Humic Acid as an Organic Biosurfactant in Amelioration of Physical Constraints of Sandy Soils

Soil productivity is often attributed to soil structure, as fertile soil with ideal soil structure and adequate moisture level is considered productive. Soil structure is a key factor that influences the movement and retention of water in the soil, the pattern of soil erosion, the formation of crusts, nutrient recycling, root penetration, and the productivity of crops. The present study aims to assess the biosurfactant property of humic acid (HA) in weakly structured sandy soil. An incubation study was carried out by soil application of different doses of HA viz;0, 2.5, 5, 10 and 15 kg ha-1 for 30 days at field capacity. Soil supplemented with 15 kg ha-1 HA was observed to have the highest percentage of water stable aggregates (WSA), water holding capacity (WHC), and porosity, and the lowest value for bulk density (BD), dispersion ratio (DR) and clay dispersion ratio (CDR). The study proves that applying HA at the aforementioned dosage can bring about a notable enhancement in the stability in poorly structured sandy soils. Such organic biomolecules capable enough to bring about consistent improvements to soil quality within a short period will be beneficial for alleviating major obstacles in sustainable agriculture.