MAKING THE MOSTOF EARLYDRILLING
Early drilling has found
favour on many arable farms
in recent seasons. But what
do growers need to do to
make the most of this
technique? Work at Morley
Research Centre aims to
provide some answers
DRILLING winter wheat in early September can increase yields by 1t/ha on light land. But seed rates must be reduced to reap the full benefits.
That is the key conclusion to emerge from three years of trials conducted at Morley Research Centre, which will be profiled at Cereals 98.
The work was initiated to build upon results from Denmark which showed that significant yield increases were possible from drilling a month earlier than normal.
"Weve been looking at four different seed rates and three different drilling dates," explains Morley agronomist Ben Freer. "And weve found that the key to higher yields with early sowing is to reduce seed rates."
The work, which began in 1995, investigated seed rates of 96, 135, 174 and 213kg/ha (target populations of 125, 175, 225 and 275 plants/sq m), drilled during the second week in September, early October and mid-October.
"In the first year, we had a 1t/ha response to the earliest sowing date and the lowest seed rate, achieving 12t/ha from 130 plants established," explains Mr Freer. "In 1996, we again saw a response to early sowing, but the seed rates used were all 200 plants/sq m.
"Last year crops gave a similar response, but the earliest sowings lodged. However, Charger was the variety used and lodging was a common problem last year."
Mr Freer believes that early sowing works well on light land where crops mature earlier. But good establishment is critical to success, he stresses.
"Seed-bed conditions and the weather at drilling are important factors. Aim to conserve moisture with minimum cultivations and choose fields where blackgrass is not a problem. Theres no point drilling early if emergence is delayed by insufficient moisture.
"The seed used must be tested and dressed," he adds. "At low seed rates, its important that germination is high."
The approach may not be appropriate every year. "After oilseed rape is an obvious choice, because you have a chance to create a seed-bed and get the crop established. It also has the added benefit of spreading the workload, which suits a number of growers."
Managing an early-sown crop is largely the same as that of October-drilled wheat, Mr Freer explains. "Operations are carried out earlier, but the treatments are the same and we are still going by growth stage.
"Plant growth regulators are important and we would expect to make two BYDV sprays. This year, our crop had emerged by Sept 10, so we applied the first chlormequat split in February and the second on Mar 20."
He admits that there are environmental concerns about early nitrogen applications and autumn IPU use. But only a small area is likely to be drilled at the beginning of September each year, he stresses.
"It comes into consideration on light land where there is oilseed rape in the rotation," he highlights. "It isnt suitable for land where blackgrass and other difficult weeds are present, or in a second wheat situation.
"The growing costs arent much greater – perhaps just an extra cypermethrin spray – which is offset by the lower seed rate and reduced cultivations.
"On heavier land, where the yield response isnt quite so dramatic, it pays on the management benefits of spreading the workload."
• Can boost light land yield by 1t/ha.
• Important to reduce seed rate accordingly.
• Extra BYDV spray, greater need for lodging control and earlier nitrogen needed.
• Management benefits alone can suit approach to heavier land.
Plant populations need careful control to make the most of early sowing, says Morleys Ben Freer.
EARLY DRILLING TRIALS
Trials are continuing at Morley to investigate which varieties are most suitable to early drilling. At the Cereals 98 site, wheats with an early flowering gene and a dwarfing gene will be on show, prompting discussion on the suitability of these traits to different drilling dates.
"Ideally, we are looking for a variety which grows slowly through the winter, so that it isnt affected by any late frosts," concludes Mr Freer. "At this early stage, Consort and Riband seem suited to early drilling, while Soissons and Abbot are not.
"But there are still a lot of questions to be answered and we need to subject the varieties to different seasons and conditions before coming up with final recommendations."
Simply getting on with autumn crop establishment can justify a move to earlier drilling even on heavier land, notes Mr Freer.