Experience has shown Neville Turner of Corrigin that to get total soil inversion with the mould board plough, the soil needs to be properly wet up before working. At least 100mm of rain is ideal and then the cover crop needs to establish quickly to prevent any erosion risk. A little bit done well each year is the key. Oaten hay crops with healthy, deep penetrating root systems is the result of plenty of lime and mould board ploughing to negate water repellency and bury brome grass seed. Good nutrition is an important part of the mix too. Neville feeds his hay crops with 100 kg/ha of Summit Vigour, 90kg/ha of MOP and 100kg/ha urea. More urea could be applied if the conditions are favourable.
Mouldboard ploughing isn't for everyone. For no-till and minimum soil disturbance converts it's outdated technology that totally goes against the grain for planting and growing crops. However for farmers like Neville and Glenys Turner, it's old technology that can still have a valuable place in today's farming.
Mouldboard ploughing has worked wonders in selected pockets of their sandplain country. For that reason Neville's not prepared to give up on the plough just yet.
The Turner's farm west of Corrigin. Some of their sandplain country had a distinctive water repellent layer at the soil surface, which led to the general array of crop germination and establishment problems.
Patchy soil wetting created herbicide issues with significant weed escapes, subsequent brome grass build-up and to top it off, many of their sandplain paddocks are low in the landscape and are hence more likely to be impacted if frosts come around flowering time.
Neville said bad frosts on wheat crops that looked like they could have gone 3t/ha have resulted in yields as low at 0.3t/ha. Barley was the same.
A change in thinking needed
Done well, mould-boarding totally inverts the soil, so for the Turners they take the soil that sits about 30cm below the surface and flip it, so it becomes the topsoil.
While Neville says it's certainly not for every soil type on his property, mouldboard ploughing has been a good way for him to deal with non-wetting soil and weed seeds, and along with incorporating lime it's also helping restore healthy soil pH.
To make it a cost effective option though, he still had to tackle the issue of frost by changing the way he did things. He couldn't keep growing crops that could be struck down before the end of the season. A decision was made to change the cropping regime in those lower lying areas and grow a lot more hay that would be less impacted by frost.
"It's like anything, you can't keep doing the same thing all the time and expect the result to be different. You've got to mix it up a bit" Neville said.
"We realised once we got the soil wet enough to get the crop established it would grow well. So, the key issues to overcome were frost and non-wetting soil.
"Crops on our low-lying sandy paddocks were getting frosted to some extent 8 out of 10 years, so we gave up trying to grow wheat on those areas.
"Mouldboard ploughing seemed to be a good fit for our non-wetting sand, and it’s done a tremendous job with about 300ha done over three years.
"In terms of nutrition, non-wetting soil at the surface was creating nutrient issues because the phosphorus we applied was in the top 10cm and if the topsoil remained dry, we weren’t getting the full benefit from it. Since we’ve inverted the soil, buried that non-wetting topsoil and brome grass seed, we’re getting much better results.
"The first year we did it the paddock went into wheat which out-yielded everything else on the property by about 1t/ha, so we knew we were onto something".
"At that stage contracted mouldboarding was $120/ha plus diesel, but it more than paid for itself in the first year and after that it’s been extra profit. We're growing oaten hay on those paddocks now and producing from 4 to 7.5t/ha of square bales for export.
"Of course, with growing hay we’re putting a lot more nutrition in, but we’re getting the return, whereas years ago when we were growing grain that was getting frosted, we were putting it in and making a loss in most years."
Neville said today's fertilizer inputs for hay crops are 100 kg/ha of Summit Vigour - which puts 12 units of K down the tube along with 12 units of P, 10 units of N, 5 units of S, Cu and Zn, along with 90kg/ha of MOP and 100kg/ha urea.
"Vigour has been a great product to handle with all the nutrients in the one granule,"he said.