Abstract Increasing threats of climate change and soil fertility decline enhance the risk of crop failure for smallholder farmers in southern Africa. The quest is to find cropping systems that provide yield stability while being sustainable. One of the strategies to use is intercropping legumes in maize-based Conservation Agriculture systems. Here, we present results of a three-year study in on-farm and on-station trials of Zimbabwe. We tested sole cropping compared to intercropping with different grain legumes and green manures as well as fertilizer application (in the case of on-station trials) on associated crop yields, total system yield, and yield stability. As methods, we used mixed modelling, best linear unbiased predictors estimation and additive main effects and multiplicative interaction analysis to analyse the data. The results show that intercropping systems with the selected legumes resulted in yield penalties. However, on-station sites showed maize/pigeonpea intercropping to be comparable to the sole maize in maize grain and biomass yield and to be superior in total system yield (108 GJ ha−1 vs. 74 GJ ha−1). Comparison of intercropping against sole cropping revealed that sole maize out-yielded all intercropping strategies in all environments on-farm while the maize/pigeon intercropping strategy out-yielded sole maize in almost all environments on-station. In general, total system yield of intercrops out-yielded sole maize in most environments signifying the ability of intercrops to enhance cropping system yields. Stability analysis on-farm showed that intercropping with cowpea and jack bean was more stable compared to sole maize as a result of better systems performance across the environments. On-station, the maize/pigeonpea intercropping strategy was in general the most stable. We conclude that intercropping is a viable option for smallholder farmers. However, there is need to investigate other crop arrangements to reduce competition for both maize and the intercrop and double-row strip cropping may be an option.

中文翻译：

---

生产力还是稳定性？探索津巴布韦小农保护性农业农民的玉米-豆类间作策略

摘要 气候变化和土壤肥力下降的威胁日益增加，增加了南部非洲小农作物歉收的风险。我们的任务是找到既能保持产量稳定又可持续的种植系统。使用的策略之一是在以玉米为基础的保护性农业系统中间作豆类。在这里，我们展示了一项为期三年的津巴布韦农场和站内试验研究的结果。我们在相关作物产量、系统总产量和产量稳定性方面测试了单作与间作不同谷物豆类和绿肥以及施肥（在现场试验的情况下）。作为方法，我们使用混合建模、最佳线性无偏预测变量估计和附加主效应和乘法交互分析来分析数据。结果表明，采用所选豆类的间作系统会导致产量下降。然而，现场站点显示玉米/鸽子豌豆间作在玉米籽粒和生物量产量方面与单一玉米相当，并且在总系统产量方面更胜一筹（108 GJ ha-1 与 74 GJ ha-1）。间作与单作的比较表明，在农场的所有环境中，单作玉米的产量高于所有间作策略，而玉米/鸽子间作策略在几乎所有的站内环境中都优于单作玉米。一般而言，在大多数环境中，间作的系统总产量超过单一玉米，这表明间作能够提高种植系统的产量。农场稳定性分析表明，与单一玉米相比，豇豆和杰克豆间作更稳定，因为在整个环境中系统性能更好。在站内，玉米/豌豆间作策略总体上是最稳定的。我们得出结论，间作是小农的可行选择。然而，需要研究其他作物安排以减少对玉米和间作的竞争，双行条带种植可能是一种选择。