Effects Of Different Straw Returning Methods On Soil Enzymes And Available Nutrients

In this experiment,maize Xiangyu 998 was used as experimental material.Five treatments including deep straw returning(SF),enriched straw returning(FJ),shallow stubble and thin stubble returning(SL),straw mulching returning(FG)and straw non-returning(CK)were set up to explore the effects of different straw returning modes on soil water content,enzyme activity,available nutrient content and yield.The results show that:1.Different straw returning methods can increase soil water content,reaching the maximum at jointing stage of maize.At maize heading stage,SF,FJ,SL and FG in 0-20 cm soil layer increased significantly compared with CK(P < 0.05);SF and FJ in 20-40 cm soil layer increased significantly compared with CK,while SL and FG had no significant difference compared with CK;SF and FJ in 40-60 cm soil layer increased significantly compared with CK,while SL and FG had no significant difference.Moreover,the effect of deep straw ploughing was the most significant in all soil layers.2.Soil catalase,invertase,urease and acid phosphatase activities increased first and then decreased during maize growth period.SF,FJ,SL and FG activities in three soil layers increased significantly compared with CK catalase,invertase,urease and acid phosphatase activities in maize heading stage,and the effect of deep straw ploughing was the most obvious.3.Soil alkali-hydrolyzed nitrogen,available phosphorus and available potassium contents in the five models increased first and then decreased during maize growth period,and the highest value was at Maize heading stage.At maize heading stage,the contents of SF,FJ,SL and FG in the three soil layers increased significantly compared with CK soil alkali-hydrolyzed nitrogen,available phosphorus and available potassium,and the effect of deep straw ploughing was the most significant.4.There were no significant differences in ear rows and ear length between the four straw returning treatments and the straw non-returning treatments.The maize yield of SF and FG increased significantly compared with CK,while the difference between FJ and SL was not significant,and deep ploughing returning had the most significant effect on Maize yield.5.According to the correlation analysis,maize yield was significantly correlated with soil water content,four soil enzyme activities and three soil available nutrients.6.Comprehensive analysis of straw deep ploughing is more conducive to improving soil water content,soil enzyme activity,soil nutrient content and maize yield,so straw deep ploughing can be used as the preferred mode of maize straw returning in Jilin Province.