Xing Fan, Jie Chang, Yuan Ren, Xu Wu, Yuanyuan Du, Ronghua Xu, Dong Liu, Scott X Chang, Laura A Meyerson, Changhui Peng, Ying Ge
Dairy production is becoming more industrialized globally, especially in developing countries. The large amount of animal wastes from industrial feedlots cannot be fully used on nearby farmlands, leading to severe environmental problems. Using China as a case study, we found that most dairy feedlots employ a semi-coupled mode that only recycles solid manure to farmlands, and only a few dairy feedlots employ a fully-coupled mode that recycles both solid and liquid animal manure. To produce one ton of milk, the fully-coupled mode could reduce greenhouse gas (including carbon dioxide, methane, and nitrous oxide in this paper) emissions by 24%, ammonia emissions by 14%, and N discharge into water by 29%, compared with the semi-coupled systems...
March 8, 2018: Environmental Science & Technology