Tillage-Induced Soil Aggregate Status as Influenced by Water Content

An experiment was conducted on Kimo silty clay loam and Eudora silt loam soils to determine water content effects on aggregate size distribution. Five water contents were investigated. Both soils were packed, irrigated, and chiselled at initial high water contents to create a uniform initial condition with large aggregates, and disk tillage performed at selected soil water contents as the plots dried naturally. Maximum aggregate breakdown and the resulting minimum tillage-induced aggregate size distribution occurred near the optimum water content for compaction of both soils. Soil water content at the time of disk tillage had a significant effect on tillage-induced soil aggregate size distribution for the silty clay loam soil. The same relationship was evident for the silty loam soil but was not statistically significant.