| For there are differences in the content and composition of organic matter among various kind of raw compost materials,the degradation and humification level of lignin and cellulose are different within material combinations.To compare the characteristics of carbon conversion,content and composition of humus in composting process with different animal manure and crop straw,4 different material combination treatments: T1: cow dung +maize straw;T2: cow dung + wheat straw;T3: sheep dung + maize straw;T4: sheep dung + wheat straw.The main results are as follows:1.The decrease of TOC and DOC content in sheep dung treatments were higher than that in cow dung treatments.The content of total oganic carbon(TOC)of all treatments decreased with the progress of composting process until the end of composting,the TOC content of T1 ~ T4 decreased by 22.1%,21.5%,23.6% and 23.7% respectively.The content changes of dissolved organic carbon(DOC)were observed to be consistent with TOC,and decreased to the minimum at the 15 th day,but presenting the different characteristics,T1 and T2 treatments of cow dung composter shown no changes until tenth days,but the DOC decrease of in T3 and T4 treatments of sheep manure composts occurred at the composter beginning.2.The degradation rate of cellulose and hemicellulose was the highest when sheep manure and corn straw were used as raw materials in composting.When composting with different raw materials,all treatments lignocellulosic components were significantly degraded,and the degradation rates of cellulose and hemicellulose during the warming and high temperature stages of composting were far higher than the cooling stage.By the end of composting,the degradation rates of cellulose and hemicellulose treated were 42.83% to 45.20% and 50.72% to 59.42%,respectively.In all treatments,the degradation rate of cellulose and hemicellulose treated with T3 is the highest.The degradation of lignin during composting was relatively low,ranging from 21.62% to 30.15%.The degradation of lignin mainly occurs in the high temperature period of composting,and the degradation rates of T1 and T3 treated with corn stover are significantly higher than those of T2 and T4 treated with wheat straw,which may be related to the different properties of compost materials.3.The contents of total humic acid,free humic acid and HA in the whole composting process with different combinations of raw materials were higher than those of cow dung.The increase of total humic acid(THA)in composting started at the 10 th day and continued increasing until the maximum at 15 th day,the THA content of T3 and T4 treatments were higher than that of T1 and T2 significantly.At the end of compost,the total humic acid content of T1,T2 and T4treatments increased by 14.8%,17.0% and1.1% compared to the beginning of composting,while the T3 treatments decreased by 16.4%,respectively.The content of free humic acid(FHA)in different treatments was similar to that of total humic acid.When the composting was carried ontill 15 th days.The content of free humic acid decreased,while contents of humus acid,HA increased gradually with the compost processing,and the FHA and HA content in T3 and T4 treatments were higher than that of T1 and T2 consistently.The content of fulvic acid during composting showed a downward trend,but with different decreasing rates,T1 ~ T4 were 54.9%,59.4%,55.5% and 44.9%,respectively.The composting process significantly increased the content of humic acid,and the degree of humification of the compost increased. |
PDF Full Text Request