Cover crops can provide a wide range of ecosystem services including soil water conservation, improved soil nutrient supply and retention, and enhanced crop yields. However, achieving these services in dryland cropping systems can be highly challenging, and cover crops may carry a greater risk of causing ecosystem disservices. Assessment of the balance of ecosystem services vs disservices is critical for understanding the potential role of cover crops within dryland cropping systems. The objective of this meta-analysis was to assess the effects of cover cropping in drylands on soil water and soil mineral nitrogen content at sowing of subsequent cash crops and their yields compared to control fallows. A total of 38 articles were examined, for a total of 1006 cash crop yield, 539 soil water, and 516 soil mineral nitrogen independent studies, spanning the period 1994–2021. On average, cover cropping reduced cash crop yield by 7%, soil water content by 18%, and soil mineral nitrogen by 25%, with significant variation across climates, soil types, and crop management conditions. Subsequent cash crop yields changed by +15, +4, −12, and −11% following cover crops in tropical, continental, dry, and temperate dryland climates, respectively. The most significant yield benefits were proportionate to soil water content and soil mineral nitrogen at the time of cash crop sowing. This is the first meta-analysis to demonstrate that minimum annual precipitation of ~700 mm represents a “break-even” point to realize significant cash crop yield benefits of cover cropping compared to control fallows in dryland environments. The successful incorporation of cover crops into dryland cropping systems requires careful planning based on context-specific biophysical conditions to minimize trade-offs between ecosystem services and disservices.

覆盖作物可以提供广泛的生态系统服务，包括水土保持、改善土壤养分供应和保持，以及提高作物产量。然而，在旱地种植系统中实现这些服务可能极具挑战性，而且覆盖作物可能会带来更大的造成生态系统损害的风险。评估生态系统服务与损害的平衡对于了解覆盖作物在旱地种植系统中的潜在作用至关重要。这项荟萃分析的目的是评估旱地覆盖作物对随后经济作物播种时土壤水和土壤矿物质氮含量的影响，以及与对照休耕相比的产量。共审查了 38 篇文章，共 1006 项经济作物产量、539 项土壤水和 516 项土壤矿质氮独立研究，跨越 1994 年至 2021 年期间。平均而言，覆盖种植使经济作物产量降低 7%，土壤含水量降低 18%，土壤矿质氮降低 25%，气候、土壤类型和作物管理条件之间存在显着差异。在热带、大陆、干旱和温带旱地气候中种植覆盖作物后，随后的经济作物产量分别变化了 +15、+4、-12 和 -11%。最显着的产量效益与经济作物播种时的土壤含水量和土壤矿质氮成正比。这是第一个荟萃分析表明，与旱地环境中的对照休耕相比，最小年降水量约为 700 毫米是实现覆盖种植的显着经济作物产量收益的“收支平衡”点。