Managing alkaline dispersive subsoil for improving farming productivity

Abstract

Key findings • Crop residue deep placement in combination with chemical fertilisers and a low rate of gypsum demonstrated consistent yield improvement (27%; averaged for four successive years) in alkaline dispersive subsoil. • Organic and inorganic amendment deep placement increased root growth, and soil water use from the deeper clay layers during the critical reproductive stages of crop development. • Improvements in grain yield with organic and inorganic amendment deep placement were associated with a reduction in subsoil pH, exchangeable sodium percentage (ESP%) and increased microbial activity, which promoted soil aggregation.