Assessing the hydrological characteristics of different biochar and its influence on soil water dynamic using the water vapor sorption isotherm (WSIs) method.

Abstract:

The aim to enhance soil productivity and ecosystem services by incorporating waste-derived material, e.g., biochar has been viewed as an ecological pathway toward sustainable food production. Here we test the hypothesis that the biochar amendment’s additional surface area increases the affinity of treated soil to both nutrients and water. We tested the wettability characteristics of various biochars derived from agricultural waste, using the water-vapor sorption isotherm (WSIs) method. The resulting water-retention characteristics were evaluated using film sorption theory and used to infer the wettable surface area of biochars. These results were further extended to infer the implication of biochar addition on moisture retention of soils at various mixing ratios. The results indicate that biochar related enhancement of water retention can play a significant role in countering moisture stress in drying coarse-textured soils. The effect of this elevated moisture retention in expanding the biologically active water potential range of soils will be discussed.