Fallowing, used mainly to kill weeds before the advent of herbicides, is being revived at Bridge House Farm, Long Buckby, this season.

The practice, keeping land cultivated but uncropped, is the key opening the door to Keith Thompson’s expansion of the family business he runs with brother, Robin.

Recent changes in cross-compliance rules have made it easier to fallow without breaking the requirement on farmers to keep land in Good Agricultural and Environmental Condition, notes brother Mike of Norfolk-based Agronomy Plus.

“GAEC rule 12 covers eligible land not in agricultural production for 15 months or less and it has been changed to allow for annual fallows.

You are no longer required to have a green cover on it from 1 March.”

In the past, apart from in countries like Canada where fallowing was often used to conserve moisture, the practice was seen as a sign of poor farming, he says.

“As my father who farmed in the 1930s said, there was a stigma attached to it because it showed that you had weedy land or that the field needed a rest.

“And the Norfolk four-course rotation didn’t include fallow.”

Until this year the Bridge House Farm operation had 230ha (568 acres) of arable on the home unit plus a further 200ha (494 acres) contract-farmed nearby.

Most of the medium/heavy self-structuring soils had been in continuous wheat since 1969, with recent yields hitting 9.2t/ha.

But the opportunity to expand by taking on another 360ha (890 acres) in two blocks within striking distance has involved a cropping re-think which includes fallowing.

“On the home farm we’re now two-thirds wheat, one third oilseed rape, while on the contract land we also have some barley,” says Keith.

By putting the newly acquired land into a 50:50 wheat/fallow rotation he calculates that he should be able to run the operation without further investment in either men or machinery.

“When we are up and running it means we should have about 550 acres already ploughed before harvest.

And by the time we have combined the rape we should have two-thirds of our wheat land cultivated and ready to drill.

That has often been our bottleneck.”

The fallowed land will ease the spreading of manure from the farm’s 55,000-head poultry flock and 600-sow breeding unit.

“Up to now we have put it on between harvest and the autumn, and there’s always been the risk that we might not get it all on if the weather broke.”

Yield increases in the wheat should be another plus.

Robigus following a small area of rotational set-aside used for getting rid of the pigs’ dirty water last year gave 10.8t/ha (4.4t/acre), he says.

Rothamsted’s Broadbalk experiments from 1968-78 showed that fallowing leaves an average of 53kg/ha (42 units/acre) of nitrogen for the following wheat, adds Mike.

“Spring beans left only 23kg/ha in the same experiment.

“With nitrogen fertiliser costing £160/t the fallow’s contribution is worth £24/ha in N alone.”

Under the continuous wheat regime ploughing was the main cultivation, and Keith foresees it continuing on the fallow, albeit without the normal press if starting early enough.

Subsequent cultivations and/or glyphosate treatments will depend on conditions nearer drilling.

One potential downside of fallowing is that it may encourage more wheat bulb fly, warns Mike.

“The cultivated bare land could be slightly more attractive to the fly laying its eggs.

“But it shouldn’t be a big problem because the wheat is likely to be drilled early.”

andrew.blake@rbi.co.uk