Legume agronomic research in Southern Africa has often focused on integrating legumes into smallholder cereal cropping systems, but there is limited information available on the feasibility and soil health implications of continuous cropping legumes in the region. Continuous legumes may be suitable in areas with large livestock populations where a premium is placed on high-quality forage, or where efforts are underway to reclaim degraded cropland. Our objectives in this study were to (i) evaluate the performance of diverse legumes under continuous cropping and conservation tillage management with no fertility inputs and (ii) assess the response of soil health parameters to continuous legumes in a semi-arid environment. A 4-year study was conducted in Limpopo, South Africa beginning in the 2011–2012 growing season in which 10 legume and fallow treatments were imposed in the same plots for 4 growing seasons. All legumes responded negatively in varying degrees to continuous cropping in terms of biomass and nutrient accumulation. Lablab (Lablab purpureus L.) was the top-performing legume in the study and accumulated 4.5–13 Mg ha−1 of biomass and 153–345, 11–34, and 75–286 kg ha−1 of N, P, and K, respectively. Lablab often outperformed natural fallow, while other legumes generally performed as well as or inferior to natural fallow, depending on species and growing season. Cowpea (Vigna unguiculata Walp) was especially incompatible with continuous cropping and averaged less than 252 kg ha−1 and 2.1 Mg ha−1 of grain and biomass, respectively, from 2012–2013 to 2014–2015. Continuous cropping did not lead to sustained improvements in soil health. By 2014–2015, soil organic matter for all treatments had either declined or resembled baseline values. Rates of potentially mineralizable N in cowpea, lablab, vining mucuna (Mucuna pruriens var. Utilis), natural fallow, and bare ground plots fell by 70–96% during the study. There was also evidence for lower recovery of leached K by legumes compared to natural fallow species. In conclusion, legumes, such as lablab, should be considered as continuous forages on marginal land in areas where high-quality forage is in demand, but continuous cropping legumes without fertility inputs are not an effective strategy for improving soil health on degraded cropland in this semi-arid region of Southern Africa. Future research efforts may focus on the grazing strategies and baling frequencies required to optimize annual biomass accumulation of continuous lablab to meet livestock demand and support smallholder livelihoods.

南部非洲的豆类农艺研究通常侧重于将豆类纳入小农谷物种植系统，但关于该地区连作豆类的可行性和土壤健康影响的可用信息有限。连续豆类可能适用于牲畜数量众多的地区，这些地区重视优质草料，或者正在努力开垦退化的农田。我们在本研究中的目标是（i）评估不同豆科植物在没有肥力投入的情况下在连作和保护性耕作管理下的表现，以及（ii）评估土壤健康参数对半干旱环境中连续豆科植物的响应。在林波波进行了一项为期 4 年的研究，南非从 2011-2012 生长季节开始，其中 10 种豆科植物和休耕处理在 4 个生长季节的同一块地块上实施。就生物量和养分积累而言，所有豆类都对连作产生不同程度的负面反应。实验室 (Lablab purpureus L.) 是该研究中表现最好的豆科植物，积累了 4.5-13 Mg ha -1的生物量和 153-345、11-34 和 75-286 kg ha -1的 N、P 和 K，分别。Lablab 的表现通常优于自然休耕，而其他豆类的表现通常与自然休耕一样好或低于自然休耕，具体取决于物种和生长季节。豇豆 ( Vigna unguiculata Walp) 与连作特别不相容，平均低于 252 kg ha -1和 2.1 Mg ha -1从 2012-2013 年到 2014-2015 年，粮食和生物量分别为。连作并没有导致土壤健康的持续改善。到 2014-2015 年，所有处理的土壤有机质要么下降，要么与基线值相似。豇豆、lablab、vining mucuna ( Mucuna pruriens var. Utilis ) 中潜在可矿化 N 的比率)、自然休耕地和裸露地块在研究期间下降了 70-96%。还有证据表明，与自然休耕物种相比，豆科植物对浸出 K 的回收率较低。总之，在需要优质草料的地区，应将豆科植物（如 lablab）视为边缘土地上的连续草料，但在没有肥力投入的情况下连作豆科植物并不是改善退化农田土壤健康的有效策略。南部非洲半干旱地区。未来的研究工作可能集中在优化连续实验室的年度生物量积累以满足牲畜需求和支持小农生计所需的放牧策略和打包频率上。