关键词: 鱼蛋白有机液肥, 小粉土, 酶活性, 微生物生物量碳、氮, 蚯蚓堆肥, 养分含量, 三维荧光光谱, 可溶性有机物, 荧光区域指数

Abstract: By the method of thermostatic culture, this paper studied the effects of different application rates (0.5, 1.5, and 2.5 ml·kg^-1) of organic fish protein liquid fertilizer on the enzyme activities and microbial biomass C and N in a silt soil, and the relationships between these parameters and soil nutrient contents. Under the application of the liquid fertilizer, soil pH varied in the range of 7.07-7.31, but had no significant difference from the control. With the increasing application rate of the liquid fertilizer, the activities of soil phosphatase, urease, and protease, as well as the soil biomass C and N, all increased significantly, and the increment was 127, 190 and 196%, 39.81, 78.06 and 173.24%, 56.37, 108.29 and 199.98%, 167, 395 and 474%, and 121, 243 and 406%, respectively, compared with the control. The peak time of the soil urease and protease activities and microbial biomass C and N differed with the fertilization treatments. Soil phosphase, urease, and protease activities and microbial biomass C and N were significantly positively correlated with soil nutrient contents, suggesting that applying organic fish protein liquid fertilizer to silt soil could improve soil microbial growth and enzyme activities, and accordingly, promote the decomposition and transformation of soil organic matter and the release of soil available nutrient elements.

Key words: organic fish protein liquid fertilizer, silt soil, enzyme activity, microbial biomass C and N, vermicomposting, nutrient content, 3DEEM, dissolved organic matter, fluorescence regional integration (FRI).