Effects of leonardite on the coastal saline soil improvement

This study investigated the influence of leonardite on coastal saline soil YX1 (very slightly saline), YX2 (slightly saline) and YX3(strongly saline) with 0/10/30/50 g/kg addition dosage during the 81-day incubation. Changes of pH, electrical conductivity, soil texture, micromorphology, functional groups and mineral constituents of soil were discussed. Results showed that the application of leonardite enhanced the urea hydrolysis, increased the activities of urease and phosphatase in the coastal saline soil. The urease and phosphatase activity reached the maximum on the 8th incubation day. Leonardite raised C and N content in the soil colloid as well as the C/N value. However, leonardite had limited effects on the soil texture and mineral components during the incubation period. The application of leonardite would promote the activity of soil micro-organisms and relative enzyme to improve the soil ecosystem. It could benefit the amelioration of coastal saline soil, and provide the theoretical direction for agricultural production.