Effect of soil organic carbon on unsaturated earth properties

Soil organic carbon (SOC) is a multifaceted and assorted combination of constituents. Due to anthropogenic actions, the earth’s SOC is lost, thus affecting soils various properties. The column and channel studies were conducted to evaluate the effect on the unsaturated earth properties by artificially entailing SOC using organic-based (natural/industrial) wastes. Natural decayed plant/ animal remains known as humus; industrial wastes like press mud, bagasse ash, and fly ash were used as the source of SOC to amend with four soils i.e. black cotton (BC), red, marshy and mountainous. Tests were designed based on response surface methodology through central composite rotatable design for five properties defined by the author as “Soil hydraulic property”—representing the effect of SOC on water holding capacity and hydraulic conductivity; “Soil perviousness property”-representing the effect of SOC on infiltration and porosity; “Soil aggregation property”—representing the effect of SOC on plasticity index and bulk density; “Soil and water conservation property”—representing the effect of SOC on erosion and runoff; “Soil stability property”—representing the effect of SOC on shrinkage limit and friability index. The developed, empirical models correlated humus for BC soil, bagasse ash for marshy soil, fly ash for red and mountainous soils, as the best soil-amendment combinations. Drained water quality was analyzed and the obtained results were within the tolerance limits, implying no harm to the quality of water seeping through amended earth.