iOSR in Germany
With most UK growers looking to finish oilseed rape sowing by the end of August, or the first week of September at the latest, crops are among the earliest in Europe to get going; growers in France and most of Germany typically have two to three weeks longer.
The difference in sowing date is also reflected in higher seed rates and plant populations, according to Syngenta’s European Oilseeds Manager, Gary Jobling. “In the UK conventional varieties are still typically sown at 70 to 80 seeds per m2, with hybrid varieties at a lower 50 seeds. In Germany it is almost exclusively hybrids, sown at 35 to 45 seeds and in France mostly at 35 to 40 seeds.”
When it comes to autumn N, he reported UK growers are increasingly applying up to 30 kg/ha, whilst in France it would almost never be used. Growers in Germany have historically applied 20 to 40 kg/ha, but they are moving away from the practice with the suggestion that it only created leaf area with no beneficial autumn root effect, and no effect on the final yield.
For spring nutrition, Mr Jobling reported growers in France were at the lowest for N applications, typically using 120 to 170 kg/ha, split in two to three doses. In Germany, N use had widely been up to 220 kg/ha, but had generally reduced to 180 kg/ha as the optimum. In comparison, UK growers were still applying 180 to 230 kg/ha in the spring.
A further agronomic difference across Europe that surprised UK growers was the fact that very few German growers, and none in France, desiccated their oilseed rape crops – compared to over 70% of crops that are chemically desiccated or swathed in the UK.
Most of the oilseed rape in Germany is grown on the larger farms in the east of the country, where the average farm size is just over 1000 hectares and the average OSR area is 188 ha per farm – equating to around 20% of the cropped area. On the smaller farms in the west of the country, with an average farm size of under 150 hectares the OSR area is around 25 hectares, or 15% of cropping.
At a total of 1.3 million hectares, the country’s Syngenta OSR Manager, Alexander Wendel, said oilseed rape is the third largest crop area, after wheat (3.3m ha) and maize (2.4m ha). Most of the large farms grow three or four varieties, with hybrids grown on 1.14m ha (88% of the area).
Growers across the country suffered severe Flea Beetle losses in 2014, with no exemption for neonicotinoid seed treatment even in the worst affected areas, reported Mr Wendel. However, most growers had heeded advice to delay sowing for around a week in the autumn and losses in 2015 had been far less severe.
But whilst the season had reduced pest pressure, Clubroot was especially bad in 2015 – and had been an increasing problem across Germany. New third-generation Clubroot resistant varieties have been showing clear yield advantages and being adopted more widespreadly.
German growers had also been quick to adopt new PGR technology for crop management, he advised. They use an autumn application of Toprex (paclobutrazol + difenoconazole) to encourage rooting, enhance overwinter hardiness and improve control of Phoma, followed by the standard spring application used by UK growers against light leaf spot and to manipulate crop architecture for leaf area and synchronised flowering.
With Sclerotinia a similar intermittent problem as experienced the UK, Mr Wendel reported growers had increasingly looked to Symetra (azoxystrobin + isopyrazam). Typically used at the start of flowering, it provided a long window of protection from disease, but also the azoxystrobin component promoted green leaf retention and physiological plant enhancement that produced higher yields every year, even if little or no disease occurred.
Agronomist, Dr Dominik Gerwes, works for Hanse Agrico, with over 400 farmers across Germany. Along with agronomy and business consultancy, the company is pioneering strip till research and the opportunity for precision sowing. He argues the technique can help to protect soils and save water, as well as enabling earlier sowing and improved agronomy. But he acknowledges the company’s trials have highlighted downsides of soil suitability, risks of field hygiene and the lack of knowledge for long-term implementation.
In dry conditions he advocated strip till sowing at 30 seed per m2 resulted in faster germination and more even emergence, compared to slower and intermittent results with conventional establishment at 45 seeds per m2. However, in wetter conditions the results were reversed, with mulch tilling performing better.
Dr Gerwes also reported that, in his research, applying autumn N actually had a negative effect on crop performance if weather and soil fertility conditions were good for growth; plants that grew vigorously in the autumn, to utilise an equivalent of 160 kg/ha N in green leaf, but then lost the leaf area in hard frosts appeared to lose the benefit of the nutrient. However, for later establishment autumn N at 20 kg/ha was helpful – with overall application proving more effective than soil placement under the seed, in his trials.
Farming two kilometres from the Baltic Sea, in the Schleswig-Holstein region of northern Germany, Heiko Lemburg’s oilseed rape has to survive temperatures typically down to -12°C in the winter and up to 29°C in the summer. Yet last year’s crop still averaged 5.2 t/ha.
The farm, at Harzhof bei Eckenforde, has been a pioneer in conservation tillage for over a decade. Whilst that has done away with the plough and power harrow combination that still predominates for oilseed rape establishment in the area, for most of the UK iOSR growers Mr Lemburg’s approach would still appear both power hungry and time consuming.
After combining he would look to make an immediate pass with a straw harrow; then wait a couple of days before making a second pass. That delay helps to achieve a better shatter of the remaining straw debris, he said.
He then makes two passes with a cultivator, the first at 10 cm depth and a second, soil conditions dependent at 20 to 24 cm depth. Following the cultivator comes a rotary tiller to create a seedbed, which is left for anything between three days and three weeks until soil conditions and forecast is good for seedling establishment – when the crop will be drilled with a tine seeder.
Mr Lemburg reported he faces some of the same challenges as UK growers, in the face of intense Flea Beetle damage in 2014, although he too found it less severe in autumn 2015. Cabbage Root Fly is only seen as a sporadic issue, however Clubroot is seen as an increasing problem; with two-thirds of the farm sown to resistant varieties.
One of the key differences for Mr Lemburg is that blackgrass is, currently, still susceptible to sulfonylurea herbicides. However, he is aware that other farms in the region have begun to see signs of resistance developing.
“We are now investigating the potential – and financial implications - for more spring cropping and to extend the rotations,” he said. “If we can see the yields of OSR and other crops in the rotation increase, it should prove positive, as well as help to alleviate the pressure of on blackgrass control that others are experiencing.”