Techniques for improving establishment of maize and soybean on cracking clay soils in the Burdekin River Irrigation Area

Abstract

Emergence of irrigated row crops is a problem on heavy clay soils in the Burdekin River Irrigation Area (BRIA). Two field trials were conducted on laser levelled land to examine the effects of sowing into ridges and beds, using before and after sowing irrigation and different opener-press wheel combinations on the emergence of maize and soybean. There was no difference between beds and ridges on establishment of both crops. Establishment of maize was a mean of 63.4% and soybean was a mean of 35.4% across all treatments. After sowing irrigation was superior to before sowing irrigation for the establishment of both maize and soybeans. Maize gave 76.5% and 50.2% for after sowing and before sowing irrigations, and soybean 45.2% and 25.5% respectively. The results suggest that the best option for improving maize and soybean establishment on the heavy clay soils of the BRIA is to use after sowing irrigation with spear point-split steel press wheels on laser levelled ground with a well aggregated seedbed consisting of less than 10% fine (<1 mm) material.