Edge-row sowing reputation grows

I know there’s near-row and in-row but edge-row is a more precise description of what could be the next big thing in one-pass crop establishment.

It can best be described as accurately sowing alongside the previous year’s plant rows without disturbing stubble and placing seeds in those rows.

It is best achieved using a hydraulically-controlled guidance hitch, which is fitted to the tractor hitch or an air seeder hitch of a tow-between model, with a GPS receiver fitted on the tractor and on the seeding bar. 

The hitch is called a ProTrakker and it is being marketed in WA by Katanning-based Burando Hill.

The ProTrakker eliminates the problem of bar drift, maintaining the bar’s line of direction within an accuracy, using RTK guidance, of plus or minus one to two centimetres. 

This contrasts with bar movements of plus or minus 20 centimtres normally associated with seeding bars.

Why edge-row?

Five years of paddock trials by Mindarabin farmer and Burando Hill director Simon Hill – and a growing band of ProTrakker users – shows the method virtually eliminates non-wetting issues and improves crop yields.

The latter is achieved because seeds are placed in a moisture zone with immediate access to residual nutrients and old root pathways.

More than 20 years of research work by CSIRO, led by their former principal research scientist Dr Margaret Roper, revealed through dye tests, that zero till preserves old plant root pathways, allowing moisture to travel beyond the water-repellent top layer of the root zone.

“In pure no-till or zero till, where discs are used, we have achieved similar results very consistently over a number of years now,” Dr Roper said.

“There is a similar pattern also using knife points, which don’t disturb old root systems.”

According to Mr Hill, trial results involving the ProTrakker, have shown a seven per cent yield increase across wheat, barley and canola trials.

“I would expect even better results in a hard finish,” Mr Hill said.

“It is definitely proving a valuable tool and a seven per cent lift in yields over a big program is significant.

“It’s easy to see the visual differences sowing alongside the stubble and sowing in the inter-row with the ProTrakker compared with conventional sowing.”

But it’s more than overcoming non-wetting.

“It’s the mineralisation effect, it’s residual nutrients, helpful bacteria, the moisture harvesting by the old row and existing root pathways,” he said.

According to Mr Hill, crop yields in WA have begun to plateau, triggering a bigger focus on overcoming yield constraint problems. 

“From what we’ve experienced and what ProTrakker users are telling me, it’s very clear we are creating a fertility strip that can be used every year,” he said. 

“On our farm, the ProTrakker has several advantages for us because we can sow our canola in semi-wet conditions drilling it into last year’s furrows without disturbing the stubble.

“And we also can sow wheat on the inter-row in high stubble residue paddocks, again without disturbing the stubble cover.

“Without the ProTrakker we couldn’t reliably sow between rows let alone seed alongside the stubble in last year’s rows.

“Now, when we know we have moisture in the ground from summer rains, we can almost pick our own break, if you like, to the season.

“This method has widened our sowing window and led to more thought about what other crops are possible and for us to grow and we’re considering peas and faba beans.”

Interestingly, Mr Hill said the edge-row sowing had “pushed us” into controlled traffic farming (CTF).

“We’ve got everything on RTK guidance and we’re always seeding in the same spot,” he said. 

“So our transition to CTF has been easy working with machinery on 12 metre multiples and wheel spacings at three metres.”

The next logical step will be to deliver the “whole package” for true one-pass crop establishment.

And this is happening right now, albeit, in trials, involving liquid products.

In the future, it is not inconceivable to envisage a management practice involving sowing seed accurately into old plant rows with tank mixes of fungicide, insecticide, fertilisers and trace elements.

Such repeatability, however, does trigger the “disease” subject.

But according to Mr Hill he sees more diseases in the inter-row.

“There’s probably a lot to the saying about healthy plants being better able to better withstand diseases,” he said.

So-called edge-row sowing is likely to gain traction because of growing “proof of the pudding”, evidence backed by scientific research. 

The biggest issue facing farmers eager to advance the system will be objective research, involving trials throughout the Wheatbelt in different soil types and moisture zones.

That aside, results so far point to edge-row sowing as the next big thing in WA crop establishment.