Abstract: The effects of different biogas slurry dosages（0, 75, 150, 225, 300 m³/hm²）and chemical fertilizer（conventional and halved）on rice growth and soil nutrients were studied through field experiments for two consecutive years. The results showed that the rice yield was the highest when the amount of biogas slurry was 150 m³/hm²+halved chemical fertilizer, and compared with the conventional pure chemical fertilizer treatment, the rice yield increased by 2.13% and 5.79% in the first and second years respectively. The biomass of rice stems and leaves was the highest when the amount of biogas slurry was 150 m³/hm² + conventional chemical fertilizer. When the amount of biogas slurry exceeded 225 m³/hm², the yield, plant height and biomass of rice stem and leaves decreased. The application of biogas slurry increased the nutrient content of soil, which increased with the increase of application amount. At the same application amount of chemical fertilizer, the content of soil organic matter increased by 8.93%~30.04%, the content of alkali hydrolyzable nitrogen increased by 4.36%~39.90%, the content of available phosphorus increased by 14.86%~39.89%, and the content of available potassium increased by 9.17%~41.25%. Biogas slurry application had no significant effect on soil pH but increased soil EC value; however, soil EC value did not increase in the second year of the same treatment. In conclusion, in this experiment, the amount of biogas slurry 150 m³/hm² and halved conventional chemical fertilizer is is the best fertilization treatment.

Key words: biogas slurry, rice, soil, yield