Lowdown on rapes

14 August 1999

Breaking a habit?

By Tom Allen-Stevens

THE future looks ever more bleak for oilseed rape: area aid is being drastically cut due to increased plantings, and no one wants it anyway because the world-wide soya harvest was so good. Many growers must be asking themselves, "Whats the point?"

Despite the dismal downturn, Dr David Ellerton of distributor group ProCam, believes the crop has a vital role to play in keeping the rotation profitable. "Weve left behind the glory days when oilseed rape was one of the most profitable crops to grow. But it is still a key part of the whole rotation. Its not only a valuable break crop, aiding control of various weeds and diseases, but it helps spread workload, which helps keeps down fixed costs," he maintains.

Evidence to show that it helps maintain the profitability of the rotation comes from some ProCam number-crunching on figures obtained from its customers. Using the actual results from the top 25% of these farmers, the gross margins of various crops over the last few years were compared. Forecasts were also made of future gross margins, based on the same yield, but with predicted fluctuations in price and area aid built in (Fig 1).

Viewed on its own, the results show that oilseed rape is plummeting from being more profitable than winter wheat to being less profitable than winter beans. Indeed, the ProCam predictions show that profitability of break crops in general will be falling away.

So why not switch to continuous wheat? To find out the effects of doing this, ProCam looked at a typical 240ha (600-acre) arable farm with a six-year rotation of wheat broken every third year by oilseed rape or beans. The projected total margin (before fixed costs) was then forecast if the farm stuck to this rotation (Fig 2). A similar forecast was carried out for the same farm abandoning its unprofitable break crops in favour of continuous wheat (Fig 3).

In the first year, continuous wheat proves to be more profitable by about £1,800. However, due to the lack of first wheats in the second year, this profit advantage is reversed; the rotation becomes more profitable by £5,500.

So what about dropping wheat in favour of winter beans? This would work out better than continuous wheat, but a first wheat following oilseed rape yields higher than a wheat after any other break crop, according to ProCams farmer figures. "Remember also that winter beans are drilled relatively late. This means you may not get the crop drilled and sprayed before winter sets in, and it could be too late for it to act as a cleaning crop as far as weeds are concerned," says Dr Ellerton.

Lowdown on rapes


SATISFACTION with this years crop is high, and oilseed rape will remain the most favoured break crop in the coming year. Thats according to the third phase of the Novartis survey, which asked growers about the progress of 450 crops from May to harvest, and about sowing intentions for 8,094ha (20,000 acres) in the 99/00 season.

For the 99/00 crop:

&#8226 Between 40 and 75% of growers with Apex, Pronto, Contact, Lipton or Synergy in the ground this year will grow the same variety again in the 99/00 season.

&#8226 100% of those growing Madrigal will grow it again in the 99/00 season.

&#8226 15% of growers will increase their planting area for the 99/00 season.

&#8226 …but 75% will not increase plantings.

&#8226 The overall area is set to fall by 7.5-8% (44,000ha including industrial crops) in the 2000 crop compared with the 1999 crop.

&#8226 42% of this rape area will be replaced with wheat.

&#8226 30% will be replaced with either peas or beans.

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