Faust Derek R, Kumar Sandeep, Archer David W, Hendrickson John R, Kronberg Scott L, Liebig Mark A
J Environ Qual. 2018 Jan;47(1):1-15. doi: 10.2134/jeq2017.08.0306.
Integrated crop-livestock systems hold potential to achieve environmentally sustainable production of crop and livestock products. Although previous studies suggest that integrated crop-livestock systems improve soil health, impacts of integrated crop-livestock systems on water quality and aquatic ecosystems are largely unknown. This review (i) summarizes studies examining surface water quality and soil leachate for management practices commonly used in integrated crop-livestock systems (e.g., no-till, cover crops, livestock grazing) with emphasis on the Northern Great Plains ecoregion of North America, (ii) quantifies management system effects on nutrient and total suspended solids concentrations and loads, and (iii) identifies information gaps regarding water quality associated with integrated crop-livestock systems and research needs in this area. In general, management practices used in integrated crop-livestock systems reduced losses of total suspended solids, nitrogen (N), and phosphorus (P) in surface runoff and soil leachate. However, certain management practices (e.g., no-till or reduced tillage) reduced losses of total N (relative median change = -65%), whereas soluble P losses in runoff increased (57%). Conversely, practices such as grazing increased median total suspended solids (22%), nitrate (45%), total N (85%), and total P (25%) concentrations and loads in surface runoff and aquatic ecosystems. An improved understanding of the interactive effects of integrated crop-livestock management practices on surface water quality and soil leachate under current and future climate scenarios is urgently needed. To close this knowledge gap, future studies should focus on determining concentrations and loads of total suspended solids, N, P, and organic carbon in runoff and soil leachate from integrated crop-livestock systems.
农牧结合系统有潜力实现作物和畜牧产品的环境可持续生产。尽管先前的研究表明农牧结合系统能改善土壤健康状况，但该系统对水质和水生生态系统的影响在很大程度上仍不为人知。本综述：（i）总结了针对北美大平原北部生态区农牧结合系统常用管理措施（如免耕、覆盖作物、牲畜放牧）对地表水水质和土壤渗滤液影响的研究；（ii）量化管理系统对养分及总悬浮固体浓度和负荷的影响；（iii）确定与农牧结合系统相关的水质信息空白以及该领域的研究需求。总体而言，农牧结合系统采用的管理措施减少了地表径流和土壤渗滤液中总悬浮固体、氮（N）和磷（P）的流失。然而，某些管理措施（如免耕或减少耕作）减少了总氮的流失（相对中位数变化=-65%），而径流中可溶性磷的流失却增加了（57%）。相反，放牧等措施增加了地表径流和水生生态系统中总悬浮固体（22%）、硝酸盐（45%）、总氮（85%）和总磷（25%）的中位数浓度和负荷。迫切需要更好地了解当前和未来气候情景下农牧结合管理措施对地表水水质和土壤渗滤液的交互影响。为填补这一知识空白，未来的研究应侧重于确定农牧结合系统径流和土壤渗滤液中总悬浮固体、氮、磷和有机碳的浓度和负荷。
