The use of cover crops in conventional agriculture is not fully accepted. This is probably due to the substantial variability in outcomes reported and is complicated by the conflation of a host of techniques under the same umbrella term, often without the appropriate benchmarking. This review addresses these issues with a quantitative synthesis of the last 11 years of research on cover crops in cereal rotations in temperate climates. Strict inclusion criteria focus the scope of the review to studies offering comparisons with an equally treated bare fallow control. Coded variables included duration, fertiliser, irrigation and tillage regime, cover and cash crop type and termination mode. The result is a quantitative review of 100 parameters covered by multiple publications, with an additional overview on 124 parameters covered by single studies. The investigated response variables range from microbiology and chemical parameters to hydrology, soil structure, weed and pest control and crop performance. Relevant trends were identified regarding strengths and weaknesses of cover cropping, with predictions formulated about the conditions necessary for their successful implementation. Additionally, trade-offs specific to cover cropping are discussed, together with the variables at play in determining the final balance of net gain or loss. The main findings are that cash crop performance is best enhanced by legume cover crops and in low-tillage regimes, and the soil biotic effects of cover crops tend to be short-lived, fading by the end of the season. Most importantly, a positive effect of cover cropping on soil carbon is potentially offset by increased GHG emissions.

传统农业中覆盖作物的使用尚未被完全接受。这可能是由于报告的结果存在很大差异，并且由于在同一总括术语下混合了许多技术而变得复杂，而且通常没有适当的基准测试。本综述通过定量综合过去 11 年温带气候谷物轮作中覆盖作物的研究来解决这些问题。严格的纳入标准将审查范围集中在与同等处理的裸露休闲对照进行比较的研究上。编码变量包括持续时间、肥料、灌溉和耕作制度、覆盖和经济作物类型以及终止模式。结果是对多个出版物涵盖的 100 个参数进行了定量审查，并对单个研究涵盖的 124 个参数进行了额外概述。研究的响应变量范围从微生物学和化学参数到水文、土壤结构、杂草和害虫控制以及作物性能。确定了覆盖种植的优点和缺点的相关趋势，并对其成功实施的必要条件进行了预测。此外，还讨论了覆盖种植的具体权衡，以及在确定净收益或损失的最终平衡中发挥作用的变量。主要发现是，豆类覆盖作物和低耕制度可以最好地提高经济作物的表现，而覆盖作物的土壤生物效应往往是短暂的，到季节结束时就会消失。最重要的是，覆盖种植对土壤碳的积极影响可能会被温室气体排放量的增加所抵消。