Dry Soil Aggregation as Influenced by Crop and Tillage

Abstract

Soil loss by wind erosion is greater in the spring due to higher wind velocities, loss of protective crop residues by tillage and decomposition, and overwinter changes in nonerodible soil aggregates. This study was conducted to determine the effect of crop species and tillage on soil aggregation. Plots of continuous winter wheat (Triticum aestivum L.), grain sorghum (Sorghum bicolor L. Moench), and soybean (Glycine max L. Merr.) with tillage treatments of mechanical, chemical, and combination of mechanical and chemical weed control were sampled for aggregate distribution, stability, and overwinter breakdown.Winter wheat plots contained more nonerodible aggregates (> 0.84 mm), and the aggregates were more aggregates from sorghum or soybean plots. Soybean plots were lowest in all three variables measured. Tillage‐treatment effects varied, with the chemical‐treated plots containing the most nonerodible aggregates and the mechanical‐treated plots having the most stable aggregates.