Maize variety choice in a changing climate

Selecting maize varieties that fit with plans for a more resilient farming future is a key consideration for one Devon farming family.

Juggling the demands of a dairy unit, several diversification enterprises and a regenerative farming project, Devon farmer Rob Taverner is always on the lookout for simple and effective ways to make his business more resilient.

Rob farms with his wife Helen and son Will, who is the fifth generation to join the business, at 500-acre Lower Brenton Farm, Kennford near Exeter.

The Taverners milk 340 cows, some of which are South Devons – affectionately known as ‘orange elephants’ on account of their long faces, size and colour. The cows lend their name to the farm’s renowned Orange Elephant ice cream parlour, which is open from Easter through to the end of September.

In addition to ice cream, Lower Brenton is home to vines, an orchard, holiday lets, a summer play meadow and a maize maze. The Taverners run their diversification enterprises alongside the farm’s Dadmore Dairy regenerative farming project, which they set up in 2021 in a bid to do what they can on their own farm to tackle some of farming’s major challenges - climate change, biodiversity loss and declining soil fertility – as well as help maintain the Devon landscape in which they farm.

“We are looking to introduce more regenerative farming practices on the farm to help us achieve these goals,” says Rob.

Drought is more often associated with the eastern counties than the South West of England, but summer dry spells are increasingly part of the weather pattern in this part of south Devon, and 2024 was no exception, despite an exceptionally wet spring which saw 677mm of rain fall by March 27, 2024, according to Met Office records.

“This year (2024) has been a bit droughty; we didn't have a lot of rain in July and August,” says Rob.

The Taverners are applying regen thinking to mitigate the effects of weather extremes on their dairy business, with careful choice of forage maize varieties, introduction of herbal leys to replace single species grassland and use of cover crops.

Soil types on the farm run the range from sandy soils to heavier loams. “But we do have a good depth of topsoil, so roots can go down,” Rob adds.

“With the farm getting increasingly dry, the herbal leys will play a crucial role in getting us through the drier months.

“We always have a cover crop after maize, either Italian ryegrass or crimson clover and grazing rye, and that works well to keep the soil alive over the winter and not allow it to slump too much.

“This not only helps to stimulate and protect the soil before we plant our maize crop it also helps us to graze our youngstock, further helping the soil.

“Having maize to feed to our dairy cows is vital for us as we self-feed silage, and maize is the perfect crop because it is easy to eke out without too much effort.”

Top of Rob’s list when selecting maize varieties are good cob size and a relatively early harvest, to help ensure winter forage for the dairy unit is safely in the clamp as autumn sets in, as well as reducing the risk of soil damage in the field.

One maize variety that has done particularly well on the farm in recent seasons is Bayer’s Dekalb variety DKC3218, an early maturing variety bred to produce high dry matter yields across a range of environments.

Rob admits he first came across the variety by chance in 2023.

“We were short of a few acres and were putting a field in late,” he recalls.

“Guy Peters from our seed supplier, ProCam, asked if we wanted to try something different, which happened to be 3218. We did and it proved to be very good last year [2023], so much so that we grew it again this year.

“We grew 12 acres last season (2023) and although it was quite a popular variety this season, we managed to get some seed, and we grew 60 acres this season (2024).

Rob Taverner, Lower Brenton Farm

“We're an early area, so with an early variety like 3218 we can get away without having to take our maize off late,” he says.

Rob’s approach to maize cultivation is a straightforward one. He grows mainly continuous maize, using a contractor to drill the crop into seedbeds created with a plough and power harrow.

Noted for its early vigour and rapid and reliable establishment, the DKC3218 was planted at a seed rate of 42,500 seeds per acre on April 22, 2024, with P and K applied as required in the form of organic manures plus 100kg/acre urea.

While the wet spring meant the 2024 season was a difficult one from the outset, the maize was drilled in better conditions than in 2023, says Rob.

“It was touch and go but, in the end, it was fine, and I was really pleased with how it all went in,” he says.

In addition to the DKC3218, Rob also had crops of RGT Agiraxx and a Pioneer variety for harvest 2024.

“It’s difficult to compare varieties as we grow on a number of different soil types and we find varieties perform completely differently on different areas,” he says.

However, he notes that the DKC3218, with its ‘stay green’ leaf senescence trait, remained noticeably greener towards the end of the season. But with a mid-September harvest the aim, by September 12 the DKC3218 had matured “as you would like it to,” says Rob.

“The sheath around the cob had gone brown, and some of the leaves had started to die back.

“It looked like it would be ready to harvest the following week and the plant, and the cob were at the stage that I like to see at the time of year.”

Conversely, in another field, the RGT variety’s cobs were ripe, but the foliage was green.

“It didn’t look like it wanted to give up,” says Rob.

He also noted differences in disease susceptibility, with eyespot noted in the other two varieties grown for harvest 2024, but no sign of the disease in the DKC3218.

“It looks like it's got some disease resistance when it's challenged,” says Rob.

He is planning to grow DKC3218 again in 2025.

“Because we're a bit drought-prone, if it gets dry in July and August, if we’re not careful we don't get the sort of cob that we want. It was a difficult year this year through July and August, but 3218 produced a good plant and a good crop in droughty conditions. That is a quality I look for and it seems to have that,” says Rob.

Bayer’s own trials have highlighted DKC3218’s exceptional early vigour and ability to perform in less favourable conditions.

Bayer technical manager Ellie Borthwick-North says: “Our own trialling, focused on less favourable maize-growing sites, has shown consistent advantages for our varieties under a broad range of conditions. That’s what Dekalb breeding is all about.”

Taking a peek over a neighbour’s hedge is an accepted part of farming practice, but in Rob’s case it’s not only his neighbours that get to take a look at his fields.

“We farm right on the side of a motorway and so everybody looks at our crops all the time,” he says. “People tell us we grow some of the best crops they’ve seen, but it does mean we've got to get it right, because everyone's looking at us.”

The Dadmore Dairy project

Practices started or planned at Lower Brenton include:

• Rotational grazing, using FYM to fertilise the soil

• Planting pasture with diverse grasses, herbs, legumes, and flowers

• Regular monitoring of soil health, including organic matter and carbon content

• Laying new traditional Devon hedgerows for wildlife to thrive

• Planting native trees to extend existing woodland

• Breeding healthy cows well suited to grazing outdoors

• Using renewable energy for farm buildings and switching to electric vehicles