Widening the harvest window with grain maize

Grain maize is often perceived as a marginal crop for the UK, but two growers have been successfully growing it for years.

Grain maize is an effective spring break crop for Oxfordshire grower Mike Harper, who is now into his eighth season with the crop, with average gross margins of £940/ha comparing favourably with beans or linseed.

He started growing grain maize for feed compounders in 2004, but now he also grows the crop for crimping for local dairy farms.

Grain maize has found a place in his rotation of wheat followed by maize, then oats, wheat and oilseed rape, at Pimlico Farm, near Bicester. Because the maize is late to harvest, with most taking place in November, when ground conditions can be poor, he prefers to follow with oats rather than wheat.

“Oats follow grain maize because we feel it’s a waste to try and grow a first wheat, due to the late planting,” he explains.

“There is a big impact on the following crop, so we direct-drill oats into the maize stubble. They don’t always go in so well and there’s a lot of trash to deal with. But oats are a hardy crop and they tend to cope better than putting in a bad crop of wheat.”

Varieties

Last year he grew 120ha of grain maize on limestone brash soils, including K13, V43, Falkone, Proxy, Feldi – and a new early variety from KWS, Coryphee.

“Coryphee did well for us this year, but it hasn’t been streets ahead of the others,” he says. “We were pleased with its early vigour. It has got a nice bold grain to it, which would be more suited to a flaking market rather than just compounding or grinding up for animal feed.”

Mr Harper says the cost of seed is a big consideration when choosing varieties, because all his varieties are hybrids and, consequently, they cannot be farm-saved.

He likes to drill his grain maize in the first week of April at a seed rate of 80-85,000/ha, but the soil temperature needs to be 8C and rising for the crop to get off to a good start.

“It likes a warm seed-bed, thrives best in hot conditions, and doesn’t like exposed or windy sites. You notice that it does really well in sheltered areas,” he adds.

Weed control

Grain maize hates weed competition, so keeping the crop clean is vital or yields will suffer, he says.

Mr Harper will generally apply a pendimethalin-based spray at pre-emergence, followed by a contact herbicide – usually Samson (nicosulfuron) – to control grassweeds. “Because we are not growing grain maize in tight rotations, we don’t have to use expensive chemistry,” he says.

No fungicides are required, although a foliar feed product, such as Maize Boost – which is a foliar phosphate with zinc, magnesium and potash, may be applied to crops that do not get off to a good start,

Mr Harper’s crops always receive a starter fertiliser at drilling, such as diammonium phosphate or mono ammonium phosphate. However, only a small amount of nitrogen is required – about 60kg/ha.

Potash indices should be kept reasonably high. “It’s quite a hungry crop in respect of P and K, but it doesn’t rob the ground of much because a lot of the bulk is going back in,” he says. “With a forage crop you are taking away 15t/acre of organic matter, whereas we are taking away three to four tonne/acre with grain maize.

“There’s a whole lot of organic matter going back onto the ground in the stalk. While we do pile on the P and K for the grain maize it does tend to give us a bit of a break for the following years.”

He combines his grain maize with a Claas Lexion 550, fitted with a specialist Claas eight-row maize header. A key factor with harvest in the UK is the need for rapid drying. “It is usually harvested at about 30-35% moisture and it needs to be dried quickly,” he says.

He uses a Carrier continuous-flow grain drier to get the crop below 15% moisture. “It’s usually put through the drier twice to get it below 15%, but this needs 50 litres of kerosene a tonne so it’s not cheap.”

One key advantage is that it spreads out harvesting. “It’s 300 acres (120ha) we don’t have to cut in August, which spreads the workload and machinery costs – but the downside is that you cannot lock the combine away at the end of summer.”

After harvesting, his grain maize is either crimped or dried before it is sold to the animal feed market.

UK-grown maize is gaining a better reputation among merchants, who are using it and importing less French grain, he notes.

Margins are not quite as good as oilseed rape or wheat, however, and the late harvesting has a significant impact on the following crop.


High margins and high drying costs 

High margins With margins regularly matching returns from Group 1 milling wheat of around £800/ha, grain maize is a key break crop for one Dorset grower, although creeping barnyard millet is becoming a problem weed.

Peter Bailey finds that the crop performs well on his drought-prone soils at East Close Farm, an 800ha unit located at Hinton, near Christchurch.

Despite the high drying costs, his grain maize crop can produce some high margins and it also helps widen his harvesting window.

Yields of 10t/ha have been achieved and the crop, which he has been growing for the animal feed market since 2003, can fetch £25/t more than wheat.

Agronomically, Mr Bailey treats his grain maize crop similarly to forage maize, although seed rates are lower at 80-85,000/ha than the 105,000/ha with forage crops.

Slurry and cow muck are widely used and phosphate levels in the soils are quite high as a result of using sludge cake from water treatment works. A little nitrogen, 35-40kg/ha, is applied where sludge cake has not been used.

Potash is applied using a variable rate spreader according to nutrient maps, with some areas getting 100kg/ha and others double this, depending on need.

Creeping barnyard millet is becoming the main problem weed on his farm, but he prefers to see target weeds before choosing an appropriate post-emergence herbicide, such as Calisto (mesotrione) or Calaris (mesotrione + terbuthylazine).

Because his ground is fairly light, manganese, boron and possibly zinc are applied as trace elements to the maize crop, often alongside the post-emergence herbicide.

The crop is dried using a Carrier continuous-flow grain drier. Surface moistures vary, but are normally between 35-38% when the crop is rain wet.

High-yielding early varieties such as Coryphee are preferred, but because of the later harvest, choosing a variety with good standing power is essential, he says.

A variety that can offer a strong visual aspect can also increase its marketability, he adds. “We select types that have a good kernel colour as buyers favour a strong, brighter yellow/orange for use in high-value chicken feeds.” 

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