Reducing the impact of water repellence on crop productivity through soil wetter agents

Authors: Jack Desbiolles¹, Nigel Wilhelm², Melissa Fraser³, Lynne Macdonald⁴, Therese McBeath⁴, James Barr¹

¹University of South Australia, Mawson Lakes, SA, 5095; ²South Australian Research and Development Institute, Urrbrae, SA, 5064; ³Primary Industries and Regions South Australia, Struan, SA, 5271; ⁴CSIRO Agriculture & Food, Urrbrae, SA, 5064

Funded By: GRDC CSP00203

Project Title: Increasing production on sandy soils in low and medium rainfall areas of the Southern Region

Peer Review: Rodrigo Da Silva

Key Messages

• A soil wetter evaluation trial conducted over 2 years compared 13 different wetter treatments under inter-row sowing conditions.
• Six wetter treatments provided large crop establishment benefits over two years at the same site, while also producing up to 0.22 t/ha (Year 1, wheat) and 1.07 t/ha (Year 2, barley) extra grain yield.
• In 2019, an on-row sowing reference performed best, providing an extra 85 plants per m2 and 1.26t/ha grain yield over the inter-row sowing control. In comparison, the best soil wetter treatment achieved 66% and 85% of the on-row establishment and yield, respectively.
• Challenges remain in selecting wetting agents for a particular sand environment due to performance variability across water repellence contexts.