[Effect and Approach of Biochar to Improve Coastal Saline Soil].

The use of biochar to improve adversity of soil has received increasing attention. biochar is used to repair coastal saline-alkali soil, which can not only utilize but can also increase the scale of the coastal land reserve. In this study, the method of soil culture experiments was used to explore the effect and pathway of 0%-3% addition of on the improvement of saline-alkali soil. The results showed that the optimum preparation temperature of biochar suitable for saline-alkali soil improvement was 400℃, and the optimum addition amount was 1.5%. At the optimum level, although the biochar had a negative effect, such as increasing soil salinity (0.12%) and pH (1.49%), it also produced positive effects, such as reducing soil Na/K by 55.73%, increasing mineral content, and improving water conductivity. biochar improved soil physicochemical and biological properties, increased nutrient content, enhanced microbial activity, improved soil nutrient availability, and produced positive effects. These positive effects were characterized by reducing soil bulk density by 11.35%, increasing organic matter by 42.64%, increasing the proportion of organic carbon in total carbon by 3.84 times, increasing the proportion of available phosphorus in total phosphorus by 4.15 times, and increasing soil invertase activity by 2.39 times, urease activity by 1.18 times, and catalase activity 1.50 times. Therefore, the positive effect of biochar on saline-alkali soil is more than negative, and it can be used for the improvement of coastal saline-alkali soil. This study provides a new path for the resource utilization of and the improvement of the ecological environment of coastal saline-alkali soil.