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

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

Please note: This content may be out of date and is currently under review.

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.

Knife points on plot seeder

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

Assess the effectiveness of wetting agents when banded with the seed compared to banded on the furrow surface.
Assess the effectiveness of soil wetting agents applied in formulations with UAN.
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

Topics