DEMO RESULTS SHOW EXTREME VARIANCE

06 AUGUST 2013
Summary
First outcomes of Dodgshun Medlin’s ground breaking seeder demonstration are showing huge variances in emergence, with results ranging from 10 to 120 plants per square metre. The burning question is ‘why?’

First outcomes of Dodgshun Medlin’s ground breaking seeder demonstration are showing huge variances in emergence, with results ranging from 10 to 120 plants per square metre. The burning question is ‘why?’


The initial demonstration, on the 10th of April at Nyarrin, involved ten no-till seeding machines sowing wheat into dry soil conditions.


“Conditions at the time were certainly tough, with heavy soil types particularly challenging for those machines aiming for disturbance directly beneath the seed row,” said Danny Conlan, head of Dodgshun Medlin’s Agricultural department.


“In these conditions, two machines in particular are producing significantly better emergence results than other disc and tine machines – in fact by as much as 120%.”
Currently leading emergence counts is the John Deere Disc with the Seed Hawk also showing high plant numbers. “The thing is, in different soil and moisture the results could be very different. That’s the vagary of agriculture,” Mr Conlan said.


Observations posed a number of questions around seeding depths, challenging the traditional practice of ripping deep beneath the seed. This has been aimed at providing a means of rhyzoctonia control, allowing a banding of nitrogen below the seed, and also creating a pathway for roots to penetrate faster and deeper into the soil profile.


Given the soil conditions presented at Nyarrin in April, those machines aiming for disturbance directly beneath the seed resulted in poorer seed placement and consequently, lower plant numbers.


“There was certainly a strong correlation with uniformity of seed placement and emergence counts and the variation of seed placement between some of the machines was surprising,” said Conlan.


Also interesting is that you can’t separate disc from tines. Of the top two machines for establishment one was disc and the other a tine, however it might be said that the leading tine machine was not aiming to place seed directly above the ‘rip’ mark, but rather to the
side, resulting in less ‘clodding’ in the seed zone and more accurate seed placement in the very dry conditions.


Establishment variances were consistent with seed depth accuracy and uniformity proving there is a direct correlation between accurate machine set-up and emergence results. “The thing to notice here is that dollars spent on high-cost machines does not always guarantee the best results – there are a lot more factors in play,” said Mr Conlan.


The demonstration day conducted by Dodgshun Medlin and supported by GRDC and Vic No Till Farmers Association celebrates a decade of successful no-till farming practices in the Mallee. While results were not replicated (as per a formal trial), the demonstration has offered farmers the opportunity to see a wide variety of machines in action and view results as they emerge.


“This is one of the great things about being independent advisors,” said Mr Conlan, “We can conduct research and development and provide clients and the wider community with advice that is completely unbiased.”

About Dodgshun Medlin

Dodgshun Medlin is a generations-deep provider of holistic business management, wealth creation, agronomy services and accountancy guidance to the Victorian & South Australian Mallee & Wimmera Regions.