Combining Profits and Environmental Benefits on Organic Farms

by Frances Willick

Organic farming produces similar yields and often higher profits compared to those of conventional farming, while consuming approximately 30% less fossil energy, eliminating pollution from herbicides and pesticides, and conserving soil life and water.

These findings, written by David Pimentel of Cornell University and published in Bioscience, are based on the 22-year Rodale Institute’s Farming Systems Trial. The study compared conventional corn and soybean production using recommended fertilizer and pesticide applications; organic production of corn, soybean, wheat, hay, and cover crops using aged cattle manure as a nitrogen source; and organic production of corn, soybean, and wheat using legume-based sources of nitrogen. Neither of the organic systems used herbicides or pesticides.

Yields of both corn and soybean were similar for all systems over the 22-year study period. Yields were lower in the organic systems during the biological transition of the first five years, but under drought conditions the organic systems yielded roughly one-third more corn than the conventional system. The authors of the review attribute this to the higher water content, increased groundwater recharge, and reduced runoff measured in the organic systems.

While energy inputs for soybean production were similar for all three systems, the energy requirements for organic corn production were approximately 30% lower than those of conventional corn.

Organic systems used 35% more labour than the conventional system. In the organic systems, however, labour was spread out over the whole summer, when the farmers were occupied with the wheat, cover crops, and mechanical cultivation. The bulk of labour in the conventional system was required at the beginning and end of the season during planting and harvesting.

Although synthetic herbicides were absent in organic plots, four herbicides were applied at recommended rates in conventional corn and soybean plots. Two of these four - metolachlor and atrazine - were detected in water leachate samples. While the Environmental Protection Agency has not set a limit for acceptable levels of metolachlor in drinking water, the levels of atrazine in the water leachate samples sometimes exceeded the EPA’s maximum contaminant level. Nitrate leaching occurred in both the organic and conventional systems, with 20%, 16%, and 10% of samples exceeding the nitrate limit in the conventional, organic legume, and organic animal systems, respectively.

Using cover crops helps retain water, prevent soil erosion, and sustains life in the soil when the land is not being used to grow a cash crop. While crop residues were left on the land in the conventional system, no cover crops were planted. In both organic systems, cover crops were used. Soil in both the organic systems contained significantly higher levels of soil carbon, soil organic matter, and beneficial fungi than the conventional system. These elements contribute to higher water content, improved disease and drought resistance, and better soil aggregation.

With all economic factors considered – input costs, labour, and yield, the annual net return for the conventional system was slightly higher ($184 per ha.) than that for the organic systems ($176 per ha.) without the price premium. However, since organic products obtain a higher price in the marketplace, the net return for organic production is often equal to or higher than that of conventional production. The study notes that the organic price premium required to equalize organic and conventional returns was only 10% above the conventional price. During the 1990s, the premiums surpassed this level, and now range between 65% and 140%, in the study area.

As the authors of the study note, the environmental and health care costs of conventional farming are significant. The effects of soil erosion, synthetic pesticide and herbicide use, and excessive fertilizer application detrimentally disrupt the planet’s ecology as well as human health. Organic farming methods reduce the negative impacts of agriculture on the environment by reducing chemical inputs and soil erosion, conserving water, and improving biodiversity. As this study indicates, these benefits come with adequate yields and good economic returns.

 

The reference for the reviewed article is Pimentel et al. 2005. Bioscience: Volume 55, pages 573 – 582.

Frances Willick is a Consultant for the Organic Agriculture Centre of Canada. Please send comments or questions by phone to 902-893-7256 or by email to oacc@nsac.ca.

Posted on the OACC website, December 2006