Effect of vermicompost with inoculated biochar on Carbon and Nitrogen mineralization in Ultisols and Alfisols.

Abstract

Abstract— Organic amendments provide good nutritional input to the soil by maintaining environmental sustainability. Availability of nutrients are less due to soil salinization and acidity in Alfisols and Ultisols, respectively.Therefore, this study aims to assess the effect of vermicompost, biochar and biodynamic formulated biochar on C and N mineralization in Alfisols and Ultisols,the main soil types that cover land area in Sri Lanka. Vermicompost and biochar with and without biodynamic formulation were applied to soil types separately according to the specific rates. After incorporating the amendments, pH, EC, nitrate-N, ammonium-N and CO2 evolution were determined up to 63 days. Statistical analysis was done using SAS software. According to the results, the pH of Ultisols with inoculated biochar shows a lowering at the initial stage, however it was not significantly different with the control. Inoculated and non- inoculated biochar with vermicompost in Alfisols decreased the EC significantly (p<0.05) in later stages reducing the salinity compared to the control. In Ultisols and Alfisols, nitrate-N increased significantly (p<0.05) in both treatments. The evolved CO2 is significantly high (p<0.05) in microbial inoculated soil treatments when compared to non-microbial inoculated soil treatments in both soil types. It can be concluded that the N and C mineralization pattern varied among the treatment in Ultisols and Alfisols and the biodynamic formulated biochar with vermicompost showed an impact on mineralization. Soil amendments have both long term and short term effects. Therefore, it is recommended to do further studies to evaluate the long term effect of organic amendments.