Cereal Responses to Ripping, Seeding and Nutrition Across the SA Mallee in 2019

Authors: Therese McBeath¹, Lynne Macdonald¹, Jack Desbiolles², Rick Llewellyn¹, Michael Moodie³, Bill Davoren¹, Willie Shoobridge¹

¹CSIRO Agriculture & Food Waite Campus, ²The University of South Australia, ³Mallee Sustainable Farming and Frontier Farming Systems

Funded By: GRDC CSP00203

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

Peer Review: Nigel Wilhelm, Rodrigo da Silva

Key Messages

• Soil strengths high enough to hurt crop performance are apparent at all our Mallee sandy sites, with non-wetting also occurring at some sites depending on season.
• The average gain from ripping across the Mallee has been 0.5 t/ha, but higher wheat yield gains of 0.75 and 1.3 t/ha depending on depth (40 cm, 60 cm) were demonstrated at Lowaldie in 2019.
• However, very dry years can also lead to yield penalties in years subsequent to ripping. Sand at Waikerie that was ripped in 2018 yielded 0.5 t/ha less than unripped soil in 2019.
• Deep tillage (20 cm) as part of the seeding pass improved crop yield in 2017 and 2018 but not in 2019 suggesting shallow ripping responses are quite sensitive to placement relative to previous rows.
• Permanent fertility strips, aiming to improve a narrow area of the furrow through targeted and repeated sowing with/without amendments (clay, organic matter, fertiliser), have not generated a significant yield advantage over a 3-year cycle.