Richard Dickmann

Winds of Change –
Minimum Tillage, Keeping the Dust Storms Away

Traditional agricultural practices such as ploughing destroy soil structures and make soils more vulnerable to wind and water erosion. During dry periods, these practices can lead to severe dust storms, which occurred in Australia particularly prior to the 1990s. As a consequence more and more farmers began to adapt conservation agriculture practices such as minimum or zero tillage.

These practices actually helped to reduce the occurrence of dust storms – even during the “Millennium Drought” from 2000 to 2009, but they also changed weed population dynamics. Bayer and the Grains Research and Development Corporation (GRDC) of Australia have teamed up in an innovative partnership to directly target the biggest threat to the Australian minimum tillage system; weed resistance.

Australia is an ancient landscape with highly weathered and largely infertile soils. The climate over most of the continent is comparatively dry and highly variable from year to year. Climate challenges have grown steadily, with a significant, long term reduction in rainfall in the main, southern agricultural areas. These challenges require innovative solutions to keep agriculture productive, profitable, and sustainable. Traditional agricultural practices, like ploughing, destroy the soil structure and make the top-soil, which contains most of the nutrients, more vulnerable to both wind and water erosion, particularly during droughts, when soil cover is low. Thus, fine soil particles can easily be picked up by the wind. The increasing number of dust storms across the cereal belt in the 1980s and early 1990s provided strong stimuli for the uptake of Conservation Agriculture (CA) principles. These principles include minimum or zero tillage, partial or full retention of crop residues to maintain soil cover, and rotation of cereals, oilseeds and legumes. Today, a significant majority of Australian broad-acre farmers grow winter cereals using Conservation Agriculture (CA) principles. Approximately 90% of all fields use some form of minimum tillage.

Richard Dickmann
Richard Dickmann
Richard Dickmann,
Head of Public & Government Affairs, Australia and New Zealand

Reducing tillage meant a significant reduction in energy demand and soil erosion. As a result, during the 10 years of the ‘Millennium Drought’, from 2000 to 2009, there was no major dust storm in southern Australia. Another important aspect of conservation agriculture is the improved soil water availability. Maintaining crop residues and reducing tillage leads to reduced evaporation and increases water infiltration. It also enables earlier sowing, thereby reducing moisture loss to weeds and/or evaporation. Despite hotter and drier conditions driven by climate change, Australian farmers have maintained and even increased their cereal yields, while improving their environment record.

However, a consequence of reduced tillage is the need to control weeds chemically, which has led to a change in weed population dynamics and challenges. A range of different herbicides have been used to control weeds. However, the continuous application of herbicides, without a full understanding of weed population dynamics, created widespread herbicide resistant weed populations. This required significant research and innovation in integrated weed management.

The challenging production environment that Australian farmers are facing has spawned a unique agricultural research and development funding system which is characterized by strong farmer participation. In the mid-1980s the Australian government established the Rural Research and Development Corporations (e.g. GRDC) matching compulsory farmer research levy contributions with government funds. The GRDC alone invests more than AUD200 million per year (USD 152 million), mainly within Australia.

Recognizing that weed resistance is a global threat, the GRDC and Bayer agreed to set up an international collaboration called the Herbicide Innovation Partnership. Among the research team are 11 postdoctoral students selected from Australia and New Zealand. Ten Australian weeds have been added to the chemical screens in Bayer Frankfurt, Germany, and the best alternatives will now be tested in Australia, in a purpose built facility.

This collaboration, resulting from Australian farmers’ challenge and their ingenuity to find answers, will contribute to innovative solutions to help maintain productive, profitable and sustainable agricultural systems around the globe.

To find out more about the GRDC and Bayer partnership: https://www.youtube.com/watch?v=d08lYFrHT9Q

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