| Straws are copious natural resources. Soil fertility and output of crops can be inproved by straw returning to the field. But the degradation rates of straw in soil are slow, then the growth of root would be hampered, nutrients of soil would be absorbed by the microorganism, this would bring the short of nitrogen of crops and a series of other problems. The cellulase in soil can promate the degeneration of straws, the protease can promate the degradation of protein and nitrogen organic compound in soil. But under the natural condition, the activeness of enzyme in soil is lower, in order to find the new way to promote the degradation rates of crop straws, the influences of outer cellulase and outer protease on the degradation rates of straws, available nutrients of soil and the effects on growth of crops were investigated by incubation experiments and pot culture experiments. The main result of study are as follows:1.The outer cellulase can promate the degradation rates of straws and improve soil fertility, The results showed that in the incubation time, the wheat straw and corn straw that added cellulase all have the significance difference compared with CK (p <0.01), when the incubation finished, the degradation rate of wheat straw added cellulase were increased 7.10%～11.86%, and the rate of corn straw were increased 8.01%～14.04%. Compared with CK, the contents of available N, available P and available K for the all treatments that added cellulase also have significance difference with CK (p<0.01). Compared with CK, the contents of soil available N, available P and available K for the optimal Tr of wheat straw were increased 4.15mg/kg, 3.60mg/kg, 32.35 mg/kg.The all treatments that given outer cellulase shown no significant... |
