Effect Of Field-scale Based Biofertilizer On Soil Conservation In Agricultural Fields

Soil conservation on agricultural land is increasingly important in the context of global environmental protection and sustainable development.Biofertilizers are widely used,but field-scale empirical studies are still limited,with multiple types available in the market and lacking comprehensive analysis.Experimental studies at the field scale are needed to screen different fertilizers and compare them with traditional organic fertilizers to optimize farmland soil conservation strategies.In this study,an experimental site in Zhongxing Town,Chongming,Shanghai,was selected and a partial least squares structural equation model was constructed to quantitatively describe the response and transfer relationships of each factor.The results of the study were as follows:（1）The use of different types of biofertilizers significantly improved soil quality.the CBM and CM treatments reduced soil bulk density by 17.52%and 16.77%,while the OM treatment resulted in a 22.4%increase in soil bulk density.the CBM treatment significantly increased the p H of acidic soils and was able to increase the content of total and hydrolyzed nitrogen in the soil.the CM and BM treatments were able to increase the organic carbon and fast-acting potassium content in the soil.The BM and OM groups showed high species richness and Shannon index,and increased soil respiration rate.Soil quality composite index increased significantly after the application of biofertilizer,and the CBM treatment was the most effective.（2）Soil properties varied with different growth periods of maize,with the highest soil bulk(1.88 g·cm^-3)at the male extraction stage and the lowest(0.72 g·cm^-3)at the maturity stage,with an initial increase in porosity,the highest（34.98%）at the male extraction stage and a decrease at the filling stage.Application of compound microbial fertilizers increased soil Cr and Zn content,reduced other heavy metals and increased soil organic matter at the pulling stage.Soil fast-acting potassium increased at the male extraction stage and decreased slightly at the filling stage;the most effective phosphorus(37.74 mg·kg^-1)at the nodulation stage and the highest(65.47 mg·kg^-1)at the maturity stage;the highest total nitrogen（0.14%）at the male extraction stage.The highest colony abundance and Shannon index were observed at the nodulation stage,and the soil respiration rate decreased from the male extraction stage.（3）Soil quality is influenced by several factors and the observed variables reflect the role of potential factors.Among them,soil biology had the most significant positive effect on soil quality（β=0.691,P<0.001）,which verified the relationship between latent variables hypothesized by the study.This emphasizes the role of biofertilizers in improving soil quality and ecological conservation,especially the importance of soil biology.