Verification And Evaluation Of Biochar Combined With Different Fertilization Methods To Control Agricultural Non-point Source Pollution

China is a big agricultural country.With the geoponics rapid development,the use of chemical fertilizers has also increased year by year.However,the Excessive use of chemical fertilizers has a profound impact on the ecological environment,and the Agricultural non-point source pollution is very serious.Biochar is often used to control agricultural non-point source pollution due to its excellent adsorption properties.However,due to the different raw materials,production processes,and soils of biochar,the research results cannot be mutually verified,and the impact of biochar on crops,planting soil and many other factors needs to be considered at the same time,so that biochar can be used in agriculture.Controversy exists in the treatment of non-point source pollution.Based on the analytic hierarchy process,this study comprehensively evaluates the three aspects of biochar treatment of non-point source pollution in runoff water,soil and crops,and finally determines the effect of biochar in treating agricultural non-point source pollution,which is a technology for the prevention and control of non-point source pollution of biochar soil.Provide reference for promotion in Fuxian Lake Basin.This study mainly observed the adsorption effect of biochar on nitrogen,phosphorus and heavy metals in runoff water by applying biochar in combination with chemical fertilizers,biogas fertilizers and organic fertilizers.Comprehensive evaluation of biochar treatment of agricultural non-point source pollution.The main conclusions are as follows:（1）Biochar has a good adsorption effect on TN,TP,Cr,Zn,Cu,and Cd in runoff,among which the adsorption effect of TN and TP on chemical fertilizer treatment is the most significant,accounting for 25.8%and 18.3%,respectively;The effect of chemical fertilizer treatment on the adsorption of heavy metals in runoff water was the most significant,and the retention effects of Cr,Zn,Cu,and Cd were 17.5%,57.7%,27.5%,and 49.4%,respectively.Biochar can increase crop yield,among which biochar + biogas fertilizer treatment has the most significant yield improvement effect,which is 13.3%,and biochar can increase the nitrogen and phosphorus content in corn kernels and the morphological indicators of crops.The addition of biochar can increase the nitrogen and phosphorus content in the soil.The growth rates of nitrogen elements in the three groups of chemical fertilizers,biogas fertilizers and organic fertilizers are 24.6%,34.9% and 16.0%respectively,and the growth rates of phosphorus elements are 24.4% and 10.9%respectively.,27.5%;through the analysis of bulk density,porosity,specific gravity,CEC,and organic matter content in the soil,it shows that the addition of biochar has a beneficial effect on soil water retention and fertilizer retention.（2）The effect of biochar treatment on agricultural non-point source pollution was comprehensively evaluated by Analytic hierarchy process,The results showed that the comprehensive scores of chemical fertilizer,biogas fertilizer and organic fertilizer on agricultural non-point source pollution control were 0.990,1.098 and 1.125.After adding biochar,the comprehensive scores of agricultural non-point source pollution control effects were 1.202,1.255,and 1.227,respectively,indicating that the comprehensive benefits of biochar combined with different fertilization methods on agricultural non-point source pollution control were better than those without biochar.Among them,the addition of biochar has the most significant improvement effect on chemical fertilizer treatment.（3）Through the analysis of the economic benefits of the addition of biochar to the soil,the results show that,without affecting the interests of farmers,the application of biochar to the soil in the second planting season still has the effect of increasing production and controlling fertilizer,respectively.The chemical fertilizer input was reduced by 11.4% and the biogas fertilizer input was reduced by 20.1%,and the biochar still maintained a good adsorption effect on TN,TP,Cd,Zn,Cu,and Cr in the runoff water in the second planting season.