out at six locations; in district Srinagar the locations were Batmaloo, Shalimar, and Dal, while in district Budgam the locations were Chadoora, Narkara, and Bugam (Jammu and Kashmir, India). Various cucurbit crops, such as cucumber, bottle gourd, ridge gourd and bitter gourd, were selected for the study. With regard to locations, mean fruit fly population was highest (6.09, 4.55, 3.87, and 3.60 flies/trap/week) at Batamaloo and Chadoora (4.73, 3.93, 2.73, and 2.73 flies/trap/week) on cucumber, bottle gourd, ridge gourd, and bitter gourd, respectively. The population of fruit flies was significantly correlated with the minimum and maximum temperature. The maximum species diversity of fruit flies was 0.511, recorded in Chadoora. Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) was the most predominant species in both Srinagar and Budgam, followed by B. dorsalis (Hendel) and B. tau (Walker), while B. scutellaris (Bezzi) was found only in Chadoora. Results of the present investigation may be utilized in developing a sustainable pest management strategy in the agroecological system.

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

    PubMed Central

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

    2014-01-01

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

  15. Organic livestock production in Uganda: potentials, challenges and prospects.

    PubMed

    Nalubwama, Sylvia Muwanga; Mugisha, Anthony; Vaarst, Mette

    2011-04-01

    Development in organic farming has been stimulated by farmers and consumers becoming interested in healthy food products and sustainable environment. Organic agriculture is a holistic production management system which is based on the principles of health, ecology, care, and fairness. Organic development in Uganda has focused more on the crop sector than livestock sector and has primarily involved the private sector, like organic products export companies and non-governmental organizations. Agriculture in Uganda and many African countries is predominantly traditional, less mechanized, and is usually associated with minimum use of chemical fertilizers, pesticides, and drugs. This low external input agriculture also referred to as "organic by default" can create basis for organic farming where agroecological methods are introduced and present an alternative in terms of intensification to the current low-input/low-output systems. Traditional farming should not be confused with organic farming because in some cases, the existing traditional practices have consequences like overstocking and less attention to soil improvement as well as to animal health and welfare, which is contrary to organic principles of ecology, fairness, health, and care. Challenges of implementing sustainable organic practices in the Ugandan livestock sector threaten its future development, such as vectors and vector-borne diseases, organic feed insufficiency, limited education, research, and support to organic livestock production. The prospects of organic livestock development in Uganda can be enhanced with more scientific research in organic livestock production under local conditions and strengthening institutional support.

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

    PubMed Central

    Vodouhè, R.; Dansi, A.

    2012-01-01

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

  17. [Sustainable diet: history lessons].

    PubMed

    Fatati, Giuseppe

    2015-11-01

    Global dietary patterns changed dramatically in the past 50 years, presenting both a boom and a threat to the health and well-being of populations everywhere. We need sustainable diets, with low-input, local and seasonal agro-ecological food productions as well as short distance production-consumption nets for fair trade. The development of a global food system able to guarantee everyone a balanced food intake requires health professionals an awareness and a commitment to increasingly complex education. Dietary changes such as the adherence of to the Mediterranean Dietary Pattern can reduce the environmental footprint and thus the use of natural resources. Increased focus on improving the utilization of freshwater fishes and the correct use of the waters of rivers and lakes should also be encouraged. Cultural heritage, food quality and culinary skills are other key aspects determining sustainable dietary patterns and food security. The Mediterranean street food (Mediterraneità), for intrinsic characteristics, can represent valid model to address the main issues concerning the sustainable food system. The issues of sustainability offer a great opportunity to nutritional science and scientists to play a more central role in the political analysis of future food systems. We are confident that preserve the past helps us understand the present and build for the future, the Mediterranean lifestyle is much more than the Mediterranean diet and, finally, the rivers and the lakes may be our future.

  18. In Vitro Propagation and Conservation of Bacopa monnieri L.

    PubMed

    Sharma, Neelam; Singh, Rakesh; Pandey, Ruchira

    2016-01-01

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

  19. Mapping Spread and Risk of Avian Influenza A (H7N9) in China

    PubMed Central

    Fang, Li-Qun; Li, Xin-Lou; Liu, Kun; Li, Yin-Jun; Yao, Hong-Wu; Liang, Song; Yang, Yang; Feng, Zi-Jian; Gray, Gregory C.; Cao, Wu-Chun

    2013-01-01

    The outbreak of human infections with an emerging avian influenza A (H7N9) virus occurred in China in early 2013. It remains unknown what and how the underlying risk factors were involved in the bird-to-human cross-species transmission. To illustrate the dynamics of viral spread, we created a thematic map displaying the distribution of affected counties and plotted epidemic curves for the three most affected provinces and the whole country. We then collected data of agro-ecological, environmental and meteorological factors at the county level, and used boosted regression tree (BRT) models to examine the relative contribution of each factor and map the probability of occurrence of human H7N9 infection. We found that live poultry markets, human population density, irrigated croplands, built-up land, relative humidity and temperature significantly contributed to the occurrence of human infection with H7N9 virus. The discriminatory ability of the model was up to 97.4%. A map showing the areas with high risk for human H7N9 infection was created based on the model. These findings could be used to inform targeted surveillance and control efforts in both human and animal populations to reduce the risk of future human infections. PMID:24072008

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

    PubMed

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

    2017-01-01

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

  1. Morphological and pathogenic variability among Macrophomina phaseolina isolates associated with mungbean (Vigna radiata L.) Wilczek from Pakistan.

    PubMed

    Iqbal, Umer; Mukhtar, Tariq

    2014-01-01

    Macrophomina phaseolina is a serious pathogen of many crops. In the present studies, 65 isolates of Macrophomina phaseolina from different agroecological regions of Punjab and Khyber Pakhtunkhwa provinces of Pakistan were analyzed for morphological and pathogenic variability. Regardless of their geographic origins, significant differences were detected among 65 isolates in their radial growth, sclerotial size, and weight as well as in pathogenicity. Sixteen isolates were rated as fast growing, 11 as slow growing, and the rest of the isolates as medium growing. Nine isolates were classified as large sized, 26 as small sized, and the remaining 30 isolates as medium sized. Thirty five isolates were ranked as heavy weight, 12 as low weight, and the rest of isolates were grouped as medium weight. Ten fungal isolates appeared to be least virulent, whereas eight isolates of diverse origin proved to be highly virulent against mungbean cultivars. The remaining isolates were regarded as moderately virulent. No relationship was found among the morphological characters and pathogenicity of the isolates. These morphological and pathogenic variations in various isolates of M. phaseolina may be considered important in disease management systems and will be useful in breeding programmes of mungbean cultivars resistant to charcoal rot.

  2. Morphological and Pathogenic Variability among Macrophomina phaseolina Isolates Associated with Mungbean (Vigna radiata L.) Wilczek from Pakistan

    PubMed Central

    Iqbal, Umer

    2014-01-01

    Macrophomina phaseolina is a serious pathogen of many crops. In the present studies, 65 isolates of Macrophomina phaseolina from different agroecological regions of Punjab and Khyber Pakhtunkhwa provinces of Pakistan were analyzed for morphological and pathogenic variability. Regardless of their geographic origins, significant differences were detected among 65 isolates in their radial growth, sclerotial size, and weight as well as in pathogenicity. Sixteen isolates were rated as fast growing, 11 as slow growing, and the rest of the isolates as medium growing. Nine isolates were classified as large sized, 26 as small sized, and the remaining 30 isolates as medium sized. Thirty five isolates were ranked as heavy weight, 12 as low weight, and the rest of isolates were grouped as medium weight. Ten fungal isolates appeared to be least virulent, whereas eight isolates of diverse origin proved to be highly virulent against mungbean cultivars. The remaining isolates were regarded as moderately virulent. No relationship was found among the morphological characters and pathogenicity of the isolates. These morphological and pathogenic variations in various isolates of M. phaseolina may be considered important in disease management systems and will be useful in breeding programmes of mungbean cultivars resistant to charcoal rot. PMID:24558345

  3. 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.

  4. Climate impacts on palm oil yields in the Nigerian Niger Delta

    NASA Astrophysics Data System (ADS)

    Okoro, Stanley U.; Schickhoff, Udo; Boehner, Juergen; Schneider, Uwe A.; Huth, Neil

    2016-04-01

    Palm oil production has increased in recent decades and is estimated to increase further. The optimal role of palm oil production, however, is controversial because of resource conflicts with alternative land uses. Local conditions and climate change affect resource competition and the desirability of palm oil production. Based on this, crop yield simulations using different climate model output under different climate scenarios could be important tool in addressing the problem of uncertainty quantification among different climate model outputs. Previous studies on this region have focused mostly on single experimental fields, not considering variations in Agro-Ecological Zones, climatic conditions, varieties and management practices and, in most cases not extending to various IPCC climate scenarios and were mostly based on single climate model output. Furthermore, the uncertainty quantification of the climate- impact model has rarely been investigated on this region. To this end we use the biophysical simulation model APSIM (Agricultural Production Systems Simulator) to simulate the regional climate impact on oil palm yield over the Nigerian Niger Delta. We also examine whether the use of crop yield model output ensemble reduces the uncertainty rather than the use of climate model output ensemble. The results could serve as a baseline for policy makers in this region in understanding the interaction between potentials of energy crop production of the region as well as its food security and other negative feedbacks that could be associated with bioenergy from oil palm. Keywords: Climate Change, Climate impacts, Land use and Crop yields.

  5. Processes of diversification and dispersion of rice yellow mottle virus inferred from large-scale and high-resolution phylogeographical studies.

    PubMed

    Traore, O; Sorho, F; Pinel, A; Abubakar, Z; Banwo, O; Maley, J; Hebrard, E; Winter, S; Sere, Y; Konate, G; Fargette, D

    2005-06-01

    Phylogeography of Rice yellow mottle virus (RYMV) was reconstructed from the coat protein gene sequences of a selection of 173 isolates from the 14 countries of mainland Africa where the disease occurred and from the full sequences of 16 representative isolates. Genetic variation was linked to geographical distribution and not to host species as isolates from wild rice always clustered with isolates from cultivated rice of the same region. Genetic variation was not associated to agro-ecology, viral interference and insect vector species. Distinct RYMV lineages occurred in East, Central and West Africa, although the Central African lineage included isolates from Benin, Togo and Niger at the west, adjacent to countries of the West African lineage. Genetic subdivision at finer geographical scales was apparent within lineages of Central and West Africa, although less pronounced than in East Africa. Physical obstacles, but also habitat fragmentation, as exemplified by the small low-lying island of Pemba offshore Tanzania mainland, explained strain localization. Three new highly divergent strains were found in eastern Tanzania. By contrast, intensive surveys in Cote d'Ivoire and Guinea at the west of Africa did not reveal any new variant. Altogether, this supported the view that the Eastern Arc Mountains biodiversity hotspot was the centre of origin of RYMV and that the virus spread subsequently from east to west across Africa. In West Africa, specific strains occurred in the Inner Niger Delta and suggested it was a secondary centre of diversification. Processes for diversification and dispersion of RYMV are proposed.

  6. [Environmental management: critical analysis, scenarios and challenges].

    PubMed

    Porto, Marcelo Firpo de Souza; Schütz, Gabriel Eduardo

    2012-06-01

    This article discusses the limits, alternatives and challenges of environmental management in contemporary globalized capitalist societies. It is based on a critical analysis supported by authors from social sciences, political ecology and public health. To this end, we systematize the meaning of hegemonic environmental management in terms of eco-efficiency and its limits to tackle environmental risks and construct democratic processes and societies. We developed four ideal scenarios involving possible combinations of environmental management and democracy. This model served as a base, together with academic studies and the theoretical and militant experience of the authors, for a reflection on the current characteristics and future trends of environmental management and democracy, with emphasis on the reality of Latin America, specifically Brazil. Lastly, we discuss possibilities for social transformation taking into consideration the contradictions and emancipatory alternatives resulting from confrontations between hegemonic tendencies of the market and counter-hegemonic utopias and social movements. The latter assume principles of environmental justice, economic solidarity, agro-ecology and sustainability as well as the construction of new epistemologies.

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

    PubMed

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

    2008-12-01

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

  8. 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.

  9. Safety nets can help address the risks to nutrition from increasing climate variability.

    PubMed

    Alderman, Harold

    2010-01-01

    Models of climate change predict increased variability of weather as well as changes in agro-ecology. The increased variability will pose special challenges for nutrition. This study reviews evidence on climate shocks and nutrition and estimates the economic consequences in terms of reduced schooling and economic productivity stemming from nutritional insults in childhood. Panel data covering up to 20 y indicate that that short-term climate shocks have long-term impacts on children that persist, often into their adult lives. Other studies document the potential for relief programs to offset these shocks providing that the programs can be implemented with flexible financing, rapid identification of those affected by the shock, and timely scale-up. The last of these presumes that programs are already in place with contingency plans drawn up. Arguably, direct food distribution, including that of ready-to-use therapeutic food, may be part of the overall strategy. Even if such programs are too expensive for sustainable widespread use in the prevention of malnutrition, scalable food distribution programs may be cost effective to address the heightened risk of malnutrition following weather-related shocks.

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

    PubMed Central

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

    2012-01-01

    Attempts to increase food crop yields by intensifying agricultural systems using high inputs of nonrenewable resources and chemicals frequently lead to de-gradation of natural resources, whereas most technological innovations are not accessible for smallholders that represent the majority of farmers world wide. Alternatively, cocultures consisting of assemblages of plant and animal species can support ecological processes of nutrient cycling and pest control, which may lead to increasing yields and declining susceptibility to extreme weather conditions with increasing complexity of the systems. Here we show that enhancing the complexity of a rice production system by adding combinations of compost, azolla, ducks, and fish resulted in strongly increased grain yields and revenues in a season with extremely adverse weather conditions on East Java, Indonesia. We found that azolla, duck, and fish increased plant nutrient content, tillering and leaf area expansion, and strongly reduced the density of six different pests. In the most complex system comprising all components the highest grain yield was obtained. The net revenues of this system from sales of rice grain, fish, and ducks, after correction for extra costs, were 114% higher than rice cultivation with only compost as fertilizer. These results provide more insight in the agro-ecological processes and demonstrate how complex agricultural systems can contribute to food security in a changing climate. If smallholders can be trained to manage these systems and are supported for initial investments by credits, their livelihoods can be improved while producing in an ecologically benign way. PMID:22957173

  11. 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.

  12. Influence of student-designed experiments with fast plants on their understanding of plants and of scientific inquiry

    NASA Astrophysics Data System (ADS)

    Akey, Ann Kosek

    2000-10-01

    This dissertation investigates the influence of student designed experiments with Fast Plants in an undergraduate agroecology course on the students' conceptual understanding of plant life cycles and on their procedural understanding of scientific experimentation. It also considers students' perspectives on the value of these experiences. Data sources included semi-structured interviews with students and the instructor, a written task, course evaluations, and observations of class meetings. Students came into the course having strong practical experience with plants from their agricultural backgrounds. Students did not always connect aspects of plant biology that they studied in class, particularly respiration and photosynthesis, to plant growth requirements. The instructor was able to bridge the gap between some practical knowledge and textbook knowledge with experiences other than the Fast Plant project. Most students held an incomplete picture of plant reproduction that was complicated by differences between agricultural and scientific vocabulary. There is need for teaching approaches that help students tie together their knowledge of plants into a cohesive framework. Experiences that help students draw on their background knowledge related to plants, and which give students the opportunity to examine and discuss their ideas, may help students make more meaningful connections. The Fast Plant project, a positive experience for most students, was seen by these undergraduate students as being more helpful in learning about scientific experimentation than about plants. The process of designing and carrying out their own experiments gave students insight into experimentation, provoked their curiosity, and resulted in a sense of ownership and accomplishment.

  13. [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.

  14. Multiple anthelmintic resistance on a goat farm in Hawassa (southern Ethiopia).

    PubMed

    Kumsa, Bersissa; Abebe, Girma

    2009-04-01

    A study was conducted to determine the presence of anthelmintic resistance on Hawassa University goat farm in southern Ethiopia. The 180 goats were stratified by age and sex and randomly assigned to treatment groups (albendazole, tetramisole and ivermectin and untreated control). Each treatment group included 15 goats and treatments were administered according to weight of each goat with 7.5 mg/kg bw albendazole, 22.5 mg/kg bw tetramisole and 0.2 mg/kg bw ivermectin dose rates recommended by scientists. Faecal samples were collected on day 0 before treatment, and again on day 12 post treatment. Efficacy of all the drugs was assessed on day 12 post treatment by faecal egg count reduction test (FECRT). Multiple anthelmintic resistance in Haemonchus spp. against albendazole, tetramisole and ivermectin was recorded in all age categories of the goats. Likewise, Trichostrongylus/Teladorsagia spp. showed resistance against ivermectin. Coprocultures from all pre- and post-treatments revealed the predominance of Haemonchus spp. Resistance against anthelmintics is attributed to the high frequency of treatment and low dosage of treatment practices on the farm. Large scale studies, however, are needed to assess the current status of anthelmintic resistance against the most commonly used anthelmintics in different agroecology, species of animals and management systems in Ethiopia.

  15. Will the damage be done before we feel the heat? Infectious disease emergence and human response.

    PubMed

    Kock, R A

    2013-12-01

    The global political economy is facing extreme challenges against a backdrop of large-scale expansion of human and domestic animal populations and related impacts on the biosphere. Significant global socio-ecological changes have occurred in the period of a single lifetime, driven by increased technology and access to physical and biological resources through open markets and globalization. Current resource consumption rates are not sustainable and ecological tipping points are being reached and one of the indicators of these may be a changing balance between hosts and pathogens. A period of extraordinary progress in reducing infection risk and disease impact on humans and domestic animals in the 20th Century is reversing in the 21st, but not always and not everywhere. Drivers for this shift are discussed in terms of demographics, agroecology, biodiversity decline and loss of resilience in ecosystems, climate change and increasing interconnectedness between species globally. Causality of disease emergence remains highly speculative, but patterns and data are emerging to commend a precautionary approach, while reassessing our global political, social and economic systems.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

    Kuznetsova, I. V.

    2013-04-01

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

  18. Impact of topography and soil factors on crop suitability in two Mediterranean areas (Egypt and Spain)

    NASA Astrophysics Data System (ADS)

    Abd-Elmabod, S. K.; Jordán, A.; Anaya-Romero, M.; Ali, R. R.; Muñoz-Rojas, M.; Zavala, L. M.; de la Rosa, D.

    2012-04-01

    The aim of this research is to study the influence of topography and soil factors on crop suitability two Mediterranean areas: Sevilla (southern Spain) and El-Fayoum (northern Egypt). The Shuttle Radar Topography Mission (SRTM) images were processed using ENVI 4.7 software to extract elevation data, slope gradient and slope direction. North-south toposequences from both areas were extracted and studied using Arc-GIS 9.3 software. Soil characteristics along these toposequences were extracted from regional soil maps, as well as land surveying and laboratory analyses. The Almagra model (included in the agro-ecological system MicroLEIS DSS) was used to evaluate agricultural soil suitability using soil factors of useful depth, texture, drainage, carbonate content, salinity, sodium saturation, and degree of development of the profile. Changes of soil characteristics through the toposequences are discussed. The results of Almagra model indicate that the crop suitability main limiting factors are soil texture, drainage, soil salinity and sodium saturation percent and topography factors elevation, slope gradient, slope direction.

  19. Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation

    PubMed Central

    Horn, Lydia N.; Ghebrehiwot, Habteab M.; Shimelis, Hussein A.

    2016-01-01

    Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985), Shindimba (IT89KD-245-1), and Bira (IT87D-453-2) were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colors and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants’ lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding. PMID:27148275

  20. Diversity studies of Azotobacter spp. from cotton-wheat cropping systems of India.

    PubMed

    Bhatia, Ranjana; Ruppel, Silke; Narula, Neeru

    2008-12-01

    Azotobacter are the favored bioinoculants being promoted for cotton crop in India. In order to develop bioinoculants, both metabolic fingerprinting and genetic fingerprinting have been used to study the diversity among Azotobacter spp. isolated from four different cotton-wheat cropping regions of India. On the basis of acetylene reduction, indole acetic acid production and ammonia excretion, from 76 free-living diazotrophs isolated from the rhizospheric soil of cotton, 20 efficient isolates were selected for further studies. Morphological characterization indicated a close resemblance of these isolates to Azotobacter spp. BIOLOG cataloguing divided them into two main groups, but amplified ribosomal DNA restriction analysis clustered the isolates from the four regions having different soil types into four separate sub-clusters. Metabolic fingerprinting was not able to detect subtle differences among the isolates as achieved with genetic fingerprinting. However, 16S rRNA is a highly conserved locus. Variations observed could be due to domestication of the isolates in different agro-ecological niches.

  1. Development and testing of crop monitoring methods to improve global agricultural monitoring in support of GEOGLAM

    NASA Astrophysics Data System (ADS)

    Gilliams, S. J. B.; Bydekerke, L.

    2014-12-01

    The SIGMA project (Stimulating Innovation for Global Monitoring of Agriculture) is funded through the EC FPY7 Research programme with the particular aim to contribute to the GEOGLAM Research Agenda. It is a partnership of globally distributed expert organizations, focusses on developing innovative techniques and datasets in support of agricultural monitoring and its impact on the environment in support of GEOGLAM. SIGMA has 3 generic objectives which are: (i) develop and test methods to characterize cropland and assess its changes at various scales; (ii) develop and test methods to assess changes in agricultural production levels; and; (iii) study environmental impacts of agriculture. Firstly, multi-scale remote sensing data sets, in combination with field and other ancillary data, are used to generate an improved (global) agro-ecological zoning map and crop mask. Secondly, a combination of agro-meteorological models, satellite-based information and long-term time series are be explored to better assess crop yield gaps and shifts in cultivation. The third research topic entails the development of best practices for assessing the impact of crop land and cropping system change on the environment. In support of the GEO JECAM (Joint Experiment for Crop Assessment and Monitoring) initiative, case studies in Ukraine, Russia, Europe, Africa, Latin America and China are carried out in order to explore possible methodological synergies and particularities according to different cropping systems. This presentation will report on the progress made with respect to the three topics above.

  2. Development of High Resolution Data for Irrigated Area and Cropping Patterns in India

    NASA Astrophysics Data System (ADS)

    K a, A.; Mishra, V.

    2015-12-01

    Information of crop phenology and its individual effect on irrigation is essential to improve the simulation of land surface states and fluxes. We use moderate resolution imaging spectroradiometer (MODIS) - Normalized difference vegetation index (NDVI) at 250 m resolution for monitoring temporal changes in irrigation and cropping patterns in India. We used the obtained dataset of cropping pattern for quantifying the effect of irrigation on land surface states and fluxes by using an uncoupled land surface model. The cropping patterns are derived by using the planting, heading, harvesting, and growing dates for each agro-ecological zone separately. Moreover, we developed a high resolution irrigated area maps for the period of 1999-2014 for India. The high resolution irrigated area was compared with relatively coarse resolution (~ 10km) irrigated area from the Food and Agricultural Organization. To identify the seasonal effects we analyzed the spatial and temporal change of irrigation and cropping pattern for different temporal seasons. The new irrigation area information along with cropping pattern was used to study the water budget in India using the Noah Land surface Model (Noah LSM) for the period of 1999-2014.

  3. Patterns and Perceptions of Climate Change in a Biodiversity Conservation Hotspot

    PubMed Central

    Hartter, Joel; Stampone, Mary D.; Ryan, Sadie J.; Kirner, Karen; Chapman, Colin A.; Goldman, Abraham

    2012-01-01

    Quantifying local people's perceptions to climate change, and their assessments of which changes matter, is fundamental to addressing the dual challenge of land conservation and poverty alleviation in densely populated tropical regions To develop appropriate policies and responses, it will be important not only to anticipate the nature of expected changes, but also how they are perceived, interpreted and adapted to by local residents. The Albertine Rift region in East Africa is one of the world's most threatened biodiversity hotspots due to dense smallholder agriculture, high levels of land and resource pressures, and habitat loss and conversion. Results of three separate household surveys conducted in the vicinity of Kibale National Park during the late 2000s indicate that farmers are concerned with variable precipitation. Many survey respondents reported that conditions are drier and rainfall timing is becoming less predictable. Analysis of daily rainfall data for the climate normal period 1981 to 2010 indicates that total rainfall both within and across seasons has not changed significantly, although the timing and transitions of seasons has been highly variable. Results of rainfall data analysis also indicate significant changes in the intra-seasonal rainfall distribution, including longer dry periods within rainy seasons, which may contribute to the perceived decrease in rainfall and can compromise food security. Our results highlight the need for fine-scale climate information to assist agro-ecological communities in developing effective adaptive management. PMID:22384244

  4. The "bringing into cultivation" phase of the plant domestication process and its contributions to in situ conservation of genetic resources in Benin.

    PubMed

    Vodouhè, R; Dansi, A

    2012-01-01

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

  5. Effects of atmospheric deposition nitrogen flux and its composition on soil solution chemistry from a red soil farmland, southeast China.

    PubMed

    Cui, Jian; Zhou, Jing; Peng, Ying; Chan, Andrew; Mao, Jingdong

    2015-12-01

    A detailed study on the solution chemistry of red soil in South China is presented. Data are collected from two simulated column-leaching experiments with an improved setup to evaluate the effects of atmospheric N deposition (ADN) composition and ADN flux on agricultural soil acidification using a (15)N tracer technique and an in situ soil solution sampler. The results show that solution pH values decline regardless of the increase of the NH4(+)/NO3(-) ratio in the ADN composition or ADN flux, while exchangeable Al(3+), Ca(2+), Mg(2+), and K(+) concentrations increase at different soil depths (20, 40, and 60 cm). Compared with the control, ADN (60 kg per ha per year N, NH4(+)/NO3(-) ratio of 2 : 1) decreases solution pH values, increases solution concentrations of NO3(-)-N, Al(3+), Ca(2+) and Mg(2+) at the middle and lower soil depths, and promotes their removal. NH4(+)-N was not detected in red soil solutions of all the three soil layers, which might be attributed to effects of nitrification, absorption and fixation in farmland red soil. Some of the NO3(-)-N concentrations at 40-60 cm soil depth exceed the safe drinking level of 10 mg L(-1), especially when the ADN flux is beyond 60 kg ha(-1) N. These features are critical for understanding the ADN agro-ecological effects, and for future assessment of ecological critical loads of ADN in red soil farmlands.

  6. Impact of climate change and variability on agricultural production. Case study of bufumbo sub county in Mt. Elgon region

    NASA Astrophysics Data System (ADS)

    David, Wafula

    2012-07-01

    Like other Sub-Saharan Africa countries,Uganda's agriculture is subsistence and rain-fed making it vulnerable to climate variability and change. Agricultural performance of the farmers in Bufumbo Sub County largely depends on climatic conditions (rainfall and temperature) implying that, there is likelihood that fluctuations in agricultural outputs are closely linked to climate variability and climate change. This study aims at assessing the impact of climate change and variability on agricultural production in a montane agro-ecological zone of Uganda-Case study of Bufumbo Sub County(Mt. Elgon region. A sample size of 180 farmers will be selected for questionnaire administration (30 respondents in each Parish) with the help of the village leaders. Secondary data on climate, crop yields and soil variables will be obtained from the department of meteorology/ satellite databases, district production/agriculture office and soil maps from FAO (1975) and department of Agriculture respectively. Statistical data will be coded, summarized in frequency tables in excel sheets and analyzed using Statistical Package for Social Sciences spreadsheet. While spatial data such as soil and satellite images will be analysed and interpreted using Envisat, ArcGIS 9.3 and ILWIS. Crop yield time series will be analysed using Fapar algorithm using MISR data. The expected results shall be inform of Geo-spatial vulnerability maps, time series satellite images of crop yields, climate change projections and practical adaptation measures for farmers.

  7. [Climatic potential productivity of winter wheat and summer maize in Huanghuaihai Plain in 2011-2050].

    PubMed

    Zhao, Jun-Fang; Guo, Jian-Ping; Wu, Ding-Rong; Fang, Shi-Bo; E, You-Hao

    2011-12-01

    Based on the daily data under B2 climate scenario (2011-2050) and baseline climate condition (1961-1990) extracted from the regional climate model PRECIS, and by using the Agro-Ecological Zone (AEZ) model, a prediction was conducted on the possible spatiotemporal changes of the climatic potential productivity of the two crops in the Huanghuaihai Plain in 2011-2050. Under baseline climate condition, the climatic potential productivities of winter wheat and summer maize presented a regional differentiation, i.e., higher in southeast and lower in northwest regions, and higher along coast and lower in inland at the same latitudes, and fluctuated within the ranges of 3893-11000 kg x hm(-2) and 5908-12000 kg x hm(-2), respectively. Under B2 climate scenario, the climatic potential productivity of winter wheat and summer maize would have a greater inter-annual change, due to the different matching degrees of light, temperature and water during the growth periods of the crops. The climatic potential productivity of winter wheat in 2011-2030 and summer maize in 2021-2040 would have an obvious increase, with great potential for development. Under the conditions of maintaining the present production, the climatic potential productivity of winter wheat in 2011-2050 would present an overall regional differentiation of reverse change in southeast and northwest regions and the same change in coastal and inland areas, whereas the climatic potential productivity of summer maize in 2011-2050 would have little regional differentiation.

  8. Epidemiology and ecology of highly pathogenic avian influenza with particular emphasis on South East Asia.

    PubMed

    Martin, V; Sims, L; Lubroth, J; Pfeiffer, D; Slingenbergh, J; Domenech, J

    2006-01-01

    Highly pathogenic avian influenza (HPAI) has been recognised as a serious viral disease of poultry since 1878. The number of recorded outbreaks of HPAI has increased globally in the past 10 years culminating in 2004 with the unprecedented outbreaks of H5N1 HPAI involving at least nine countries in East and South-East Asia. Apart from the geographical extent of these outbreaks and apparent rapid spread, this epidemic has a number of unique features, among which is the role that asymptomatic domestic waterfowl and more particularly free-ranging ducks play in the transmission of highly pathogenic H5N1. Field epidemiological studies have been conducted by the Food and Agriculture Organization and several collaborative centres to explore the factors that could have led to a change from infection to the emergence of widespread disease in 2003-2004 and 2005. Domestic waterfowl, specific farming practices and agro-ecological environments have been identified to play a key role in the occurrence, maintenance and spread of HPAI. Although there are some questions that remain unanswered regarding the origins of the 2004 outbreaks, the current understanding of the ecology and epidemiology of the disease should now lead to the development of adapted targeted surveillance studies and control strategies.

  9. 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.

  10. Food security politics and the Millennium Development Goals.

    PubMed

    McMichael, Philip; Schneider, Mindi

    2011-01-01

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

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

    PubMed

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

    2016-02-01

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

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

    PubMed

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

    2015-03-01

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

  13. New emergy indices for sustainable development.

    PubMed

    Lu, Hong-fang; Lan, Sheng-fang; Li, Lei; Peng, Shao-lin

    2003-07-01

    The emergy indices for the evaluation of system's sustainable development ability were studied. Results indicated that the emergy indices are simplified and merged, and a new emergy index for sustainable development (EISD) is deduced. Employing EISD, two cases are conducted. The first one is to compare three different dike-pond agro-ecological engineering modes, which are: melon-melon-cabbage-four domestic fishes (mode I), melon-melon-cabbage-pig-four domestic fishes (mode II) and melon-melon-cabbage-pig-four domestic fishes combined with Siniperca chuatsi B. (mode III). The result is that the EISD of mode I is 0.53. Mode II's EISD is 5.26 times of mode I, and mode III's EISD is 6.83 times of mode I. The second one is to evaluate the development of Zhongshan City, Pearl Delta, during 1996 to 2000. The result indicated that the EISD of Zhongshan had appreciably declined from 1996 to 1998, and quickly improved from 1998 to 2000, partly because of its environment protection and product construction. Both of the two cases studies showed that EISD can assessment the sustainable development ability more roundly, with the consideration of environmental impact and social-economic effect at the same time.

  14. Factors affecting stem borer parasitoid species diversity and parasitism in cultivated and natural habitats.

    PubMed

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Calatayud, Paul-André; Dupas, Stéphane

    2010-02-01

    The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance, and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya. Comparing habitat types, we found partial support for the "natural enemy" hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, parasitoid richness was mainly influenced by stem borer density and/or its interaction with stem borer richness, whereas parasitoid abundance was mainly affected by stem borer abundance. Parasitoid richness was higher in localities (with bimodal rainfall distribution) with increased spatial and temporal availability of host plants that harbored the borers. Across seasons, parasitoid richness was lower in both cultivated and natural habitats in the driest locality, Mtito Andei. Overall, parasitoid diversity was low in Suam and Mtito Andei, where maize cultivation was practiced on a commercial scale and intense grazing activities persist across seasons, respectively. Across localities, habitats, and seasons, stem borer parasitism was positively correlated with parasitoid richness and abundance. Furthermore, the interaction of rainfall and altitude influenced the presence and absence of parasitoids, and consequently, stem borer parasitism. Parasitism was positively and negatively correlated with temperature in cultivated and natural habitats, respectively. Overall, natural habitats seem to serve as important refugia for sustaining parasitoid diversity, which in turn can affect stem borer parasitism in the cereal cropping system.

  15. The use of MP-AES for determination of plant available P in soil by DL method and distribution of soils into P status classes by DL, AL and Mehlich 3 methods.

    NASA Astrophysics Data System (ADS)

    Toomsoo, Avo; Jürgens, Meit; Kõlli, Raimo; Künnapas, Allan; Albre, Imbi; Tõnutare, Tõnu; Rodima, Ako

    2017-04-01

    Only small percentage of soil total phosphorus is easily exchangeable between solid and solution phase. Plants are able to assimilate P from environment only in the form of orthophosphate ions (H2PO4- and HPO42-) from soil solution. Deficit of P in soil solution prevents plant normal growth and decreases yield quantity and quality. The excess of P in soil solution causes the pollution of environment and eutrophication of water bodies. Therefore it is important to give to the plant producers the correct fertilization recommendations. Lot of analytical methods are developed for the determination of plant available P in soils. In the Baltic Sea region seven different soils' P analysis methods in use. Each method has its own gradation and often there is more than one gradation for the same method depending from agroecological conditions. For agricultural soils in Estonia there are soil P status gradations according to Mehlich 3, DL and AL methods. Phosphate content in soil can be determined by molybdate method Vis-spectrometrically. Very often for analysis of soils' P content also ICP-OES, ICP-MS and also MP-AES instrumental methods are used The aim of our work was to investigate the possibility of using MP-AES for determination of plant available P in soil by DL method and also to compare how the analysed soils are distributed to M3, AL and DL fertilizer requirement groups according to the P content.

  16. Association between Grape Yeast Communities and the Vineyard Ecosystems

    PubMed Central

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

    2017-01-01

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

  17. Ovine helminthosis, a major health constraint to productivity of sheep in Ethiopia.

    PubMed

    Biffa, Demelash; Jobre, Yilma; Chakka, Hassen

    2006-01-01

    Small ruminants represent an important component of the Ethiopian livestock production system, providing 12% of the value of livestock products consumed at the farm level and 48% of the cash income generated. Ethiopia is second in Africa and sixth in the world in terms of sheep population. The country has, however, benefited little from this enormous resource owing to a multitude of problems, disease being the most important. Disease alone accounts for mortalities of 30% in lambs and 20% in adults. Productivity losses attributable to helminth parasites are often substantial. A loss of US $ 81.8 million is reported annually due to helminth parasites. In a country confronted with challenges of an ever-rising human population and food shortage, such enormous losses caused by helminth parasites, 'the silent predators', are intolerable. Therefore, helminth control should receive special attention in poverty reduction strategies through improved productivity of livestock if the present and future challenges of food shortage are to be addressed. Productivity loss due to helminth infections can be substantially reduced through implementation of effective disease control strategies, which require an understanding of the epidemiology and ecology of parasites and parasitic infections under local conditions. This paper reviews extensive evidence demonstrating that helminthosis is a major constraint to productivity of sheep in Ethiopia. It also discusses epidemiology and ecology of major helminth parasites in the country and suggests strategies for improved control in various agro-ecological zones and production systems.

  18. [Effects of Nitrogen Fertilization on Soil Respiration and Temperature Sensitivity in Spring Maize Field in Semi-Arid Regions on Loess Plateau].

    PubMed

    Jiang, Ji-shao; Guo, Sheng-li; Wang, Rui; Liu, Qing-fang; Wang, Zhi-qi; Zhang, Yan-jun; Li, Na-na; Li, Ru-jian; Wu, De-feng; Sun, Qi-qi

    2015-05-01

    Understanding the effects of nitrogen fertilization on soil respiration rate and its temperature sensitivity (Q10) is of critical importance to predict the variability of soil respiration in cropland. A field experiment was established in a rain-fed spring maize cropland (Zea mays L. ) in the State Key Agro-Ecological Experimental Station in the Loess Plateau in Changwu County, Shaanxi Province, China. The experiment comprised of two treatments: no N-fertilizer application ( CK) and N-fertilizer application with 160 kg N · hm(-2) (N). Soil respiration rate, soil temperature, soil moisture, yields, aboveground biomass and root biomass were measured in two continuous spring maize growing seasons from April 2013 to September 2014. The cumulative soil CO2 emissions were increased by 35% in 2013 and 54% in 2014 in N treatment as compared to CK treatment. Though nitrogen fertilization significantly increased the cumulative soil CO2 emissions (P < 0.05), it did decrease evidently the temperature sensitivity of soil respiration (P < 0.05) . The Q10 values in N treatment were decreased by 27% and 17% compared with CK treatment in 2013 and 2014, respectively. Nitrogen fertilization significantly increased the maize yields, aboveground biomass and root biomass (P < 0.05). Root biomasses in N treatment were 32% and 123% greater than those in CK treatment of 2013 and 2014, respectively. Nitrogen fertilization had no marked influence on soil temperature or moisture. Root biomass was a critical biotical factor for variation of soil respiration under nitrogen fertilization.

  19. Alternative amendment for vineyards from by-products of pyro-bituminous shale: Effect on wine amino acids and biogenic amines.

    PubMed

    Alañón, M E; Schumacher, R; Díaz-Maroto, M C; Gómez-Alonso, S; Pérez-Coello, M S

    2017-11-01

    With the aim of looking for a model of agroecological production, the use of by-products from pyro-bituminous shale as amendment, and its effect on wine amino acids and biogenic amines has been evaluated. Field trials aimed to compare the effect of different doses of conventional and limestone shale from by-products of pyro-bituminous. Four replicates for six different fertilization treatments were arranged in a split plot design during 2009/2010 and 2010/2011 vintage. A chromatographic analysis was carried out to evaluate the impact of fertilization treatments on the amino acid and biogenic amine content of wines produced. Results showed few significant differences among fertilization treatments tested according to the amino acids composition of wines, although it seemed that a combination of conventional and pyro-bituminous shale could be the best option. By-products of pyro-bituminous shale seem to be a good partial substitutive amendment for Brazilian vineyards. This research seems to be a new approach for sustainable revalorization of domestic fertilizers to enable minor environmental impacts and lower production costs without detriment to quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation.

    PubMed

    Horn, Lydia N; Ghebrehiwot, Habteab M; Shimelis, Hussein A

    2016-01-01

    Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985), Shindimba (IT89KD-245-1), and Bira (IT87D-453-2) were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colors and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants' lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding.

  1. Total Economic Value of Wetlands Products and Services in Uganda

    PubMed Central

    Kakuru, Willy; Turyahabwe, Nelson; Mugisha, Johnny

    2013-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  3. Genetic variability of ten Chinese indigenous goats using MHC-linked microsatellite markers.

    PubMed

    E, Guang-Xin; Huang, Yong-Fu; Zhao, Yong-Ju; Ma, Yue-Hui; Na, Ri-Su; Zhang, Jia-Hua; Gao, Hui-Jiang; Wu, Xin

    2015-10-15

    In this study, the genetic variability of Chinese indigenous goat breeds (Capra hircus) was analyzed using the MHC-associated microsatellite markers BF1, BM1818, BM1258, and DYMS1. To examine genetic variability, the levels of heterozigosity, degrees of inbreeding, and genetic differences among the breeds were analyzed. The mean number of alleles ranged from 5.50±3.70 in Enshi black goats (EB) to 11.50±3.70 in the Jianyang big ear (JE) breed. The mean observed heterozygosity and mean expected heterozygosity varied from 0.25±0.04 in Jining Qing goats (JQ) to 0.54±0.05 in Chuannan black goats (CN) and from 0.49±0.18 in Hechuan white goats (HW) to 0.78±0.05 in JE, respectively. The mean FIS values ranged from 0.23 in HW to 0.51 in JQ. In addition, the genetic variation among populations and geographic location did indicate a correlation of genetic differences with geographic distance, which was revealed by the phylogenetic network. In conclusion, the high variability and population structure among Chinese native goats in the Major Histocompatibility Complex would be caused by co-evolution between MHC alleles and the epidemic history or pathogens in different agro-ecological zones.

  4. Validity of food consumption indicators in the Lao context: moving toward cross-cultural standardization.

    PubMed

    Baumann, Soo Mee; Webb, Patrick; Zeller, Manfred

    2013-03-01

    Cross-cultural validity of food security indicators is commonly presumed without questioning the suitability of generic indicators in different geographic settings. However, ethnic differences in the perception of and reporting on, food insecurity, as well as variations in consumption patterns, may limit the comparability of results. Although research on correction factors for standardization of food security indicators is in process, so far no universal indicator has been identified. The current paper considers the ability of the Food Consumption Score (FCS) developed by the World Food Programme in southern Africa in 1996 to meet the requirement of local cultural validity in a Laotian context. The analysis is based on research that seeks to identify options for correcting possible biases linked to cultural disparities. Based on the results of a household survey conducted in different agroecological zones of Laos in 2009, the FCS was validated against a benchmark of calorie consumption. Changing the thresholds and excluding small amounts of food items consumed were tested as options to correct for biases caused by cultural disparities. The FCS in its original form underestimates the food insecurity level in the surveyed villages. However, the closeness of fit of the FCS to the benchmark classification improves when small amounts of food items are excluded from the assessment. Further research in different cultural settings is required to generate more insight into the extent to which universal thresholds can be applied to dietary diversity indicators with or without locally determined correction factors such as the exclusion of small amounts of food items.

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

    PubMed

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

    2016-03-11

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

  6. Effect of soil moisture stress on growth and yield of cassava in Nigeria.

    PubMed

    Aina, O O; Dixon, A G O; Akinrinde, E A

    2007-09-15

    Nine cassava genotypes were evaluated for their growth responses and adaptability to soil moisture stress on the field and in the screenhouse in Nigeria. Genotypes were evaluated in three savanna agroecologies in a randomized complete block design with three replicates. Screenhouse evaluation was conducted using three moisture regimes of 75, 50 and 25% Field Capacity (FC) in a two-factor factorial experiment in CRD with three replicates. Morphological and yield data were collected on the field and in the screenhouse. Results showed significant (p < 0.05) difference among genotypes on the field and in the screenhouse. Field moisture stress led to a decline in plant height by 47%, stem girth by 15%, number of tubers by 95% and tuber yield by 87%. Screenhouse moisture condition of 25% FC led to a reduction in plant height by 12.6 and 21.2%, stem girth by 16.3 and 21.7%, number of roots by 94.5 and 88.7% and root weight by 93.3 and 94.9%, respectively at 16 and 30 WAP. Moisture stress therefore resulted into considerable reduction in both vegetative growth and yield of cassava genotypes. Therefore, a concerted effort in breeding cassava for drought tolerance is needed as cassava cultivation is expanding into nontraditional semiarid regions of sub-Saharan Africa. Germplasm introduced from Latin America (especially north-eastern Brazil) is providing a unique source of variability to further broaden the genetic base for drought tolerance in cassava.

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

    PubMed

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

    2016-05-04

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

  8. Communal goat production in Southern Africa: a review.

    PubMed

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

    2009-10-01

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

  9. Changing trend of percentile-based temperature indices over Pakistan

    NASA Astrophysics Data System (ADS)

    Saleem, Farhan; Adrees, Muhammad; Abbas, Farhat; Ibrahim, Muhammad; Zeng, Xiaodong

    2017-04-01

    This study evaluates the annual to interannual trends of percentile-indices temperature extremes during 1981-2010 for 27 synoptic stations spatially distributed over Pakistan. The indices were estimated using homogenized daily minimum (Tmin) and maximum (Tmax) temperatures. Indices defining the cold and hot extremes were calculated with the help of RClimDex software. A nonparametric Mann-Kendall test and Sen's slope estimates were used to determine the statistical significance and magnitude of a trend, respectively. The magnitude of trend was determined for various agro-ecological zones across Pakistan. We found that spatially averaged trends of cool nights (TN10p) and hot nights (TN90p) are more pronounced for the Northern Irrigated Plains during winter and spring. The zone of Sandy Deserts experienced the largest decrease in the frequency of cool days (TX10p) while, hot days (TX90p) frequency index was found to be more pronounced and significant for the Wet Mountains zone during spring. On an annual timescale, the magnitude of trend in hot nights was found to be larger than for hot days. The rate of change of warming in cool nights and cool days was found to be higher during spring and fall when compared to that of winter and summer. Overall, we found significant differences within the spatial distribution of day and night temperature extremes, indicating a trend of regional warming across Pakistan.

  10. Canadian economic and emissions model for agriculture, C.E.E.M.A., version 1.0, report 2: Preliminary results of selected scenarios

    SciTech Connect

    Kulshreshtha, S.N.

    1999-09-01

    This is one of three technical reports which document an integrated agro-ecological economic modelling system that can be used to simultaneously assess the economic and the greenhouse gas emission impacts of agricultural policies at the regional and national levels. After an introduction on the importance of agricultural emissions of greenhouse gases and the need for a study of this issue, chapter 2 reviews the greenhouse gas emission model. Chapter 3 contains model-based estimates of greenhouse gas emission levels for the base year of 1990. Chapter 4 predicts future levels of emissions under medium-term baseline projections. Chapter 5 reviews some of the mitigation strategies available to Canadian farmers and assesses their impact on greenhouse emissions. Implications of trends in livestock production are also examined as a separate scenario. Using the scenarios developed in chapter 5, chapter 6 presents results of greenhouse gas emission estimates for individual gases, various production regions, and various emissions activities. The final chapter summarizes major results and discusses their implications for agricultural policy. Appendices include a description of the modelling methodology and a table showing estimates of the distribution of greenhouse gas emissions by crop and livestock production activities under various scenarios.

  11. Canadian economic and emissions model for agriculture, C.E.E.M.A., version 1.0, report 1: Model description

    SciTech Connect

    Kulshreshtha, S.N.

    1999-09-01

    This is one of three technical reports which document an integrated agro-ecological economic modelling system that can be used to simultaneously assess the economic and the greenhouse gas emission impacts of agricultural policies at the regional and national levels. After an introduction on the background to the model and on the importance of agricultural emissions of greenhouse gases, chapter 2 outlines a conceptual basis for developing a sub-model for emission of greenhouse gases. It includes the conceptual linkages between agricultural production activities and the nature of greenhouse gas emissions. An overview of the sub-model and considerations involved in its development are provided in chapter 3. Chapter 4 follows with a description of the methodology adopted in the estimation of various emission coefficients for crop and livestock production activities. Results of a baseline scenario, agricultural production in 1994 as estimated in the CRAM model, are shown in chapter 5, and results of two alternative scenarios are presented in chapter 6. The final chapter summarizes the report and discusses areas of further research.

  12. Impact of Climate Change on Components of the Water and Nitrogen Budgets of Dryland Wheat Systems in the US Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Karimi, T.

    2015-12-01

    As part of the Regional Approaches to Climate Change (REACCH) project (funded by USDA-NIFA), a regional assessment of historical and future yields and greenhouse gas (GHG) emissions of dryland wheat-based cropping systems in the US Pacific Northwest is being conducted. Two issues of interest in the region are changes in the water footprint and nitrogen use of wheat-based systems as a result of climate change. These two are related to the interaction between crop performance and the partitioning of water and nitrogen budget components. They also inform the tradeoff between crop production and environmental services and the sustainability of wheat systems in the future. Computer simulation-based assessment is being done using the CropSyst cropping systems model and daily weather data downscaled to a 4x4 km grid. Future weather is projected using 14 general circulation models (GCMs) and two representative concentration pathways of future atmospheric CO2 (RCP 4.5 and RCP 8.5). The study region is divided in 3 agro-ecological zones (AEZ): low, intermediate and high precipitation zones. The following rotations were included by AEZ: WW - SF (low precipitation), WW - SW - SF (intermediate precipitation), and WW - SW - SP (high precipitation), where WW is winter wheat, SW is spring wheat, SP is spring peas, and SF is summer fallow. A typical conventional tillage (CT) cropping system in each AEZ is evaluated as a baseline.

  13. Video monitoring of brown planthopper predation in rice shows flaws of sentinel methods

    PubMed Central

    Zou, Yi; de Kraker, Joop; Bianchi, Felix J. J. A.; van Telgen, Mario D.; Xiao, Haijun; van der Werf, Wopke

    2017-01-01

    Immobilized preys are routinely used in agro-ecological exposure studies to quantify predation of pests under field conditions, but this method has not been validated. Our purpose was to determine the validity of using immobilized adults of the major rice pest Nilaparvata lugens, brown plant hopper (BPH), as sentinels. We used direct observation by video recording to determine the causal agents of removal of field exposed BPH sentinels with two experiments: 1) we recorded removal events of dead, immobilized BPH; and 2) we compared removal of (i) dead, immobilized BPH, (ii) live, immobilized BPH, and (iii) live, mobile BPH. Long-horned grasshoppers were responsible for most removals of dead, immobilized BPH, in both experiments. Predatory ground beetles removed most of the live, immobilized BPH, whereas frogs were the major predators of live, mobile BPH. Overall, we showed that removal of immobilized sentinel prey is not representative for predation of live, mobile prey, stressing the need for a critical assessment of commonly used sentinel methods. In addition, we found that frogs played the major role in predation of BPH in rice. As current strategies to enhance biocontrol of planthoppers in rice focus on arthropod natural enemies, this finding could have major implications. PMID:28211500

  14. Video monitoring of brown planthopper predation in rice shows flaws of sentinel methods.

    PubMed

    Zou, Yi; de Kraker, Joop; Bianchi, Felix J J A; van Telgen, Mario D; Xiao, Haijun; van der Werf, Wopke

    2017-02-17

    Immobilized preys are routinely used in agro-ecological exposure studies to quantify predation of pests under field conditions, but this method has not been validated. Our purpose was to determine the validity of using immobilized adults of the major rice pest Nilaparvata lugens, brown plant hopper (BPH), as sentinels. We used direct observation by video recording to determine the causal agents of removal of field exposed BPH sentinels with two experiments: 1) we recorded removal events of dead, immobilized BPH; and 2) we compared removal of (i) dead, immobilized BPH, (ii) live, immobilized BPH, and (iii) live, mobile BPH. Long-horned grasshoppers were responsible for most removals of dead, immobilized BPH, in both experiments. Predatory ground beetles removed most of the live, immobilized BPH, whereas frogs were the major predators of live, mobile BPH. Overall, we showed that removal of immobilized sentinel prey is not representative for predation of live, mobile prey, stressing the need for a critical assessment of commonly used sentinel methods. In addition, we found that frogs played the major role in predation of BPH in rice. As current strategies to enhance biocontrol of planthoppers in rice focus on arthropod natural enemies, this finding could have major implications.

  15. 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.

  16. Research collaboration in parasitology between Indonesia and Australia.

    PubMed

    Copland, J

    1997-10-01

    Indonesia and Australia are close neighbours sharing agro-ecological zones and common parasitological interests. Australia is an industrialised country and Indonesia is both industrialising and a developing country. The types of collaboration, contractual, collegiate, research collaboration and partnerships are briefly described. All forms of collaboration have and continue to exist between Australia and Indonesia. A survey of mammalian parasitology publications over the last 23 years indicates that the bulk of papers have been by Indonesian and non-Australian authors. Australian and Indonesian authors provided 4% of the total number of publications. The rational for collaboration is suggested to be the high degree of common multiple interests and the synergy of effort that can be derived from research partnerships. The most difficult issues in research collaboration are establishing the research priorities and, to a lesser extent, funding. The globalisation of the international research centre, International Livestock Research Institute, to include Asia will expand the opportunities for research collaboration. Details of the Australian Centre for International Agricultural Research mandate in supporting parasitology research collaboration is briefly described. The past and current research collaborative activities are reviewed and opportunities for future collaboration are listed.

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

    PubMed

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

    2016-01-12

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

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

    PubMed Central

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

    2015-01-01

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

  19. Isolation, Screening, and Identification of Novel Isolates of Actinomycetes from India for Antimicrobial Applications

    PubMed Central

    Singh, Vineeta; Haque, Shafiul; Singh, Harshita; Verma, Jyoti; Vibha, Kumari; Singh, Rajbir; Jawed, Arshad; Tripathi, C. K. M.

    2016-01-01

    The search for novel bioactive compounds from the natural environment has rapidly been gaining momentum with the increase in multi-drug resistant (MDR) pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569, and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes. PMID:27999566

  20. Characterisation of fungal communities of developmental stages in table grape grown in the northern region of South Africa.

    PubMed

    Carmichael, P C; Siyoum, N; Chidamba, L; Korsten, L

    2017-09-01

    To determine fungal communities that characterise table grapes during berry development. Two agro-ecologically different table grape commercial farms (site A and B) were used in this study. Samples were collected at full bloom, pea size and mature stages, from three positions (inside centre, eastern and western peripheral-ends) per site. Total DNA extraction, Illumina sequencing and analysis of 18 pooled samples for fungal diversity targeting ITS1-2 generated a total of 2035933 high quality sequences. The phylum Ascomycota (77.0%) and Basidiomycota (23.0%) were the most dominant, while the genera, Alternaria (33.1%) and Cladosporium (24.2%) were the overall dominant postharvest decay causing fungi throughout the developmental stages. Inside centre of site A were more diverse at full bloom (3.82) than those at the peripheral-ends (<3.8), while at site B, the peripheral-ends showed better diversity, particularly the eastern part at both full bloom (3.3) and pea size (3.7). Fungal population diversity varies with different phenological table grape growth stages and is further influenced by site and vine position within a specific vineyard. The information on fungal diversity and succession in table grapes during preharvest growth stages is critical in the development of a more targeted control strategy, to improve postharvest quality of table grapes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Identifying risk factors of highly pathogenic avian influenza (H5N1 subtype) in Indonesia

    PubMed Central

    Leo, Loth; Marius, Gilbert; Jianmei, Wu; Christina, Czarnecki; Muhammad, Hidayat; Xiangming, Xiao

    2016-01-01

    Highly pathogenic avian influenza (HPAI), subtype H5N1, was first officially reported in Indonesia in 2004. Since then the disease has spread and is now endemic in large parts of the country. This study investigated the statistical relationship between a set of risk factors and the presence or absence of HPAI in Indonesia during 2006 and 2007. HPAI was evaluated through participatory disease surveillance (PDS) in backyard village chickens (the study population), and risk factors included descriptors of people and poultry distribution (separating chickens, ducks and production sectors), poultry movement patterns and agro-ecological conditions. The study showed that the risk factors “elevation”, “human population density” and “rice cropping” were significant in accounting for the spatial variation of the PDS-defined HPAI cases. These findings were consistent with earlier studies in Thailand and Vietnam. In addition “commercial poultry population”, and two indicators of market locations and transport; “human settlements” and “road length”, were identified as significant risk factors in the models. In contrast to several previous studies carried out in Southeast Asia, domestic backyard ducks were not found to be a significant risk factor in Indonesia. The study used surrogate estimates of market locations and marketing chains and further work should focus on the actual location of the live bird markets, and on the flow of live poultry and poultry products between them, so that patterns of possible transmission, and regions of particular risk could be better inferred. PMID:21813198

  2. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  4. Global climate shocks to agriculture from 1950 - 2015

    NASA Astrophysics Data System (ADS)

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

    2016-12-01

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

  5. Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary.

    PubMed

    Almathen, Faisal; Charruau, Pauline; Mohandesan, Elmira; Mwacharo, Joram M; Orozco-terWengel, Pablo; Pitt, Daniel; Abdussamad, Abdussamad M; Uerpmann, Margarethe; Uerpmann, Hans-Peter; De Cupere, Bea; Magee, Peter; Alnaqeeb, Majed A; Salim, Bashir; Raziq, Abdul; Dessie, Tadelle; Abdelhadi, Omer M; Banabazi, Mohammad H; Al-Eknah, Marzook; Walzer, Chris; Faye, Bernard; Hofreiter, Michael; Peters, Joris; Hanotte, Olivier; Burger, Pamela A

    2016-06-14

    Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species' range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the "restocking from the wild" hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments.

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

    PubMed

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

    2016-12-01

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

  7. Effect of sorting on incidence and occurrence of fumonisins and Fusarium verticillioides on maize from Nigeria.

    PubMed

    Afolabi, Clement G; Bandyopadhyay, Ranajit; Leslie, John F; Ekpo, Ephraim J A

    2006-08-01

    Fumonisin mycotoxins are commonly found on maize and pose a health risk to humans and domesticated animals. Visible sorting of grain has been suggested as a simple technique that can be used to reduce exposure to fumonisins. We collected maize samples in 2003 from different farms in the Kaduna state of Nigeria (Northern Guinea Savanna agroecological zone) that had been sorted by farmers as either good quality or poor quality. The amount of fumonisins and the presence of Fusarium verticillioides were determined for each sample. All 13 poor quality samples and the 5 good quality samples positive for fumonisins contained F. verticillioides. Twelve of 13 poor quality samples contained fumonisins (1.4 to 110 microg/g), as did the five good quality samples that were positive for F. verticillioides (0.2 to 3.7 microg of fumonisins per g). Thus, the visible sorting of grain as a technique to reduce the exposure of subsistence farmers to fumonisins could be successful if there were enough good quality grain available to permit the poor quality grain to be used for another purpose or discarded.

  8. Carbon dioxide fixation and respiration relationships observed during closure experiments in Biosphere 2

    NASA Astrophysics Data System (ADS)

    Nelson, Mark; Dempster, William; Allen, John P.

    Biosphere 2 enclosed several ecosystems - ones analogous to rainforest, tropical savannah, thornscrub, desert, marsh and coral reef - and a diverse agro-ecology, with dozens of food crops, in virtual material isolation from Earth's environment. This permits a detailed examination of fixation and respiration from the continuous record of carbon dioxide concentration from sensors inside the facility. Unlike the Earth, all the ecosystems were active during sunlight hours, while phyto and soil respiration dominated nighttime hours. This resulted in fluctuations of as much as 600-700 ppm CO2 daily during days of high sunlight input. We examine the relationships between daytime fixation as driven by photosynthesis to nighttime respiration and also fixation and respiration as related to carbon dioxide concentration. Since carbon dioxide concentrations varied from near Earth ambient levels to over 3000 ppm (during low-light winter months), the response of the plant communities and impact on phytorespiration and soil respiration may be of relevance to the global climate change research community. An investigation of these dynamics will also allow the testing of models predicting the response of community metabolism to variations in sunlight and degree of previous net carbon fixation.

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

    PubMed

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

    2014-08-01

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

  10. Mycoflora and natural occurrence of aflatoxins and fumonisin B1 in cassava and yam chips from Benin, West Africa.

    PubMed

    Gnonlonfin, G J B; Hell, K; Fandohan, P; Siame, A B

    2008-02-29

    The presence of fungi, aflatoxins and fumonisin B1 in cassava and yam chips (during 28 processing and storage) were evaluated during two consecutive seasons in two agroecological zones of Benin (Northern Guinea Savannah, NGS and Sudan Savannah, SS). The Benin samples were assessed for moisture content, fungal infestation and total aflatoxin and fumonisin B1 contamination. During the two seasons, samples collected from the NGS, had moisture contents ranging from 10.0 to 14.7% in cassava chips and from 11.4 to 15.3% in yam chips. In samples from the SS, moisture content ranged from 10.1 to 14.5% and 11.1 to 14.5% in cassava and yam chips, respectively. A. flavus was the predominant fungal species. The maximum cfu/g in cassava and yam chips was 8950 and 6030, respectively. Other fungal species isolated included P. chrysogenum, M. piriformis, Phoma sorghina, F. verticillioides, R. oryzae and Nigrospora oryzae. High performance liquid chromatography analysis of both cassava and yam chips showed no contamination by either aflatoxins or fumonisin B1.

  11. Avian conservation practices strengthen ecosystem services in California vineyards.

    PubMed

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

    2011-01-01

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

  12. GMDPtoolbox: A Matlab library for designing spatial management policies. Application to the long-term collective management of an airborne disease.

    PubMed

    Cros, Marie-Josée; Aubertot, Jean-Noël; Peyrard, Nathalie; Sabbadin, Régis

    2017-01-01

    Designing management policies in ecology and agroecology is complex. Several components must be managed together while they strongly interact spatially. Decision choices must be made under uncertainty on the results of the actions and on the system dynamics. Furthermore, the objectives pursued when managing ecological systems or agroecosystems are usually long term objectives, such as biodiversity conservation or sustainable crop production. The framework of Graph-Based Markov Decision Processes (GMDP) is well adapted to the qualitative modeling of such problems of sequential decision under uncertainty. Spatial interactions are easily modeled and integrated control policies (combining several action levers) can be designed through optimization. The provided policies are adaptive, meaning that management actions are decided at each time step (for instance yearly) and the chosen actions depend on the current system state. This framework has already been successfully applied to forest management and invasive species management. However, up to now, no "easy-to-use" implementation of this framework was available. We present GMDPtoolbox, a Matlab toolbox which can be used both for the design of new management policies and for comparing policies by simulation. We provide an illustration of the use of the toolbox on a realistic crop disease management problem: the design of long term management policy of blackleg of canola using an optimal combination of three possible cultural levers. This example shows how GMDPtoolbox can be used as a tool to support expert thinking.

  13. Spatio-temporal dynamics of genetic diversity in Sorghum bicolor in Niger.

    PubMed

    Deu, Monique; Sagnard, F; Chantereau, J; Calatayud, C; Vigouroux, Y; Pham, J L; Mariac, C; Kapran, I; Mamadou, A; Gérard, B; Ndjeunga, J; Bezançon, G

    2010-05-01

    The dynamics of crop genetic diversity need to be assessed to draw up monitoring and conservation priorities. However, few surveys have been conducted in centres of diversity. Sub-Saharan Africa is the centre of origin of sorghum. Most Sahel countries have been faced with major human, environmental and social changes in recent decades, which are suspected to cause genetic erosion. Sorghum is the second staple cereal in Niger, a centre of diversity for this crop. Niger was submitted to recurrent drought period and to major social changes during these last decades. We report here on a spatio-temporal analysis of sorghum genetic diversity, conducted in 71 villages covering the rainfall gradient and range of agro-ecological conditions in Niger's agricultural areas. We used 28 microsatellite markers and applied spatial and genetic clustering methods to investigate change in genetic diversity over a 26-year period (1976-2003). Global genetic differentiation between the two collections was very low (F (st) = 0.0025). Most of the spatial clusters presented no major differentiation, as measured by F (st), and showed stability or an increase in allelic richness, except for two of them located in eastern Niger. The genetic clusters identified by Bayesian analysis did not show a major change between the two collections in the distribution of accessions between them or in their spatial location. These results suggest that farmers' management has globally preserved sorghum genetic diversity in Niger.

  14. Isolation and characterization of culturable seed-associated bacterial endophytes from gnotobiotically grown Marama bean seedlings.

    PubMed

    Chimwamurombe, Percy Maruwa; Grönemeyer, Jann Lasse; Reinhold-Hurek, Barbara

    2016-06-01

    Marama bean (Tylosema esculentum) is an indigenous non-nodulating legume to the arid agro-ecological parts of Southern Africa. It is a staple food for the Khoisan and Bantu people from these areas. It is intriguing how it is able to synthesize the high-protein content in the seeds since its natural habitat is nitrogen deficient. The aim of the study was to determine the presence of seed transmittable bacterial endophytes that may have growth promoting effects, which may be particularly important for the harsh conditions. Marama bean seeds were surface sterilized and gnotobiotically grown to 2 weeks old seedlings. From surface-sterilized shoots and roots, 123 distinct bacterial isolates were cultured using three media, and identified by BOX-PCR fingerprinting and sequence analyses of the 16S rRNA and nifH genes. Phylogenetic analyses of 73 putative endophytes assigned them to bacterial species from 14 genera including Proteobacteria (Rhizobium, Massilia, Kosakonia, Pseudorhodoferax, Caulobacter, Pantoea, Sphingomonas, Burkholderia, Methylobacterium), Firmicutes (Bacillus), Actinobacteria (Curtobacterium, Microbacterium) and Bacteroidetes (Mucilaginibacter, Chitinophaga). Screening for plant growth-promoting activities revealed that the isolates showed production of IAA, ACC deaminase, siderophores, endoglucanase, protease, AHLs and capacities to solubilize phosphate and fix nitrogen. This is the first report that marama bean seeds may harbor endophytes that can be cultivated from seedlings; in this community of bacteria, physiological characteristics that are potentially plant growth promoting are widespread.

  15. Assessment of Aflatoxin and Fumonisin Contamination of Maize in Western Kenya.

    PubMed

    Mutiga, S K; Hoffmann, V; Harvey, J W; Milgroom, M G; Nelson, R J

    2015-09-01

    We conducted a survey of aflatoxin and fumonisin in maize in western Kenya. In a regional survey of aflatoxin conducted in 2009 across three agroecological zones within three administrative regions, milled maize samples were collected from 985 patrons of 26 hammer mills. Aflatoxin contamination was detected in 49% of samples and was above the regulatory (10 ppb) in 15% of the samples overall; 65% of samples from a drought-prone area were over the limit. In a detailed survey in Bungoma County, we investigated aflatoxin and fumonisin contamination in four popular maize varieties at harvest and after 2 and 4 months of storage. We collected whole-grain samples from farmers' storage sheds and milled samples from patrons of local mills. Mean aflatoxin contamination was identical for storage sheds and mills at 2.3 ppb. In all, 41% of the samples from mills had detectable aflatoxin, with 4% over the regulatory limit, whereas 87% had detectable fumonisin, with 50% over the regulatory limit (1 ppm). Mean contamination levels did not change during storage. Maize varieties differed in fumonisin contamination, with the most popular varieties vulnerable to both mycotoxins and weevils, which are potential factors in exacerbating mycotoxin contamination. Mycotoxin surveillance is important not just in areas known previously for aflatoxin contamination and acute poisoning but also is needed in all maize-producing regions.

  16. Isolation, Screening, and Identification of Novel Isolates of Actinomycetes from India for Antimicrobial Applications.

    PubMed

    Singh, Vineeta; Haque, Shafiul; Singh, Harshita; Verma, Jyoti; Vibha, Kumari; Singh, Rajbir; Jawed, Arshad; Tripathi, C K M

    2016-01-01

    The search for novel bioactive compounds from the natural environment has rapidly been gaining momentum with the increase in multi-drug resistant (MDR) pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569, and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes.

  17. 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.

  18. Effect of agricultural activities on prevalence rates, and clinical and presumptive malaria episodes in central Côte d'Ivoire.

    PubMed

    Koudou, Benjamin G; Tano, Yao; Keiser, Jennifer; Vounatsou, Penelope; Girardin, Olivier; Klero, Kouassi; Koné, Mamadou; N'goran, Eliézer K; Cissé, Guéladio; Tanner, Marcel; Utzinger, Jürg

    2009-09-01

    Agricultural activities, among other factors, can influence the transmission of malaria. In two villages of central Côte d'Ivoire (Tiémélékro and Zatta) with distinctively different agro-ecological characteristics, we assessed Plasmodium prevalence rates, fever and clinically confirmed malaria episodes among children aged 15 years and below by means of repeated cross-sectional surveys. Additionally, presumptive malaria cases were monitored in dispensaries for a 4-year period. In Tiémélékro, we observed a decrease in malaria prevalence rates from 2002 to 2005, which might be partially explained by changes in agricultural activities from subsistence farming to cash crop production. In Zatta, where an irrigated rice perimeter is located in close proximity to human habitations, malaria prevalence rates in 2003 were significantly lower than in 2002 and 2005, which coincided with the interruption of irrigated rice farming in 2003/2004. Although malaria transmission differed by an order of magnitude in the two villages in 2003, there was no statistically significant difference between the proportions of severe malaria episodes (i.e. axillary temperature>37.5 degrees C plus parasitaemia>5000 parasites/microl blood). Our study underscores the complex relationship between malaria transmission, prevalence rate and the dynamics of malaria episodes. A better understanding of local contextual determinants, including the effect of agricultural activities, will help to improve the local epidemiology and control of malaria.

  19. Sustainability of a privatized community-based animal health worker system in Mwingi District, Kenya.

    PubMed

    Rubyogo, J C; Murithii, P M; Agumbah, G J O; Obhai, G

    2005-05-01

    This paper describes a study on the sustainability of Community-based Animal Health Worker (CAHW) services in Mwingi District, Kenya. These services began in 1992 and were supported by the District Veterinary Authority (DVA) with assistance from the Integrated Food Security Programme-Eastern (IFSP-E). Over time and using a process of participatory reviews with multiple stakeholders, the system evolved into a network of CAHWs. The study focused on CAHWs' service sustainability and their relationships with other animal health service providers. A mutually beneficial and supportive arrangement existed between the CAHWs and Animal Health Assistants (AHAs), based on a private drug supply system, referral and backstopping support. The CAHWs derived sufficient income from their veterinary work to maintain their interest in the system. Seventy percent of CAHWs were continuing to offer adequate animal health services 3 years or more after their initial training and the withdrawal of donor support. Ninety-five percent of sampled CAHWs (n = 40) viewed their business as successful and expanding. Considering the agro-ecological and socio-economic conditions of the district, the CAHW system can be viewed as an initial stage in the process of extending quality private sector veterinary services.

  20. 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

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

    PubMed

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

    2015-03-18

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

  2. 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.

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

    PubMed Central

    Zimmerer, Karl S.

    2013-01-01

    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

  4. `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.

  5. Efficacy of Bacillus amyloliquefaciens as biocontrol agent to fight fungal diseases of maize under tropical climates: from lab to field assays in south Kivu.

    PubMed

    Kulimushi, Parent Zihalirwa; Basime, Géant Chuma; Nachigera, Gustave Mushagalusa; Thonart, Philippe; Ongena, Marc

    2017-06-09

    In the province of South Kivu (Democratic Republic of Congo), warm and humid climatic conditions favor the development and spreading of phytopathogens. The resulting diseases cause important losses in production both in crop and after harvest. In this study, we wanted to evaluate the potential of Bacillus amyloliquefaciens as biocontrol agent to fight some newly isolated endemic fungal pathogens infesting maize. The strain S499 has been selected based on its high in vitro antagonistic activity correlating with a huge potential to secrete fungitoxic lipopeptides upon feeding on maize root exudates. Biocontrol activity of S499 was further tested on infected plantlets in growth chamber and on plants grown under field conditions over an entire cropping period. We observed a strong protective effect of this strain evaluated at two different locations with specific agro-ecological conditions. Interestingly, disease protection was associated with higher yields and our data strongly suggest that, in addition to directly inhibit pathogens, the strain may also act as biofertilizer through the solubilization of phosphorus and/or by producing plant growth hormones in the rhizosphere. This work supports the hope of exploiting such technologically advantageous bacilli for the sake of sustainable local production of this important crop in central Africa.

  6. Monitoring of the CO2 emission and the contents of microbial biomass in agroecosystems on gray forest soils of the Cisbaikal region under conditions of fluoride pollution

    NASA Astrophysics Data System (ADS)

    Pomazkina, L. V.

    2015-08-01

    The influence of the technogenic pollution of gray forest soils in the forest-steppe zone of the Cisbaikal region with fluorides emitted by aluminum smelters on the functioning and state of local agroecosystems was studied within the framework of a long-term agroecological monitoring program. Hydrothermic conditions of the growing season during the monitoring period (1997-2012) were compared with the climatic norm (1961-1990). It was found that the adverse effect of the technogenic pollution on the agroecosystem becomes more pronounced during the years with abnormal weather conditions. An increase in the CO2 emission into the atmosphere as a response of the microbial complex to the rise in the air temperatures was characterized by the linear dependence irrespectively of the degree of soil contamination. The methods of systems analysis were applied to generalize the results. The considered agroecosystem was studied as the system of particular components (soil-microorganisms-plants-atmosphere) integrated by the carbon fluxes. The regimes of the agroecosystem functioning and the ecological loads on it were estimated on the basis of data on the fluxes of net mineralized and (re)immobilized carbon. The environmental factors affecting the state and functioning of the agroecosystem were identified.

  7. Larvicidal, insecticidal, brine shrimp cytotoxicity and anti-oxidant activities of Diospyros kaki (L.) reported from Pakistan.

    PubMed

    Nisar, Mohammad; Shah, Syed Muhammad Mukarram; Khan, Imran; Sheema; Sadiq, Abdul; Khan, Shahzeb; Shah, Syed Muhammad Hassan

    2015-07-01

    Diospyros kaki is cultivated in different agro-ecological zones of Pakistan, especially in Malakand division. The current study was designed to investigate the hide potential of the vulnerable species of the plant. Aqueous extracts of Diospyros kaki leaves were screened for larvicidal, insecticidal cytotoxic and antioxidant activities. The extract exhibited moderate to outstanding larvicidal activity (100 to 28%) at 100, 80, 70, 50, 40, 30, 20 and 10% concentrations respectively after 24 hours, showing 42% LC₅₀. Permitrin displayed 100% lethality at 0.3%. The extract demonstrated outstanding cytotoxic action against brain shrimps nauplii (Artemia salina), showing 10 ppm LC50 which is closed to the LC50 (9.8μg/ml) of standard drug Etoposide. Similarly profound insecticidal potential (100%) was recorded after 15 min against Cimex lectularius. In DPPH scavenging activity the extract demonstrated moderate 30.22%, while Quercetin, Gallic acid and Acetic acid showed 98, 96 and 97% activity respectively at 100 ppm. Thus on the basis of our finding it could be concluded that the decoction of the leaves of D. kaki is a good natural alternative for the control of insects and neoplasia.

  8. Changes in soil C-isotopic composition in an agroecosystem under Free Air Carbon dioxide Enrichment (FACE) treatment during a crop rotation period.

    PubMed

    Giesemann, Anette

    2005-01-01

    FACE (Free Air Carbon dioxide Enrichment) has been used since 1999 to evaluate the effects of future atmospheric CO(2) concentrations on an arable crop agroecosystem. The experiment conducted at the Institute of Agroecology at the Federal Research Centre in Braunschweig consists of a typical local crop rotation of winter barley, a cover crop, sugar beet and winter wheat. The atmospheric CO2 concentration of ambient air is about 375 ppm with a delta13C value of -7 to -9 per thousand, and 550 ppm (delta13C value = -20.2 per thousand) during daylight hours in the rings fumigated with additional CO2. Thus, the surplus C can be traced in the agricultural system. Over the course of the first experimental period (3-year crop rotation period), the C-isotopic composition and the C concentration in soil were monitored monthly. Plant samples were analysed according to the relevant developmental stages of the crop under cultivation. A 13C depletion was observed in plant parts, as well as in soil samples from the FACE rings under CO2 enrichment, indicating that labelled C has reached both respective ecosystem compartments. Albeit farming management practice (especially ploughing) leads to a mixing of 'old' and 'new' C compounds throughout all soil horizons down to the end of the ploughing layer and resulted in a heterogeneous distribution of newly formed C compounds in the soil, isotope analysis of soil C reflected where the surplus C went.

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

    PubMed Central

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

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2017-02-01

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

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

    PubMed

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

    2015-12-22

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

  12. Thermodynamics of Cadmium Sorption on Different Soils of West Bengal, India

    PubMed Central

    Paul, Ranjit Kumar; Das, D. K.; Boruah, Romesh K.; Sonar, Indira

    2014-01-01

    A sorption study was conducted on different soils collected from five agroecological zones of West Bengal, India, to understand the soil environmental behavior and fate of cadmium. For this purpose batch adsorption experiments were carried out at the native soil pH and at three different temperatures (25°C, 35°C, and 45°C). The adsorption data fitted by a linear least squares technique to the different sorption isotherms. Most data obtained give the good fit to both Freundlich and modified Langmuir isotherms, but they are not consistent with the linear Langmuir adsorption model. Thermodynamic parameters, namely, thermodynamics equilibrium constant at a particular temperature T  (KT0), Gibbs free energy at a particular temperature T  (ΔGT0), and change of enthalpy (ΔH0) and change of entropy at temperature T  (ΔST0), were also determined by applying sorption value and concentrations of Cd in equilibrium solution within the temperature range. The thermodynamic parameters revealed that Cd sorption increases as the values of KT0, ΔGT0, ΔH0, and ΔST0 were increased on reaction temperatures. The spontaneous sorption reaction can be concluded due to high values of ΔGT0. The positive values of ΔH0 indicated that the Cd sorption is an endothermic one. Under these present conditions, the soil and its components possibly supply a number of sites having different adsorption energies for cadmium sorption. PMID:24683322

  13. Suitability Evaluation for Lowland Rice in Inland Valleys in West Africa

    NASA Astrophysics Data System (ADS)

    Hideto, Fujii; Muralikrishna, Gumma; Prasad, Thenkabail; Regassa, Namara

    A GIS based model developed by the authors are applied for selecting suitable rice cultivation area in inland valleys that has high potential for rice production in West Africa where rice consumption is increasing very rapidly. The model has the following features. 1) The model is to evaluate the suitability of the land for lowland rice based on score distribution maps respectively made by the data of 29 evaluation parameters. 2) The parameters are classified into 4 categories; bio-physical, technical, socio-economic and health-environmental parameters. 3) Each scored map (layer) is integrated to obtain total scores by multiplying a weight which is determined by the importance of parameters. The suitability for rice in two study sites was evaluated using the model. Mankran and Jolo-Kwaha watershed selected as the study sites from different agro-ecological zone in Ghana. Applying the data of 12 parameters acquired in the study sites to the model, “very suitable” or “suitable” occupies around 30% in Mankran study site and around 60% in Jolo-Kwaha study site.

  14. Association between Grape Yeast Communities and the Vineyard Ecosystems.

    PubMed

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

    2017-01-01

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

  15. Molecular assessment of the bacterial community associated with Cassava (Manihot esculenta Crantz) cultivation in Cameroon.

    PubMed

    Sarr, Papa Saliou; Sugiyama, Akifumi; Begoude, Aime Didier Boyogueno; Yazaki, Kazufumi; Araki, Shigeru; Nawata, Eiji

    2017-04-01

    Bacterial communities play an important role in nutrient cycles and plant development. Their distribution and activity may depend on location and environmental heterogeneity. This study characterized soil bacterial communities in cassava fields of Eastern (Andom) and Southern (Bityili) Cameroon using molecular tools. In both sites, two improved varieties (TMS-96/1414; TMS-92/0326) and a local variety (Local) were grown in a randomized block design. Composite bulk soils were collected at 10months after planting from cassava plots. The 16S rDNA region was amplified, MiSeq was performed and sequence data analyzed. The same 17 bacterial phyla were present in both Andom and Bityili, while Chlorobi and Deinococcus-Thermus were only specific to Andom. The phyla Proteobacteria, Planctomycetes, Actinobacteria and Acidobacteria were dominant. Although both sites shared similar phyla, the principal coordinate analysis revealed significant variations in their composition, suggesting that the functions of the bacteria in nutrients cycling are likely to differ between Andom and Bityili. Cassava yields were generally higher in Andom which also displayed a higher diversity of bacterial communities. This study provides useful information on the composition of bacterial communities in cassava fields in two agro-ecologies of Cameroon. It constitutes to our knowledge the first report describing soil bacterial communities in association with cassava growth in the country, using molecular tools.

  16. Impact of Climate Change on Yields and Components of the Water and Nitrogen Budgets of Dryland Wheat Systems in the US Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Karimi, T.; Stockle, C.; Nelson, R.

    2016-12-01

    As part of the Regional Approaches to Climate Change (REACCH) project (funded by USDA-NIFA), a regional assessment of historical and future yields and greenhouse gas (GHG) emissions of dryland wheat-based cropping systems in the US Pacific Northwest is being conducted. Two issues of interest in the region are changes in the water footprint and nitrogen use of wheat-based systems as a result of climate change. These two are related to the interaction between crop performance and the partitioning of water and nitrogen budget components. They also inform the tradeoff between crop production and environmental services and the sustainability of wheat systems in the future. Computer simulation-based assessment is being done using the CropSyst cropping systems simulation model and daily weather data downscaled to a 4x4 km grid. Future weather is projected using 12 general circulation models (GCMs) and two representative concentration pathways of future atmospheric CO2 (rcp 4.5 and rcp 8.5). The study region is divided in 3 agro-ecological classes (AECs): grain fallow, grain fallow transition and continuous cropping classes. The following rotations were included by AEC: WW - SF, WW - SW - SF and WW - SW - SP, where WW is winter wheat, SW is spring wheat, SP is spring peas, and SF is summer fallow. A typical conventional tillage (CT) cropping system in each AEC is evaluated as a baseline.

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

    PubMed

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

    2016-09-29

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

  18. The sulfated laminarin triggers a stress transcriptome before priming the SA- and ROS-dependent defenses during grapevine's induced resistance against Plasmopara viticola.

    PubMed

    Gauthier, Adrien; Trouvelot, Sophie; Kelloniemi, Jani; Frettinger, Patrick; Wendehenne, David; Daire, Xavier; Joubert, Jean-Marie; Ferrarini, Alberto; Delledonne, Massimo; Flors, Victor; Poinssot, Benoit

    2014-01-01

    Grapevine (Vitis vinifera) is susceptible to many pathogens which cause significant losses to viticulture worldwide. Chemical control is available, but agro-ecological concerns have raised interest in alternative methods, especially in triggering plant immunity by elicitor treatments. The β-glucan laminarin (Lam) and its sulfated derivative (PS3) have been previously demonstrated to induce resistance in grapevine against downy mildew (Plasmopara viticola). However, if Lam elicits classical grapevine defenses such as oxidative burst, pathogenesis-related (PR)-proteins and phytoalexin production, PS3 triggered grapevine resistance via a poorly understood priming phenomenon. The aim of this study was to identify the molecular mechanisms of the PS3-induced resistance. For this purpose we studied i) the signaling events and transcriptome reprogramming triggered by PS3 treatment on uninfected grapevine, ii) grapevine immune responses primed by PS3 during P. viticola infection. Our results showed that i) PS3 was unable to elicit reactive oxygen species (ROS) production, cytosolic Ca(2+) concentration variations, mitogen-activated protein kinase (MAPK) activation but triggered a long lasting plasma membrane depolarization in grapevine cells, ii) PS3 and Lam shared a common stress-responsive transcriptome profile that partly overlapped the salicylate- (SA) and jasmonate-(JA)-dependent ones. After P. viticola inoculation, PS3 specifically primed the SA- and ROS-dependent defense pathways leading to grapevine induced resistance against this biotroph. Interestingly pharmacological approaches suggested that the plasma membrane depolarization and the downstream ROS production are key events of the PS3-induced resistance.

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

    PubMed

    Borras, Saturnino M

    2010-01-01

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

  20. What Does It Cost to Improve Household Diets in Nepal? Using the Cost of the Diet Method to Model Lowest Cost Dietary Changes.

    PubMed

    Biehl, Erin; Klemm, Rolf D W; Manohar, Swetha; Webb, Patrick; Gauchan, Devendra; West, Keith P

    2016-07-03

    In Nepal, limited availability and affordability of nutritious foods contribute to malnutrition. To identify nutrient deficiencies in commonly consumed diets and model lowest cost changes that could improve diet quality in 3 agroecological zones of Nepal. In August to September 2014, we collected market price and women's food frequency data from 3 representative villages in Nepal's mountains (Mahat Gaun, Jumla, n = 181 households), hills (Sitapur, Arghakhanchi, n = 166), and terai (Saigaun, Banke, n = 232) and verified local diets during women's group discussions. Using the Cost of the Diet method, we compared models of the most nutritious version of a commonly consumed diet given locally available foods ("common diet") with the cheapest possible diet meeting nutrient requirements, including foods not currently available ("optimal diet"). The household common diet lacks sufficient vitamin B12, riboflavin, and calcium in the mountains; B6, B12, calcium, and iron in the hills; vitamin A, calcium, and iron in the terai. Adding fish to the mountain and hill diets and increasing dark green leafy vegetable consumption in all zones yielded nutritional adequacy. Optimal diets are more expensive than the common diet in the mountains and hills but less expensive in the terai. The modeled lowest cost diet commonly eaten in 3 Nepalese communities lacks key nutrients. Policies and interventions that increase market availability and consumption of vitamin B12- and calcium-rich fish and dark green leafy vegetables could improve local diets, particularly in the mountains and hills. © The Author(s) 2016.

  1. Migration, isolation and hybridization in island crop populations: the case of Madagascar rice.

    PubMed

    Mather, Kristie A; Molina, Jeanmaire; Flowers, Jonathan M; Rubinstein, Samara; Rauh, Brad L; Lawton-Rauh, Amy; Caicedo, Ana L; McNally, Kenneth L; Purugganan, Michael D

    2010-11-01

    Understanding how crop species spread and are introduced to new areas provides insights into the nature of species range expansions. The domesticated species Oryza sativa or Asian rice is one of the key domesticated crop species in the world. The island of Madagascar off the coast of East Africa was one of the last major Old World areas of introduction of rice after the domestication of this crop species and before extensive historical global trade in this crop. Asian rice was introduced in Madagascar from India, the Malay Peninsula and Indonesia approximately 800-1400 years ago. Studies of domestication traits characteristic of the two independently domesticated Asian rice subspecies, indica and tropical japonica, suggest two major waves of migrations into Madagascar. A population genetic analysis of rice in Madagascar using sequence data from 53 gene fragments provided insights into the dynamics of island founder events during the expansion of a crop species' geographic range and introduction to novel agro-ecological environments. We observed a significant decrease in genetic diversity in rice from Madagascar when compared to those in Asia, likely the result of a bottleneck on the island. We also found a high frequency of a unique indica type in Madagascar that shows clear population differentiation from most of the sampled Asian landraces, as well as differential exchange of alleles between Asia and Madagascar populations of the tropical japonica subspecies. Finally, despite partial reproductive isolation between japonica and indica, there was evidence of indica/japonica recombination resulting from their hybridization on the island.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  3. Ecological intensification of cereal production systems: yield potential, soil quality, and precision agriculture.

    PubMed

    Cassman, K G

    1999-05-25

    Wheat (Triticum aestivum L.), rice (Oryza sativa L.), and maize (Zea mays L.) provide about two-thirds of all energy in human diets, and four major cropping systems in which these cereals are grown represent the foundation of human food supply. Yield per unit time and land has increased markedly during the past 30 years in these systems, a result of intensified crop management involving improved germplasm, greater inputs of fertilizer, production of two or more crops per year on the same piece of land, and irrigation. Meeting future food demand while minimizing expansion of cultivated area primarily will depend on continued intensification of these same four systems. The manner in which further intensification is achieved, however, will differ markedly from the past because the exploitable gap between average farm yields and genetic yield potential is closing. At present, the rate of increase in yield potential is much less than the expected increase in demand. Hence, average farm yields must reach 70-80% of the yield potential ceiling within 30 years in each of these major cereal systems. Achieving consistent production at these high levels without causing environmental damage requires improvements in soil quality and precise management of all production factors in time and space. The scope of the scientific challenge related to these objectives is discussed. It is concluded that major scientific breakthroughs must occur in basic plant physiology, ecophysiology, agroecology, and soil science to achieve the ecological intensification that is needed to meet the expected increase in food demand.

  4. 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.

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  7. Barley: a translational model for adaptation to climate change.

    PubMed

    Dawson, Ian K; Russell, Joanne; Powell, Wayne; Steffenson, Brian; Thomas, William T B; Waugh, Robbie

    2015-05-01

    Barley (Hordeum vulgare ssp. vulgare) is an excellent model for understanding agricultural responses to climate change. Its initial domestication over 10 millennia ago and subsequent wide migration provide striking evidence of adaptation to different environments, agro-ecologies and uses. A bottleneck in the selection of modern varieties has resulted in a reduction in total genetic diversity and a loss of specific alleles relevant to climate-smart agriculture. However, extensive and well-curated collections of landraces, wild barley accessions (H. vulgare ssp. spontaneum) and other Hordeum species exist and are important new allele sources. A wide range of genomic and analytical tools have entered the public domain for exploring and capturing this variation, and specialized populations, mutant stocks and transgenics facilitate th