Organic farms can be more energy efficient than conventional farms that mass produce crops using unsustainable practices, a surprising result from a study co-authored by a York University professor.
Researchers analyzed 130 studies to compare the energy use and global warming potential of organic versus conventional farming. They concluded that organic farms were more energy efficient on both a per-hectare and per-product basis, with the exception of fruit farming and poultry production, where data is limited.
“These findings shake up the concept that ‘bigger’ is always better. Higher crop yields, bigger equipment, less genetic diversity, and more fertilizer and pesticides do not equal a more energy-efficient operation,” says Rod MacRae (left), a professor in York’s Faculty of Environmental Studies.
Critics of organic farming commonly argue that lower yields make it unsustainable in the long term. “As population increases and land availability decreases, it’s assumed that an ‘assembly line’ approach to agriculture is the only way to keep up with our food needs. While this is the dominant way of thinking, this logic is also deeply flawed,” MacRae says. “For example, many regions in the global south show better yield performance with organic farming. Even in North America, organic yields are not far behind conventional ones.”
MacRae points out that there is an enormous amount of waste in conventional systems. Significant amounts of edible food are lost at harvest, during processing and distribution, at retail and in consumers’ homes. “By some accounts, up to 40 per cent of what gets farmed never makes it to our mouths, and this adds enormously to energy waste. This can result in the perception that we’re not producing enough food,” he says.
Studies of conventional and organic grain growers in the prairie region showed significant benefits for organic methods, including 50 per cent lower energy use in a 12-year study of forage and grain crop rotations. The absence of nitrogen fertilizer was a main contributor to reduced energy inputs and greater efficiency. Modelling studies of a Canada-wide conversion to organic canola, wheat, soybean and corn concluded we would consume 39 per cent less energy and generate only 77 per cent of the global warming emissions and 17 per cent of ozone-depleting emissions of conventional wheat farming.
|Above: Organic cultivation of mixed vegetables|
In terms of dairy farming, a study in Atlantic Canada found that an organic, seasonal grazing system was 64 per cent more energy efficient and emitted 29 per cent less greenhouse gases compared with the average of conventional systems. Cows consuming an organic diet may also have a longer lifespan, increasing efficiency and reducing methane emissions when calculated over time.
Where livestock is concerned, fewer studies exist and comparisons are more difficult because of dramatic differences in operations from farm to farm, particularly for hogs and poultry. Conventionally raised beef is widely accepted as the least environmentally friendly meat, requiring seven times as many inputs for an equivalent output of calories. Organic beef production is considered to be more efficient because the animals consume more grass and less grain than humans can consume.
The study, “The Carbon and Global Warming Potential Impacts of Organic Farming: Does It Have a Significant Role in an Energy Constrained World?” was published in the journal Sustainability. Its lead author is Professor Derek Lynch, Department of Plant & Animal Sciences, Nova Scotia Agricultural College.