Effects Of Different Tillage Practices And Organic Materials Input On Soil Quality And Peanut Yield In A Continuous Cropping System

The field experiments were conducted at the Agricultural Experimental Station of Shandong Agricultural University in 2021.The peanut variety 604L-3 was used as the material and grown in a long-term continuous cropping farm.The treatments were arranged in a completely random design with three replications,including non-tillage treatment before winter fallow,and rotary tillage before peanut sowing（RT）;ploughing treatment before winter fallow,and rotary tillage before peanut sowing（PT）;GM management consisted of growing winter wheat after harvesting the peanut crop from the previous growing season and applying the wheat as green manure at the heading stage（GM）;corn straw biochar application treatment（BC）.We studied the effects of different tillage practices and organic materials input on soil physicochemical properties,soil microbial community structure and function,root morphology and dry matter accumulation,peanut yield and its constituent factors in a continuous cropping system.The results were expected to provide theoretical basis and technical guidance for solving the problem of continuous cropping obstacles in peanut production.The main results of the study were as follows:1.Effects of different tillage practices and organic materials input on soil physicochemical properties of continuous cropping peanutsCompared with RT treatments,PT,GM and BC treatments significantly reduced soil bulk density in the 0-30 cm soil layer of continuous cropping peanuts,and increased soil porosity and mass specific gravity of large aggregates（>2 mm）;PT and BC treatments significantly increased the water content of the 0-20 cm soil layer.Compared with RT treatment,the total nitrogen content of GM treatment in non-rhizosphere soil and rhizosphere soil was increased by 8.23% and 8.66%,respectively,during the full fruit period of peanut.The total nitrogen content in BC treatment increased by 7.90% and 7.02%,respectively.The total organic carbon content of non-rhizosphere soil and rhizosphere soil treated with GM increased by 9.89% and 13.55% at the flowering needle stage of peanut,respectively.The total organic carbon content of BC treatment increased by 9.79% and 24.50%,respectively.In addition,compared with RT treatment,GM and BC treatments increased the activities of urease and soil sucrase in the non-rhizosphere soil of peanut during the podding stage and full fruit stage,and in the rhizosphere soil at the full growth stage.The above research results showed that both GM and BC treatments could reduce soil compaction,increase soil enzyme activity,promote nutrient cycling of soil topsoil,and improve soil physicochemical properties.2.Effect of different tillage practices and organic materials input on soil microbial function and community diversityCompared with RT treatment,PT,GM and BC treatments significantly increased the species richness,evenness,diversity and relative abundance of Bacteroidetes,Chlorobacter,Acidobacteria,RB41 in bacterial communities,but significantly reduced the relative abundances of Armoriomycota,Planctomycetes and Bacillus phyla.Compared with RT treatment,PT treatment significantly increased the relative abundance of Basidiomycota and Cyanobacteria,but significantly decreased the relative abundance of Fusarium and Microsporum.GM treatment significantly increased the relative abundance of Ascomycota and Chaetomium,and decreased the relative abundance of Fusarium and Aspergillus.BC treatment significantly increased the relative abundances of Glomus and Mortierella,and significantly decreased the relative abundances of Fusarium,Microfusarium and Aspergillus.The similarities of bacterial and fungal community structures among the treatments were significant,and the soil microbial community of continuous cropping peanut was optimized.Compared with RT treatments,GM and BC could effectively improve the metabolic intensity of total carbon source utilization by soil microorganisms in continuous cropping peanut soil,and the utilization rate of carbon sources of carbohydrates,amino acids,carboxylic acids and polymers was significantly increased.3.Effects of different tillage practices and organic materials input on root growth of peanutCompared with RT treatment,PT treatment significantly increased the average root diameter of peanut at pod setting stage.GM treatment significantly increased the root length,root length density and root dry matter accumulation at peanut podding stage by 20.62%,21.96% and 6.51%,respectively.BC treatment increased the root length,root length density and root dry matter accumulation of peanut by 13.88%,14.06%and 23.23%,respectively.In addition,compared to the RT treatment,the accumulation of dry material in the ground stem and leaves of the plants treated with GM and BC increased by 25.69%,67.60% and 30.41%,78.04% at the peanut pod setting stage and full fruit stage,respectively.The above research results showed that both GM and BC treatments could accelerate the uptake of soil nutrients by roots,promote root morphogenesis and the growth and development of shoots and leaves above ground.4.Effects of different tillage practices and organic materials input on peanut yield and its constituent factorsCompared with RT treatment,PT treatment increased fruit weight;GM treatment increased kernel rate and fruit number per plant;BC treatment increased fruit weight and fruit number per plant.The peanut pod yields of GM and BC treatments increased by 29.85% and15.44%,respectively,and the seed kernel yields increased by 32.55% and 16.23%,and the straw pressing green treatment had the most significant increase in yield.Based on soil physical and chemical properties,soil structure and function of microbial community,morphological formation of roots and pod yield,straw pressing treatment can effectively alleviate the obstacle of continuous cropping and provide theoretical basis and technical guidance for the stable and efficient production of peanuts.