Liang Kang, Zhang Xuesong, McCarty Gregory W, Zhao Kaiguang, Gao Feng
Oak Ridge Institute for Science and Education, Oak Ridge, TN USA.
USDA-ARS Hydrology and Remote Sensing Laboratory, Beltsville, MD USA.
NPJ Sustain Agric. 2025;3(1):47. doi: 10.1038/s44264-025-00090-0. Epub 2025 Aug 28.
Agricultural management practices such as conservation tillage is promoted in the U.S. Midwest for improving soil health, mitigating nutrient loss, and reducing hypoxia in the Gulf of America (GOA). However, large-scale evaluations of tillage impact on soil organic carbon (SOC), water quality, and the implications for hypoxia in the Gulf are lacking. By combining a meta-analysis of field experiments with watershed modelling, this study finds that by 2050, no-till (NT) farming could enhance SOC by ~5.4 MgC ha , increase streamflow by 17.3%, and reduce soil erosion by ~4.9%, compared to high-intensity tillage (HT). However, widespread NT adoption could raise nitrogen loss, thus expand summer hypoxia of the GOA to 16,500 km², 21.5% larger than the HT scenario. Despite its soil health benefits, conservation tillage may complicate efforts to reduce hypoxic zones to the targeted 5000 km² by 2035. These tradeoffs underscore the need for balanced approaches in future conservation strategies.
美国中西部地区推广保护性耕作等农业管理措施，以改善土壤健康状况、减少养分流失并缓解美国海湾（GOA）的缺氧问题。然而，目前缺乏对耕作方式对土壤有机碳（SOC）、水质的影响以及对海湾缺氧问题影响的大规模评估。通过将田间试验的荟萃分析与流域模型相结合，本研究发现，到2050年，与高强度耕作（HT）相比，免耕（NT）农业可使土壤有机碳增加约5.4 MgC/公顷，使径流增加17.3%，并减少约4.9%的土壤侵蚀。然而，广泛采用免耕可能会增加氮素流失，从而使美国海湾夏季缺氧面积扩大到16,500平方公里，比高强度耕作情景下大21.5%。尽管保护性耕作对土壤健康有益，但它可能会使到2035年将缺氧区域减少到目标5000平方公里的努力变得复杂。这些权衡凸显了未来保护策略中采取平衡方法的必要性。
