Nitrogen mineralization potential in sludge amended soils

Abstract

An incubation study was done to study nitrogen mineralization potential of sludge amended soils. Three type of soils i.e. alluvial red and black soil wereused, sludges were mixed with soils at the rates of 0, 25 and 50 g sludge kg-1 soil (dry weights). It was observed that total mineralized nitrogen increased with increasing the period of incubation. The mineralized nitrogen content initially higher in black soil as compare to red and alluvial soil, but in latter stages the total mineralized nitrogen content is highest in alluvial soil. The mineraliseable nitrogen content increased with the increase in amount of sludge application. The mineralization of nitrogen was greatly affected by the soil type. In black soil i.e. high clay content soil having slow rate of mineralization which highest for alluvial soil and the rate is highest for alluvial soil and intermediate in red soil. First order model of kinetics of nitrogen mineralization was best suited for nitrogen mineralization. The estimated rate constant for black soil, red soil and alluvial soil was 0.42, 0.89, and 1.05 respectively having correlation coefficient (r2 ) 0.99.