College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural University, 2 Yuanmingyuan West Road, Beijing100193, China.
Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, College of Resources and Environment, Southwest University, Tiansheng Road 02, Chongqing400715, China.
Environ Sci Technol. 2022 Dec 20;56(24):17591-17603. doi: 10.1021/acs.est.1c08808. Epub 2022 Nov 29.
Livestock production poses a threat to water quality worldwide. A better understanding of the contribution of individual livestock species to nitrogen (N) pollution in rivers is essential to improve water quality. This paper aims to quantify inputs of dissolved inorganic nitrogen (DIN) to the Yangtze River from different livestock species at multiple scales and explore ways for reducing these inputs through coupling crop and livestock production. We extended the previously developed model MARINA (Model to Assess River Input of Nutrient to seAs) with the NUFER (Nutrient flows in Food chains, Environment, and Resource use) approach for livestock. Results show that DIN inputs to the Yangtze River vary across basins, sub-basins, and 0.5° grids, as well as across livestock species. In 2012, livestock production resulted in 2000 Gg of DIN inputs to the Yangtze River. Pig production was responsible for 55-85% of manure-related DIN inputs. Rivers in the downstream sub-basin received higher manure-related DIN inputs than rivers in the other sub-basins. Around 20% of the Yangtze basin is considered as a manure-related hotspot of river pollution. Recycling manure on cropland can avoid direct discharges of manure from pig production and thus reduce river pollution. The potential for recycling manure is larger in cereal production than in other crop species. Our results can help to identify effective solutions for coupling crop and livestock production in the Yangtze basin.
畜牧业生产对全球水质构成威胁。更好地了解个别牲畜物种对河流氮（N）污染的贡献，对于改善水质至关重要。本文旨在通过耦合作物和畜牧业生产，从多个尺度量化不同牲畜物种向长江输入的溶解无机氮（DIN），并探索减少这些输入的方法。我们扩展了先前开发的 MARINA（评估营养物向海洋输入的模型）模型，采用了 NUFER（食物链、环境和资源利用中的养分流动）方法来描述畜牧业。结果表明，DIN 向长江的输入因流域、子流域和 0.5°网格以及牲畜物种而异。2012 年，畜牧业生产导致 2000 克 DIN 输入长江。猪生产造成与粪便相关的 DIN 输入占 55-85%。下游子流域的河流接收的与粪便相关的 DIN 输入高于其他子流域的河流。约 20%的长江流域被认为是与粪便相关的河流污染热点地区。在农田中回收粪便可以避免猪生产中粪便的直接排放，从而减少河流污染。在谷物生产中，粪便回收的潜力大于其他作物。我们的研究结果有助于确定长江流域耦合作物和畜牧业生产的有效解决方案。
