Assessing options for managing water repellent gravel soils 2015 trial report

Page last updated: Friday, 21 October 2016 - 1:16pm

Please note: This content may be out of date and is currently under review.

On water-repellent loamy gravels (forest gravels) banded soil wetting agents and one-off deep tillage can significantly improve crop establishment, growth and grain yield.

Strategic (one-off) deep tillage using a modified one way plough reduced topsoil water repellence and improved crop establishment and yield.

Strategic deep tillage provides an opportunity to incorporate lime or other soil amendments and can improve nutrient availability and uptake.


Numerous options exist for managing soil water repellence on deep sands including improved furrow sowing methods, strategic deep tillage and clay spreading or delving. For the water repellent gravel soils it is less clear which options are consistently effective and some of the existing options may not be appropriate.


To determine which management options can successfully overcome soil water repellence and improve crop yields on water repellent forest gravel soils.

Trial details

Table 1 Trial details
Property Upwood, north Kojonup
Soil type Loamy forest gravel
Crop/variety Hindmarsh barley
Paddock rotation 2014 - canola, 2013 - barley


1) Control – untreated (off-row sown from 2016)

2) On-row seeding (from 2016)

3) Wetter banded on furrow at 2L/ha (on-row sown from 2016)

4) Wetter banded on furrow at 2L/ha (off-row sown from 2016)

5) Wetter banded with seed at 2L/ha

6) Blanket wetter (applied every second year)

7) One-way disc ploughing – with pre-emergent herbicide

8) One-way disc ploughing – no pre-emergent herbicide

9) Mouldboard ploughing – with pre-emergent herbicide

10) Mouldboard ploughing – no pre-emergent herbicide

Replicates Three
Sowing date >4 May 2015
Seeding rate 100kg/ha
Fertiliser (kg/ha) Pre-emergent: 100kg/ha Urea; 120kg/ha Gusto Gold
Post-emergent: 50L/ha UAN
Growing season rainfall April – October: 251mm
Herbicide Pre-emergent: 1.8L/ha Glyphosate; 2L/ha Trifluralin (excluding selected plough treatments)
Post-emergent: 670mL/ha Velocity; 300mL/ha Axial
Insecticide Pre-emergent: 500mL/ha Chlorpyrifos; 200mL/ha Bifenthrin
Post-emergent: 100mL/ha Transform

Assessing options for managing water repellent gravel soils 2015 trial report


Stephen Davies
Glenn McDonald
Chad Reynolds