Korean Journal of Soil Science and FertilizerISSN:0367-6315(Print) 2288-2162(Online)한국토양비료학회

This study was conducted to evaluate the effect of application of various organic materials for long-term on the changes of soil chemical properties and the quality and productivity of watermelon growing in the plastic film house. Five treatments were established as follows: straw alone (RS1, RS2) or mixed with Protaetia brevitarsis larvae manure (PLM), rice hull biochar (RHB), and wood crumb (WC), respectively. The soil pH and organic matter content increased, and the EC (Electrical conductivity) decreased significantly in the first year and showed a stagnation period after second year. The available P₂O₅ content increased until the second year and then decreased. Exchangeable K increased to the third year and then decreased, and exchangeable Ca decreased to the second year. Exchangeable Mg did not change until the third year, but decreased in the fourth year. The watermelon weight was the heaviest in the RS2+PLM plot in the first year and RS2+RHB plot in the second year, but there was no difference in the plot section in the third and fourth years. The sugar content increased with the long-term application of organic materials. Therefore, mixed application of Protaetia brevitarsis larvae manure, rice hull biochar, and wood crumb with rice straw for more than three years, to grow watermelons organically in the plastic film house, is considered effective in improving the soil environment and the yield and quality of watermelons.