[Effects of Biochar Input on Changes of Available Nutrient Elements in Riparian Soils with Different Landuse Types]

Biochar, as a new environmentally friendly material, has been used to improve soil quality and for pollution remediation. Biochar input has a significant impact on available nutrients in the soil. Based on the different land use types (forestland, grassland, cultivated land, and barren land) in the riparian zone of Taihu Lake, the effects of biochar application on the available content of nutrients in different land use types of soil were compared, and the dynamics of nutrient change was also discussed. Results show that the addition of biochar can significantly affect the available nutrient content in riparian soil, however the influential degrees for carbon, nitrogen, and phosphorus were different. After the input of biochar, dissolved organic carbon in riparian soils showed a clear downward trend, while the available nitrogen increased slightly, and the available phosphorus increased significantly. For woodland, grassland, arable land and wasteland soils, the contents of dissolved organic carbon decreased by 33.3%, 27.4%, 29.5%, and 51.4%, while the contents of available nitrogen increased by 10.8%, 18.2%, 16.4%, and 15.2%, and the contents of available phosphorus increased by 40.0%, 50.2%, 34.0%, and 43.6%, respectively. Compared with the concentrations between the control group soil (CK) and the biochar additive group soil (BC), the concentrations of dissolved organic carbon and available phosphorus exhibited large differences between the two groups regarding available nitrogen concentrations. Among the four types of riparian soils, the effects of biochar on the availability of different nutrients were different.