Baxter Lisa L, West Charles P, Brown C Philip, Green Paul E
Department of Crop and Soil Sciences, University of Georgia, Tifton, GA 31793, USA.
Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA.
Animals (Basel). 2021 Jan 16;11(1):212. doi: 10.3390/ani11010212.
The imminent depletion of the Ogallala Aquifer demands innovative cropping alternatives. Even though the benefits of cover crops are well recognized, adoption has been slow in the Southern High Plains (SHP) of the United States because of concerns that cover crops withdraw soil water to the detriment of the summer crops. This small plot experiment tested the interacting effects-production, soil water depletion of the cover crops, and subsequent teff [ (Zucc.) Trotter] summer hay crops-of irrigation and tillage management with five cover crop types to identify low-risk cover crop practices in the drought-prone SHP. Dryland rye ( L.) produced modest forage biomass (>1000 kg ha), even in a dry year, but it was found that light irrigation should be used to ensure adequate forage supply (>1200 kg ha) if winter grazing is desired. No-till management and timely termination of the winter cover crops were crucial to reducing the negative impact of winter crops on summer teff production. The results indicated no detriment to soil water content that was attributable to planting no-till cover crops compared with the conventional practice of winter fallow. Therefore, producers could take advantage of the soil-conserving attributes of high-quality winter forage cover crops without experiencing significant soil water depletion.
奥加拉拉含水层即将枯竭，这就需要创新的种植替代方案。尽管覆盖作物的益处已得到广泛认可，但在美国南部大平原（SHP），其采用率一直很低，因为人们担心覆盖作物会消耗土壤水分，对夏季作物不利。这项小区试验测试了灌溉和耕作管理与五种覆盖作物类型对覆盖作物产量、土壤水分消耗以及随后的画眉草[（Zucc.）Trotter]夏季干草作物的交互作用，以确定在易干旱的南部大平原地区低风险的覆盖作物种植方式。即使在干旱年份，旱地黑麦（L.）也能产出适量的牧草生物量（>1000千克/公顷），但研究发现，如果想要进行冬季放牧，应采用轻度灌溉以确保充足的牧草供应（>1200千克/公顷）。免耕管理和及时终止冬季覆盖作物对于减少冬季作物对夏季画眉草产量的负面影响至关重要。结果表明，与传统的冬季休耕做法相比，种植免耕覆盖作物对土壤含水量没有不利影响。因此，生产者可以利用优质冬季牧草覆盖作物的土壤保护特性，而不会导致显著的土壤水分消耗。
