[Major chemical components of poultry and livestock manures under intensive breeding]

Owing to the wide use of feed additives in modern intensive poultry and livestock production, the major components and their concentrations of domestic animal manures may be greatly changed, as compared with those in traditional breeding. An investigation on the 61 samples of chicken, pig and pigeon manures from the intensive poultry and livestock farms of Guangdong Province showed that the concentrations of total N, P and K in chicken and pig manures were obviously higher than those of traditional breeding, and the P/N ratio of three test manures was greater than that of common crops. The concentrations of total soluble salts (TSS) of test manures averaged 49.0, 20.6 and 60.3 g x kg(-1) , respectively, which were mainly composed of the sulfate and chloride of potassium and sodium. The mean concentrations of Cu, Zn and As reached 107.5, 366.6 and 21.6 mg x kg (-1) in chicken manure, 765.1, 1128.0 and 89.3 mg x kg(-1) in pig manure, and 56.1, 210.9 and 2.9 mg x kg(-1) in pigeon manure, respectively. These manures were low in Pb, Cd and Cr contents, from non-detectable to 12.0 mg x kg(-1). According to the limiting criteria of heavy metals in fertilizers, the Cu, Zn and As in the three manures were the major elements exceeding the limits, especially for Zn.