51 research outputs found

    Water Use and Yield of Millet Under the Zai System: Understanding the Processes Using Simulation

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    In the drylands of Africa about 90% of the population is rural and depends on subsistence agriculture for their livelihoods. There is an increasing pressure on the natural resources due to the high population growth, and farmers are constrained to cultivate marginal lands, thereby compounding the land degradation problem. Low and erratic rainfall, its poor distribution within the growing season, prolonged dry spells, lack of adequate water supply due to soil physical degradation (soil crusting) and nutrient shortage adversely affect crop growth and yields. To address these problems, indigenous, easy to implement innovations such as the zai system may provide solutions to increase productivity. The effect of three planting techniques (Flat, zai pit of 25 cm and zai pit of 50 cm diameter) and three fertility management options (control, crop residue, cattle manure) were tested at Damari in 1999 in Niger. Soil water was monitored from weekly measurements using a Didcot Wallingford neutron probe throughout the growing period. Data from that experiment were used to determine if the CERES-Millet model of the Decision Support System for Agrotechnology Transfer (DSSAT) is sufficiently robust to predict yield response to the zai water harvesting system. The model simulated the observed yield response of the control and the manure-amended plots with high r-square (0.99), low residual mean error square (340 kg·ha−1 for above ground biomass and 94 kg·ha−1 for grain yield) and high d-statistic (0.99), but this was not the case for the crop residue treatment, which was over-predicted. Soil water content and extractable soil water were also well simulated for the control and manure treatments. This evaluation of DSSAT provides a starting point for research to evaluate the performance of these technologies over wider areas in West Africa. The application of models for such studies must be interpreted in the context of limitations of the model to address some constraints. Nevertheless, the highly variable crop responses due to interacting effects of rainfall, management and adverse soil conditions in this region make this an extremely important approach in planning for technology ­adoption in an area and in interpreting results from experimental field researc

    Modeling nutrient and water productivity of sorghum in smallholder farming systems in a semi-arid region of Ghana

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    The CERES-sorghum module of the Decision Support System for Agro-Technological Transfer (DSSAT) model was calibrated for sorghum (Sorghum bicolor (L.) Moench) using data from sorghum grown with adequate waterand nitrogen and evaluated with data from several N rates trials in Navrongo, Ghana with an overall modified internal efficiency of 0.63. The use of mineral N fertilizer was found to be profitable with economically optimal rates of 40 and 80 kg N ha−1 for more intensively managed homestead fields and less intensively managed bush fields respectively. Agronomic N use efficiency varied from 21 to 37 kg grain kg−1 N for the homestead fields and from 15 to 49 kg grain kg−1 N in the bush fields. Simulated grain yield for homestead fields at 40 kg N ha−1 application was equal to yield for bush fields at 80 kg N ha−1. Water use efficiency generally increased with increased mineral N rate and was greater for the homestead fields compared with the bush fields. Grain yield per unit of cumulative evapo-transpiration (simulated) was consistently higher compared with yield per unit of cumulative precipitation for the season, probably because of runoff and deep percolation. In the simulation experiment, grain yield variability was less with mineral N application and under higher soil fertility (organic matter) condition. Application of mineral N reduced variability in yield from a CV of 37 to 11% in the bush farm and from 17 to 7% in the homestead fields. The use of mineral fertilizer and encouraging practices that retain organic matter to the soil provide a more sustainable system for ensuring crop production and hence food securit

    Rothamsted carbon model reveals technical options to maintain soil organic carbon under semi-arid climate

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    Soil organic matter in the Sahel is severely reduced by continuous cultivation. Reductions of soil organic matter decrease in turn soil productivity. Nonetheless, reports show that organic matter application in the Sahel improves crop yield. However, long-term effects of organic matter application on soil fertility have not been fully studied. In particular, it is essential to get information on organic matter decomposition and annual carbon requirement. Model simulation is suitable for evaluating long-term sustainability. The Rothamsted carbon model is convenient and has been recently validated for use in Sahelian conditions. Here, we studied the annual carbon requirement for sustainable soil organic carbon management in the Sahelian zone using datasets of short-term trials conducted in the Sahel. We estimated the long-term effect of various agricultural managements on soil organic carbon dynamics as one of the soil fertility indices. The 10-year soil organic carbon value changes were predicted by the Rothamsted carbon model for 59 treatments. Results show that, contrary to previous short-term experiments that indicated crop yield enhancement, these technical options also cause a decline in soil organic carbon if enough organic resource is not applied. Soil productivity should therefore decrease. The annual carbon requirement to maintain the soil organic carbon level is approximately 0.8 tons of carbon per hectar

    Germplasm Enhancement for Increasing Groundnut Productivity and Production in West and Central Africa

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    West ond Central Afnca (WCA) account for almosl 70% of groundnut production in Africa playing an important role to farmers' livelihood and signfically contributes to the export sector of the countries in the region.However, the productivity in the region is limited due to many factors includmg biotic and abiotic constraints..

    Germplasm Enhancement for Increasing Groundnut Productivity and Production in West and Central Africa

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    West ond Central Afnca (WCA) account for almosl 70% of groundnut production in Africa playing an important role to farmers' livelihood and signfically contributes to the export sector of the countries in the region.However, the productivity in the region is limited due to many factors includmg biotic and abiotic constraints..

    Priority interventions for transformational change in the Sahel

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    The Sahel region holds both challenges and opportunities for smallholder agriculture and agro pastoralism. Market opportunities for food producers in the region have improved due to population growth, urbanization, income growth, dietary diversification and higher output prices. However, alongside land degradation and climate change, conflicts and epidemics, an increased dependence on dynamic food (and feed) value chains and on volatile markets indicates the need to address structural constraints such as limited access to high-potential agricultural innovations, ineffective policies, an underdeveloped business environment, poor infrastructure and processing facilities and a generally poor market infrastructure. To support the agricultural transformation required to meet these challenges, evidence needs to be provided to countries in the Sahel to enable them make informed decisions on policy reforms and supporting actions where and when needed. Several scaling approaches and technological solutions have been demonstrated to be effective and this document outlines proposed priority actions to achieve higher adoption of climate smart agriculture through Public-Private-Partnerships. A particular focus will be on the role of women and youth, both through improved household nutrition (and other attendant health and development benefits) and through improved job creation and wealth generation in various components of selected value chains. Meanwhile, the importance of improved agro-industrialization and trade for income generation and poverty reduction underscores the critical role of enhanced interaction with a vibrant private sector. This document presents some of the main routes by which R4D can contribute to agricultural transformation in the Sahel towards inclusive and sustainable economic growth, social development and resilience, including climate smart agricultural technologies appropriate to smallholder farming families. This will be achieved through a six-pronged strategy: (i) Increasing the efficiency of tree, crop and livestock value chains, (ii) Empowerment and increased employment opportunities for women and youth in agriculture, (iii) Co-creation of context-specific, climate smart innovations to enhance climate resilience (iv) Value addition and improved nutrition, (v) Improved soil and water conservation and its utilization for production, Improved policy and institutional enabling environments

    Evaluation of multiple stress tolerant groundnut genotypes for productivity and nutritional quality in Nigeria

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    Groundnut plays a very important economic role for smallholder farmers in the semi-arid tropics as a major cash crop for many households; a nutritious and safe food thereby contributing to improved health of the rural population. It is rich in protein, oil and micronutrients such as iron and zinc. High iron and zinc contents are especially beneficial for women and children at risk of anemia and have proven to be genetically malleable. High oleic acid and low linoleic acid make groundnut oil ideal for storage and better human health. Evaluation of 541 advanced breeding lines along with locallandraces and improved varieties for their reaction to drought, rosette and foliar diseases besides productivity parameters over two locations during 2014 main season resulted in identification of 45 promising lines with significantly superior pod yield (1304-2796 kg/ha) compared to check entries (189-1005 kg/ha). Further, these superior genotypes were evaluated for nutritional quality and in trials during 2014115 dry season to confirm their superiority. Nutritional quality (oil, OIL ratio, protein, Fe and Zn content) analyses lead to the identification of nutritionally dense genotypes. Genotypes ICGV IS 11060, Samnut 23, ICGV 00064, ICGV 01276, ICGV IS 07827 and Kampala had high oil content (53-54%); while ICGV 07813 had high OIL ratio of 6.1 followed by ICGV IS 09992, ICGV SM 05593 and ICGV SM 06722 with 3.0 OIL ratio. Genotypes ICGV IS 07833, ICGV IS 3980, ICGV SM 08553 and rCG 5891 had high protein (30-32%), Zn (46-51 ppm) and Fe (23-34 ppm) content. These serve as ideal genetic resources to develop agronomically superior and nutritionally enhanced groundnut cultivars with multiple resistances to biotic and abiotic stresses

    Integrated use of fertilizer micro-dosing and Acacia tumida mulching increases millet yield and water use efficiency in Sahelian semi-arid environment

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    Limited availability of soil organic amendments and unpredictable rainfall, decrease crop yields drastically in the Sahel. There is, therefore, a need to develop an improved technology for conserving soil moisture and enhancing crop yields in the Sahelian semi-arid environment. A 2-year field experiment was conducted to investigate the mulching effects of Acacia tumida pruning relative to commonly applied organic materials in Niger on millet growth, yields and water use efficiency (WUE) under fertilizer micro-dosing technology. We hypothesized that (1) A. tumida pruning is a suitable mulching alternative for crop residues in the biomass-scarce areas of Niger and (2) combined application of A. tumida mulch and fertilizer micro-dosing increases millet yield and water use efficiency. Two fertilizer micro-dosing options (20 kg DAP ha−1, 60 kg NPK ha−1) and three types of organic mulches (millet straw, A. tumida mulch, and manure) and the relevant control treatments were arranged in factorial experiment organized in a randomized complete block design with four replications. Fertilizer micro-dosing increased millet grain yield on average by 28 %. This millet grain yield increased further by 37 % with combined application of fertilizer micro-dosing and organic mulch. Grain yield increases relative to the un-mulched control were 51 % for manure, 46 % for A. tumida mulch and 36 % for millet mulch. Leaf area index and root length density were also greater under mulched plots. Fertilizer micro-dosing increased WUE of millet on average by 24 %, while the addition of A. tumida pruning, manure and millet increased WUE on average 55, 49 and 25 %, respectively. We conclude that combined application of micro-dosing and organic mulch is an effective fertilization strategy to enhance millet yield and water use efficiency in low-input cropping systems and that A. tumida pruning could serve as an appropriate mulching alternative for further increasing crop yields and water use efficiency in the biomass-scarce and drought prone environment such as the Sahel. However, the economic and social implications and the long-term agronomic effects of this agroforestry tree in Sahelian millet based system have to be explored further

    CGIAR Operations under the Plant Treaty Framework

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    The history of CGIAR and the development and implementation of the International Treaty on Plant Genetic Resources for Food and Agriculture (“Plant Treaty”) are closely intertwined. In accordance with the agreements that 11 CGIAR centers signed with the Plant Treaty’s Governing Body under Article 15 of the treaty, >730,000 accessions of crop, tree, and forage germplasm conserved in CGIAR genebanks are made available under the terms and conditions of the multilateral system of access and benefit sharing, and the CGIAR centers have transferred almost 4 million samples of plant genetic resources under the system. Many activities of CGIAR centers and their genebanks (e.g., crop enhancement, improved agronomic methods, seed system strengthening, and capacity building) are influenced by, and promote, the Plant Treaty’s objectives. The continued existence and optimal functioning of the Plant Treaty’s multilateral system of access and benefit sharing is critically important to CGIAR in the pursuit of its mission. However, the multilateral system has encountered some challenges since the Plant Treaty came into force. The successful conclusion of the ongoing process for enhancing the functioning of the multilateral system could increase monetary benefit sharing and incentives for exchanging more germplasm. In the meantime, increased efforts are necessary to promote nonmonetary benefit sharing through partnerships, technology transfer, information exchange, and capacity building. These efforts should be integrated into countries’ and organizations’ work to implement the Plant Treaty’s provisions on conservation and sustainable use of plant genetic resources, and farmers’ rights

    Setting a baseline for global urban virome surveillance in sewage

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    The rapid development of megacities, and their growing connectedness across the world is becoming a distinct driver for emerging disease outbreaks. Early detection of unusual disease emergence and spread should therefore include such cities as part of risk-based surveillance. A catch-all metagenomic sequencing approach of urban sewage could potentially provide an unbiased insight into the dynamics of viral pathogens circulating in a community irrespective of access to care, a potential which already has been proven for the surveillance of poliovirus. Here, we present a detailed characterization of sewage viromes from a snapshot of 81 high density urban areas across the globe, including in-depth assessment of potential biases, as a proof of concept for catch-all viral pathogen surveillance. We show the ability to detect a wide range of viruses and geographical and seasonal differences for specific viral groups. Our findings offer a cross-sectional baseline for further research in viral surveillance from urban sewage samples and place previous studies in a global perspective
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