Some effects of cover, seed size, and soil moisture status on establishment of seedlings by direct drilling

Abstract

The amount and nature of cover over seeds direct drilled into dead turf depends on the shape of the furrow openers or coulters, as well as the covering device. In a field experiment sown with hoe coulters the importance of bar harrowing to cover large seeds, such as maize and barley, was demonstrated in terms of seedling emergence, but little or no advantage was apparent from harrowing smaller, lucerne seeds. Coulters and covering devices were laboratory tested under continuous soil moisture stress using a tillage bin technique. This confirmed the advantage of bar harrowing after passage of both the hoe coulters and experimental chisel coulters.