Conventional farming wins on several key fronts: U. of Minnesota study

Combine harvester cutting crops in barley field during harvest under dramatic cloudy sky Photo: Thinkstock

By Commodity News Service Canada

A meta analysis of 164 scientific papers that compared crop yields, land use, pesticide use, and fuel use between conventional and organic farming systems, suggest conventional agriculture has several key advantages.

The study found that conventional farming’s benefits compared to organic farming were most pronounced in the amount of land required to produce the same volume of crops.

The authors of “Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice” from the University of Minnesota said however, there were important practices conventional farmers could learn from organics.

Graduate student Michael Clark and David Tilman an ecology professor at the university, published their findings in the June issue of Environmental Research Letters.

The study compared conventional and organic farming in the areas of land use, greenhouse gas emissions (GHG), energy use, increase of acidity in the ecosystem and eutrophication potential, in which agricultural practices impact the environment by increasing algal blooms and harming aquatic systems.

“Our analyses show that the comparative environmental impacts of agricultural production systems differ depending on the systems, food, and environmental indicator examined. Per unit of food produced, organic systems had higher land use and eutrophication potential, tended to have higher acidification potential, did not offer benefits in GHGs, but had lower energy use…” the study stated in its conclusion.

The study said the scientific papers it analyzed found that organic systems require 25-110 per cent more land to produce the same volume of crops, have 37 per cent greater potential for causing eutrophication than conventional systems per unit of food produced and had 13 per cent higher acidification potential than conventional farming systems. Organic farming systems, however, used 15 per cent less energy per unit produced and produced four per cent less GHG, which researchers deemed not statistically significant.

The study added there are many other environmental impacts that were not part of this analysis. It also pointed out that more than 30 per cent of food production is wasted and reducing food waste would offer one of the greatest environmental benefits while requiring no change in current practices. As well, the authors said there are more differences in environmental impacts between the types of food being produced than in the farming system used. For example, the study said the environmental impacts of ruminant-derived meats, such as beef, are three to 10 times greater than those of other animal-based foods, and 20 to 100 times great than those of plant-based foods.

The study said, “adoption of lower-impact foods, of lower-impact production systems, and of systems with high agricultural input efficiency is necessary before agriculture causes substantial, and potentially irreversible, environmental damage.”