Changes in the structure of differently tilled soil in a growing season

Changes in the structure of tilled soil over a growing season were investigated. Structural data from ten differently tilled plots were collected at the 40–50 mm depth on sectioned tilth block samples impregnated with paraffin wax. At the end of the growing season, significant increases in clod size and decreases in void size were observed. In some plots also a significant reduction in percentage of small (1–5 mm) aggregates was observed, but a crop cover (barley) increased the percentage of small aggregates.