Agriculture that appears to be more eco-friendly but uses more land may actually have greater environmental costs per unit of food than “high-yield” farming that uses less land, a new study has found.
There is mounting evidence that the best way to meet rising food demand while conserving biodiversity is to wring as much food as sustainably possible from the land we do farm, so that more natural habitats can be “spared the plough”.
However, this involves intensive farming techniques thought to create disproportionate levels of pollution, water scarcity and soil erosion. Now a study, published in the journal Nature Sustainability,by an international team of scientists, led by the University of Cambridge and including the University of Bristol’s Dr Taro Takahashi, shows this is not necessarily the case.
Scientists have put together measures for some of the major “externalities” – such as greenhouse gas emission and water use – generated by high- and low-yield farming systems and compared the environmental costs of producing a given amount of food in different ways.
Previous research compared these costs by land area. As high-yield farming needs less land to produce the same quantity of food, the study’s authors say this approach overestimates its environmental impact.
Their results from four major agricultural sectors suggest that, contrary to many people’s perceptions, more intensive agriculture that uses less land may also produce fewer pollutants, cause less soil loss and consume less water.
However, the team behind the study, caution that if higher yields are simply used to increase profit or lower prices, they will only accelerate the extinction crisis we are already seeing.
Andrew Balmford, Professor of Conservation Science from Cambridge’s Department of Zoology and lead author, said: “Agriculture is the most significant cause of biodiversity loss on the planet. Habitats are continuing to be cleared to make way for farmland, leaving ever less space for wildlife.
“Our results suggest that high-yield farming could be harnessed to meet the growing demand for food without destroying more of the natural world. However, if we are to avert mass extinction it is vital that land-efficient agriculture is linked to more wilderness being spared the plough.”
Source: University of Bristol