Oilseed rape lost appeal for some farmers following the banning of neonics and issues arising from cabbage stem flea beetle attacks. However, prices are on the rise, and many are now considering whether oilseed might be a worthwhile investment.
Natalie Wood, Country Arable Agronomist at Yara, recently spoke on Yara’s Grow the Future podcast about how those planning for a 2022 crop can best get started over the next couple of months.
“With oilseed rape, it really depends on autumn sowing conditions,” says Natalie. “Last year, we saw an increase as the weather was almost ideal for establishment. Moisture is key for establishing oilseed… if we have enough in that August to mid-September drilling window, we’ll see good establishment conditions again.
Nutrition is a large factor in the successful establishment of a crop. Where possible, Natalie suggests the use of seed treatments to increase that initial speed of emergence.
“Coating the seed ensures that the nutrients in the treatment are concentrated at the source,” says Natalie. “This means as soon as the seed germinates and roots start to develop, nutrients are being taken up.”
Natalie recommends a product containing equal amounts of phosphorous and manganese, both crucial for this early growth stage. Phosphorous assists energy transfer and shoot development, providing a crucial supply for the freshly germinated seed. Manganese plays a role in chlorophyll production, enzyme activation, and carbohydrate metabolism – without it, deficiency will impact photosynthetic efficiency and limit the plant.
How much difference does the right product make? “A trial in 2020 showed weight increases of roots and shoots by about 20%,” said Natalie. “That can make a difference between a vulnerable growth stage to one more able to cope if flea beetle migration has occurred, for example.”
Remember: robust plants are more resistant to any threats that could compromise yields.
As the objective is to improve establishment and get the crop away quickly, Natalie states that fertiliser should be applied as soon as possible after drilling. “It can be tempting to wait until the crop is up and established before applying,” says Natalie. “But that can lead to a self-fulfilling prophecy. If you haven’t set the crop up with its best chance, you can’t expect it to establish very well.”
In terms of product, an NPK is ideal as a starter fertiliser. Potassium also helps root growth and water regulation, which is beneficial if a dry spell hits after drilling. Yara trials have also shown positive associations between NPKS addition and winter survival: a 38% survival rate for NS grades is far below the 90-100% when applying an NPKS, in part due to potassium acting as an antifreeze to prevent frost damage.
“Looking at trial data, we also saw an increase of 0.21 tonnes per hectare when placing fertiliser compared to broadcasting,” says Natalie. “At current prices, that’s roughly £90 per hectare. Having both P and K in your fertiliser will also increase nitrogen use efficiency (NUE). Over nine different sites, trials reported an average 20% increase in N uptake due to P and K – one site even reached 40%, showing just how important P and K are for increasing nitrogen uptake.”
“We need to try and make sure there are no limiting factors as the crop moves through its growth stages pre-winter,” says Natalie. She lists some key micronutrients that are important for oilseed in particular: Magnesium, calcium, boron, manganese, and molybdenum.
“If conditions are right, OSR can put on a lot of biomass in the autumn, which risks deficiencies,” says Natalie. “Taking care of micronutrients will ensure there are fewer limiting factors and trials show an increase of about 0.31 tons per hectares from an application in the autumn and the spring – so micronutrient applications are definitely a good return on investment.”
Looking to 2022
For those looking to invest in OSR for 2022, Natalie is clear that, by taking the right steps, it’s possible to give your crop the best possible start and take advantage of the higher prices: “If it’s possible and you still have capacity, give your seed the best possible start with a nutritional seed treatment“, adds Natalie. “In addition, at drilling – or as soon as possible afterwards – apply an NPKS fertiliser to ensure key nutrients are not limited.”