Resource Utilization of Returned Rapeseed Straw and Its Effect on Soil Fertility and Crop Yields

In order to study the decomposition characteristics of returned rapeseed straw in the process of resource utilization and the effect on soil fertility and crop yields, different treatments of soil with returned rapeseed straw were conducted using the nylon net bag method of field trials. Different treatments include varied amounts of straw, depths to be buried in soil, and addition of straw decomposing bacteria. The results showed that the decomposition ratio of rapeseed straw increased with time and the decomposition rate of rapeseed straw was faster in the first 30 days and then slowed down until the end of 120 days. Straw decomposition rate was negatively correlated with the amounts of returned rapeseed straw. The decomposition rate of rapeseed straw on the soil surface was faster than that buried 20cm below the soil surface, which is also faster than that 10cm below the soil surface. Decomposition ratio of rapeseed straw with addition of decomposing bacteria was higher than without decomposing bacteria. The returned straw improved the physical and chemical properties of soil and increased the soil nutrient content and rice yields. The study provided the basic parameters for controlling the rapeseed straw decomposition rate, which improved the agricultural eco-environment.