F armer Alastair Leake is standing in a field of sprouting winter wheat, pointing at his experiment. One side was ploughed before planting, with green shoots breaking through neat rows of upturned soil. On the other, the crop was drilled directly into the earth, emerging through a messy carpet of “trash” – stems, stubble and crop residue from previous harvests.

“When we’re watching to see where the birds are landing to feed, none of them are going on to the ploughed side,” says Leake, the director of the Allerton Project farm, standing on the trashy side. “They’re all coming and feeding down here.

Alastair Leake stands on the ‘beetle bank’ where 1,300 beetles per sq metre make their home. Photograph: Fabio De Paola/The Guardian

“That’s because that’s where the seeds, the earthworms and the insects are. On the ploughed side, they’re all buried.”

It is experiments such as these that have enabled the Allerton Project to buck the decline in farm bird populations across the UK .…