The pot experiment was conducted to study the effect of animal excrement,animal remnant,herb residues and woody residues on elemental composition of humic acid(HA),fulvic acid(FA) and humin.The results showed as follows: Compared with control treatment(CK),after five years,application of organic materials resulted in significant decrease of carbon(C) and hydrogen(H),but enhanced condensation degree and content of nitrogen containing group,and the role of herb residues was the most obvious.Apart from animal ...