Effects of Rice Straw Returning on Nutrients in Soil Solution and Activities of Soil Enzymes

Rice straw returning plays an important role in both increasing soil organic matter and reducing carbon emissions.This experiment focus on the cold rice,and studies the effect of the straw returning on nitrogen,phosphorus,potassium in soil solution and soil enzyme activities under the condition of straw returning for three years.The result showed that during the period of rice growing,the inorganic nitrogen in soil solution exhibited a low-high-low curve on straw returning or not.The content of phosphorus and potassium in soil solution was decreasing.The rice straw returning made the content of inorganic nitrogen at tillering stage reduce,and made the content of phosphorus during the whole growth in soil solution reduce.What's more,it made the content of potassium increase at the same time.Straw returning treatment reduced the soil the activity of urease and increased activity of sucrose.In addition,straw returning treatment has less effect on acid phosphatase and catalase.