Be bird-friendly with herbicides, advises CSL

Cereal growers hoping to encourage farmland birds should think carefully about the herbicides they intend to apply. Some are more bird-friendly than others, explains the CSL’s Nigel Boatman.

SAFFIE trials, building on experience at the Game Conservancy Trust where Dr Boatman formerly worked, indicate that for light land growers in particular with relatively little blackgrass there was scope to choose weed-killers which encouraged the more desirable species at the expense of others without compromising yields.

Desirable species included chickweed, annual meadow grass and polygonums like knotgrass.

“A lot of the value [to birds] with stubbles is in the weed seed produced after harvest from things like knotgrass,” says Dr Boatman. “It can be very valuable over winter provided it isn’t sprayed off with Roundup.”

Of the range of products tested on the sandland at ADAS Gleadthorpe and the chalk at ADAS High Mowthorpe, Eagle (amidosulfuron) appeared particularly useful in leaving more than 10% mainly desirable weed cover against the untreated plots’ 20%. Other products and mixtures left less than 5%.

“The key thing is that there is very little [negative] impact on yield,” he says.

“We’re not yet ready to advise people to do specific things, but the work has thrown up some potential differences.”

It is up to agronomists with detailed knowledge of individual fields and their weed populations to weave the selective approach into their recommendations, he suggests.

“It didn’t work well on the heavy land at ADAS Boxworth which has blackgrass.”