1. Temporal patterns of infiltration into a water repellent soil under field conditions Phil Ward, Margaret Roper, Ramona Jongepier and Shayne Micin April 28, 2014 PLANT INDUSTRY / SUSTAINABLE AGRICULTURE FLAGSHIP

2. Water repellency in south-western Australia Infiltration into water repellent soil| Phil Ward Hopetoun DAFWA: agric.wa.gov.au

3. Climate averages 1981-2010 Infiltration into water repellent soil| Phil Ward

4. Landscape Infiltration into water repellent soil| Phil Ward

5. Zero-till versus full cultivation Residue retained versus residue burnt 4 replicates Tillage and burning: 12 April 2011 and 15 April 2012 Seeding 21 April 2011 (canola), and 14 May 2012 (wheat) Plot size 12 m x 20 m Crops sown between rows of previous crop – 30 cm row spacing Measurements: Soil carbon and water repellency (MED) ~ 6 times per year Soil water content 0-12 cm ~ 6 times per year Soil water content at 5 cm, at 15-minute intervals, in two replicates. Trial details 2011 (canola) - 2012 (wheat) Infiltration into water repellent soil| Phil Ward 16 plots, commenced in 2008

6. TreatmentMED No-Till, residue retained1.5 Conventional cultivation, residue retained1.4 No-Till, residue burnt1.6 Conventional cultivation, residue burnt1.0 LSD0.3 Soil water repellency 0-5 cm – Feb 2013 at the conclusion of the experiment Infiltration into water repellent soil| Phil Ward

7. TDR, in crop row and inter-row positions Infiltration into water repellent soil| Phil Ward Residue burnt, soil cultivated Residue retained, zero-till

8. All the data... Infiltration into water repellent soil| Phil Ward Approx. crop lower limit Approx. drained upper limit

9. July 28, 2011 – rain on wet soil 7.8 mm Infiltration into water repellent soil| Phil Ward Approx. crop lower limit Total  S (mm) 7.3 7.1 6.1 6.2

10. June 7, 2012 – dry(ish) soil 7.0 mm Infiltration into water repellent soil| Phil Ward Total  S (mm) 6.0 2.2 4.9 4.5

11. October 2, 2011 – canola 11.2 mm Infiltration into water repellent soil| Phil Ward Total  S (mm) 9.3 6.4 5.8 4.7

12. September 27, 2012 – wheat 13.0 mm Infiltration into water repellent soil| Phil Ward Total  S (mm) 6.8 3.2 5.1 5.8

13. March 19, 2012 – rain on dry soil 7.2 mm Infiltration into water repellent soil| Phil Ward Total  S (mm) 8.1 4.1 7.9 4.3

14. On wet soils, residue and tillage treatments have little effect on patterns of infiltration. Infiltration into dry WR sand is affected in both timing and magnitude by previous soil disturbance and arrangement of vegetation Tillage destroys previous preferred pathways and can perturb infiltration patterns for at least 11 months. Accounting for rainfall can be used as a measure of field expression of water repellence Tillage in agricultural crop production should be carefully managed in water repellent sands. Conclusions Infiltration into water repellent soil| Phil Ward

15. Thank you PLANT INDUSTRY / SUSTAINABLE AGRICULTURE FLAGSHIP