Different Types Of Organic Materials Return Fields On The Quality Of Black Soil Fertility And Evaluation Research

Due to the long-term high-intensity utilization of black soil resources and unreasonable farming methods in Northeast China,the soil fertility and soil quality of black soil have been decreasing year by year,and reasonable organic fertilization measures can improve the soil fertility level and soil quality.Therefore,in this study,a multi-year localization experiment located in the central part of the black soil zone was used as a platform.Seven treatments were selected: no fertilizer(CK),chemical fertilizer alone(NPK),chemical fertilizer with corn straw(NPK+JG),chemical fertilizer with compost(NPK+DF),chemical fertilizer with cow manure(NPK+NF),chemical fertilizer with chicken manure(NPK+JF)and chemical fertilizer with pig manure(NPK+ZF),to study the changes in physical,chemical and biological indicators of the soil in the cultivated layer(0 ～ 20 cm)after the return of different types of organic materials to the field.We also calculated the soil quality index(SQI)for each treatment by combining principal component analysis with Norm value to calculate the minimum data set of evaluation indexes,to comprehensively evaluate and rank the soil quality of different types of organic materials returned to the field.The main results are as follows:1.Fertilizer with organic material can effectively reduce soil bulk,increase the water content of the soil,increasing water stable macroaggregate content,average mean weight diameter and geometric mean diameter,and reducing microaggregate content.Among them,chemical fertilizer with compost treatment is the best for improving the physical properties of the soil.Compared with the treatment of single fertilizers,the soil bulk of chemical fertilizer with compost treatment in 2021 and 2022 decreased by 7.9% and 8.2%,respectively,and the water content increased by 18.3% and 7.2%,respectively.2.Fertilizer with organic material can increase soil p H and soil cation exchange capacity,Compared with the treatment of single fertilizers,the chemical fertilizer with chicken manure treatment in 2021 and 2022 was the best effect on increasing soil p H and soil cation exchange capacity,15% and 20.1% in 2021 and 13.9% and 13.7% in 2022,respectively.Fertilizer with organic material can also improve soil organic matter content and soil ammonium nitrogen and nitrate nitrogen content,increase soil total and available nutrient content.Among them,chemical fertilizer with compost treatment,chemical fertilizer with pig manure treatment and chemical fertilizer with chicken manure treatment improved soil chemical properties the best.3.Fertilizer with organic material can improve the soil microbial biomass carbon and nitrogen content,where chemical fertilizer with pig manure treatment improves the best effect and chemical fertilizer with compost treatment has good effect.4.The minimum data set for soil quality evaluation in this study is composed of four indicators: soil p H,organic matter,total phosphorus and available phosphorus.Based on the two year data,the soil quality index of each treatment is as follows: NPK+ZF(0.84)>NPK+JF(0.75)> NPK+NF(0.59)> NPK+DF(0.54)> NPK+JG(0.41)> NPK(0.30)> CK(0.15),it shows that the highest level of soil quality for chemical fertilizer with pig manure treatment is the highest in the soil quality,and the best effect of improving soil fertility.It shows that chemical fertilizer with organic material is an effective way to improve the comprehensive quality of black soil in Northeast China.