Abstract Land use intensity is increasing in Andean smallholder systems, and innovations are needed to sustain soil fertility and productivity of potato-cereal rotations with shortening fallow periods. In collaboration with farmers in central Peru, we assessed forage-based fallows in 58 fields across three production zones over three years. Fallow treatments selected with farmers tested grass-legume mixtures with different combinations of Vicia Sativa (vetch), Avena sativa (oats), Lupinus mutabilis (Andean lupine), Trifolium pratense (red clover), Medicago sativa (alfalfa), and Lolium multiflorum (ryegrass) compared to an unseeded control fallow with natural revegetation. The ability of fallows to quickly cover soil was tested, as was their biomass production in years one and three. Following the incorporation of fallow vegetation in a sub-set of nine fields, we also tested fallows’ effects on soil pH, available phosphorus (P), permanganate-oxidizable carbon (POXC) and potato yield. In year one managed fallows produced from 1.9 to 5.4 Mg ha−1 of forage biomass compared to 0.5 to 1.1 Mg ha−1 in unseeded controls. Managed fallows also exceeded controls in nutrient uptake, soil cover, and forage quality (lower lignin and higher protein content). First-year biomass of vetch and Andean lupine responded differently to soil pH in fields, indicating that appropriate fallow options likely depend on soil context. After three years, total biomass did not differ among treatments. However, legumes had greater biomass in treatments employing perennial species (0.79–1.18 Mg ha−1 of legumes) than in controls (0.15 Mg ha−1). Potato yield and soil fertility was not reduced in managed fallows compared to the control, and an alfalfa + liming treatment yielded higher than the control (p

中文翻译：

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与秘鲁中部安第斯山脉的农民一起在土壤梯度上改进牧草/休耕选择的参与式设计

摘要 安第斯小农系统的土地利用强度正在增加，需要创新来维持土壤肥力和马铃薯谷物轮作的生产力，同时缩短休耕期。我们与秘鲁中部的农民合作，在三年内评估了三个生产区 58 个农田的草料休耕情况。农民选择的休耕处理测试了草豆科植物混合物与不同组合的 Vicia Sativa (Vetch)、Avena sativa (燕麦)、Lupinus mutabilis (Andean 羽扇豆)、Trifolium pratense (红三叶草)、Medicago sativa (alfalfa) 和 Lolium multiflorum (黑麦草）与具有自然重新植被的未播种对照休耕相比。测试了休耕快速覆盖土壤的能力，以及它们在第一年和第三年的生物量生产。在将休耕植被纳入九个田地的子集之后，我们还测试了休耕对土壤 pH 值、有效磷 (P)、高锰酸盐可氧化碳 (POXC) 和马铃薯产量的影响。在第一年管理的休耕地产生了 1.9 到 5.4 Mg ha-1 的草料生物量，而未播种的对照则为 0.5 到 1.1 Mg ha-1。管理休耕在养分吸收、土壤覆盖和草料质量（较低的木质素和较高的蛋白质含量）方面也超出了控制范围。野豌豆和安第斯羽扇豆的第一年生物量对田间土壤 pH 值的反应不同，表明适当的休耕选择可能取决于土壤环境。三年后，不同处理的总生物量没有差异。然而，在使用多年生物种（豆科植物的 0.79–1.18 Mg ha-1）的处理中，豆科植物的生物量高于对照（0.15 Mg ha-1）。