BTO head of land-use research Gavin Siriwardena told the ADAS vegetable conference: "Vegetable farms tend to have more farmland birds, apart from jackdaws and starlings. The difference isn't huge, but for particular species there has been a divergence in recent years."
But these findings do not represent a causal link, he stressed. "Growing vegetables isn't by itself a solution to declining numbers," he said.
The BTO study, carried out for the Horticultural Development Company, included an analysis of bird populations in horticultural areas compared with other agricultural land.
The charity also found that the entry-level stewardship introduced in 2005 had so far failed to reverse the decline in bird populations.