Effects of microbial inoculants on wheat straw and urea during composting at static state

The objective of the study was to research the potential mechanism of microbial inoculants on the static agricultural waste composting process. An experiment was conducted with mixed materials of wheat straw and urea to study the changes of temperature and activities of hydrolase during composting at static state. The results revealed that the highest temperature of three treatments, under the conditions of adding microbial inoculants which was activated by glucose (G+J), adding microbial inoculants (J) and no microbial inoculants (CK), were 66.0℃, 67.1℃ and 59.5℃, respectively, and the temperature of G+J above 50℃ lasted for 240 h, those of J and CK were 120 h and 96 h respectively during the whole composting process. The peak value of the cellulose enzyme activity in the treatment of G+J was observed at the nigth day, and was earlier than that of J and CK for three days and six days, among them the values were 334.37, 271.59 and 236.67 mg/(g·d), respectively. The peak values of sucrose enzyme in the treatments of G+J and J were 2.53 times and 2.33 times as much as that of CK, respectively. The activities of urea enzyme in three treatments were lower than 20.00 mg/(g·d) after 23 days. Correlation analyses showed that the activities of cellulose enzyme were negatively related to the temperature (P＞0.05) of the three treatments, however, not significantly related. And the activity of sucrose enzyme in the treatment of G+J was greatly significantly negatively related to the temperature, and that of J was significantly negatively related to the temperature. The activities of urea enzyme were siginificantly negatively or greatly siginificantly negatively related to the temperature of the three treatments (P＜0.05, P＜0.01). The results indicate that microbial inoculants can change the temperature and activities of hydrolase during the composting process.