Cover crops can protect soil health and increase climate resilience of crop production systems. Agronomic crop producers in the southern USA often demand information on the best cover crops for their locality and cropping system and on the potential impacts of cover crops on stored soil water. The present research evaluated biomass production and water use efficiency (WUE) of single species and multispecies winter cover crops in South Carolina. Overall, a five-species mixture of Austrian winter pea, rye, crimson clover, hairy vetch, and oats and a single species of rye had the greatest biomass production (4600–6480 kg ha⁻¹) at the end of the season (19 April 2017 in season-1 and 10 May 2018 in season-2). The five-species mixture also had the greatest WUE (2184–2232 g m⁻³). None of the cover crops depleted soil water (in 60 cm depth) greater than a weed-free fallow maintained through herbicide application and a weedy fallow (no herbicide application). Since both the seasons, in which the present study was conducted, received greater than normal rainfall, further studies should verify the applicability of the results in dry years.

中文翻译：

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南卡罗来纳州2016/17和2018年冬季湿润季节中七种不同覆盖作物的生物量生产和水分利用效率差异

覆盖作物可以保护土壤健康并提高作物生产系统的气候适应能力。美国南部的农作物生产者经常要求提供有关其所在地区和种植系统的最佳覆盖作物以及覆盖作物对土壤水储量的潜在影响的信息。本研究评估了南卡罗来纳州单一物种和多物种冬季覆盖作物的生物量生产和水分利用效率（WUE）。总体而言，在本季节结束时，奥地利冬豌豆，黑麦，深红色三叶草，毛v子和燕麦这五种混合物和一种黑麦的生物量最高（4600-6480 kg ha ^-1）。第一季为2017年4月，第二季为2018年5月10日）。五种混合物的WUE也最大（2184–2232 gm ^-3）。没有覆盖作物的土壤水（60厘米深）消耗量大于通过除草剂施用和无草休耕（不施用除草剂）维持的无杂草休耕地。由于进行本研究的两个季节都比正常降雨多，因此进一步的研究应验证该结果在干旱年份的适用性。