A COMPARISON OF THE EFFECT OF CERTAIN CROPPING AND FERTILIZER AND MANURING PRACTICES ON SOIL AGGREGATION OF DUNMORE SILT LOAM

Abstract

The effect of crops, fertilizer and manure, and cropping systems on soil aggregation of a silt loam from long-time fertility expts. was investigated in the laboratory. A specially designed wet screening apparatus was used for measuring soil aggregation. The size distribution curve of the soil aggregates and "relative surface" gave a more complete picture of the aggregate condition of the soil than % soil aggregation. Soil aggregation is a dynamic process with large aggregates forming in the soil when it is allowed to remain in sod for several yrs. Some of the physicochemical changes accompanying the formation of large soil aggregates were indicated. Aggregation formation can be hastened by manuring or fertilizing the soil.