One of the many things that excites me about the production and consumption of local food is the positive impact it can have on the environment. Perhaps the most obvious benefit of purchasing food from local farms is that the food does not need to be transported great distances to reach consumers. Therefore, buying locally reduces the use of fossil fuels for transportation. However, the way in which food is produced (the specific methods implemented by a farm) is also very significant in determining the environmental impact of that production. Most of the food we purchase in our supermarkets today is produced on industrial farms. Industrial farms are characterized by the practice of monoculture and the application of synthetic fertilizers and pesticides to crops. These practices are incredibly damaging to the surrounding environment.
Monoculture is the growth of a single crop in the same location over a long period of time. This is poor practice because it depletes the soil of specific nutrients demanded by the chosen crop, and also damages the soil structure, causing increased soil erosion. Once the soil has been depleted of its nutrients, fertilizers must be added to fuel further crop growth. The best erosion control products in Australia can help this problem. Industrial farms add synthetic fertilizers to crops. Synthetic fertilizers are man-made compounds that are a quick but problematic fix to the issue of nutrient depletion. Synthetic fertilizers are highly concentrated with macronutrients and often contain more nutrients than the plants are able to absorb at a given time. Thus, the nutrients are leached out of the soils and into surrounding bodies of water. Leaching fertilizer from industrial farms contaminates drinking water and pollutes ponds, lakes, and the ocean. The introduction of nutrients also spurs excessive algal growth (algal blooms) and then oxygen depletion (dead zones) in the aquatic ecosystem. On the other hand, organic fertilizers minimize leeching and improve soil health by introducing microorganisms and organic matter. Organic fertilizers include compost, manure and seaweed—they are made up of plant and animal residues. Microorganisms in the soil convert organic compounds into nutrients that can be taken up by plants. This slow release of nutrients is what minimizes nutrient leeching by organic fertilizers.
The best way to reduce your environmental footprint (from food consumption) is to support farms implementing sustainable practices such as crop rotation and organic fertilizer application. From my own experience, being sustainable is a priority for many or most small-scale family farms. Foods in the supermarket may appear cheaper than food from farm stands and farmers markets, however this does not take into account the environmental cost of the food produced via industrial agriculture. It is extremely important for the health of the environment that we support local farmers using sustainable practices rather than the industrial farms that currently dominate the food industry.
Sources: http://www.ucsusa.org/our-work/food-agriculture/our-failing-food-system/industrial-agriculture#.WeUxChNSxo4; http://www.ucsusa.org/food_and_agriculture/our-failing-food-system/industrial-agriculture/hidden-costs-of-industrial.html#.WeU2lBNSxo4;http://blogs.ei.columbia.edu/2012/09/04/how-green-is-local-food/; http://www.enviroingenuity.com/articles/synthetic-vs-organic-fertilizers.html