Effects of different C/N of composting materials on main indexes of high-temperature aerobic composting of chicken manure and sawdust

Using chicken manure and sawdust as materials,the high-temperature aerobic composting was conducted to study the effect of different proportion of chicken manure and sawdust on carbon and nitrogen transformation.The initial carbon-nitrogen ration of composting materials were 15,25 and 40,respectively,labeled as T1,T2,and T3.The results showed that:1) When the initial C/N was 25,the compost reached the highest temperature 66 ℃ after 3 days.2) The pH value of T1,T2 and T3 appeared to have the same trend of rise first and then fall.3) When the compost was maturity,total carbon of T1,T2,and T3 were declined somehow.During composting,total nitrogen of T2,and T3 showed a trend of increase,but T1's total nitrogen decreased at first,but increased later,then decreased slightly at last.At the end of composting,the C/N of T1,T2,and T3 all decreased somehow,but the T1 had a special trend of increase first and decrease later.4) When the compost was maturity,the NH+4-N of T1,T2,and T3 decreased 44.12%,74.37%,56.83% respectively,and the NO-3-N increased 855.72,731.68 and 532.23 mg/kg respectively.The above results indicated that co-composting of chicken manure and sawdust in C/N of 25 is a favorite condition to the transformation of carbon and nitrogen;adding sawdust into chicken manure had an objective effect on temperature of co-composting in low C/N of 15.