EFFECT OF MOISTURE INCUBATION AND MANURE APPLICATIONS ON MECHANISM OF SOIL AGGREGATES STABILITY

Abstract

A research was conducted on a clay loam soil, to study the interactions of various parameters on soil aggregates stability. Typic Torrifuvent natural aggregates of topsoil were sieved throughout 8 mm sieve, mixed with three levels of manure material and incubated for three intervals under three levels of soil moisture content. The changes in aggregates stability at the end of each incubation period (7, 30 and 60 days) were determined by wet sieving method. Moisture incubation treatments with manure applications gave larger proportions of stable aggregates than that without manure applications. Under dry incubation, the type of manure added had little effect on soil stability. With saturation incubation, the manure applications revealed lower increase in proportions stability than did with other moisture treatments. Interaction effects between incubation, moisture and manure application treatments were significant. Soil aggregates with moisture or with manure become more stable under incubation intervals than controls, which may indicate differences in the binding mechanisms of the soil particles. The changes in stability of soil moisture treatments suggested mechanical and physical rather than microbiological effects.