Effects Of No-tillage And Resuide Mulch On Winter Wheat And Soil In South Mountainous Area Of Ningxia

No-tillage with straw mulch is a conservation tillage method that can improve soil quality and soil water storage capacity,which plays an important role in sustainable agricultural development.The application of organic fertilizer can increase soil nutrients and promote crop growth.The paper takes the winter wheat farmland ecosystem as the research object,the field positioning experiment with the two-factor experimental design method were used to study the continuous 3-year no-tillage without fertilizer(NC),the traditional farming without fertilizer(TC),the traditional farming application of organic fertilizer(TF),No-tillage application of organic fertilizer(NF)four different treatments.The effects of four different treatments on soil physicochemical properties,soil biological characteristics,soil microbial structure,and winter wheat yield and their relationship with soil physicochemical and biological characteristics were studied.The results show:1.The total nitrogen,organic matter,alkali-hydrolysis nitrogen and available potassium of winter wheat farmland soil after 3 years of continuous no-tillage with residue mulch was slightly higher compared with the conventional tillage treatment,but there was no significant difference in soil total nitrogen and organic matter content among different treatments.Application of organic fertilizers has a tendency to lower the pH of the soil.2.No-tillage significantly affected the soil bulk density and field water holding capacity.With the increase of soil depth,the soil bulk density gradually increased and the soil water holding capacity decreased with no-tillage treatment.Compared with conventional tillage,the soil bulk density increased by an average of 0.1-0.13 g/cm3 in 0-20 cm soil layers,and the soil water holding capacity in 0-5 cm,5-10 cm,10-15 cm,and 15-20 cm soil layers were decreased 12.12-24.51%,9.65-13.37%,25.90-27.28%,16.86-18.12%,separately.3.No-tillage with residue mulch improves soil catalase activity.Traditional cultivation is benefit to the improvement of soil urease and alkaline phosphatase activity.4.Among the soil microbial populations,the biomass of bacteria,fungi,and actinomycetes marked by PLFA was higher under the conditions of TF.The biomass of bacteria,Gram-positive bacteria and Gram-negative bacteria was significantly higher under TF than NC.The application of organic manure significantly increased the biomass of soil microbial communities,bacteria had an dominant position in the composition of microbial communities.No-tillage with straw mulch is conducive to the transformation of soil to high-fertility "bacterial" soil types.Soil microbial community structure under different treatments is mainly affected by relevant soil factors.Among them,there was a significant negative correlation between soil pH and the biomass of soil bacteria,fungi,and actinomycetes.The biomass of AM fungi was significantly positively correlated with soil available P and available K.5.After 3 years of continuous no-tillage,the biomass of AM fungi in soil showed that NC were significantly higher than TC,NF was higher than NC.Soil arbuscular mycorrhizal fungi neutral lipid(NLFA)and total biomass showed a significant upward trend.No-tillage with straw mulch is beneficial to promote the growth and development of AM fungi.6.The application of organic fertilizers helps to increase the spore density of soil AM fungi.In the no-tillage with straw mulch,the spore density under the application of organic fertilizer increased by 7.63%compared to the non-fertilizer treatment.Under traditional tillage cultivation,the spore density under application of organic fertilizer increased by 22.34%compared to no fertilizer treatment Tillage and organic fertilizer application will affect the mycorrhizal infection rate of AM fungi.Compared with no-tillage with straw mulch,the mycorrhizal infection rate decreased by 24.22-24,93%after traditional tillage.7.The results of two-factors(tillage and mulch,fertilizer)random experimental design showed that the total glomalin content of the arbuscular mycorrhizal fungi and the content of glomeomycin easily extracted were not affected by the experimental factors.The ratio of easily extractable glomalin to soil organic carbon is 2.79%?3.01%.Total glomalin accounted for 12.35%to 14.69%of soil organic carbon.There was a significant positive correlation between soil total glomalin and soil organic carbon(P<0.05).There was a significant positive correlation between soil-extractable glomalin and soil available phosphorus(P<0.01).8.The results after three years of the fixed experiments showed that there was no significant difference in winter wheat economic yield between different treatments,but the winter wheat yield and aboveground biomass under conventional tillage increased by 11.77-34.96%and 13.24-36.13%,respectively,compared with no-tillage treatment.Compared with conventional tillage without fertilizer(TC),conventional tillage with fertilizer(TF)and no-tillage without fertilizer(NC),there was a significant difference in aboveground biomass between winter wheat.Cultivation management measures affect the accumulation and distribution of dry matter in the winter wheat field.9.There is a significant negative correlation between winter wheat yield and soil arbuscular mycorrhizal fungi.The winter wheat yield under different cultivation and management measures was positively correlated with soil organic matter and total phosphorus,and negatively correlated with soil available potassium and alkaline dissolved nitrogen,and negatively correlated with soil alkaline phosphatase,catalase,and urease.