Having an effective plan B is vital when growing oilseed rape, as making the wrong decision when redrilling a failed crop can cost farmers up to £674/ha in lost margins, according to data analysis.

This season is set to see the smallest OSR crop for more than 40 years, with the recent AHDB Early Bird Survey forecasting just 239,000ha.

This decline from 530,000 in 2019 is down to the increased risk of crop failures since the loss of neonicotinoid seed treatments.

See also: How an Essex oat grower hit variable cost of £48.50/t

Spring management

For those farmers persisting with the struggling crops, they face the decision of how to best manage them in spring.

Do they persist with a patchy thin crop with a reduced yield potential or redrill with a spring crop? And if opting for the latter, is spring barley the best option to salvage some returns?

© Tim Scrivener

Costs for range of scenarios

To offer some pointers, data firm Yagro has analysed variable costs to identify the likely impact to gross margins of a range of scenarios.

These include sticking with the crop and accepting a lower yield, redrilling with spring wheat, redrilling with spring oats or using the opportunity to opt for a longer-term SFI option such as AB15 legume fallows.

The analysis was carried out using Yagro data for all variable costs incurred up to 31 December 2023 and offset against the average gross margins of spring crops in that season.

Becca Doherty, data analyst at Yagro, says unsurprisingly, the highest gross margin was for an OSR crop yielding more than 1.5t/ha, with a median gross margin of £1,153.48.

This was based on an OSR price of £541/t.

However, persisting with an oilseed rape crop with a lower yielding turned a loss of £315.83/ha.

Becca says this shows it is easy to lose money with rapeseed if farmers get it wrong. The average winter variable cost of OSR was £261.38/ha.

Oats and barley

One popular option is to redrill with spring barley and this resulted in a gross margin of £179.68, so back to a positive return.

However, opting for spring oats instead saw this rise to £357.98/ha.

This greater return reflects the lower cost of growing oats (£371.62/ha versus £439/ha) and stronger oat prices.

Risks

In conclusion, Becca says the data highlights that oilseed rape can be a risky crop. While nothing replaces a good OSR crop, the worst option is a poor crop of OSR.

She says it highlights the need to have a good handle on costs and to have a good back-up plan based on data.

“Spring barley is a popular alternative, but as the data shows, it may not be the best option.

“Analysing the numbers allows farmers to make informed decisions, rather than sticking with something because it’s what they have always done in the past.”

These figures are part of Yagro’s Harvest 2024 Analysis report, which is due to be published in the coming days at yagro.com