Frozen food company Birds Eye, whose vining pea operations are based in Yorkshire, is going to great lengths to secure the long-term future of local pea growing by developing and adopting sustainable farming methods.

Over the past five years, Birds Eye has been developing a pathway to increase vining pea productivity while protecting the fertility and viability of the land for future generations.

This approach includes breeding new resistant varieties, developing a new drill to aid establishment, and trialling and adopting the latest biological products.

See also: 5 key factors for maximising pea yields

Challenges

In 1924, Clarence Birdseye invented “plate frosting” as a way to rapidly freeze fish, starting the frozen food revolution.

The company’s frozen peas have become a household staple and for the past 50 years, UK production has been located around Hull.

A key differentiator for the company is the quality of its peas, and this is achieved by freezing within 2.5 hours of being picked.

Richard Wilson, the UK agriculture manager, explains that this is because once picked, fermentation starts in the pea and this results in bitter, off flavours.

“Therefore, we need to stop this process as fast as possible.”

This time constraint sets the maximum radius of growers around the factory.

When combined with the long history of legume cropping in the local area, there is a need to sustainably manage the land to enable another 50 years of pea growing, he says.

True sustainability

For Birds Eye, this means raising production as well as having an environmental focus.

Richard explains that if they can raise output per hectare, they can reduce the land required, thereby enabling farmers to extend their rotations.

Increasing productivity also increases the profitability to growers and results in more efficient operations such as harvesting and hauling peas at harvest.

Ultimately, the measures will also reduce the carbon dioxide emission footprint of the operation.

Farmers Weekly looks at several measures being developed and deployed by Birds Eye and the Green Pea Company, which exclusively grows vining peas for the processor.

Extending rotations

Back in the 1950s and 1960s, peas were typically grown in one-in-four rotations, but this risks the build-up of pathogens such as foot-rot.

Crops are now grown in wider rotations with the minimum being one in six years, and higher risk fields being one in eight or even longer. 

Trying to avoid the build-up of soil pathogens is critical, as data from Sweden shows it takes up to 20 years for pathogens to fall back to acceptable levels after removing legumes from the rotation.

One way Birds Eye is managing these levels is through soil pathogen testing.

Two years ahead of growing a crop, soils are tested in the higher risk fields to get a clear picture of the land bank.

Soils are sampled over the winter months with the samples sent to an R&D site in Sweden, which is owned by Birds Eye’s parent company, Nomad Foods.

Seed is sown in the samples and soil pathologists carefully examine the subsequent root structure for any signs of disease like foot-rot.

James Mason, Birds Eye senior agriculture fieldsman, says: “This gives us a snapshot two years ahead of planting and we can decide whether to risk planting a crop or to rest the land for longer.”

If they do decide to sow a crop, some of the risk can be managed by selecting more resistant varieties, opting for later drilling when soils are drier, or the use of biological products.

Birds Eye tests about 350 fields annually, which equates to around half of the growing area. Higher risk sites include lower glacial soils that easily retain moisture, while the more free-draining soils on the Wolds are lower risk.

“This is because at 40% field capacity, you get free movement of pathogens,” James explains.

Drill technology

The Green Pea Company (GPC) co-op uses Herriau precision pea drills.

James explains that rather than having a disc coulter, these precisely place the seed using a chisel tine followed by a steel press wheel to cover the seed.

He recalls that inconsistent establishment in the 1990s prompted the adoption of the specialist drill.

The aim is to precisely place seed in moisture to achieve uniform emergence.

“If they emerge together, they will flower together and be harvested together at the same quality,” he says.

“A staggered emergence can impair eating quality as peas will be at different stages of maturity.”

The benefits are especially evident in a dry spring like this year’s, helping to make establishment more resilient in extreme conditions, both wet and dry.

New folding drill

This spring saw the debut of a folding version of the drill built by the GPC.

Mark Stocks, grower and board member of the co-op, explains that it is easier to transport on the road and is also much lighter after removing the fans, replacing them with electric singulation of seed.

Reducing weight will save on fuel and, ultimately, it can be pulled with a smaller, lighter tractor which helps reduce the soil compaction risk.

The co-op is planning to build a second drill in time for spring 2027.

Biological products

With the Wakil seed treatment no longer used, vining pea growers need new solutions to manage damping-off, downy mildew and ascochyta species.

One promising alternative highlighted by James is Prestop.

Based on a naturally occurring soil fungus that contains mycelium and spores of the Clonostachys rosea strain J1446, it is a biological fungicide used in the production of vegetables, fruits, herbs and ­ornamentals.

The product was trialled on early drilling land in Lincolnshire which has a relatively high pathogen load.

It is placed near the seed using an applicator on the drill. In trials, they saw 50% control of the pathogens including foot-rot and its use has been subsequently rolled out across 700ha.

Last year saw an average 92% return for the grower group, and this year they are seeing 100-106%, with more peas being produced from the same area.

Also being applied at drilling is a soil inoculant aimed at improving soil phosphate availability.

James explains that in later drillings, they can see phosphate lock-up, especially on the high Wolds.

The seed-bed product Rise-P consist of a Bacillus subtilis strain which is symbiotic with pea roots and unlocks some of the phosphate in soil.

Nitrogen

Another product being used is a photo catalyst which is applied as a foliar spray.

The coating converts nitrous dioxide in the air into nitrate in the leaf, which the plant can use.

The Green Pea Company is seeing a 10% increase in pea yields.

The greenhouse gas benefits are being quantified in a project with the University of Lincoln. Researchers are measuring greenhouse gas levels to quantify and validate any savings in emissions.

James explains that nitrous oxide is 234 times more potent than carbon dioxide as a greenhouse gas.

Not only is the product feeding the plant and increasing yields, it removes carbon dioxide equivalents from air. So it is good for the environment.

Wild flower margins

While Birds Eye does not prescribe growing flower margins near peas, it is a useful option for unproductive parts of the field, resulting in a more efficient use of crop and operational inputs.

To help farmers, the company offers free seed in a seven-species mix which is Sustainable Farming Incentive AHL2 compliant.

The mix contains clover so that it fixes nitrogen, thereby offering a similar benefit to the following crop in terms of fixed nitrogen in the soil.

Some growers including Mark – whose family farm near Bishop Burton has been growing peas since 1968 – also sow summer cover crops after the peas.

He says this avoids leaching from June to October, capturing nitrogen ahead of the following wheat crop.

Future challenges

Aphids are becoming a bigger problem due to climate change.

Birds Eye has adopted an integrated strategy by harnessing natural varietal resistance (variety) and location.

“We tend to see fewer aphids on the top of the wolds and less virus.

Down at river level, we are seeing higher levels and so may need to change the timing in the coming years,” says James.

It is also working with the Processors and Growers Research Organisation which is carrying out virus surveillance to identify risk and allow a more targeted, threshold-based approach to aphid control with the insecticide Teppeki (flonicamid).