YORK, United Kingdom—Combining conventional with organic farming may be better to maintain food production and protect wildlife, according to a new study from the University of York.
The study, published in Ecology Letters, is the first of its kind to establish the tradeoff between the most efficient use of farmland and the most effective way to conserve wildlife in the United Kingdom and has important implications for how agricultural land should be managed.
Researchers measured the density and numbers of species of butterflies in organic farms, conventional farms and grassland nature reserves in 16 locations in the South of England, the Midlands and Yorkshire. They used butterflies as a wildlife example because of their sensitivity to small-scale habitat change, and focused on winter cereal and pasture fields because they are among the most common crops.
Their findings suggest a combination of conventional farming and nature reserves would be better for butterflies if the organic yield per hectare falls below 87 percent of conventional yield. However, if the uncultivated land is not specifically managed for wildlife organic farming would be better whenever organic yields rise above 35 percent of conventional yields. The tradeoff also might be different for other types of wildlife. For example, wildflowers benefit more from organic farming than butterflies, and many birds do not benefit at all. The results suggest organic farming will be better when organic yields are high and when spared land has low value to wildlife; conventional farming will be better when organic yields are low and spared land is of high wildlife value.
“It’s not enough to know how much biodiversity an agricultural field supports, we also need to know how much food it produces. If ‘sharing’ our farmland with wildlife means that more total land will be taken into production to produce our food, then there may be a hidden cost of hurting wildlife somewhere else," the researchers wrote.
