Yam, a major food crop for West Africa, has not been managed to reach its potential productivity. The current practice of planting yam continuously for years after clear-cutting a field is not sustainable and has led to deforestation and nutrient depletion. By examining the effect of improved management on yam cultivation in Ghana, this study aimed to solve the tradeoff between improving yam yield and sustaining soil organic carbon (SOC). We used a calibrated and validated process-based crop simulation model, Systems Approach to Land Use Sustainability, to assess the impact of four management treatments: continuous unfertilized rainfed yam (control), pigeonpea-yam rotation, yam with 3 Mg/ha pigeonpea residue incorporated and yam with 23−23 N-P₂O₅ kg/ha fertilizer added. We modeled 10 years of yam yield and SOC across cropland in Ghana with varying levels of soil carbon, rainfall amount, and precipitation pattern. On average, simulated yam tuber yield was the highest with a pigeonpea residue incorporation treatment (4.1–11.9 Mg/ha, average of 7.5 Mg/ha). The rotation (average yield of 6.4 Mg/ha) and fertilizer (average of 7.0 Mg/ha) treatments produced comparable increases in yam yield over the control treatment (1.9–9.2 Mg/ha, average of 4.9 Mg/ha). The low yam yield of the control treatment was mostly attributed to nutrient deficiency (nitrogen and phosphorus). Drought also limited yam growth, particularly in northern Ghana. The three improved management treatments increased soil nutrient availability and thus improved yield. SOC declined under all four tested treatments over the simulated 10 years, but declined least with residue incorporation (average rate -0.3 Mg/ha/year), followed by fertilizer addition (-0.43 Mg/ha/year), rotation (-0.42 Mg/ha/year), and the control (-0.51 Mg/ha/year) management. Our work provides a benchmark for yam yield response to alternative management across Ghana, and highlights pigeonpea’s contribution to sustainable intensification of yam. Further research is needed to untangle the interacting effects of land use and agronomic management on SOC.

薯类是西非的主要粮食作物，尚未得到实现其潜在生产力的管理。在清除田地后连续多年种植山药的现行做法是不可持续的，并导致了森林砍伐和养分消耗。通过研究改进管理对加纳山药种植的影响，本研究旨在解决提高山药产量与维持土壤有机碳（SOC）之间的权衡问题。我们使用经过校准和验证的基于过程的作物模拟模型“土地利用可持续性的系统方法”来评估四种管理措施的影响：连续未施肥的雨养山药（对照），木豆-山药轮作，具有3 Mg / ha木豆残留的山药并用23-23 NP ₂ O _5包山药公斤/公顷肥料。我们对加纳农田中10年的山药产量和SOC进行了建模，模拟了土壤碳含量，降雨量和降水模式的变化。平均而言，采用木豆渣掺入处理的模拟山药块茎产量最高（4.1-11.9 Mg / ha，平均7.5 Mg / ha）。轮作（平均产量为6.4 Mg / ha）和肥料（平均产量为7.0 Mg / ha）处理的山药产量与对照处理（1.9-9.2 Mg / ha，平均4.9 Mg / ha）相比相当。对照处理的山药产量低主要归因于养分缺乏（氮和磷）。干旱也限制了山药的生长，特别是在加纳北部。三种改良的管理措施增加了土壤养分的利用率，从而提高了产量。在模拟的10年中，所有四种测试处理的SOC均下降，但随着残渣掺入（平均速率-0.3 Mg / ha /年），其次是肥料添加（-0.43 Mg / ha /年），轮作（-0.42 Mg）的下降最小/公顷/年）和对照（-0.51毫克/公顷/年）管理。我们的工作为加纳全国其他管理对山药产量的响应提供了基准，并着重介绍了木豆对山药可持续集约化的贡献。需要进一步研究以阐明土地利用和农艺管理对SOC的相互作用。我们的工作为加纳全国其他管理对山药产量的响应提供了基准，并着重介绍了木豆对山药可持续集约化的贡献。需要进一步研究以阐明土地利用和农艺管理对SOC的相互作用。我们的工作为加纳全国其他管理对山药产量的响应提供了基准，并突出了木豆对山药可持续集约化的贡献。需要进一步研究以阐明土地利用和农艺管理对SOC的相互作用。