Effect Of Straw Return And Density Treatment On Soil Microenvironment And Maize Yield

The objective of this study was to improve the effectiveness of soil nutrient uplift under seed direct harvest maize stover return conditions,to investigate the effects of direct seed harvesting of maize straw on the physicochemical properties of the land,soil microbiology and maize yield formation,and it makes the straw return method and planting density suitable for direct harvest corn straw return in Ningxia seeds are determined,the aim is to provide a theoretical basis for the decomposition of straw from seed direct harvest maize in the region after return to the field and the effective use of land nutrient resources.In this study,the soil environment of straw return and seed direct harvest maize crop in Ningxia Yellow Irrigation District was studied,the response of soil physicochemical properties,soil enzyme activity and maize yield components to changes in seed direct harvest maize stover return and planting density are discussed.Differences in the composition and function of soil microbial populations in the tillage layer at maize maturity under each treatment in the experiment were analyzed using Illumina MiSeq sequencing technology,also environmental drivers of changes in the composition and function of microbial populations in agricultural fields have been studied.The main results are as follows:(1)Soil physical properties and soil microbial community activity under straw return combined with low planting density treatment were the best among all treatments,and the low-density treatment performed better than the high-density treatment.Soil nutrient content and soil pH were promoted to increase by straw return,while soil total salt content was suppressed by straw return.Soil nutrient indicators showed a trend of increasing and then decreasing with increasing planting density.Soil total salt content was promoted to increase by increasing planting density.Soil urease,alkaline phosphatase,catalase and sucrase activities were all promoted to increase by straw return,and showed a trend of increasing and then decreasing with the increase of planting density.(2)Ascomycota,Basidiomycota,Mortierellomycota and Chytridiomycota are the main dominant fungal phyla in the cultivated soils of the region.The phylum level composition of the local soil bacterial community was relatively stable,and the phylum Proteobacteria was the dominant phylum common to all treatments.The soil bacterial community was affected by different straw returning treatments to produce large differences,and the differences caused by planting density were smaller.Differences exist in the response of different microbial genera prompted by environmental changes.(3)The number of ears,grains and weight of 100 grains per mu were increased by the straw treatment.While maize yield increases with increasing planting density,the number of ears and 100 grain weight are limited by high density,The increase in yield showed less and less with increasing planting density.In summary,Soil physicochemical properties,soil enzyme activity,soil microbial community and maize yield components were significantly affected by straw return and planting density.Optimization of soil physical properties and soil nutrient accumulation are promoted by straw return,soil enzyme activity and soil microbial community growth and reproduction were also promoted.Soil nutrient accumulation and soil enzyme activity enhancement can be promoted by reasonable planting density.The optimization of soil physical properties and the growth and reproduction of soil microbial communities were promoted by straw return combined with reduced planting density.Promote the increase of maize ears grain number and 100 grain weight.