EFFECT OF LIQUID BACTERIAL FERTILIZER PREPARED BY BIOGAS SLURRY FROM FOOD WASTE DIGESTING ON PHYSICAL AND CHEMICAL PROPERTIES OF FARMLAND SOIL

In order to study the effect of liquid microbial fertilizer prepared by digesting biogas slurry of food waste on soil physical and chemical properties, winter wheat and rice soils of typical crops in northern China were analyzed during a whole growth cycle of crops. The results showed that the liquid bacterial fertilizer prepared by digesting biogas slurry from food waste significantly increased the effective nitrogen and phosphorus contents in winter wheat and rice soil. The optimum application rate of liquid bacterial fertilizer for winter wheat soil was 500 L/mu (1 mu=666.67 m²). The effective phosphorus content in the soil increased to 94.00 mg/kg, and the maximum increase was 81.12%. The maximum available nitrogen content increased to 1673.00 mg/kg, with the maximum increase of 84.88%. The optimum application rate of liquid bacterial fertilizer for rice soil was 400 L/mu. The effective phosphorus content in the soil increased to 220.80 mg/kg, and the maximum increase was 137.22%. The maximum available nitrogen content increased to 1140.00 mg/kg, with the maximum increase of 127.07%. There was a slight accumulation of soluble total salt and Cl^- content in winter wheat and rice soils. Through RDA analysis, the total phosphorus, total nitrogen, Cl^-, etc., in winter wheat soil and rice soil were positively correlated with the dosage of liquid bacterial fertilizer. This result indicated that liquid bacterial fertilizer promoted the increase of nutrients. The application of liquid waste fertilizer prepared by digesting biogas slurry of food waste is of great significance in improving the organic components of crop soil and soil fertility.