Wind erosion on a stubble paddock during cyclone. Image – DPIRD.

STRATEGIC paddock and grazing management over Summer and Autumn will be crucial to protect valuable topsoil and crops in 2024, according to Western Australia’s Department of Primary Industries and Regional Development and the state’s soil commissioner.

Satellite imagery shows properties in the state’s north-east grainbelt could be particularly susceptible this year, with low levels of pasture coverage in some areas.

Commissioner of Soil and Land Conservation Melanie Strawbridge has called on landholders to maintain stubble and manage vulnerable land carefully to prevent soil erosion.

“A short growing season, below average rainfall and an early start to the 2023 harvest all point to conditions where cover is inadequate to prevent erosion,” he said.

“Healthy soil is a property owners’ primary asset and after years of managing and improving soil, now is the time to ensure it remains in place.”

The Department of Primary Industries and Regional Development (DPIRD) Season 2023 webpages have articles on ‘Managing stubble for wind erosion control in Western Australia’ and ‘Managing wind erosion in southern Western Australia’ with valuable advice.

DPIRD research scientist Justin Laycock said planning was key to maintain at least 50 percent ground cover through to the start of the 2024 growing season to stop soil from blowing away.

“Keeping more than 50 percent vegetative cover will allow landholders to manage properties without fear of your soil blowing away,” he said.

“For example, dry seeding next year will be less risky in a paddock with adequate ground cover than one with less cover, while stubble retention allows Summer weeds to be eliminated rather than maintained to protect the soil from strong erosive winds.”

A stubble of 1.5 tonnes per hectare from a wheat crop yielding 750 kilograms per hectare should provide adequate cover, while farmers can also lay the stubble over to estimate the proportion of bare soil to determine the percentage of coverage, DPIRD said.

Options to reduce the risk of soil erosion include keeping stock off paddocks with low cover by confinement feeding, agisting or selling stock before paddocks and stock lose condition.

DPIRD said it is important to limit vehicle movements in susceptible paddocks and protecting small bare areas that could lead to larger soil blowouts, such as sheep camps, around gateways and laneways, by applying clay, gravel, straw or a binding spray.

There are additional benefits from retaining stubble, including improved rainfall infiltration, reduced soil water loss, improved soil organic matter and soil structure, as well as protecting seedlings from sand blasting in the new season.

Mr Laycock said landholders considering grazing stubbles would be wise to examine the longer term impact on paddocks carefully.

“Sheep only eat about six per cent of stubbles and with more efficient harvesting techniques and weed control, stubble paddocks contain less nutritional value these days,” he said.

“We recommend managing grazing to retain at least 600 kilograms per hectare of dry matter on pasture paddocks to prevent soil erosion.

“Feed budgeting will be essential to help manage pasture cover and livestock health.”

Landholders are also encouraged to delay soil amelioration activities until the soil is moist, to reduce soil disturbance and the erosion risk.

In severe cases, the commissioner can issue a Soil Conservation Notice to direct a landholder to manage existing or prevent further erosion.

More information on ways to minimise the risk of soil erosion this summer is available on the department’s Season 2023 webpages, linked to the homepage www.agric.wa.gov.au.

Source – DPIRD.