Manure generated from livestock farming is currently the focus of attention of global scientific community. China's livestock manure is extremely rich with a high potential for heavy metal contamination. Here, data were collected for 2000e2018.6 from China's National Statistical Data, Elsevier, China National Knowledge Infrastructure and other literature databases and analyzed for "feedefecesesoil" chain of heavy metals. An integrated analysis was done to explore the reductive effect of existing technologies on heavy metals in cattle manure. Excessive addition of heavy metal elements to feed is widespread in China. High amounts of undigested heavy metals are excreted through animal manure. The study showed that spatial variability of heavy metal contents in cattle manure was extremely large. The excess cupper (Cu) was higher than that of zinc (Zn), and was higher in southern than in northern China. Chemical treatments were more effective than physical and biological ones in controlling heavy metal pollution. The optimal reduction ratios of the effective Zn and Cu contents were 21.72% and 33.11%, respectively. The Zn and Cu contents could be reduced by 1.96 
 107 and 5.92 
 106 kg per year, respectively. This could reduce the risks posed by heavy metals after manure-based fertilizer applications in crop cultivation.

Keywords: Large-scale farming, Feed-feces-soil chain, Heavy metal pollution, Livestock manure, Passivating agent

Corresponding authors: Jing Li, jingli@igsnrr.ac.cn, Li Xu, xuliforever@163.com