Carbon and nitrogen mineralization characteristics of different types of organic manures

The incubation experiment was used to study carbon(C) and nitrogen(N) mineralization characteristics of 9 organic manures sampled from the bases of sunlight greenhouses in Guanzhong district,Shaanxi Province.The results show that there are significant differences in the C and N mineralization and their mineralization rates(the ratio of C or N mineralization to total organic C or total organic N) among the different manures.The range of C mineralization rates of different manures is from 22.24% to 87.16%,with CV(coefficient of variation) of 90.30%,and the range of N mineralization rates of different manures is from 29.07% to 84.87%,with CV of 67.36%.The mean amounts of C and N mineralization,and mineralization rates of chicken manure are significantly higher than those of pig and cattle manures,and there is no difference between pig and cattle manures.For a same type of organic manure,there are also significant differences in the C and N mineralization and mineralization rates among the manures collected from different places.The amounts of C and N mineralization of organic manure are linearly related with their total N contents,indicating that the N content of organic manure is the key factor affecting the mineralization of C and N from manures.