Soil wetting agents for water repellent forest gravel soils 2015 trial report

Page last updated: Friday, 21 October 2016 - 1:06pm

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Banding soil wetting agents with the seed can improve establishment on water repellent soils often having the same effect as seed placement on the furrow surface.

Some soil wetting agents are compatible with UAN, fungicides and other liquid applications and can be applied through existing liquid in-furrow banding systems. These soil wetting agents may be useful as a carrier for liquid nutrients.

Banded wetters seem particularly beneficial on water repellent loamy gravels with substantial increases in grain yield in the 2015 season.

Background

Banded soil wetting agents have been typically applied in a continuous stream on top of the furrow following the press wheels to improve the consistency of soil wetting in the furrow and improve crop establishment on water repellent soils. There is some evidence that banding soil wetters near the seed can also be effective at improving establishment. Some recent soil wetters are compatible in formulations with UAN and may improve plant access to nutrients. In 2015 a number of trials were established to assess the impact of these developments on crop establishment and yield for crops growing on repellent soils.

Aims

  1. Assess the effectiveness of wetting agents when banded with the seed compared to banded on the furrow surface.
  2. Assess the effectiveness of soil wetting agents applied in formulations with UAN.
  3. Assess the effectiveness of soil wetting agents on water repellent forest gravels.

Trial details

Table 1 Trial details
Property Fairbanks, South Kojonup
Soil type Loamy forest gravel
Growing season rainfall April – October: 292mm
Table 2 Summary of seeding details, soil water repellence rating and treatments applied for three trials

Variety, rate and sowing date

Treatments Topsoil (0-5cm) water repellence MED Topsoil (0-5cm) water repellence rating
Hyola 525 RT canola, 2.5kg/ha, 5 May

Experiment 1:
1) Water only banded on furrow or with seed
2) Wetter 1: penetrant banded on furrow or with seed
3) Wetter 2: penetrant and absorber banded on furrow or with seed
4) Wetter 3: penetrant and absorber banded on furrow or with seed

All wetters banded at 2L/ha

3.2 Very severe
Bass barley, 110kg/ha,13-14 May

Experiment 2:

1) Control (nil banding)
2) Water only banded on furrow
3) Wetter 1: penetrant and absorber banded on furrow at 1 or 2L/ha
4) Wetter 2: penetrant banded on furrow at 1 or 2L/ha
5) Wetter 3: absorber and penetrant banded on furrow at 1 or 2L/ha
6) Wetter 4: penetrant and absorber banded on furrow at 1 or 2L/ha

4.1 Very severe
Bass barley 110kg/ha, 13-14 May

Experiment 3:

1) Control: water banded on furrow or with seed
2) UAN banded on furrow or with seed
3) Wetter 1 banded on furrow or with seed
4) Wetter 1 + UAN banded on furrow or with seed
5) Wetter 2 banded on furrow or with seed
6) Wetter 2 + UAN banded on furrow or with seed

4.0 Very severe
Table 3 Summary of fertiliser and pesticide applications for the soil wetting agent trials
Fertiliser, herbicide, or pesticide application Canola pre-emergent Canola (experiment 1) post-emergent Barley (experiments 2 and 3) pre-emergent Barley (experiments 2 and 3) post-emergent
Fertiliser 100kg/ha urea + 120kg/ha Gusto Gold 20L/ha UAN + 50L/ha UAN 65kg/ha Urea + 100kg/ha Gusto Gold

 

50L/ha UAN + 40L/ha UAN

 

Herbicide 1.5L/ha Sprayseed + 1L/ha Propyzamide 900g/ha Roundup Dry + 1.5kg/ha Atrazine + 900g/ha Roundup Dry 1.5L/ha Avadex + 3g/ha Ally + 2L/ha Sprayseed + 2.5L/ha Trifluralin

 

1L/ha Velocity
Insecticide 0.5L/ha Chlorpyrifos + 0.2L/ha Bifenthrin 0.1L/ha Transform 1L/ha Chlorpyrifos + 0.3L/ha Bifenthrin 0.5L/ha Chlorpyrifos
Fungicide None None None 0.3L/ha Prosaro

Contact information

Authors

Stephen Davies
Glenn Mcdonald
Chad Reynolds