Baltimore, MD—At Expo East, The Organic Center hosted an education session titled, “Environmental Benefits of Organic Agriculture” in which Tracy Misiewicz, associate director of science programs for the Center explained how organic farming is a more sustainable approach to agriculture than conventional farming. The most significant difference has to do with soil composition. With 90% of food produced on soil, it greatly influences the quality of our food as well as the integrity of the surrounding environment.
Soil is composed of organic matter, minerals, air and biodiversity to name a few things, making up the base of the food web, a complex ecosystem in which organisms interact in important ways, enriching the soil in the process. The Earth’s soil accounts for 80% of terrestrial carbon storage and acts as a natural filter for water. Unfortunately, most conventional farming practices deplete the soil, releasing excess carbon into the atmosphere when tilled and allowing nitrates from synthetic fertilizers as well as residue from herbicides and pesticides to seep into waterways.
Eutrophication of waterways can lead to dead zones. For example, when too much nitrogen accumulates in the water, algae grows in excess on the surface of the water, blocking the sun from reaching aquatic plants beneath the surface eventually causing death to fish and other aquatic life. Organic farming, however, uses manure and legumes to fertilize instead of dangerous synthetic fertilizers and practices crop rotation, which helps the soil maintain its integrity and encourages the biodiversity that is severely lacking in today’s farming.
One study conducted by the University of Illinois’ Department of Natural Resources and Environmental Sciences compared the soil organic matter of three different farm management techniques based on fertility source, from nine established farming system trials (1). These techniques were manure and legume fertilized organic, legume fertilized organic and conventional. Results showed that while short-term differences between the management systems weren’t great, over the long term, the organic management systems had greater soil organic carbon and nitrogen concentrations than conventional methods. Soil organic carbon increased by 14% in organic systems after an average of 10 years (1). Soil organic carbon is the main source of energy for microorganisms and nitrogen is an important nutrient for plant growth (2).
Organic management methods also showed a 30-40% enrichment of particulate organic matter carbon and nitrogen concentrations (1). This is important because particulate organic matter is a source of food for microorganisms, nutrients for plant growth and enhances aggregate stability, water infiltration and soil aeration (3). Overall, organic crop management systems maintain soil quality over time, an important factor when you want to have a continued source of nutritious food. They also encourage a thriving ecosystem, prevent the release of greenhouse as well as pollution from synthetic fertilizers and herbicides or pesticides.
1. Marriott, E. E., and M. M. Wander. 2006. Total and Labile Soil Organic Matter in Organic and Conventional Farming Systems. Soil Sci. Soc. Am. J. 70:950-959. doi:10.2136/sssaj2005.0241
2. “Total Organic Carbon,” http://soilquality.org/indicators/total_organic
_carbon.html, accessed 10/8/2016
3. “Particulate Organic Matter,” http://soilquality.org/ http://soilquality.org/indicators/pom.html, accessed 10/8/2016
Published in WholeFoods Magazine November 2016