Abstract Cover crops are often recommended as a valuable practice to develop more sustainable cropping systems but, despite many benefits, their adoption in practice is still limited mainly because the effects on productivity and economic return are variable. Furthermore, it is still unclear under which combinations with other management practices (e.g. tillage, fertilization, weed control) cover crops can provide the highest paybacks. Here we tested whether cover crops are a suitable management tool to reduce fertilizer input, tillage intensity and herbicide use in Swiss arable cropping systems. We compared the effects of four different cover crop treatments (fallow, radish, subterranean clover and hairy vetch) on maize at two fertilization levels combined with three levels of tillage intensity. To unravel the effects of cover crops on maize growth, we assessed vegetation dynamics using the Normalized Differential Vegetation Index (NDVI) from aerial spectral imagery. Cover crops on average increased yields by 12 % (+7 % to +20 %) and cover crop effects depended on tillage intensity, fertilization level and cover crop treatment for most of the assessed maize parameters. Best results were obtained with hairy vetch, which increased maize N uptake by 79 kg ha−1 on average. As a consequence, at least combinations of two of the three targeted inputs (tillage, fertilization and herbicides) could be successfully reduced, e.g. tillage and fertilization under no tillage or tillage and herbicides under reduced tillage. Even under intensive tillage, both legume cover crops allowed a reduction of fertilization without compromising yield. Spectral imagery analysis showed that legume cover crops compensated for delayed N availability in reduced and no tillage systems and cover crops contributed to enhanced N uptake and crop growth later in the season. We provide evidence that cover crop based cropping systems can be used to reduce synthetic inputs and tillage without compromising yield, thus presenting an example of ecological engineering. We highlight the importance of considering the whole set of management practices when adopting cover cropping in order to maintain or increase productivity with reduced anthropogenic inputs under conventional cropping.

中文翻译：

---

覆盖作物作为减少传统耕作系统中对集约化耕作和施氮肥的依赖的一种工具

摘要 覆盖作物通常被推荐为开发更可持续的种植系统的一种有价值的做法，但尽管有很多好处，但它们在实践中的采用仍然有限，主要是因为对生产力和经济回报的影响是可变的。此外，目前尚不清楚在何种情况下与其他管理措施（例如耕作、施肥、杂草控制）组合覆盖作物可以提供最高的回报。在这里，我们测试了覆盖作物是否是减少瑞士耕作系统中肥料投入、耕作强度和除草剂使用的合适管理工具。我们比较了四种不同的覆盖作物处理（休耕、萝卜、地下三叶草和多毛紫云英）在两个施肥水平和三个耕作强度水平下对玉米的影响。为了阐明覆盖作物对玉米生长的影响，我们使用来自航空光谱图像的归一化差异植被指数 (NDVI) 评估了植被动态。覆盖作物平均增加了 12%（+7% 至 +20%）的产量，覆盖作物的效果取决于大多数评估的玉米参数的耕作强度、施肥水平和覆盖作物处理。使用多毛紫云英获得了最好的结果，平均增加了 79 kg ha-1 的玉米 N 吸收量。因此，至少可以成功减少三种目标投入中的两种（耕作、施肥和除草剂）的组合，例如免耕下的耕作和施肥或少耕下的耕作和除草剂。即使在密集耕作下，两种豆类覆盖作物都可以在不影响产量的情况下减少施肥。光谱图像分析表明，豆类覆盖作物补偿了减少和免耕系统中延迟的氮供应，覆盖作物有助于提高氮的吸收和作物生长。我们提供的证据表明，基于覆盖作物的种植系统可用于在不影响产量的情况下减少合成投入和耕作，从而提供生态工程的一个例子。我们强调在采用覆盖种植时考虑整套管理实践的重要性，以便在传统种植下通过减少人为投入来保持或提高生产力。我们提供的证据表明，基于覆盖作物的种植系统可用于在不影响产量的情况下减少合成投入和耕作，从而提供生态工程的一个例子。我们强调在采用覆盖种植时考虑整套管理实践的重要性，以便在传统种植下通过减少人为投入来保持或提高生产力。我们提供的证据表明，基于覆盖作物的种植系统可用于在不影响产量的情况下减少合成投入和耕作，从而提供生态工程的一个例子。我们强调在采用覆盖种植时考虑整套管理实践的重要性，以便在传统种植下通过减少人为投入来保持或提高生产力。