Effect of organic manuring on the activities of the enzymes hydrolysing sucrose and urea and on soil aggregation

Abstract

The effect of organic manuring with farm-yard manure, maize stalk, and Pongamia cake (Pongamia glabra) at 1 per cent organic carbon level on the activities of the enzymes hydrolysing sucrose and urea, in relation to changes in soil microbial populations and on soil reaction and aggregation was investigated in a red sandy loam soil. Farm yard manuring did not alter the invertase activity to any appreciable extent; but both maize stalk and Pongamia cake enhanced the invertase activity of the soil significantly. While appreciable increase in urease activity was also observed due to the application of both maize stalk and Pongamia cake, the latter treatment maintained the soil urease activity at a higher level. No definite correlation could be observed between the changes in the microbial populations and the enzyme activities during the incubation period. The pH of the soil treated with Pongamia cake was considerably increased. Organic manuring significantly increased aggregation of soil particles and maximum soil aggregation was observed in the case of maize stalk application.