The limitation of soil amendments and insufficient and irregular rainfall are the main factors accounting for the decline in crop yields in the Sahelian low-input cropping systems. This study explored the agronomic and economic responses of integrated use of millet glume-derived compost with synthetic fertilizer in cowpea-based cropping system. A two-year field experiment was laid out as factorial design arranged in randomized complete blocks with three rates of compost (0, 4000, and 8000 kg ha−1) and three rates of recommended synthetic fertilizer (0, 50, and 100%). Cowpea grain yield increased markedly with combined application of compost and synthetic fertilizer. The combined use of compost applied at 8000 kg ha−1 and 50% of the recommended rate of synthetic fertilizer increased cowpea grain yield by 51% compared to the application of 100% of the recommended rate of synthetic fertilizer. The rainwater use efficiency (RaUE) increased by 52 and 49% with the combined application of compost at 8000 kg ha−1 along with 50% of the recommended rate of synthetic fertilizer when compared to the application of 100% of the recommended rate of synthetic fertilizer in 2013 and 2014, respectively. All treatments induced a positive net income, and the highest value/cost ratio was achieved with combined application of compost and synthetic fertilizer. This study highlights the possibility of improving cowpea productivity through combined use of composted locally available organic input with half of the recommended rate of synthetic fertilizer. This combination would reduce the investment in mineral fertilizer currently made by smallholder farmers in the Sahelian low-input cowpea cropping system and reduce environmental pollution resulting from the current practice of burning the millet glume.

中文翻译：

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豇豆生产综合养分管理方案的农艺和经济效益

土壤改良的限制以及降雨不足和不规律是导致萨赫勒低投入种植系统作物产量下降的主要因素。本研究探讨了在豇豆种植系统中综合使用小米颖片堆肥与合成肥料的农艺和经济响应。一项为期两年的田间试验被安排为随机完整区组的因子设计，具有三种堆肥率（0、4000 和 8000 kg ha-1) 和三种推荐的合成肥料比例（0、50 和 100%）。堆肥与化肥配施可显着提高豇豆籽粒产量。堆肥的组合使用量为 8000 公斤公顷-1与100%的合成肥施用量相比，50%的合成肥推荐用量使豇豆籽粒产量增加51%。在 8000 kg ha 堆肥时，雨水利用效率 (RaUE) 分别提高了 52% 和 49%-1与 2013 年和 2014 年分别为 100% 的合成肥料施用量相比，施用了 50% 的合成肥料。所有处理均产生了正的净收入，而堆肥和合成肥料的组合施用达到了最高的价值/成本比。这项研究强调了通过将当地可用的堆肥有机投入物与推荐比例的一半合成肥料结合使用来提高豇豆生产力的可能性。这种组合将减少目前萨赫勒低投入豇豆种植系统中小农户对矿物肥料的投资，并减少目前燃烧小米颖片的做法造成的环境污染。