To assess amelioration options for water repellent sandplain soils.

These grower scale on-farm soil amelioration demonstrations have been managed by the growers according to standard practice. Both soil types are highly water repellent and in general the amelioration treatments have improved crop establishment, vigour and grain yield. Economic analysis indicates that the return on investment has been large as the benefits from the treatments have tended to last for at least 5-years or more at these sites. While it is possible to improve establishment, water and nutrient use efficiency and crop productivity using these techniques it is important to recognise that other constraints such as poor water and nutrient holding, soil acidity and compaction can still limit the yield potential of these soils and this needs to be considered when investing in amelioration. Liming to improve the soil pH and very deep ripping to remove compaction below 30-40 cm may well provide further yield gains beyond those achieved through amelioration of the top 10-30 cm only, and this may also help sustain the benefits of amelioration over a longer time.