Abstract Elimination of tillage and planting winter cover crops are two conservation practices employed in agricultural row crop production to promote the accumulation of plant residues on the soil surface, improve soil structure, reduce erosion, and decrease losses of excess nutrients in runoff. The purpose of the current study was to assess the effects of no till management and two different cover crop species, Elbon rye (Secale cereal L.) and Crimson clover (Trifolium incarnatum L.), on microbial aspects of soil health, namely microbial biomass and enzyme activities (phosphatase, β-glucosidase, N-acetylglucosaminidase, and fluorescein diacetate [FDA] hydrolysis) in order to determine potential impacts on the size and nutrient cycling capabilities of microbial communities in lower Mississippi Delta soybean (Glycine max L.) field soils over a three-year period. Microbial biomass in surface soil was elevated under no till and both cover crop treatments. Soil enzyme activities associated with organic matter breakdown were increased by cover crop more than tillage, while phosphatase and FDA hydrolysis were increased by both. The higher activities due to cover crop input appear to be the result of an enlarged microbial community as well as increased substrate availability. While these enhanced soil biological traits did not translate into higher soybean yields, longer evaluation periods may be necessary to fully appreciate the benefits of improved soil health in crop production systems.

中文翻译：

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冬季覆盖作物和免耕管理提高大豆田土壤中的酶活性

摘要 免耕和种植冬季覆盖作物是农业中耕作物生产中的两种保护措施，以促进植物残留物在土壤表面的积累，改善土壤结构，减少侵蚀，减少径流中多余养分的损失。本研究的目的是评估免耕管理和两种不同的覆盖作物物种 Elbon 黑麦（Secale 谷物 L.）和深红色三叶草（Trifolium incarnatum L.）对土壤健康的微生物方面的影响，即微生物生物量和酶活性（磷酸酶、β-葡萄糖苷酶、N-乙酰氨基葡萄糖苷酶和荧光素二乙酸酯 [FDA] 水解），以确定对密西西比河三角洲下游大豆（Glycine max L. ) 三年期间的田间土壤。在免耕和两种覆盖作物处理下，表层土壤中的微生物生物量均有所提高。覆盖作物比耕作增加了与有机物分解相关的土壤酶活性，而两者都增加了磷酸酶和 FDA 水解。由于覆盖作物投入而导致的较高活性似乎是微生物群落扩大以及底物可用性增加的结果。虽然这些增强的土壤生物特性并没有转化为更高的大豆产量，但可能需要更长的评估期才能充分了解改善作物生产系统土壤健康的好处。覆盖作物比耕作增加了与有机物分解相关的土壤酶活性，而两者都增加了磷酸酶和 FDA 水解。由于覆盖作物投入而导致的较高活性似乎是微生物群落扩大以及底物可用性增加的结果。虽然这些增强的土壤生物特性并没有转化为更高的大豆产量，但可能需要更长的评估期才能充分了解改善作物生产系统土壤健康的好处。覆盖作物比耕作增加了与有机物分解相关的土壤酶活性，而两者都增加了磷酸酶和 FDA 水解。由于覆盖作物投入而导致的较高活性似乎是微生物群落扩大以及底物可用性增加的结果。虽然这些增强的土壤生物特性并没有转化为更高的大豆产量，但可能需要更长的评估期才能充分了解改善作物生产系统土壤健康的好处。