Effect of Straw Burning on Soil Enzyme Activity, Soil Microbial Quantity and Physical and Chemical Properties of Soil in Different Plough Layer
The topsoil which was covered with burned straw as the research object, this paper investigated effects of the different topsoil on the activities of catalase, phosphatase, urease and polyphenol oxidase, and soil microbial quantity. Meanwhile, this study discussed the relevance between the activities of enzyme and the content of soil organic matter, water content, available nutrient and microorganism quantity. The results showed that the activities of catalase, phosphatase, urease and polyphenol oxidase of topsoil which was covered with burned straw had been decreased, there were significantly difference soil enzyme activity changes before and after straw burning in the plough layer of 0--2 cm and 2--5 cm, small changes of the soil enzyme activity in the plough layer of 5--12 cm, there was no change of soil enzyme activity in the plough layer of la --20 cm. The soil microbial quantity was greatly reduced in the plough layer of 0--2 cm because of straw burning, reduce degree at about 80%, there were different degrees of reduced from 43%-52% of the soil microbial quantity in the plough layer of 2--5 cm, the soil microbial quantity had not changed in the plough layer of 5--1a cm and 13--20 cm. The correlation analysis showed that: Only the decrease of urease activity and the increase of the content of available P reached significant correlation, correlation coefficient was 0. 959. Bacteria, fungi, actinomycete numbers of lower level and polyphenol oxidase activity degree of lower were into extremely significant correlation, correlation coefficient of respectively were 0. 998 , 0. 999 , 0. 998 . Urease activity of lower level and bacteria, fungi, actinomycete numbers of lower level were into significant correlation, correlation coefficient of respectively were 0. 977 , O. 974 , 0. 954.
straw burning soil enzyme activity soil microbial quantity physical and chemical properties of soil