Kansas State University, Department of Agronomy, 2004 Throckmorton Plant Sciences Center, 1712 Claflin Rd., Manhattan, KS, 66506, USA.
Kansas State University, Department of Agronomy, 2004 Throckmorton Plant Sciences Center, 1712 Claflin Rd., Manhattan, KS, 66506, USA.
J Environ Manage. 2022 Jan 1;301:113818. doi: 10.1016/j.jenvman.2021.113818. Epub 2021 Sep 28.
Best management practices that reduce potential phosphorus (P) loss and provide flexibility in P fertilizer management are needed to help producers protect water quality while maintaining crop yield. This study examined the impacts of P fertilizer management (no P, fall broadcast P, and spring injected P) and cover crop use on annual concentrations and loads of sediment, total P, and dissolved reactive P (DRP) in edge-of-field runoff from a no-till corn (Zea mays)-soybean (Glycine max) rotation in the Central Great Plains, USA, from September 2015 through September 2019. The spring injected P fertilizer treatment generally had 19% less total P and 33% less DRP loss compared to the fall broadcast treatment, confirming the importance of P fertilizer management as a practice for reducing P loss. The addition of a cover crop had an inconsistent effect on total P loss, with no effect in 2016 and 2017, increasing loss in 2018 by 56%, and decreasing it in 2019 by 40%. The inconsistent impact of cover crops on total P loss was related to cover crop effects on sediment loss. Although cover crop impacts on total P losses were inconsistent, the addition of a cover crop increased DRP loss in three of four years. Cover crop use consistently reduced sediment loss, with greater sediment reduction when P fertilizer was applied. Results from this study highlight the benefit of cover crops for reducing sediment loss and the continued need for proper fertilizer management to reduce P loss from agricultural fields.
为了帮助生产者在保护水质的同时保持作物产量，需要采用最佳管理实践来减少潜在磷（P）流失，并为 P 肥管理提供灵活性。本研究调查了 P 肥管理（不施 P、秋季撒播 P 和春季注入 P）和覆盖作物利用对免耕玉米（Zea mays）-大豆（Glycine max）轮作中田间边缘径流水体中年度泥沙、总磷和溶解反应性磷（DRP）浓度和负荷的影响，该研究在美国大平原中部进行，时间跨度为 2015 年 9 月至 2019 年 9 月。与秋季撒播处理相比，春季注入 P 肥处理的总 P 和 DRP 流失量通常分别减少 19%和 33%，这证实了 P 肥管理作为减少 P 流失的实践的重要性。覆盖作物的添加对总 P 流失的影响不一致，2016 年和 2017 年没有影响，2018 年增加了 56%，2019 年减少了 40%。覆盖作物对总 P 流失的影响不一致与覆盖作物对泥沙流失的影响有关。尽管覆盖作物对总 P 流失的影响不一致，但在四年中有三年添加覆盖作物增加了 DRP 流失。覆盖作物的使用始终降低了泥沙流失，且在施用 P 肥时降低幅度更大。本研究的结果突出了覆盖作物对减少泥沙流失的好处，以及继续需要适当的肥料管理来减少农业领域的 P 流失。
