Properties of Biochar with Different Raw Materials and Carbonization Conditions and the Effect of Its Application on the Growth of Salt-tolerant Crop in Saline Soil

Abstract

In this study, biochar was made from three different raw materials (rice husk, rice straw, and bagasse) at different pyrolysis temperatures and time, and its properties and effect of biochar on the growth of salt-tolerant crop (Sesbania cannabina) when applied to saline soil (EC_e = 0 dS/m, 4.0 dS/m, 8.0 dS/m) were determined. Pyrolysis temperatures of 250°C to 300°C were suitable for carbonization, and yields (ratio of mass after carbonization to mass before carbonization) decreased with increasing pyrolysis time. The content of water-soluble ions tended to increase with higher temperatures and longer time. In the Sesbania cannabina cultivation test, rice husk biochar and rice straw biochar application significantly increased dry matter weight compared to the control and bagasse biochar application at a soil salinity of EC_e = 8.0 dS/m. The cultivation tests using rice husk biochar and rice straw biochar prepared under different carbonization conditions showed no significant differences in dry matter weight, suggesting that the application of biochar using a simple method, in which the material is packed in a pail and heated from the outside by a fire, is the most suitable for Sesbania cannabina cultivation in saline soils.