Organic upland unit cuts N and raises margins
Clover plays a vital role on
one North Yorks moors
organic farm, visitors at a
recent open day found out.
Simon Wragg reports
CLOVER could replace nitrogen on upland farms looking to cut inputs and boost flagging livestock margins.
It is already paying dividends on one North Yorks organic farm.
Howard and Rosemary Wass, who farm 78ha (193 acres) at The Green, Fadmoor, Kirkbymoorside, completed conversion to organic status in 1992.
The switch to organic production offered a more viable income off a traditional upland farm, they explained to visitors at a recent MAFF and Institute of Grassland and Environmental Research open day looking at clovers potential on-farm.
Recognising the benefit of clover to his system, Mr Wass told the meeting that clover use on conventional farms could reduce fertiliser applications even when artifical nitrogen is about £85/t.
Margins are boosted further by finishing cattle and lambs. These are sold almost exclusively through the Organic Livestock Marketing Co-operative, achieving deadweight prices of £2.40p/kg and £2.80p/kg at carcass grade R4L.
The 26-cow cross-bred Limousin suckler herd and 200-ewe Suffolk and Mule flock graze about 45ha (110 acres) of grassland rising to 200m (650ft) above sea level. The rotation includes a three-year ley, potatoes, winter wheat, vegetables and spring cereals.
"There is a lot of talk about picking the right grasses to suit clover, but here we use a commercially available mix of 1.5kg/acre white clover blend, 1kg Timothy, 2kg Portstewart, 3kg Moy, 3kg Condesa and 3kg Rosalin," said Mr Wass.
Red clover is sown as a green manure under wheat and ploughed in to help boost soil fertility in the arable rotation.
Ian Rhodes, head of clover breeding at IGER Aberystwyth, told visitors that clover required a firm, shallow seed-bed in a soil of neutral pH. Clovers lifespan is largely dependent on how heavily it is grazed, whether additional N is applied and whether it is allowed to seed, said Mr Rhodes.
Clover has many benefits apart from fixing nitrogen, he said. "It does not germinate all at once. Some seeds may lie dormant for up to 18 months allowing new growth throughout the leys life."
Although early clover growth could be disappointing compared with grassland receiving inorganic N, new varieties could tolerate applications of 200kg/ha of nitrogen a year (160 units/acre), and show sustained growth, he added.
But management of clover-rich swards demanded attention, said Mr Wass. "Grazing sheep firms up the ley, whereas cattle tend to poach our ground."
But over-grazing with sheep on new swards must be avoided as they ate it down to the ground and it would not recover, warned Mr Rhodes.
Care is taken not to graze fresh pastures until they were mature otherwise bloat could occur, explained Mr Wass. Breeding new clover varieties with high levels of natural tannin could overcome bloat risk. These should be available in the near future, according to IGER researchers.
Weed control is also important. Clover-safe herbicides can be used but are more costly than conventional sprays, therefore, weeding is done manually or mechanically. Spear thistle is hand-pulled each spring and creeping thistle is grazed and/or mown later in the growing season. Docks are pulled out of cereal crops in the rotation by hand.
Poppies are prolific and can be a problem. If seeds are trapped in straw fed during the winter they will pass through dung and manure to germinate in grass leys during spring. "It is better to sacrifice some baled forage rather than risk introducing poppies again next year," said Mr Wass.
Despite a lacklustre start to the growing season compared to N-treated conventional swards, the grass/clover mix provides highly digestible forage at a time when poor third-cut silage would normally be taken.
Mr Wass finishes all stock mainly off grass/clover swards. Lambs are finished at about 40kg liveweight from July onwards, while cattle go at 20 months old or about 600kg liveweight. In their second winter, calves are housed from October to March and fed ad-lib silage and up to 700g a head a day (1.5lb a head) of rolled barley before finishing on spring grass.
"We have to watch the heifers though; it is not an intensive system and they tend to get fat before hitting the target weight," said Mr Wass. This means heifers often fetch a lower price as they fall outwith the R4L grade. "The last heifer sent away weighed 290kg dead and graded R4H, making £2.30/kg deadweight."
Lambs destined for the supermarket trade go via the co-op. "Even though some lambs have not achieved the target, premiums have been paid as there has been a shortage of supply," he said. *
• Fine, firm seeded needed.
• Avoid overgrazing with sheep.
• Lower bloat risk with new varieties.
• More tolerant of nitrogen.
Organically reared stock fetches a good premium for Howard Wass, who finishes cattle and sheep at The Green, Fadmoor, North Yorks.
IGERs Ian Rhodes (left) discusses the benefits of clover with upland organic producer Howard Wass.
Howard Wass (centre, white shirt) explains the widening appeal of clover at the recent MAFF/IGERopen day held on his farm.