Study On Temperature And Moisture Content Effect On Decomposition Of Crop Straws And Relevant Index In Soil

This study researches on the decomposition rate of four kinds of crop straws, namely, rice, canola, corn and ramie and their effect on soil nutrients and enzyme activity by the method of the nylon netting, which provides important technical support and theoretical basis for the scientific management of the nutrients of tobacco fields and management measures for agricultural production. The main results obtained in this study are as follows:1.35℃and conventional moisture (moisture content is60%-70%) are appropriate conditions for the decomposition of those four kinds of crop straws. The decomposition rate and decomposition amount of the four crop straws in the temperature and moisture conditions were higher than those conditions that under alternate wetting and drying and soaking and the temperature of10℃and25℃.2. The decomposition rate of crop straws in the soil is high at the early stage and low at the late stage. During the100days of the trial, the accumulated rate of decomposition of the four crop straws is rice> ramie> rape> maize. In terms of nutrient release, the three kinds of straws are manifested as K> P> N.3. Crop straws can significantly increase organic matter and nutrient content in the soil, and can remarkably influence the nitrogen, phosphorus and potassium content. Different crop straws differ in the process of influencing the soil nutrient content:for organic matter, rice> rape> maize> ramie; for nitrogen, corn> ramie rape rice; for phosphorus, ramie> rice> corn> rape; but there are no significant differences for potassium release among the four crop straws.4. The decomposition of crop straws has influenced the activity of peroxide catalase, urease and cellulase in the soil. The activity of the peroxide catalase shows the trend of first increasing and then decreasing, and the differences among the four kinds of straws are not significant; The activity of the urease in the soil enhances after crop stalk rots, and the influence in turn is manifested as rice> rape> maize> ramie; The changes of the cellulose are similar to those of the enzyme catalase, showing the trend of first increasing and then decreasing, and the differences in the effects of the decomposition of the four crop straws on the changes of the cellulose are represented as rice>rape> maize> ramie.