Satusteam™ for Weed Control in Vineyards

Satusteam™: Steam Weed Control For Sustainable Vineyards

Vineyards aiming for sustainability (1) adopt a holistic approach to production. They consider how best to manage energy and water usage, land design, material selection, conserve and regenerate biodiversity and build living soils.
Vineyards are cost-intensive with their long growing season, numerous seasonal management stages, and high labour requirements. Which is why implementing sustainability should result in a reduction of inputs, increased soil fertility and long term productivity. Satusteam™ weed control achieves organic accreditation, soil sustainability, lower inputs and reduces labour costs.

Weed management in vineyards

Weed management is a challenge for vineyards moving towards sustainability, particularly when they have been used to applying herbicides and having a bare earth policy under their vines. It starts with rethinking what is actually a weed.

Weeds in a vineyard can be defined as the non beneficial vegetation which among other things competes for valuable soil nutrients and water in the rootzone of the vine during the growing season. (2)

Organic and biodynamic growers use various methods including beneficial cover crops, seasonal grazing, manual chipping, mechanical tillage, mowing, organically certified herbicides and thermal weed control. There is no silver bullet and each land manager will have a different combination of tools. Satusteam™ is a thermal weed control that deserves consideration.

Thermal weed control

Thermal weed control uses heat at above 60ºC, lethal heat , to cook vegetation. Lethal heat can cook weeds slowly, but when the temperature is delivered at 100ºC the process of thermal shock is much more explosive on the cells of the soft tissue leaves and stems. Various embodiments of flamers, hot water and foam machines and steamers have been developed over the past 35 years. Dry heat flamers pose risks to irrigation pipes, vine trunks and can easily cause runaway fires if conditions are dry. In contrast, wet thermal machines have shown promise but needed to overcome challenges of speed, efficacy, adaptability to terrain and efficiency with resources for power, water and fuel.

Satusteam™ weed control

Weedtechnics have developed the process of generating a mixture of saturated steam and boiling water for weed control. We named the process and mixture Satusteam™. Satusteam™ is created through a process of pressurising water as it is drawn from a water tank; heating it to 118ºC as it is pumped through a heat exchanger; depressurising the liquid superheated water through a unique nozzle system, into a low pressure mixture of saturated steam and boiling water – Satusteam™. It destroys soft leaves and stems on contact.

The challenge was how to apply the Satusteam™ to the vegetation without the Satusteam™ cooling even a few degrees. Therefore, we evolved a range of applicator heads to encapsulate the heat and create an atmosphere which maintains the Satusteam™ at temperature during delivery. For vines we developed the Rowtech™, a 55cm or 80cm diameter stainless steel cone with a unique combination of central stainless steel nozzle assembly in a free spinning bearing. It has an elegantly designed one piece bumper ring and replaceable brush skirt.

The solution for vineyards

Vineyard infrastructure such as vines, posts and irrigation are obstacles which posed the next hurdle in creating a fit for purpose weed tool. Using applicators on the end of a hand held lance has its place, but not for kms of vine rows. Simple spring loaded arms to hold the Rowtech ™ applicators heads, which gently rolled around the obstacles, showed promise. However, the ground beneath vines is rarely flat and often varies in slope and camber along a row. There can be holes, clods and debris that cause the applicator head to lift, flip or worse still, fold.
Necessity required us to develop a system which tracked the ground, adjusted to slopes keeping the Rowtech ™ always parallel to the terrain it was passing over, as well as retract and roll around obstacles and self spring back into alignment. The result is the Tracktech™.
This combination of Rowtech ™ and Tracktech™ allows for continuous forward movement delivering Satusteam onto the 55cm or 80cm band of unwanted weeds under vines, along fence lines, through orchards and anywhere else that requires lineal band weed control.

 

Hidden costs of weeding

Organic, biological, biodynamic and regenerative farming practices all have the fundamental core principle of increasing life in the soil. A sustainable vineyard should, to achieve sustainability accreditation, be able to measure;

• The increase in soil life
• Organic matter
• Improved structure and consequential sequestered carbon

Actions that;

• Destroy the soil structure
• Expose the soil to erosion
• Leave residues that are toxic to beneficial soil organisms
• Disrupt the vines’ ability to function optimally

Are undesirable and have hidden costs.
Satusteam™ explodes the cells of soft leaved and stemmed vegetation. It destroys the protective cuticle that prevents the plant from dehydrating. The vegetation is left in a permanent wilted softened (cooked) state. Within a day of sunshine the vegetation is browned off, straw like and becomes thin mulch.  This mulch protects the soil from sun, breaking the force of rain and providing a slow release of nutrients back into the soil. A healthy living soil will recycle the vegetation, releasing the minerals and storing the carbon.

Steam weed control and the root zone

A misconception about steam weed control is that it injects deep into the ground, this is untrue for Satusteam™. Satusteam™ penetrates into the top 3-10mm of soil to destroy or damage the growth point of the weed. The growth point is where the roots meet the shoots, so it either destroys the plant or retards its ability to reshoot. Satusteam™ does not penetrate into the root zone of the vine. This is a fundamental difference in action from cutting with mowers and whipper snippers, burning or using a desiccating spray. The growing point of most weeds have evolved to be just below ground level, protecting them from fire and ruminants. Results are evident for weeks after treatment and has been visible at Costa Berries in Australia. Costa have seen 3-4 times the residual control than they were achieving with a desiccant spray.
Penetrating deep into the rootzone can only be achieved with alternative apparatus. Apparatus designed to deliver steam at high pressure or by applying steam vapour or hot water for minutes per m2. Our Satusteam™ is delivered at low pressure, about 60 psi, at 12 -20 meters a minute.
The steam vapour emitted from under the Rowtech wafting up through the canopy has no damaging heat and is safe for the vines and beneficial insects. We think it’s actually pretty cool.

 

Satusteam™ and the seed bank

Satusteam™ will either;

• De-nature a seed in the seed bank so it won’t germinate

or

• The heat and water combined with the elimination of surface vegetation will encourage germination.

It depends on the species and location in the soil profile.
It is usual after treatment of Satusteam™ to see germination of the seed bank of the more prolific invasive species. This is the next generation of weeds and a 2nd treatment of Satusteam™ allows for quick elimination. Subsequent treatments will see fewer weeds, fewer species and the more persistent tap rooted species will have less vigour. Speed of application increases and costs reduce over time.
Oscar Duckworth of Duckworth family farms relied on woofer volunteers to manually chip his blueberry orchard. He stated that Covid cut off his access to labour in 2020. The Rowtech Tracktech Satusteam™ combination allowed him to do the work of 20 and he says it saved his farm.

 

Undervine Satusteam™ Weed Control System

Introducing the revolutionary undervine Satusteam™ weed control system! Designed for the vineyard and blueberry industries the system is ruggedly built for intensive all day operation. Features of this unit are:

• a 3000L UV stabilised water tank,
• Rowtech heads,
• Tracktech arms,
• options for hydraulic or PTO drive water pumps,
• wireless In-Cab controls for regulation of Satusteam™ output, heat exchanger and hydraulic arms.

This is a fully customisable system with smart design for varying row widths and individual weed control needs.

Tested and proved results in vineyards and Blueberries.
If you are experiencing the hidden costs of weed management and are adopting practices that assist in building soil health, consider Satusteam™. We’ve come a long way in 25 years, it’s time we spoke.

Sources:
(1) https://sustainablewinegrowing.com.au/
(2) Organic Farming: Vineyard Weed Management