Abstract: SUMMARY When the aggregates of fairly dry, medium-coarse soil were broken down and firmed over the seed by moderate or heavy pressure, slug damage was reduced. Coarse soil aggregates did not break down so well, particularly under heavy pressure; many seeds remained exposed and were damaged. The seed was also protected by deep planting, with the penalty of late emergence of the seedlings.

Abstract: SUMMARY Four different systems of tillage were compared in the semi-deciduous forest zone of Ghana on a sandy clay soil with a slope of 3·5%. The reduced system of tillage (plough-plant) caused the least compaction, maintained high porosity and, consequently, had the least soil and water losses. The next desirable tillage system was the conventional (plough-harrow-plant), followed by hand cultivation. The severe tillage caused the greatest compaction and had the highest amount of runoff and soil loss.

Abstract: The effect of initial profile water storage and soil compaction below the seed on the growth and the yield of dryland wheat in field experiments during two years was determined. Compaction reduced water use from deeper layers and decreased grain yield during both years. Compared with lower initial water storage, higher initial water storage in the profile resulted in more vigorous plants, deeper rooting, greater water use from lower soil layers and higher yields

Abstract: Plant growth possibly is reduced in soils which contract sufficiently with drying to compress or deform the roots. Small holes, which simulated root holes, were made in moist clods with a tapered awl. The hole diameter decreased as the moist clods dried. The amount the diameter decreased was significantly related to clay content and the difference between the dry- and moist-clod bulk densities but not to the sand content.