Effect of water regimes on sorptivity and organic matter humic components of soil

The aim of the study was to find the effect of water regimes on soil sorptivity and humic components of organic matter. Physicochemical parameters were also determined. Steady state cumulative infiltration was the highest (60-100 mm) in non-irrigated upland soil and the lowest (8-10 mm) in waterlogged soil. The highest sorptivity of 4.0-4.5 mm min-1/2 was found in non-irrigated upland soil and the lowest in seasonally waterlogged soil (1.0-1.5 mm min-1/2). Organic carbon content of all soils was low (<1%), EC values were also low (< 4 dS m-1). Saturated moisture was high in waterlogged soil. The non-irrigated upland soils had a higher fraction of fulvic acid (0.15-0.2%), due to which they were more capable of infiltration, whereas waterlogged soils had a greater fraction of insoluble humic acid (0.29-0.35%) and exhibited less cumulative infiltration. Sorptivity decreased as the clay content, pH, EC, porosity and humic acid content of the soil increased.