Effects Of Drainage Sludge Organic Fertilizer Forestland Utilization On Soil In Beijing Municipality

In order to explore the application effect of urban drainage sludge organic fertilizer in sandy soil of Beijing Plain and provide theoretical reference for the utilization of urban drainage sludge in agriculture and forestry,this study selected nursery land and plain ecological forest land as the test site,selected the urban drainage sludge organic fertilizer made by high temperature hot water hydrolysis-anaerobic digestion technology as the test material,and explored the changes of soil physical and chemical properties,soil microbial community structure and soil heavy metal content in two test sites under different fertilization methods and different fertilization rates.The results showed that the suitable amount of municipal sludge organic fertilizer could improve the physical and chemical properties of soil,increase the nutrient content of soil and enhance the microorganism in soil The content and microbial diversity,and will not cause heavy metal pollution in soil,but the effect of different fertilization methods is also different,and too high fertilization amount still has a certain negative impact on soil conductivity,soil microbes,etc.The main conclusions obtained are as follows:(1)The application of suitable amount of municipal drainage sludge organic fertilizer can reduce the soil bulk density,increase the soil porosity and increase the maximum soil water holding capacity in the sandy land of Beijing Plain.(2)The soil organic matter,available potassium and alkali-hydrolyzed nitrogen content can be increased by applying suitable amount of municipal drainage sludge organic fertilizer.The effect was most obvious when applying fertilizer in 6kg/m2 and 9kg/m2,and the effect was most obvious when applying fertilizer 75kg/ plants.(3)Using principal component analysis,we preliminarily determined the amount of urban drainage sludge organic fertilizer applied to improve the soil quality of nursery soil and plain ecological forest:nursery soil :9 kg/m2;plain ecological forest soil :75 kg/ plants.(4)The application of municipal drainage sludge organic fertilizer can increase the number of microorganisms and the diversity of microbial species and structure in the sandy soil of Beijing Plain.There was little effect on the soil microbial quantity of nursery,but the fertilization amount of 9 kg/m2 could increase the microbial species and structure diversity of soil layer 0-20 cm microbial species and structural diversity increased significantly.(5)The application of suitable amount of municipal drainage sludge organic fertilizer will not cause heavy metal pollution in soil.The contents of copper,zinc,nickel,cadmium,chromium,lead,mercury and arsenic in nursery soil were lower than the soil risk screening value under each fertilization amount,and the cadmium content in plain ecological forest soil exceeded the soil risk screening value when no fertilization was applied,which was lower than the soil risk screening value after fertilization.in the short term will not cause the ecological risk of heavy metal pollution.