Department of Entomology, University of Nebraska-Lincoln, NE 68583, USA.
Environ Entomol. 2023 Jun 16;52(3):371-378. doi: 10.1093/ee/nvad022.
Greater cover crop biomass is expected to result in a favorable microhabitat for beneficial arthropods. Natural Resources Conservation Service (NRCS) cover crop termination guidelines are based on the cash crop planting date. Therefore, a delay in cash crop planting could result in greater cover crop biomass. However, studies on delays in cash crop planting and greater cover crop biomass have led to a decrease in cash crop yield. Thus, a field study was conducted in eastern Nebraska over two years to evaluate the impact of early and late corn planting dates with at-plant cover crop terminations on pest potential, beneficial arthropod activity, and agronomic parameters. To measure arthropod activity and pests in the system, pitfall traps, and corn injury assessments were performed during the early stages of corn development. A total of 11,054 and 43,078 arthropods were collected in 2020 and 2021, respectively. The results have shown no impact of the corn planting dates with at-plant cover crop termination on arthropods but identified that cereal rye cover crop supports greater Araneae activity while its alternative prey varied when compared to the no-cover treatment. Significant yield penalties were observed when cover crop was used regardless of the corn planting dates. Pest pressure was not significant in any year, however, future research using cereal rye and different cover crop species should be used in this system with an artificial infestation of a pest to be able to evaluate the trade-offs between possible cash crop yield reductions and potential biological control of pests.
预计更多的覆盖作物生物量将为有益节肢动物提供有利的微生境。自然资源保护服务（NRCS）的覆盖作物终止指南是基于经济作物的种植日期。因此，经济作物种植的延迟可能会导致覆盖作物生物量增加。然而，关于经济作物种植延迟和覆盖作物生物量增加的研究导致了经济作物产量的下降。因此，在过去两年内，在内布拉斯加州东部进行了一项田间研究，以评估早期和晚期玉米种植日期与种植前覆盖作物终止对潜在害虫、有益节肢动物活动和农业参数的影响。为了测量系统中的节肢动物活动和害虫，在玉米发育的早期阶段进行了陷阱和玉米损伤评估。在 2020 年和 2021 年分别收集了 11054 和 43078 只节肢动物。结果表明，玉米种植日期与种植前覆盖作物终止对节肢动物没有影响，但发现谷物黑麦覆盖作物支持更大的蜘蛛类活动，而与其替代猎物相比，当与无覆盖处理相比时，其替代猎物则有所不同。无论玉米种植日期如何，使用覆盖作物都会导致显著的产量损失。任何一年的害虫压力都不显著，然而，在这个系统中，应该使用谷物黑麦和不同的覆盖作物物种进行未来的研究，并对害虫进行人工侵染，以评估可能的经济作物产量减少和害虫潜在生物控制之间的权衡。
