Blewitts happy to break the mould

Kate MatthewsCountryman

The mouldboard plough is coming back into fashion and it's helping farmers increase yields not just in the Wheatbelt but in the Great Southern.

Over the past few years, the GRDC has been trialling mouldboard ploughing to lift yields in sandy soils and recently said deep soil testing before hand is critical.

In the Great Southern, Kojonup grain grower Mark Blewitt told farmers during last week's Southern DIRT field day he started using a mouldboard plough last year to control ryegrass and improve non-wetting gravels and overall soil health.

Farming with his sons, Ben and Sam, they use a five-furrow reversible mouldboard plough that varies between 12 to 20 inches but has it set to 16 inches with auto reset.

"The guys further north don't have the problem we have with so many trees and so many foreign objects under the ground. They have shear bolts, but if you have the auto reset, the furrows spring back automatically," Mr Blewitt said.

During last year's drought, Mr Blewitt used the plough on two paddocks which were sown to canola and wheat and said both yielded half a tonne more than other paddocks.

Although it costs him about $28/ha and takes 10 hours to plough up to 20ha, Mr Blewitt said the results were pleasing.

"The idea is to bury the weed seeds underneath. We plough at eight inches deep … and you need to leave them for several years to make sure they are no longer active," he said.

"It's not something you would do every year, probably every 10 to 15 years per paddock."

After the first year, the Blewitts have increased the size of their roller to nine tonnes and 3.2 metres wide.

"Another problem we had last year was we went in with knife points and because it ploughed through the ground between four to five inches deep, it brought up some of the ryegrass seed we buried," Mr Blewitt said.

"This year, we modified a combine and cut off the bottom of the knife points so we just had enough cover to protect the tine so we didn't disturb any of the underground weed seeds."

This year's wheat crop was sown with 1t/ha of lime before ploughing and half a tonne after as well as 100kg of urea while last year's mouldboard ploughed paddocks were also given 80kg/ha of MAP.

Mr Blewitt said they wanted to compare yields.

Southern DIRT executive officer Erin Gorter said up to 60 members took part in the field day.

They looked at a trial sites for canopy management trial, non-kill cropping, wetting agents, pasture varieties and the National Variety Trials.

A set of new sheep yards was also inspected along with spring and autumn-sown perennials.

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