Arable and dairy producers in a marginal maize growing region are reporting significantly higher yields and early harvesting by growing maize under film.

Mark Pethick and Patrick Barrett farm four miles apart near Callington in east Cornwall and both grow large acreages of maize.

Mr Pethick produces around 2,000 tonnes of crimped maize grain to sell to livestock farmers and Mr Barrett grows 150 acres of forage maize, which accounts for 70 per cent of his Holstein herd’s feed ration.

They have both been growing maize under film using the Samco System for five years and are delighted with the results.

Mr Pethick, of Church Park Farm, says he has increased the crop yield by two tonnes/acre of grain and achieving moisture levels of just 35 per cent harvesting early while Mr Barrett has doubled yields to over 20 tonnes/acre yields with a starch and dry matter levels of over 30 per cent.

Both agree that maize production had been challenging before they used film on the crop. “I was really struggling to ripen the cobs and this meant I had poor starch levels, low yields and very acidic wet silage. I had to feed a starch supplement to counter this,’’ says Mr Barrett, who milks 450 high yielding Holsteins at Trellasick Farm, Stoke Climsland.

Agronomist Barry Mills, of The Grain Maize Company, says growing maize under plastic will accelerate harvesting by four weeks with obvious benefits.

“If maize is being grown conventionally, it is a bonus if a farmer can plant a crop the same autumn after grain maize. Using the Samco System more or less guarantees that,’’ he says.

There are benefits for the soil too. “Crimped maize is usually harvested in November or December and this can damage the soil structure, impacting on the yields of the following crops. A field can take years to recover,” says Mr Mills.

Mr Pethick has harvested crimped maize at the end of September since he started using the Samco System.

He farms 900 acres of arable crops, including 400 acres of maize. His land rises to 700 feet and the average rainfall is 1700mm. He admits the conditions are less than ideal for maize production.

“We had been muddling along for years but were getting poor yields. Film guarantees us a decent crop, in a good year we can get forage yields up to 27 tonnes/acre,’’ he says.

Mr Pethick adopted the Samco System when he made the decision to focus on growing maize for crimping. “We couldn’t get the crop mature enough in this area without film. It brings maturity forward by up to six weeks,’’ he says.

He is also able to drill earlier – this year on March 23 – because the soil temperature under the film quickly reaches around 20 degrees C and protects the germinating seeds and young plants. “Without plastic we would have to wait until the soil temperature was around 8-10 degrees C but with plastic it can be as low as three degrees C. We have even drilled it in the snow,’’ he says.

The soil at Church Park Farm is a medium loam and the soil analysis is typically 2 index for phosphate and 1 index for potash.

Crucial to the success of the maize crop is the structure of the seedbed. Residual herbicides applied to protect the crop from weeds rely on a fine seedbed to be effective.

Mr Pethick ploughs, subsoils and power harrows before drilling. He uses several Pioneer seed varieties including Justina and Benicia.

At Trellasick Farm, consistent yields and crop quality are a priority for Mr Barrett. “Plastic film is our insurance policy, it smoothes out any seasonal variations and means we have a large enough crop to feed 12 months of the year,’’ he says. “We are getting good starch and D values and that gives us an ME of over 11. That’s what drives milk production.’’ His herd produces a milk yield average of 9,500 litres with a butterfat average of 3.4 per cent and 3.3 per cent protein.