THE EFFECT OF INITIAL SOIL-WATER CONTENT AND TILLAGE IMPLEMENT ON SEEDBED FORMATION

This study was undertaken to determine the effect of initial soil water content and various tillage implements in producing a suitable seedbed tilth on a cracking clay soil (Entic Chromustert). The soil was tilled with one, two and three passes of a tined implement, a disc and a rotary hoe at three different initial soil water contents. Bulk density, aggregate size distribution and cone index were measured before and after tillage. Soil water content was measured before tillage only. Results tend to indicate that finer tilths were produced at drier initial soil water contents and with an increasing number of implement passes. Soil bulk density and cone index were reduced after tillage. Initial soil water content appears to be the controlling factor in producing a suitable seedbed tilth. All combinations of implement, number of passes and initial soil water contents appeared to produce reasonable seedbed tilths over the range of water contents examined.