Difference of decay process of cellulose and lignin in wheat straw

Wheat straw was incubated under flooded soil condition,and cellulose and ligin in residual straw were extracted and measured at different stages during incubation period.Then dynamic decay processes of cellulose and lignin and response of their decay processes to nitrogen addition were compared and analyzed.Results showed that the cumulative decay rates at 60 dof incubation were 61.8% for cellulose and 57.2% for lignin.Both cellulose and lignin decomposed quickly during early stages of incubation and slowly at late stages.However,compared with cellulose,decay speed of lignin was higher but declined more sharply with the incubation time,which led to a much lower decay speed for lignin at late stages.Days required for cellulose to complete 25%,50%and 75% of whole decay process were longer than those of lignin,which indicated that cellulose can maintain active decay for longer time than lignin.Nitrogen addition delayed active decay of cellulose but had no apparent effect on that of lignin.Compared with lignin,the decay process of cellulose was closer to the overall process of straw.