Learning from the Professionals

Farmers looking for top oilseed rape yields year after year need to apply experience, intuition, flair and a well developed cropping concept in their management. And even all that isn't enough. Every single item has to be exactly right when coaxing best performance out of the new high-yield varieties: cultivations, fertilising, plant protection and, above all, the rotation.

What are the strategies applied by Europe's successful rape growers? To find out, we asked leading farmers from a selection of European regions and here are the answers concentrating on the most important cultivation points such as soil preparation, rotation, fertilising, plant protection and selection of varieties.

Soil cultivations and a well thought out straw management concept emerged as the keys to success. However this may be achieved, the crop should be drilled early and into a fine-crumbed seedbed so that there's a good chance of sufficient development in autumn. Priorities are a well-formed taproot and a root collar diameter of 10 cm.

The limiting factor in the high yield sector is water supply right through the growth period and this can become a problem particularly in continental locations. Barley as opening crop is favoured in such conditions for its role in conserving soil moisture. First of all, barley allows four to six weeks between harvest and drilling of the rape crop, time enough for thorough stubble cultivation. Barley draws less water out of the soil than wheat and this helps growers such as Heinrich-Wyrich Adolphi in Mecklenburg-Pomerania retain soil moisture for rape drilling. The emergence is thus improved.

Minimum cultivation or plough? Cultivations also help achieve a well-aerated soil. Very important with both approaches is the avoidance of barriers in the soil cross section (plough pans, straw mats). Harvest trash from the previous crop must be worked intensively into the surface soil layer. On Deert Rieve's farm in coastal Pomerania, for instance, this is achieved with the Horsch Tiger that works deeper than the plough. When the weather is adverse, however, Petr Baranyk in the Czech Republic reduces the number of bouts in his cultivations. These operations affect the following crop and shallow to medium cultivation depths are required. On nearly all farms very similar straw management strategies are followed. This is the theory, at any rate. Often, however, application of the strategies is very poor due to unsuitable implements being used.

Whichever methods are applied, much depends on the careful matching of rape variety and the targeted plant population in the field. Crop treatment must be "variety-specific" in order to achieve the targeted success. This is where experience counts. With reduced plant population /m2 every variety can develop its own yield potential. Although there are already very good hybrids on the market the majority of our farmers prefer classic line varieties. Only in Mecklenburg are new paths being followed now with 50% hybrid varieties grown.

The right approach for fertiliser application? Especially with no-plough crop establishment, N management in autumn has particular importance. Generally, the top farms in our survey tend to start off with a small initial N application in autumn. Further applications then depend on crop development before the onset of winter. During normal conditions this means 2/3 of total amount and a final application at shooting. Basically, fertiliser application tends to follow a set programme without too many readjustments. Micronutrients and trace elements are often more the problem than the rough guidelines for main nutrients‚ where the fertiliser application scheme can often simply be carried over.

Even when fertiliser application strongly follows a blueprint, soil nutrient supply still remains the yield-limiting factor, particularly in Poland and the Czech Republic and all the more so in a close rotation. This is why, for instance, Axel Herweg in northern Poland puts more emphasis in applying trace nutrients in autumn so that the plants get a good safe start.

Finally, a young growth phase without pressure from biological competitors is of decisive importance. This means that the correct selection of herbicides is important to knock out the weeds especially in autumn. In no case should a targeted insecticide/slug treatment be omitted because, parallel to weeds, pests such as slugs/snails and flea beetle are often underestimated in autumn and destroy a large proportion of the young plant. This is where the top performance farms draw away from the average ones. Because there is no guaranteed formula for treatment of the flea beetle: here: only own judgement and natural damage thresholds. Experience, careful monitoring and correct time of insecticide applications according to requirement are demanded. Skill here decides over the success of the action.

In plant protection decisions, top-performance farms do not belong to the timid players. Dressed seed provides a good starting basis. Weed control is taken very seriously in all the farms. Where minimum cultivation is followed a sharp eye has to be kept on volunteer cereals (barley, wheat, rye) so that these do not develop into competitors for available moisture. "A light remaining dicotyledonous weed population can be tolerated without any great problem but this certainly does not apply to monocotyledons", said Deert Rieve. Herbicide treatments are specific to the situation on the actual location and here there is nothing wrong with using the same approach as the previous year if this has proved itself. Part of standard treatment is fungicide application in autumn and spring (with the exception of the French farm). The autumn applications, in particular, tend to take place in a single operation, or are split when drilling is early to exploit the growth regulator applications. This is particularly important with the taller, older hybrids which tend to be used on Polish farms.

In spring all farmers apply a spray at flowering as an insurance. And, where conditions warrant it, a spray might be applied at budding. Here too, growth regulator applications can be exploited. In France, sunflower crops increase the risk of phoma and sclerotinia pressure so that the solution lies in a widened rotation. Three insecticide applications finish off the plant protection work. Only on the Mecklenburg coast can one keep insecticide applications down to two with a good conscience while northern Poland is subject to an enormous pest pressure so that, there, up to four insecticide applications may occur.

There are wide differences in how the individual farmers form their rotations. Whereas financial grounds are behind 30% rape in Mecklenburg and northern Poland, the farmers in France, England and the Czech Republic prefer (as far as possible) a four crop rotation. In all cases, a cereal is used as opening crop, the crop before this can be sunflowers in France, or grain maize or sugar beet.

Should the economic situation alter, all farmers say they would adjust the rotation. And they would also widen it if pest pressure increased and a readiness was expressed to also make rotation changes to cope with increased weed populations including volunteer rape, as well as intensified disease challenge.

This survey was carried out together with Andreas Baer, NPZ, as well as international cropping advisers Detlev Dölger, Hanse-Agro, and Franz Hollmann.

Heinrich-Wyrich Adolphi, Northern Germany
Barley as opening crop helps save water and improves rape emergence.
Minimum cultivation is preferred although this means volunteer barley has to be sprayed.
Uses four-row cultivator with spring tines and inversion shares + following implement (tine cultivator with disc harrows).
Stubble cultivates, incorporating barley straw, three times, last time deeper.
Aims for good crop establishment in autumn.
Basic manuring with poultry dung.
A full plant protection programme.

Heinz-Josef Dauck, Southern Poland
Seedbed preparation must be right. Prefers winged shares to exploit their tearing effect.
Uses a cultivator-seed drill combination.
Minimum cultivation system with heavy tine straw harrows and cultivator with extra-narrow shares.
Widened rotation with only 25% rape in winter wheat and grain maize.
Favours stubble fertilising in autumn with approx. 40 kg/N and applies more fertiliser afterwards according to requirements. Phosphate is applied at drilling.
Applies a high intensity plant protection programme, important targets are the pests at flowering in spring.

Pierre Lichon, central France
Variable rotation (four or six course) winter wheat/sunflowers, always uses cereals as opening crop.
Prefers minimum cultivations, cereal stubble is always harrowed before the ground is levelled with a skim plough.
Straw is driven-off and stubble incorporated.
Slug pellets are mixed with the seed at the ratio of 2:3 (two parts seed).
Phoma and sclerotinia tolerant varieties are used, autumn application of fungicide is considered as a possibility.

Axel Herweg, Pezino, Northern Poland
Drills early.
Ploughing preferred. Stubble cultivations with two bouts. Aims to avoid establishment of plough pans with chisel ploughing or through variation of ploughing depth.
Mainly grows line varieties but for late drilled crops turns to Polish hybrids.
Because of high pest pressure has to apply insecticides four times.

Deert Rieve, Muuks, Northern Germany
Avoids plough pans through using the Horsch Tiger (deeper than the plough).
Applies no fertiliser on stubble but part applications of magnesium, manganese and boron.
Drills hybrid rapes 14 days later than line varieties.
Applies fungicides very early in autumn, small amounts in split applications.
Perspective: At least 30% and more rape in the rotation, minimum cultivation with the aim of encouraging better rooting.

James Green, England
Aims for a fine seedbed and an earlier drilling date for a long pre-winter development.
Drills rape every fourth year, three times wheat in between.
Line varieties preferred.
Stubble fertilisation applied when plants are under stress (20 to 40 kg N).
Follows an intensive plant protection programme and emphasises good weed control.

Petr Baranyk, Czech Republic
Timely drilling, approx. four to five days earlier; needs an optimum and healthy stand before winter sets in.
Seeding rate to give only 40 plants/m2 where there's no weed competition.
Limited treatment bouts when weather conditions are not good.
Short chopping of previous crop straw and straw distribution evenly along with fertiliser.
Recommends not too fine soil surface. Uses a rotary harrow.

Source: agrifuture (Magazine of the DLG)