Trying it out
on big scale
Coppice cropping got a kick-start when three power station projects were approved under the Non-Fossil Fuel Obligation last December. Here
Robert Harris and Peter Hill assess progress, relay one farmers experiences with coppice and report on continuing enthusiasm in the Borders
• Operator – South Western Power
• Sites at Eye, Suffolk and Cricklade, Wilts
• 5.5mW each – enough for 20,000 homes total.
• Planning permission expected spring 1996 and autumn 1996
• On line in 1997-98
• 2500ha of coppice to supply 33,000t.
• Minimum 10ha at each site to make harvesting viable – neighbours could share area.
COMMERCIAL size plots of willow coppice are growing at several sites across southern England to pave the way for thousands more hectares expected by the end of the decade.
The crop will be the main fuel for wood-burning power stations operated by South Western Power at Eye, Suffolk and Cricklade, Wilts, which are expected to be generating electricity by 1997.
Eight sites, each of 4-7ha (10-17.2acres), have been planted from Suffolk to Hants on a range of soil types, says Nigel Viney, energy production manager of fuel supplier Banks Agriculture. The aim is to discover and solve the problems of growing coppice on a commercial scale. "Anyone can grow good yields of weed-free coppice on small plots," he says.
Between five and 15 varieties have been planted at each site to find out which do best on particular soils. Project co-ordinator Ros Twemlow hopes to discover why crop output varies across seemingly uniform soils by using SOYL nutrient maps to see how growth compares with soil nutrient status.
This could then be used to target fertiliser, as sewage sludge, to suit.
Herbicide studies will identify which products to use and when, she adds. "There are few contact herbicides that can be used on willow. Once residuals applied at planting have broken down, it can be difficult to mop up remaining weeds."
Varieties are grouped in blocks, because the sites are being used as a source of cuttings for future sites. In farm plantations, these would be mixed to reduce the spread of potentially devastating willow rust.
"We hope to plant at least as much next year, but we shall use poyclonal mixes to identify those giving the best control," says Miss Twemlow.
A few growers will be sought next spring. But most of the 15 year index-linked contracts will be sent out in time for planting in spring 1997, says Mr Viney. He is confident that the 2500ha (6175 acres) needed to supply most of the 33,000t of dry matter which will be burnt at the power stations each year will be planted. The balance will consist of forestry residues and existing coppice.
"There has been a good level of farmer interest, though the current level of income on arable farms has blunted enthusiasm somewhat. But with the balancing of rotational and non-rotational set-aside, at least they wont suffer a penalty for planting coppice."
Mr Viney is coy on the price Banks will pay for the fuel. "We realise it will have to make a premium over set-aside."
The crop is a low input one, emphasises Miss Twemlow. "Farmers will have to prepare the seedbed and apply herbicides for the first two years – the root structure and leaf mulch should stop further competition. But planting, harvesting and haulage will be carried out by contractor."
Predicted minimum yield is 12t of dry matter/ha (4.85t/acre) a year. But Mr Viney believes that is conservative. "Once farmers get hold of it, with their level of skill and timeliness, I think yields will rocket."
Norfolk farmer Stephen Rash (right) is host to a 3.5ha willow trial at Hall Farm, Wortham, near Diss. Banks Agricultures Ros Twemlow (left) and Nigel Viney will investigate nutrient effects at the site. Narrow-leaved varieties have put on "startling growth" on the loamy sand site despite little rain since June. With beet and cereals underpinning profits, Mr Rash suggests coppice will have to give him £250/ha (£100/acre) profit a year to be a worthwhile enterprise on his farm.