Oilseed rape crops are showing great promise this year, but careful management will be required to ensure that they achieve their full potential.
While forward crops have taken up reasonable levels of nitrogen during the autumn and winter, the extreme rainfall earlier in the year has led to significant leaching, and early season soil tests show that nitrogen reserves are low. Combine this with the difficulty of completing nitrogen applications before crop height prevented accurate spreading and it is clear that an application of a foliar product, such as Omex Oilseed Extra, will be especially beneficial this year.
Edward Downing, Frontier's southern fertiliser technical manager is clear about the benefits "Oilseed Extra is a foliar nitrogen and micronutrient product which has been specially designed for all varieties of oilseed rape. It applies late season nitrogen, magnesium, sulphur and a range of trace elements to boost the crop through pod-fill and seed ripening."
He continues "If your OSR runs out of nitrogen during the pod filling stage it will senesce prematurely, significantly knocking the yield potential. An application of Oilseed Extra onto pods and upper leaves immediately after flowering keeps the crop growing longer, increasing seed size and subsequent yield."
Andy Eccles, an agronomist with Omex, explains that oilseed rape is a hungry crop in terms of micronutrient requirements. "Published work has shown that foliar application of copper and molybdenum after flowering can increase yield and oil content. We therefore formulated Oilseed Extra with micronutrients, including copper and molybdenum, in addition to magnesium and a biostimulant."
He goes on to note that trials have shown almost double the yield increase following application of Oilseed Extra, compared to foliar urea, and this is supported by Frontier's findings of an average yield increase of around 0.5 t/ha from Oilseed Extra, compared to HGCA reports of an average increase from foliar urea of 0.25 t/ha.
Edward Downing has been closely involved with the Frontier trials. "Over 5 years, we have seen consistent positive yield responses when it is applied in addition to a standard base fertiliser programme" he says. "The average increase we've seen is 0.52 tons per hectare, based on an application rate of 200 litres per hectare."
The results were particularly impressive in 2011 when an increase of 0.8t/ha was seen. "The dry conditions that year meant crops struggled to take up enough nitrogen. If we see a prolonged dry spell, this could easily be replicated this season."
The outcomes observed in the trials are supported by experience in the field. Farming at Lodge Farm, Near Ashby de la Zouch in Leceistershire, Alan and Ken Bonser have used Oilseed Extra for the last 4 years, after they trialled it on one field and could see an improvement in yield and oil content at harvest. This year, the 60 hectare rape crop looks promising, with good flowering and a full stand of a healthy crop. They recently changed from conventional drilling to wider spacing and a lower seed rate, which Alan feels helps get a bolder plant.
"The crop is a lot more forward this year compared to last year, where in some places you could hardly find it! Last year we had to plough up 2 fields due to poor root establishment, not helped by late frost lift. This year the crop is looking good, with just a little waterlogging in the corners, but no big problem. We have high expectations for an improvement over last year"
"We buy the Oilseed Extra though Frontier and apply it after petal fall diluted with water as a single pass. Full petal fall was nearly at the end of June last year, but this year is looking like it will be much earlier, during May".