Early sowing brings gains and challenges
GroundCover™ Issue: 110 | Author: Nicole Baxter
Variable seasons are teaching Ewen Peel some valuable lessons in managing early sowing in the effort to achieve reliably higher yields in the high-rainfall zone.
With waterlogging one of the biggest constraints to crop production near Inverleigh on the heavy clay soils in south-east Victoria’s high-rainfall zone, Ewen Peel and his father Ross are now sowing seven to 10 days earlier than usual in a bid to improve yields at harvest.
Ewen says GRDC-supported trials and his own experience have shown the benefits of early sowing. He says early sowing gives crops the best chance to establish well and outcompete weeds before the weather turns cold and wet.
However, Ewen says the decision to move the sowing date forward was not made lightly. He first learnt about the benefits of earlier sowing in 2012 after seeing the results of trials by CSIRO and his local grower group, Southern Farming Systems.
He was so convinced about the potential, he sowed his family’s entire 2012 crop before the end of May, two weeks earlier than usual.
Although the finish to 2012 was unkind, with a long stretch of dry weather cutting back grain yields, he estimates earlier sowing still may have added about 10 to 15 per cent to the yield.
Although Ewen hoped to bring sowing dates forward again in 2013, the late arrival of season-breaking rain meant sowing did not start until the third week in May.
Conditions turned wet and cold in June and continued that way until September, causing heavy waterlogging over much of the Peels’ land.
“We had about seven months of rainfall arrive over the three winter months in 2013,” Ewen says. “Our crops can struggle to handle winter conditions in a normal year, so they really battled in such extremely wet weather.”
By September, Ewen says, the wheat crops sown in May looked superior to those sown in June.
“Last year really showed us that crops sown early are more vigorous and better able to handle waterlogged conditions than smaller, less-developed crops,” he says.
“The boggy conditions also made it difficult to drive on the paddocks to add extra nitrogen to some of the crops. The wet soil combined with no nitrogen at a critical stage meant crop growth stalled and plants quickly turned yellow. It was a disaster.”
In 2013, the Peels sowed three wheat varieties and Ewen says he was surprised with the results.
SQP Revenue, a red wheat variety that becomes semi-dormant through the winter, was sown at 105 kilograms per hectare by the third week in May. Looking back, Ewen says it really proved the crop was established three weeks too late as it became overrun by weeds, and only yielded 2.5 tonnes/ha.
Bolac, sown a week later, at 80kg/ha, outcompeted the weeds and went on to yield almost 5t/ha. A newer variety called LongReach Phantom, sown at about 100kg/ha close to its optimum sowing date, did not tiller well and competed poorly with weeds, yielding lower than hoped at 3t/ha.
“I was expecting SQP Revenue to yield more than it did, so this year we will move all our sowing dates forward by seven to 10 days from our traditional start time to allow the canopy to develop more quickly and outcompete weeds before soil and air temperatures decrease,” he says. “Once soil temperature reaches about 6°C to 7°C, crop growth is just too slow.”
For LongReach Phantom, Ewen adjusted seeding rates up to about 120kg/ha this year; and nitrogen rates at sowing were increased from 15 units to between 20 and 25 units to bolster early crop growth.
Aside from early sowing, Ewen has this year switched more of his land from canola to faba beans because of the pulse crops’ capacity to better handle waterlogged conditions.
In 2013, Ewen says canola was a disaster, failing to yield more than 1t/ha.
However, he was pleased with a 30ha paddock of PBA Rana faba beans, which yielded 3t/ha, despite being planted late and subject to waterlogging.
“Faba beans seem to be more robust than canola. They also can be sown dry, and add a much-needed nitrogen boost, as well as assisting with cereal weed and disease control,” he says.
“Canola has become a challenge to grow, particularly with the added pressure provided by slugs, earwigs and redlegged earth mites.
“I think CSIRO’s James Hunt has proven the benefits of sowing some of our varieties earlier than what we’ve done in the past,” he says. “From now on, we plan to start sowing on 25 April come rain, hail or shine.”
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GRDC Project Code CSP00111, CSP00178