Even though stock feed is scarce, failed crop stubbles offer very little grazing value anyway, so keeping stock off low density stubble is now essential to minimise the risks of wind erosion.

“The biggest challenge ahead, whatever harvest we do get, will be minimising further soil loss through wind erosion,” DPI Hillston based agronomist Barry Haskins has warned.

“Wind erosion devastated southern and central NSW following the drought of 2002,” he said.

“Crops which yielded less than 0.5 tonnes per hectare simply didn’t have the stubble load required to prevent erosion, especially when hungry sheep and cattle were added to the equation.”

When this season started late in the south, average yields towards early September were still possible but devastating predictions of failure for this year’s winter crop have now become reality for a large proportion of the cropping belt in central and southern NSW.

Current estimates are that less than 40 per cent of the central and southern crop will be worth harvesting for grain, a figure which worsened as no rain fell.

“Unfortunately since late August it hasn’t rained, and what were once good looking crops have now either been cut for fodder or are not worth harvesting.”

According to Mr Haskins, research has shown that strip ripping and surface roughening can minimise wind erosion, however experiences from previous droughts suggest practices such as these are a last resort option, as it is expensive to do and delivers poor results, compared to retaining stubble in most soils.

Nathan Border, Condobolin district agronomist said “cultivating or strip ripping to prevent wind erosion sounds ironic, however as a last resort it can help minimise losses if performed properly on heavier soil types”.

“Strip ripping involves ripping 10 to 20 centimetre deep, on about two metre spacings, aiming to make the surface rough enough to trap any loose soil that may be blown across, however on some lighter sandy soils this practice only magnifies the problem,” Mr Border said.

Long term trials undertaken in Wagga Wagga over 30 years showed that wheat yields were halved when soil loss of only 6.5 millimetres (or 84 tonnes/ hectare) occurred.

Based on this information, every one millimetre of lost topsoil has the potential to reduce crop yields by seven per cent.

Trials in the Mallee area of northern Victoria have estimated that it costs farmers more than $2 per hectare for every minute of a 75 kilometre an hour wind event – depending on fallow management.

These costs are associated with lost production and replacement costs of nutrients.

“Now is the time to be managing your stubbles properly by either stocking them very lightly, or not grazing them at all,” Mr Border said.

“Expensive and invasive practices like strip ripping are a last resort, and if farmers can do something to avoid it, they will be much better off in the long run.”

Contact Barry Haskins, Hillston, (02) 6960 1320.