Abstract In West Africa, new management practices such as conservation agriculture with crop residue mulching can improve crop yields for individual farmers. However, in a context of complex social interactions between farmers, the introduction of such practices can also lead to conflicts between private interests and communal use of resources, for example the free grazing of crop residues. The objective of this paper was to assess ex-ante the impacts of the practice of crop residue mulching on crop productivity in a village of central Burkina Faso using an agent-based model, AMBAWA, that simulates the flows of biomass and nutrients between crop and livestock systems at the village scale. The model considers the interactions between four types of farmers that were identified in the study site: subsistence-oriented crop farmers, market-oriented crop farmers, agro-pastoralists and pastoralists. The model simulated increased cattle migration outside the village due to increased crop residue scarcity during the dry season with increased proportions of cropland under the practice of conservation agriculture, decreasing the manure availability at village scale. Consequently, the assumed direct yield increases due to soil moisture conservation as a result of mulching did not compensate for the yield losses resulting from lesser amounts of manure available. This effect was felt most strongly by farmers who own relatively large numbers of cattle (agro-pastoralists and pastoralists). The total maize production at village level depended more on the proportion of cropping land that was available for grazing by cattle, and thus not mulched, than on a possible direct effect of mulching on yield per se. The AMBAWA model can support discussion among stakeholders (farmers, traditional and administrative authorities) who are involved in the private and communal management of crop residues and other biomass resources, in order to co-design effective arrangements and practices for their sustainable use.

中文翻译：

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西非农牧村的生物质流：谁从作物残茬覆盖中受益？

摘要 在西非，新的管理实践，如保护性农业和作物残茬覆盖，可以提高个体农民的作物产量。然而，在农民之间复杂的社会互动背景下，这种做法的引入也可能导致私人利益与资源的公共利用之间的冲突，例如作物残留物的自由放牧。本文的目的是使用基于代理的模型 AMBAWA 模拟作物和作物之间的生物量和养分流动，事前评估在布基纳法索中部一个村庄进行作物残留覆盖的做法对作物生产力的影响。村级畜牧系统。该模型考虑了研究地点确定的四类农民之间的相互作用：自给型农作物农民、以市场为导向的农作物农民、农牧民和牧民。该模型模拟了由于在旱季作物残茬稀缺增加以及保护性农业实践下农田比例增加导致村庄外的牛迁移增加，从而减少了村庄规模的粪便供应。因此，由于覆盖导致土壤水分保持而假设的直接产量增加并不能补偿由于可用粪便量减少而导致的产量损失。拥有相对大量牛的农民（农牧民和牧民）对这种影响最为强烈。村一级的玉米总产量更多地取决于可供牛放牧的耕地比例，因此没有覆盖，而不是覆盖对产量本身的可能直接影响。AMBAWA 模型可以支持参与作物残留物和其他生物质资源的私人和公共管理的利益相关者（农民、传统和行政当局）之间的讨论，以便共同设计有效的安排和实践以实现可持续利用。