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Metadata only record ; Many socio-economic, political, biological, and market issues influence the adoption of conservation agriculture practices in sub-Saharan Africa. The following presentation reviews QAToCA, a qualitative expert assessment tool that can be used to predict the likelihood of adoption and scalability of those innovations.

International audience ; Le développement de la traction animale se sont traduits par une extension des surfaces cultivées et des tensions croissantes pour l'utilisation de l'espace agropastorale et des résidus de récolte. La recherche/développement a promu des pratiques et technologies innovantes telles que les fosses fumures ou l'agriculture de conservation qui accentuent l'appropriation des résidus de cultures et vraisemblablement les tensions à l'échelle du territoire villageois. L'objectif de cet article est de présenter un modèle conceptuel d'analyse avec les acteurs de l'impact de l'agriculture de conservation. Cette étude à été menée dans deux villages du Burkina situés en zones soudanienne et soudanosahélienne. Une cinquantaine de producteurs ont été enquêtés afin de décrire les échanges de biomasses au sein de l'exploitation ainsi qu'avec les autres producteurs du village. Le modèle conceptuel est composé de trois entités. L'entité exploitation qui est le lieu ou les décisions sont prises pour les diverses pratiques (les changements des pratiques d'utilisation de terre, la gestion de la fertilité, etc.), l'entité parcelle où sont mises en oeuvre ces pratiques et qui ont une influence sur la fertilité de sol et l'entité bétail car les animaux par leurs activités participent au transfert de la fertilité et au flux de biomasses. Cet outil reste à implémenter sous la plateforme Cormas (Common-pool resources and multiagents systems) afin de réaliser des simulations avec la modélisation multi-agent. Il sera utilisé en tant qu'outil de discussion concernant différents scénarios d'agriculture de conservation co-construits avec les acteurs impliqués au sein des plateformes d'innovation mises en place dans le cadre du projet Abaco qui vise à expérimenter cette technique.

International audience ; Le développement de la traction animale se sont traduits par une extension des surfaces cultivées et des tensions croissantes pour l'utilisation de l'espace agropastorale et des résidus de récolte. La recherche/développement a promu des pratiques et technologies innovantes telles que les fosses fumures ou l'agriculture de conservation qui accentuent l'appropriation des résidus de cultures et vraisemblablement les tensions à l'échelle du territoire villageois. L'objectif de cet article est de présenter un modèle conceptuel d'analyse avec les acteurs de l'impact de l'agriculture de conservation. Cette étude à été menée dans deux villages du Burkina situés en zones soudanienne et soudanosahélienne. Une cinquantaine de producteurs ont été enquêtés afin de décrire les échanges de biomasses au sein de l'exploitation ainsi qu'avec les autres producteurs du village. Le modèle conceptuel est composé de trois entités. L'entité exploitation qui est le lieu ou les décisions sont prises pour les diverses pratiques (les changements des pratiques d'utilisation de terre, la gestion de la fertilité, etc.), l'entité parcelle où sont mises en oeuvre ces pratiques et qui ont une influence sur la fertilité de sol et l'entité bétail car les animaux par leurs activités participent au transfert de la fertilité et au flux de biomasses. Cet outil reste à implémenter sous la plateforme Cormas (Common-pool resources and multiagents systems) afin de réaliser des simulations avec la modélisation multi-agent. Il sera utilisé en tant qu'outil de discussion concernant différents scénarios d'agriculture de conservation co-construits avec les acteurs impliqués au sein des plateformes d'innovation mises en place dans le cadre du projet Abaco qui vise à expérimenter cette technique.

APES, a modular model was developed in the SEAMLESS project (Van Ittersum et al., 2008)to assess, in different EU regions, the impact of farm management on crop production andenvironmental externalities. Such purpose assumes the capability of APES to simulatecropping systems in a wide range of climate, soil and crop management. The main topic ofthis study is to evaluate APES, under different stresses and management practices(temperature, water and nitrogen), to simulate crop production and nitrogen and waterdynamics. For this evaluation, APES was compared to the CropSyst (Stöckle et al., 2003)model (widely evaluated and used under different biophysical conditions and managementpractices). An explicit description of the limitations and specificities of each modellingapproach is related to the behaviour of each model in different situations.

Low crop productivity, food insecurity, hunger and malnutrition; inadequate farming knowledge and skills, implements and inputs are characteristic of smallholder agriculture in Southern Africa. Many researchers argue that conservation agriculture can guarantee higher crop productivity, food security, improved livelihoods and environmental protection, better than the unsustainable traditional systems of slash and burn practices. In this paper, we present the results of a meta-analysis of over 40 academic publications to review conservation agriculture s role in influencing desired livelihood outcomes in Southern Africa. We conclude that the effectiveness of conservation agriculture towards better livelihood outcomes in Southern Africa remains debatable, especially when supportive government policies are lacking. ; Peer-reviewed

Intended to test broad hypotheses and arrive at unifying conclusions, meta-analysis is the process of extracting, assembling, and analyzing large quantities of data from multiple publications to increase statistical power and uncover explanatory patterns. This paper describes the ways in which meta-analysis has been applied to support claims and counter-claims regarding two topics widely debated in agricultural research, namely organic agriculture (OA) and conservation agriculture (CA). We describe the origins of debate for each topic and assess prominent meta-analyses considering data-selection criteria, research question framing, and the interpretation and extrapolation of meta-analytical results. Meta-analyses of OA and CA are also examined in the context of the political economy of development-oriented agricultural research. Does size matter? We suggest that it does, although somewhat ironically. While meta-analysis aims to pool all relevant studies and generate comprehensive databases from which broad insights can be drawn, our case studies suggest that the organization of many meta-analyses may affect the generalizability and usefulness of research results. The politicized nature of debates over OA and CA also appear to affect the divergent ways in which meta-analytical results may be interpreted and extrapolated in struggles over the legitimacy of both practices. Rather than resolving scientific contestation, these factors appear to contribute to the ongoing debate. Meta-analysis is nonetheless becoming increasingly popular with agricultural researchers attracted by the power for the statistical inference offered by large datasets. This paper consequently offers three suggestions for how scientists and readers of scientific literature can more carefully evaluate meta-analyses. First, the ways in which papers and data are collected should be critically assessed. Second, the justification of research questions, framing of farming systems, and the scales at which research results are extrapolated and discussed should be carefully evaluated. Third, when applied to strongly politicized topics situated in an arena of scientific debate, as is the case with OA and CA, more conservative interpretations of meta-analytical results that recognize the socially and politically embedded nature of agricultural research is are needed.

Intended to test broad hypotheses and arrive at unifying conclusions, meta-analysis is the process of extracting, assembling, and analyzing large quantities of data from multiple publications to increase statistical power and uncover explanatory patterns. This paper describes the ways in which meta-analysis has been applied to support claims and counter-claims regarding two topics widely debated in agricultural research, namely organic agriculture (OA) and conservation agriculture (CA). We describe the origins of debate for each topic and assess prominent meta-analyses considering data-selection criteria, research question framing, and the interpretation and extrapolation of meta-analytical results. Meta-analyses of OA and CA are also examined in the context of the political economy of development-oriented agricultural research. Does size matter? We suggest that it does, although somewhat ironically. While meta-analysis aims to pool all relevant studies and generate comprehensive databases from which broad insights can be drawn, our case studies suggest that the organization of many meta-analyses may affect the generalizability and usefulness of research results. The politicized nature of debates over OA and CA also appear to affect the divergent ways in which meta-analytical results may be interpreted and extrapolated in struggles over the legitimacy of both practices. Rather than resolving scientific contestation, these factors appear to contribute to the ongoing debate. Meta-analysis is nonetheless becoming increasingly popular with agricultural researchers attracted by the power for the statistical inference offered by large datasets. This paper consequently offers three suggestions for how scientists and readers of scientific literature can more carefully evaluate meta-analyses. First, the ways in which papers and data are collected should be critically assessed. Second, the justification of research questions, framing of farming systems, and the scales at which research results are extrapolated and ...

Low crop productivity, food insecurity, hunger and malnutrition; inadequate farming knowledge and skills, implements and inputs are characteristic of smallholder agriculture in Southern Africa. Many researchers argue that conservation agriculture can guarantee higher crop productivity, food security, improved livelihoods and environmental protection, better than the unsustainable traditional systems of slash and burn practices. In this paper, we present the results of a meta-analysis of over 40 academic publications to review conservation agriculture's role in influencing desired livelihood outcomes in Southern Africa. We conclude that the effectiveness of conservation agriculture towards better livelihood outcomes in Southern Africa remains debatable, especially when supportive government policies are lacking.

Sustainable food production requires approaches that reconcile agricultural production with the conservation and sustainable use of natural resources, biodiversity and associated ecosystem services. While the contribution of agriculture to the provision of individual ecosystem services has received considerable scientific attention, little is known about the extent to which tropical landscapes can meet societal expectations related to food production and environmental sustainability simultaneously. We assessed how the spatial configuration of pedo-morphology and land uses influences the provision of three soil-based ecosystem services in eastern Amazonia: carbon storage (CS), habitat for biodiversity (HB), and agricultural commodity production (CP). We use the Functional Land Management framework to assess the supply and demand of these ecosystem services in a spatially explicit manner to identify areas of (mis)matches and trade-offs in the municipality of Paragominas, Brazil. The supply of ecosystem services was informed by a literature review for the various combinations of pedo-morphological characteristics and land uses in the region. The demand for ecosystem services was mapped based on federal and state policy targets. Mapping the supply and demand of CS indicated that half of the carbon in the region is stored in remnants of undisturbed forest which cover only a third of the municipality. Demand for HB in terms of forested area is met but it does not guarantee safeguarding biodiversity. Roughly a third of the territory shows scarce quality of HB even when compliant with legislation. Concerning CP, we identified areas where both supply and the demand to increase production are relative high due to road access and lower intensification costs. The demand for agricultural production can eventually incentivize the expansion of agriculture on fertile soils, which could compromise environmental targets. Our results suggest that the simultaneous delivery of multiple ecosystem services may require land-use ...

Poor yields of East African highland bananas (Musa spp., AAA-EAHB) on smallholder farms have often been attributed to problems of poor soil fertility. We measured the effects of mineral fertilizers on crop performance at two sites over two to three crop cycles; Kawanda in central Uganda and Ntungamo in southwest Uganda. Fertilizers were applied at rates of 0N–50P–600K, 150N–50P–600K, 400N–0P–600K, 400N–50P–0K, 400N–50P–250K and 400N–50P–600K kg ha−1 yr−1. In addition 60Mg–6Zn–0.5Mo–1B kg ha−1 yr−1 was applied to all treatments, with the exception of the control plots which received no fertilizer. Fresh bunch mass and yield increased with successive cycles. Yield increases above the control ranged from 3.1 to 6.2 kg bunch−1 (average bunch weight for all treatments 11.5 kg bunch−1) and 2.2–11.2 Mg ha−1 yr−1 (average yield for all treatments 15.8 Mg ha−1 yr−1) at Kawanda, compared with 12.4–16.0 kg bunch−1 (average bunch weight for all treatments 14.7 kg bunch−1) and 7.0–29.5 Mg ha−1 yr−1 (average yield for all treatments 17.9 Mg ha−1 yr−1) at Ntungamo. The limiting nutrients at both sites were in the order K > P > N. Potassium, N and P foliar nutrient mass fractions were below previously established Diagnosis and Recommendation Integrated System (DRIS) norms, with the smallest K mass fractions observed in the best yielding plots at Ntungamo. Total nutrient uptakes (K > N > P) were higher at Ntungamo as compared with Kawanda, probably due to better soil moisture availability and root exploration of the soil. Average N, P and K conversion efficiencies for two crop cycles at both sites amounted to 49.2 kg finger DM kg−1 N, 587 kg finger DM kg−1 P and 10.8 kg finger DM kg−1 K. Calibration results of the model QUEFTS using data from Ntungamo were reasonable (R2 = 0.57, RMSE = 648 kg ha−1). Using the measured soil chemical properties and yield data from an experiment at Mbarara in southwest Uganda, the calibrated QUEFTS model predicted yields well (R2 = 0.68, RMSE = 562 kg ha−1). We conclude that banana yields can be increased by use of mineral fertilizers, but fertilizer recovery efficiencies need to improve substantially before promoting wide-scale adoption. ; European Union ; Peer Review

Global support for Conservation Agriculture (CA) as a pathway to Sustainable Intensification is strong. CA revolves around three principles: no-till (or minimal soil disturbance), soil cover, and crop rotation. The benefits arising from the ease of crop management, energy/cost/time savings, and soil and water conservation led to widespread adoption of CA, particularly on large farms in the Americas and Australia, where farmers harness the tools of modern science: highly-sophisticated machines, potent agrochemicals, and biotechnology. Over the past 10 years CA has been promoted among smallholder farmers in the (sub-) tropics, often with disappointing results. Growing evidence challenges the claims that CA increases crop yields and builds-up soil carbon although increased stability of crop yields in dry climates is evident. Our analyses suggest pragmatic adoption on larger mechanized farms, and limited uptake of CA by smallholder farmers in developing countries. We propose a rigorous, context-sensitive approach based on Systems Agronomy to analyze and explore sustainable intensification options, including the potential of CA. There is an urgent need to move beyond dogma and prescriptive approaches to provide soil and crop management options for farmers to enable the Sustainable Intensification of agriculture.

Sustainable food production requires approaches that reconcile agricultural production with the conservation and sustainable use of natural resources, biodiversity and associated ecosystem services. While the contribution of agriculture to the provision of individual ecosystem services has received considerable scientific attention, little is known about the extent to which tropical landscapes can meet societal expectations related to food production and environmental sustainability simultaneously. We assessed how the spatial configuration of pedo-morphology and land uses influences the provision of three soil-based ecosystem services in eastern Amazonia: carbon storage (CS), habitat for biodiversity (HB), and agricultural commodity production (CP). We use the Functional Land Management framework to assess the supply and demand of these ecosystem services in a spatially explicit manner to identify areas of (mis)matches and trade-offs in the municipality of Paragominas, Brazil. The supply of ecosystem services was informed by a literature review for the various combinations of pedo-morphological characteristics and land uses in the region. The demand for ecosystem services was mapped based on federal and state policy targets. Mapping the supply and demand of CS indicated that half of the carbon in the region is stored in remnants of undisturbed forest which cover only a third of the municipality. Demand for HB in terms of forested area is met but it does not guarantee safeguarding biodiversity. Roughly a third of the territory shows scarce quality of HB even when compliant with legislation. Concerning CP, we identified areas where both supply and the demand to increase production are relative high due to road access and lower intensification costs. The demand for agricultural production can eventually incentivize the expansion of agriculture on fertile soils, which could compromise environmental targets. Our results suggest that the simultaneous delivery of multiple ecosystem services may require land-use ...