Improvements in aggregation and infiltration characteristics of a krasnozem under maize with direct drill and stubble retention

Abstract

Maize was grown for 6 years in a 7-year trial at Kairi, on the Atherton Tableland, North Queensland. Conventional tillage, direct drilling and reduced tillage were compared and each tillage practice was imposed with and without stubble retention. Direct drilling and stubble retention were found to have significant positive effects on aggregate water stability, water-stable aggregation under rain, dry aggregate size distribution and resistance to abrasion. Effects on infiltration were not significant, although cumulative infiltration (using the rainfall simulator) was higher for direct drilling and reduced tillage with stubble retention. Significant differences were found between row and inter-row for all measurements that enabled this comparison.