While cover crops and mixtures are increasingly used to provide ecosystem services in agroecosystems, some fundamental questions remain about how cover crop performance and composition vary in different conditions, limiting optimal cover crop use. We conducted a field experiment at a research farm in New York, including a subset of treatments in three working farm fields. We selected two common cover crops, hairy vetch (Vicia villosa Roth), a legume, and common wheat (Triticum aestivum L.), a grass, with multiple cultivars of each. We looked at the effect of cover crop composition spanning intraspecific and grass–legume mixtures on five ecosystem services: cover crop productivity, weed suppression, total biomass nitrogen, soil N retention, and long‐term N supply via legume fixed N. We did not find intraspecific diversity to have an effect on any ecosystem services we measured, nor was that response context dependent. We did observe significant ecosystem service improvements in the grass–legume mixture, though this was context dependent and the performance of the mixture varied relative to the monocultures at different farm sites. Regardless of this interaction however, the grass–legume mixture was as good as or better than either monoculture for all services and sites, except soil N accrual at one site. Consequently, increasing complexity in cover crops through grass–legume mixtures is a low risk practice that may have the potential to deliver ecosystem service outcomes greater than those of monocultures across a range of growing conditions.

中文翻译：

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覆盖作物混合物和单一栽培的生态系统服务提供取决于环境

尽管在农业生态系统中越来越多地使用掩盖作物和混合物来提供生态系统服务，但仍然存在一些基本问题，即在不同条件下掩盖作物的性能和组成如何变化，从而限制了最佳的掩盖作物的使用。我们在纽约的一个研究农场进行了实地实验，包括在三个工作农场中的部分处理方法。我们选择了两种常见的被覆作物，多毛紫etch（Vicia villosa Roth），豆类和普通小麦（Triticum aestivumL.），一种草，每个草都有多个品种。我们研究了跨种内植物和豆科植物混合物的覆盖作物组成对五种生态系统服务的影响：覆盖作物生产力，杂草抑制，总生物量氮，土壤氮保留和通过豆类固氮长期供应氮。我们没有发现种内多样性对我们测得的任何生态系统服务都具有影响，也不依赖于响应环境。我们确实观察到草-豆混合物中生态系统服务的显着改善，尽管这取决于具体情况，并且混合物的性能相对于不同农场场所的单一栽培而有所不同。但是，无论这种相互作用如何，对于所有服务和场所而言，草-豆混合物的质量均优于或优于单一栽培，但在一个场所累积的土壤氮除外。所以，