and the environment

10 January 1997

Benefits for the bank

and the environment

How do you fancy a £2000/ha cereal gross margin? According to work at ADAS Terrington organic wheat is economically viable and can outperform the best conventionally-grown crops. Edward Long reports

ORGANICALLY-GROWN wheat yields 40% less than conventionally-grown crops, but lower input costs and higher prices mean it is more profitable.

That is the picture emerging from a MAFF-funded study at ADASs Terrington siltland research centre near Kings Lynn, Norfolk. Organic farming has been studied there for several years.

A total of 10ha (25 acres) of marine silty clay loam has been converted. Wheat, potatoes and beans are cropped with red clover in a five-year rotation.

"We are doing this on 2ha blocks, not small plots, and have been amazed at the results so far," says Terringtons Bill Cormack. "After four harvest years we have the makings of an economically-viable organic rotation, with no livestock to provide the fertility."

Currently a lot of the chemical-free wheat used here is shipped in from overseas. MAFF is keen for those imports to be cut by UK arable farmers supplying more organic wheat.

Terringtons five-course rotation starts with Merviot red clover, which is included in the set-aside allocation. It is cut four times and mulched into the soil to boost initial fertility for following crops.

The first cash-generating crop is Sante potatoes, followed by Hereward wheat, then Alfred spring beans. Axona spring wheat, undersown with clover, brings the rotation full-cycle.

Winter wheat and potatoes are the main money spinners, spring wheat and beans just about hold their own economically, and beans fix atmospheric N to top-up soil reserves before clover comes round again, explains Dr Cormack.

The marine silt is easily damaged and compaction a constant threat, so a minimum cultivation policy operates. After potatoes are lifted the land is not usually ploughed for the following wheat.

Hereward is put in with a pneumatic drill in October at a seed rate of 200kg/ha (180lb/acre). That is more than normal, as a thick crop is needed to suppress early weeds. Non-organic seed is used, but left undressed.

Initially the plan was to delay sowings to give time to tackle weeds and minimise autumn disease. But awkward soil conditions in late October and November delayed drilling and forced a rethink.

After drilling little else is done, apart from tine weeding in the spring, if needed. It is hard to match crop growth stage to weed development and soil conditions, so this is not particularly successful.

The threat from weeds is Dr Cormacks biggest worry, particularly a build-up of perennial thistles and couch. A drag harrow has been used to pull up rhizomes for a gang of casual labour to collect.

Disease has not been a particular threat in the organic wheat. In some years, not 1996, sulphur was sprayed to control mildew.

In 1996 Hereward yielded 9.8t/ha (4t/acre) of grain at over 9% protein. With a premium-loaded price of £200/t for milling, an area aid payment of £267/ha (£108/acre), and input costs totalling just £65/ha (£26/acre), it produced a gross margin of over £2000/ha (£809/acre).

The farms conventionally grown Riband and Hunter yield 11-12t/ha (4.5-4.9t/acre) and last year gave a gross margin of £1150/ha (£465/acre). That year organic Hereward did £1700/ha (£688/acre).

"Soil is the key to success," says Dr Cormack. "We have ideal land, which is highly moisture-retentive, and nutrients are available for longer in the rotation."

The marine silt is alkaline with a pH of 7.5 and organic matter levels are creeping up from a low of 2%. N levels are also increasing slowly. Phosphate has declined a little, so Reddslagg is applied after beans.

"Soil analysis suggests our organic system is sustainable. We were concerned at the outset that it may not be, but so far so good," says Dr Cormack.

Organic wheat production has given good results at ADAS Terrington. Protecting soil quality has been the key to preserving productivity, says Bill Cormack.

Not just friendly to the environment, but beneficial to the bank balance, too. Organic wheat has secured a gross margin of £2000/ha.


MAFF is funding an ADAS survey of physical and financial data from 10 commercial organic farms in eastern England with arable-based systems which will be included in gross margin predictions. This information is being compared with the Terrington results to help farmers decide whether or not to convert.

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