Re-engineering soils to improve the access of crop root systems to water and nutrients stored in the subsoil.

Multiple interacting soil constraints are reducing Plant Available Water (PAW), grain production and long-term profitability of crops across most of the 12 M ha of sandplain soils in the medium-high rainfall zone (van Gool 2018) of the Western Region resulting in lost yields with an estimated value of $1.2 Billion per year (Peterson, 2016). Current soil amelioration options (liming, deep ripping, spading, mouldboard ploughing) address one or more constraints to a depth up to 40cm. The potential yield benefits of addressing multiple constraints through complete soil profile re-engineering to a depth of 80cm is unknown.

This investment aims to:

1. Identify the most profitable and long-lasting soil amelioration and amendment strategies for managing multiple interacting soil constraints.
2. Demonstrate the benefits of re-engineering the soil profile through a combination of deep soil loosening; reconstituting profile layers and deep placement of nutrients and soil amendments.