Farm Trials Highlight OSR Efficiency Advantages

Commercial strip trials on a Hertfordshire farm have shown major harvesting efficiency advantages from low biomass oilseed rape even in the one of the easiest OSR harvests on record.

For the first time this year Charles Carter direct cut the entire 150 ha of oilseed rape he grows at Harps Farm, Great Hallingbury near Bishops Stortford. And he was able to compare harvesting speeds alongside yields in the farm scale strip trials he ran to assess the relative performance of top varieties in hectare blocks.

Across the whole area, the 74 ha of Canberra and 74 ha of Recital yielded similarly to average around 3.8 t/ha. However, low biomass Canberra topped the variety strip trials at an impressive 6.17t/ha, out-yielding leading conventional RL variety, Winner by 11%. At an average 2.1 ha/hour the Canberra was combined nearly 17% faster than higher biomass Winner (1.8 ha/hour) too.

"Traditionally we've swathed all our rape," Charles Carter explained. "But it's costly and far from easy to manage. The advent of shorter, stiffer-strawed varieties has made direct cutting with side knives an attractive option. And this year everything was so short we decided to desiccate and direct combine the lot.

"Overall, we've been very pleased with the result. The crops dried out much faster than we thought they would after a wet spell and we've had no problem with pod shatter." Charles Carter and his team confirm the results of their strip trials in the ease with which they've been able to harvest their Canberra in particular. They stress the value of the uniformity of the low biomass crop as much as its shortness and stiffness, pointing out that constant stopping and starting is what really gets in the way of OSR combining.

Indeed, combine drivers David Barlow and David Mugele say that harvesting the low biomass variety has been an absolute pleasure this year.

"We've had no blockages, which has made a real difference," explained David Mugele. "They can easily take half an hour to clear, and the piles of chaff left behind invariably cause incorporation difficulties.

"From inside the cab the Canberra looked really clean underneath the pods, which were all concentrated in a convenient 16-inch block along the stem. This and the great evenness of the crops across the fields made all the difference."

David Barlow points out that the harvesting speed advantages seen in the trial field have been apparent across the acreage, saving them as much as a day in a week's harvesting. "This has allow us to get our rape off in record time and make an early start on the barley harvest," he said.

Compared with taller varieties, low biomass oilseed rape is really producing the goods at Harps Farm. Even this year when everything has been so easy to harvest, Charles Carter estimates it has increased harvesting speed by as much as 15%. "Taller varieties - especially the hybrids - have always caused us combining problems, even with swathing," he noted. "And dealing with stubbles and trash is a problem. We plough after the rape so we need to cut the stubbles low to the ground to minimise the amount of trash we have to bury.

"Alongside yield and oils content, reliability and harvesting efficiency are key factors we consider in choosing our rape varieties," Charles Carter added. "We also value autumn vigour and disease resistance. We look at the national position, but our own trials give us a better feel for the way varieties will perform for us; which is what really counts."