THE CONSISTENT quality of maize silage compared with grass silage has long been the preferred route to high yields for Velcourt”s Evershot Farm near Dorchester, Dorset.

But with access to just 182ha (450 acres) on which to grow continuous maize, and 720 high yielding cows to feed, every maize plant and cob has to count.

And for the past few seasons, the farm has been looking at ways of producing more maize from the same area, to cut reliance on grass silage which has been found to be less consistent in quality, says farm manager Allaster Dallas.

“We can just about grow enough maize to keep the cows fed,” he reckons. “Without any more land suitable – or available – to grow the crop, we had to look at ways of improving husbandry to get extra maize silage in the clamp.”

The answer Mr Dallas was looking for came in the guise of close-row maize drilling, a planting technique developed by Kverneland for its Accord Optima precision drill, which creates a diamond-shaped seed spacing between adjacent rows of plants.

By precisely staggering the plants in adjacent rows, the manufacturer reckons row widths can be reduced to 37.5cm (15in) while still providing a generous amount of room for each plant to develop.

“It seemed logical to suggest the technique could give each plant more growing space, as critical growth is from 0-4 leaf-stage,” he says. “Anything that can help the crop to establish quickly is a bonus.”

His maize contractor, SC Marsh of Maiden Newton, was in the process of renewing its maize drill and both parties worked together to ensure that the replacement drill – a 12-row Accord Optima – could be cost-effective to both the contractor and Velcourt.

But rather than go all-out at 37.5cm (15in) row widths, 50cm (20in) was chosen to suit wheel and tyre equipment when spraying.

“We only needed a very slight yield increase to offset the additional 12.35/ha (5/acre) that Marsh Contractors needed to cover the extra cost of the drill and we were prepared to give it a try,” he says.

“The crop grew well, and the diamond pattern stopped the plants from bunching up and competing with each other,” he says. “But there really was no indication that we were going to get more than we bargained for.”

Past experience at Evershot has found that 76cm (30in) rows have produced about 37t/ha (15t/acre), giving the farm more than the 6500t it needs to keep its cows producing 10,000 litres a year.

But at 50cm (20in) row spacing, last year”s crop netted 8900t from the same acreage.

“I thought there may have been a few extra cobs and perhaps an increase in starch, but not such a significant increase in yield,” he says. “In fact we”ve gained over 35% more forage, averaging about 20t/acre.”

And Mr Dallas believes the growing season was no fluke, either. A colleague on an adjacent diary unit grew the same variety, but planted in the traditional way, which yielded 37t/ha (15t/ha).

“We aim for a 70:30 ratio between maize and grass silage in our ration,” he says. “The extra forage volume means we can now look at increasing that ratio while cutting back on concentrates.”

Convinced that close-row maize is a cost-effective means of gaining extra forage, Mr Dallas is looking to introduce maize to youngstock, too.

“We”ll be staying with close-row for next season to ensure that this season”s yield was not just a flash in the pan,” he concludes. fwmachinery@rbi.co.uk