Soil Research Mechanism Of Combining Straw Returning With Plastic Film Mulching To Increase Rice Yield

In order to explore the effects of straw returning and film mulching on the physicochemical properties,nutrient content,soil enzyme activity and rice yield of paddy soil,Jijing 88 was selected as the test material for film grafting(F)and no film(F0).Under the two cultivation modes,5 sets of straw returning field gradients were 0%?20%?40%?60%?100%(S0?S1?S2?S3?S4),and the soil physical and chemical properties,nutrient content,Soil enzyme activity and rice yield were used to explore the effects of straw returning and film mulching on soil fertility and rice yield.The results are as follows:1.Under the same amount of straw returning,the film mulching increased by 5 cm,10 cm soil temperature by 0.3°C~1.8°C,0.1°C~0.9°C.At 15 cm and 20 cm depth,straw returning and film mulching had little effect on soil temperature.2.Under the same straw returning amount,the soil bulk density and pH value of the film-mulching treatment were lower than that without film treatment;the soil bulk density showed that under the film-covering conditions,there were minimum values under S2 and S3treatments in 2017 and 2018,respectively.Other treatments reduced soil bulk density by 4.1%~10.4%and 5.2%~11.9%.The pH value of the soil showed that under the condition of film mulching,there was a minimum under S2 and S3 treatment in 2017 and 2018 respectively,and the soil pH decreased by 1.2%~5.3%and 0.2%~3.2%compared with other treatments.3.Under the same straw returning amount,the content of total nitrogen,organic matter(except S0 treatment),alkali nitrogen,available phosphorus and available potassium in the soil treated with plastic film was higher than that without film treatment,and whether or not the film was coated,The increase in the amount of straw returned to the field showed an increase and then decreased.In 2017 and 2018,the maximum was reached under the treatment of FS2 and FS3 respectively.4.The activities of catalase,phosphatase and urease were consistent in 2017 and 2018.No matter whether the film was coated or not,the activity of each enzyme increased first and then decreased with the increase of straw returning volume.2017 In the year and 2018,the maximum was achieved under S2 and S3 treatments,and under the same straw returning amount,the catalase,phosphatase and urease activities of the film treatment were higher than those without film treatment.5.Film mulching and straw returning significantly affect production.Under the same straw returning amount,the grain yield of the mulching treatment was higher than that without the mulching treatment;with the increase of the straw returning amount,the yield increased first and then decreased.Under the conditions of film mulching,the highest values of 11.93 t/hm~2and 12.9 t/hm~2 were treated in S2 and S3 in 2017 and 2018,respectively.The composition factors of different treatment yields showed that the straw returning treatment significantly affected the number of effective panicles,the number of panicles,the seed setting rate and the1000-grain weight.The effect of plastic film mulching treatment on the number of kernels,seed setting rate and 1000-grain weight was not significant,but significantly increased the number of effective panicles.Regardless of whether the film was covered or not,the number of effective panicles and the number of grains per panicle increased with the increase of the amount of straw,but increased first and then decreased.Above all,straw returned with plastic film mulching,can reduce soil bulk density and soil pH value,can increase 5 cm~10 cm of soil temperature,soil can increase soil organic matter,total nitrogen,alkali solution nitrogen,available phosphorus and available potassium content,increase soil catalase,urease and phosphatase activity,thus increasing the production of rice.