Conservation agriculture has been promoted to sustainably intensify food production in smallholder farming systems in southern Africa. However, farmers have rarely fully implemented all its components, resulting in different combinations of no-tillage, crop rotation, and permanent soil cover being practiced, thus resulting in variable yield responses depending on climatic and soil conditions. Therefore, it is crucial to assess the effect of conservation agriculture components on yield stability. We hypothesized that the use of all three conservation agriculture components would perform the best, resulting in more stable production in all environments. We evaluated at, eight trial locations across southern Africa, how partial and full implementation of these components affected crop yield and yield stability compared with conventional tillage alone or combined with mulching and/or crop rotation. Grain yield and shoot biomass of maize and cowpea were recorded along with precipitation for 2 to 5 years. Across different environments, the addition of crop rotation and mulch to no-tillage increased maize grain by 6%, and the same practices added to conventional tillage led to 13% yield increase. Conversely, adding only mulch or crop rotation to no-tillage or conventional tillage led to lower or equal maize yield. Stability analyses based on Shukla’s index showed for the first time that the most stable systems are those in which mulch is added without crop rotation. Moreover, the highest yielding systems were the least stable. Finally, additive main effects and multiplicative interaction analysis allowed clarifying that mulch added to no-tillage gives stable yields on sandy soil with high rainfall. Similarly, mulch added to conventional tillage gives stable yield on sandy soil, but under low rainfall. This is the first study that highlighted the crucial role of mulch to enhance the stability and resilience of cropping systems in southern Africa, supporting their adaptability to climate change.

促进了保护性农业，以可持续地增强南部非洲小农农业系统中的粮食生产。然而，农民很少充分实施其所有组成部分，导致实行免耕，轮作和永久性土壤覆盖的不同组合，从而导致取决于气候和土壤条件的可变产量响应。因此，评估保护性农业成分对单产稳定性的影响至关重要。我们假设使用所有三个保护性农业成分将发挥最佳效果，从而在所有环境中均能实现更稳定的生产。我们在南部非洲的八个试验地点进行了评估，与单独传统耕作或与覆盖和/或轮作组合相比，这些成分的部分和全部实施如何影响作物产量和产量稳定性。记录了2至5年的玉米和and豆的籽粒产量和茎生物量以及降水量。在不同的环境中，免耕增加作物轮作和覆盖都使玉米籽粒增加了6％，而传统耕作增加了相同的作法导致单产提高了13％。相反，在免耕或常规耕作中仅增加覆盖或轮作会导致玉米产量降低或相等。根据舒克拉指数进行的稳定性分析首次显示，最稳定的系统是不覆盖作物而添加覆盖物的系统。而且，最高产量的系统最不稳定。最后，添加剂的主要作用和乘性相互作用分析使得澄清免耕添加的覆盖物在高降雨的沙质土壤上具有稳定的产量。同样，在常规耕作中添加覆盖料可以在沙质土壤上保持稳定的产量，但降雨少。这是第一项强调覆盖物在增强南部非洲种植系统的稳定性和复原力，支持其对气候变化适应性方面的关键作用的研究。