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IRRIGATOR Banding Soil Wetter

IRRIGATOR Banding Soil Wetter  IRRIGATOR Label
 IRRIGATOR MSDS

IRRIGATOR is a specialty soil wetting agent for hydrophobic soils. The problem of water repellent soils is well known in Australia and particularly in Western Australia. Despite this, limited focus has been placed on finding a solution until recently. The use of furrow sowing techniques in combination with surfactants has been trialled for many years in the Western Australian wheat belt to improve crop and pasture germination. However yields have often fallen despite dramatic increases in the number of seeds germinated.

Seeding Conditions Application Rate Water Rate

No till furrow seeding with press wheels
at 9-12 inches
(25-30cm) spacing

1-3 L/ha
15-30L/ha

SACOA's partners have investigated a range of formulations to optimise yields and solve this issue. The result of this research is IRRIGATOR.

The Issue of Hydrophobic Soils

Surfactants Overview

Advantages Over Traditional Wetters

How IRRIGATOR Works

Trial Results

How to apply IRRIGATOR


The Issue of Hydrophobic Soils

Water repellent soils are poorly penetrated by opening autumn rains in Mediterranean climates such as in the WA wheat belt.

The causes:

  • Hydrophobic organic waxes coat soil particles eg, from legume production;
  • Low soil clay content (< 5%); Past native vegetation;
  • Soil types with a high percentage of very fine soil particles ie, have an increased surface area.

Effects on crop establishment:

  • Staggered germination;
  • Poor crop and pasture seed germination;
  • Diversional flow of fertiliser and herbicides.

Potential solutions:

  • Claying provides an adequate long term solution but is slow and costly;
  • Furrow sowing assists in water harvesting;
  • Addition of soil wetting agents such as SACOA's IRRIGATOR

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An Overview of Surfactants and Band Spraying

The advantages of choosing the right surfactant for the right conditions include:

  • Certain soil surfactants can help overcome hydrophobic soils.
  • They can provide increased initial wetting and re-wetting.
  • Improvement of crop establishment.
  • Reduced evaporation.

Some Wetters Are Too Persistent In The Soil

Problems relating to persistence exist with some surfactant types, so always use sufficiently degradable products. One example is the horticultural style soil wetters that can be excessively persistent for broadacre applications.

Extended persistence in the soil can cause water to leach soluble nutrients, longer-term yield reductions and reduction in micro herds (ie, beneficial soil microbes).

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IRRIGATOR's Advantages Over Traditional Soil Wetters

IRRIGATOR offers a number of advantages over other soil wetters. These include:

  • Higher degradability than current soil wetters.
  • Minimal leaching risk.
  • Easier application, minimum water rates required – 15 – 50L/ha.
  • Compatibility with certain nutrients such as trace elements and other crop protection products (NOTE: IRRIGATOR is not compatible with liquid urea eg, Flexi-N).
  • Future potential: Investigation work is ongoing with other crop protection products including fertilisers, trace elements, biopesticides and fungicides.
Fig 1. In-furrow application of IRRIGATOR

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How IRRIGATOR Works

The application of IRRIGATOR involves minimal soil disturbance with precision sowing and spraying and it works from germination through to crop establishment. This process is illustrated in the diagram below.

                    

    

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Trial Results

IRRIGATOR has been trialled for over 10 years, and there have been good and consistent results shown across WA. Below are a few trials done over this period of time :

Frankland

Kojonup

Badgingarra

Marchagee

Mingenew

Frankland

Location Frankland (WA)
Crop Barley (Baudin)
Sowing Date 23rd May 2012
Soil Type Sandy gravel
Irrigator Rate 3L/ha
Trial Design Randomised complete block - 3 repetitions
Yield Increase 420 kg

Fig 2. Machine set up for IRRIGATOR application behind the press wheel
Fig 3. Head count done for UTC and IRRIGATOR at 3L/ha  at 60cm
Fig 4. Head weight done for UTC and IRRIGATOR at 3L/ha
Fig 5. Derived yield based on Tiller/m2 counts and average oven dry grain weight

*based on Tiller/m2 counts and average oven dry grain weight

Fig 6. Calculated yield improvement

This trial shows a 2110kg/ha improvement when the plot was sprayed with IRRIGATOR at 3L/ha.

* Added value is calculated based on $270/tonne

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Kojonup

Location Kojonup (WA)
Crop Barley (Baudin)
Sowing Date 2nd June 2012
Soil Type Non wetting forest gravel
Irrigator Rate 1L/ha
Trial Design 10 randomly selected zones
Yield Increase 990 kg

Fig 7. 13 Sept. 2012 IRRIGATOR 1L/ha (Right) vs UTC (Left), Kojonup
Fig 8. 2 Nov. 2012 IRRIGATOR 1L/ha (Right) vs UTC (Left), Kojonup
Fig 9. Yield derived from head weight oven dried
Fig 10. Calculated yield improvement

This trial shows a 990kg/ha improvement when the plot was sprayed with IRRIGATOR at 1L/ha.

* Added value is calculated based on $270/tonne

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Badgingarra

IRRIGATOR trials were organised in 2012 in collaboration with the West Midlands Group and the Department of Agriculture and Food of WA (DAFWA). This data is reinforcing the positive results already observed through previous trials and customer feedback, and show the importance of good conditions of application.


A B C D E
Location D. Paish C. Sattler C. McAlpine C. McAlpine D. Paish
Crop Canola (Cobbler) Canola
(Cobbler)
Lupin (Tanjil) Wheat (Mace) Wheat
(Mace)
Sowing Date 12 May 2012 8 June 2012 14 May 2012 17 May 2012 1 June 2012
Soil Type Sand over gravel Sand over gravel Sandy Gravel and sand Sandy Gravel and sand Sand over gravel
Irrigator Rate 1L/ha 1L/ha 1L/ha 1L/ha 1L/ha
Trial Design 1 rep 3 reps 3 gravel
4 sand
4 reps 1 rep
Other Wetting agents used for last 4 years Wind damaged trial DAFWA Trial*
Heavy stubble
DAFWA Trial* 40mm rainfall shortly after seeding

*These research trials were funded by DAFWA and GRDC through the "Delivering agronomic strategies for water repellent soils in WA, DAW00204’ research project"

Fig 11. D. Paish Wheat control (left) vs Irrigator 1L/ha (right), Bagingarra 2012

Fig 12. Summary of grain yields from on-farm banded wetting agent trials conducted with West Midlands Group growers in the Badgingarra and Warradarge area in 2012.

Note: Grain yields from Paish wheat trial (Trial E), sown 1 June, not included on chart as yields were much larger than other trials, control yield was 4.99 t/ha and Irrigator 5.16 t/ha.

Trial A - Canola: Wetting agents have been used on this paddock for the last 4 years. Even though IRRIGATOR doesn't persist in the soil, its benefits can be observed when it is used consistantly. Residual root systems were present in the whole paddock, regardless of the presence or absence of Irrigator. This helped in crop establishment, and good results were observed for both treatments. The canola yield assessment didn't show any significant difference between the treatments.

⇒ Benefits of regular use of Irrigator

Trial B - Canola: This site was wind damaged by pre-frontal winds, causing an extremely low yield. This trial still shows a 150kg/ha improvement (+27%) when the plot was sprayed with IRRIGATOR at 1L/ha.

⇒ Choice of presswheels and wind conditions at applications are crucial


Fig 13. Calculated yield improvement - Trial B Canola

* Added value is calculated based on $550/tonne

Trial C - Lupin: For this lupin trial, the plots were sown across heavy wheat stubble. This caused the tynes to bounce and probably interrupted the IRRIGATOR stream and application in the furrows. It resulted in insignificant differences in establishment and yield response when IRRIGATOR was compared with the untreated control.

⇒ Disrupted application of Irrigator will greatly reduce its efficacy

Trial D - Wheat: On the deep sand banded wetter increased yield by 350kg/ha (+32%) when the plot was sprayed with IRRIGATOR at 1L/ha.
Fig 14. Calculated yield improvement

* Added value is calculated based on $310/tonne

On sandy gravel, yield increased by 460kg/ha (+31%) when the plot was sprayed with IRRIGATOR at 1L/ha.



Fig 15. Calculated yield improvement

* Added value is calculated based on $310/tonne

Trial E: This trial received a large 40mm rainfall event shortly after seeding, enabling a sufficient crop establishment regardless of the treatments. High yields were achieved on this site, for both treatments, 4.99t/ha for the untreated control and 5.16t/ha for the IRRIGATOR treatment.

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Marchagee

Location Marchagee (WA)
Crop Wheat
Sowing Date 19th May 2003
Soil Type Light yellow sand
Irrigator Rate 1.2L/ha
Trial Design Randimised complete block - 3 repetitions
Yield Increase 420 kg

Fig 16. Without IRRIGATOR (Left) / With IRRIGATOR at 1.2L/ha (Right)
Fig 17. Yield (T/ha) UTC vs IRRIGATOR at 1.2L/ha Marchagee
Fig 18. Calculated yield improvement

This trial shows a 420kg/ha improvement when the plot was sprayed with IRRIGATOR at 1L/ha.

* Added value is calculated based on $310/tonne

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Mingenew

Location Mingenew (WA)
Crop Wheat
Sowing Date 20th May 2003
Soil Type Light/medium sand
Irrigator Rate 1.2L/ha
Trial Design Randimised complete block - 3 repetitions
Yield Increase
360 kg


Fig 19. Yield (t/ha) UTC vs IRRIGATOR at 1.2L/ha Marchagee

Fig 20. Calculated yield improvement

This trial shows a 360kg/ha improvement when the plot was sprayed with IRRIGATOR at 1L/ha.

* Added value is calculated based on $310/tonne

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How to apply IRRIGATOR

It is recommended that SACOA IRRIGATOR is diluted in water and the solution applied to the soil by spraying.

Fig 25. In-furrow application of IRRIGATOR

Set up Seeding Equipment

Farmers are able to utilise sprayer components commonly used for the application of liquid fertilisers.
This may be an expensive option on larger tillage equipment, but the results are generally superior.


Fig 26. Cross section view for a suggested single press and double or gang press setup

Fig 27. Various applications used for setting up seeding equipment

Some farmers have been successfully using micro irrigation fittings and 19 mm low density poly pipe for manifolds (delivery lines). This system is easy to set up and very cost effective. Figure 28 to the right provides examples of the microjet sprays commonly used.

The size and mounting of tanks will depend on the size of the tillage equipment. The use of spray tank trailers can be also be coupled to the rear of the tillage equipment or seed carts. The recycling of old disused boom sprays such as the common computer sprayers can be useful with the boom arms removed.
A seven metre machine can be set up for approximately $500 plus a spray cart.

Fig 28. Microjet sprays commonly used

Application Rates

The information below recommends application rates for broadacre cropping. Recommended rates are influenced by the severity of soil / water repellency so optimum use rates may need to be established through field trials.

Seeding Conditions Application Rate Water Rate
No till furrow seeding with press wheels at 9-12 inches (25-30cm) spacing 1 - 3 L/ha
15-30L/Ha
  • Cereals: can be dry or wet sown.
  • Lupins, pasture species and canola: more suited for dry sowing.

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