EFFECT OF UNCONVENTIONAL SOIL CONDITIONERS ON SOIL PHYSICOCHEMCAL PROPERTIES

ABSTRACT The application of unconventional soil conditioners such as biochar and humic acids has emerged as an effective strategy to improve soil physical and chemical properties, thereby enhancing soil quality and productivity. This study investigated the effects of biochar and humic acids, applied singly and in combination, on selected physical and chemical properties of agricultural soils. The experimental treatments included control (no amendment), biochar, humic acids, and a biochar–humic acid mixture, applied at varying rates. Results revealed that bulk density (BD) significantly decreased from in treated soils, while total porosity (TP) under treatment, reflecting improvements in soil structure and aeration. Chemical properties also showed marked improvements. Exchangeable bases (Ca2+, Mg2+, K+, Na+) increased significantly across treatments. Effective cation exchange capacity (ECEC) and organic carbon (OC) also improved, while exchangeable acidity declined, suggesting reduced soil acidity and better nutrient retention. Moreover, available phosphorus increased, indicating that biochar and humic acids enhanced P availability by reducing Al and Fe fixation and promoting nutrient mobilization. The combined application of biochar and humic acids proved effective, reflecting a synergistic effect in improving soil structure, increasing nutrient availability, and reducing acidity. These findings highlight the potential of unconventional soil conditioners as sustainable alternatives to conventional amendments such as lime and gypsum, offering long-term benefits for soil fertility restoration and sustainable crop production.