Letter from Europe: Europe's revolution in sowing systems

Monday, April 5, 2010

Though plowing could remain in favour for some time yet, sowing systems are changing fast, with broadcasting and band sowing making headway

by NORMAN DUNN

Never has European cereal and oilseed production been more diversified when it comes to ways of establishing the crop: From central France to Sweden, no-plow
systems have gained a good hold. In Britain and France, for instance, an estimated 40 to 50 per cent of arable land is now under minimum tillage.

But it's a tough task unearthing precise statistics, because I come across farmers every year who officially stopped using the plow on their wheat, barley and canola fields maybe 20 years ago but who have started again, at least in some years.

Try direct drilling a badly rutted field after a wet sugar beet or potato harvest, for instance. There's nothing to beat the plow for levelling disaster areas like these. Then there's the growing problem of herbicide resistant grass weeds. Minimum – or conservation – cultivation seems to encourage their growth in some areas. Plowing at least buries the seeds deep.

Of course, the various no-plow systems can be much cheaper than inversion. Recent research in France and Germany claims reduction in costs from 25 to 30 per cent. And then there's the role a low level of field surface disturbance has in reducing soil-moisture loss or erosion, surely among the biggest arguments for stopping soil inversion.

Because Europe hasn't these problems to the same extent as regions such as North America, plowing could well stay an important part of this continent's cultivations for the time-being anyway.

But changing relentlessly in Europe, and particularly in Britain, are sowing systems. For instance, canola is increasingly being broadcast into uncultivated stubble straight from the combine.

A few years ago electronic or hydraulic canola seed broadcasters first made their appearance mounted on the cutter bars of combine harvesters, and last fall in England I noticed more than ever in use.

Fall-sown canola is common there and farmers I've spoken with who use the header broadcasting system claim they get the same yield as with conventionally drilled canola – although sowing rate is usually upped by 10 per cent. This spreads the seed direct on the stubble, where it's then covered by the straw from the back of the combine, ideally evenly-chopped and distributed. In damp British conditions, snail control pellets are a necessity and many operators mix those 50:50 with the canola seed in the broadcasters. 

Broadcasting cereal seed from a fertilizer spreader on plowed or minimum-till land and harrowing it in was a simple and efficient establishment method that maybe didn't lead to great yields, but it certainly harvested great news stories for the European farming press back in the 1980s.

Now, a variation on this theme is becoming more popular: This January at LAMMA, Britain's largest farm equipment show, one grain drill after the other offered alternatives to the more common single-row drilling of cereals with seed being spread over a number of centimetres instead of placed one after the other in a slit.

For instance, this "band sowing" approach has been taken up by the British "Simba" manufacturing company with winged coulters or seed shares effectively spreading the seed even wider than this, so that the corn covers around 80 per cent of the field surface. As sowing rate is not increased, this offers more space per plant with resultant better rooting and tillering.

Other companies are offering new drills with 75-millimetre bands for this spring's sowing season. The British manufacturer, Claydon, has also just launched a new "Hybrid" drill that sows grain in 180-millimetre-wide bands, which are themselves 300 millimetres apart. A single tine ahead of each winged seed coulter creates a thin cultivated strip in the stubble with the coulter spreading the seed onto the displaced soil. Instead of conventional press wheels or rollers for reconsolidation of the sown strips, simple metal "paddles" then press the soil down, levelling the field surface.

Development manager Spencer Claydon says that this new pneumatic drill incorporates a relatively simple design, which can cover six metres at a pass and still fold into under three metres breadth to conform with European highway traffic laws. There's a 1,600-litre seed hopper and centrally-mounted wheels controlling drilling depth.

Why was the "band format" chosen this time? "Well, we actually started band sowing with earlier drills manufactured by our family firm because we found that the concept, with its simple cultivated strips and up to 30-centimetre undisturbed stubble between them, gives a pattern that offers best possible seedling emergence as well as ensuring a lot more light into the growing crop," he explains.

"And the simple tine set-up leaves the farmer flexible, whether drilling is into undisturbed stubble, minimum cultivations or plowed land."

The Claydon family firm tests its machines on the stiff clay soils of its own 1,100-acre farm and says the load-bearing capacity of the field surface is also greatly boosted by the band sowing system, as is erosion resistance and drainage.

This band-sowing idea has certainly been saving on inputs. In farm trials last fall, direct drilling wheat into stubble this way saved around C$120 per acre in crop establishment costs compared with conventional drilling into minimum till on the same land six years ago. BF

Norman Dunn writes about European agriculture from Germany.