Modification of the cracking pattern on a black earth of the Darling Downs, Queensland.

Abstract

A technique involving missed row planting was applied to field wheat crops in an attempt to improve the water intake capacity of the natural pattern of cracking. Where moisture storage at planting was high, the cracking pattern at harvest differed markedly from that occurring under block planting. Gross cracks in excess of the largest occurring normally occupied up to 20% of the original width of the bare area, and extended almost the entire length of areas treated. The cracking pattern in adjacent areas was substantially modified, the effect decreasing with distance from the major cracks. Where moisture storage at planting was low, no satisfactory pattern of cracking could be induced. An assessment was made of factors leading to the development of large induced cracks and of factors which may affect their ultimate size.