Dry weather has meant many growers did not put in a crop this season. Crops that have gone in have struggled to establish. This has left extensive areas of bare soil exposed to wind erosion.
Wind erosion is not always a big dust storm. Sometimes large particles roll across the soil surface and only move a few meters. Erosion and topsoil loss might not be noticeable from day to day but are still very important.
How wind erosion affects you
Wind erosion affects soil fertility, yields, and can have off-site costs. Erosion in 2018 can cause carry-over problems into the next few years.
Soil fertility loss
Wind erosion can mean a substantial loss of nutrients from the farm. Losing 1 mm of soil means losing about 10-12 tonnes of soil per hectare.
It’s not just lost nutrients that are a problem. Losing the clay and organic fractions means the soil’s water and nutrient holding capacity is reduced. Recovering soil fertility, especially regenerating soil organic matter (OM), can take years.
Losing just 1 cm of soil can reduce crop yields by up to 25%. Western Australian research in the late 1970s found that losing 2 mm of soil meant a 2-12% yield loss and 8 mm of soil meant a 5-25% yield loss.
Compared to a cultivated soil, no-till systems concentrate more OM and nutrients near the surface. This means fertility loss is a greater risk in exposed, no-till soils.
Severe storms can expose subsoils. Subsoil constraints can make revegetating and restoring productivity difficult.
Other impacts include soil deposited on roads, waterways, and dams, and buried or stranded fence lines. This requires time and resources to remove. Air pollution from finer particles can cause health problems.
What wind erosion means for next season
Soil nutrients might be lower than expected or moved elsewhere on the farm. Re-test paddocks to take stock of soil nutrients and organic matter levels.
Applying more fertiliser might not return the soil to its previous fertility level. The soil may have a reduced nutrient holding capacity. If possible, do a full soil analysis to gauge the status of your soil.
These eroded areas are vulnerable to grazing so stocking these areas needs very careful management.