Organic food sales reached $26.6 billion in 2009, according to the Organic Trade Association. Organic food is grown without the use of chemical fertilizers or pesticides. Organic fertilizers are derived from natural sources and are a part of a sustainable, renewable system of agriculture. Chemical fertilizers continue to be used as an important part of the agribusiness system, despite their harmful effect on human health and the environment.
Organic farming and the use of organic fertilizer is the oldest form of agriculture on earth. In 1908, Fritz Haber invented the process for turning air into liquid ammonia and then into nitrogen. This became the basis for chemical weaponry and for manufactured fertilizer. The World Resources Institute now considers nitrogen overload from chemical fertilizers to be the primary cause of global toxic pollution.
The International Fertilizer Association defines fertilizer as “any natural or manufactured material that contains at least 5 percent of one or more of the three primary nutrients: nitrogen (N), phosphorous (P), or potassium (K).” These nutrients are derived from chemical manufacturing processes. Organic fertilizer is derived from natural sources such as mined potassium, seaweed, alfalfa meal, bat guano, animal manure, cottonseed meal, feather meal, blood and bone meal.
Nutrients in chemical fertilizer are released immediately into a plant’s root system. Nitrogen causes an immediate burst of growth. “Organic products require the activity of soil microorganisms before nutrients are available for plant uptake,” according to Colorado State University’s report on organic fertilizers. The nutrients in organic fertilizers are continuously available as the plant grows. This is called a nutrient cycle.
Plants need 20 nutrients to grow well, 17 of them from soil. “Among the nutrients, nitrogen, phosphorus, and potassium are the most important,” states Cornell University, but a lack of any of the other nutrients “may limit plant growth and development.” Chemical fertilizers supply the three essential nutrients, and organic fertilizers “tend to have a lower, more variant analysis.”
Tiny living organisms in soil digest organic materials to create nutrients that become nutritious food. Chemical fertilizers stimulate plant growth directly but do not provide material for microorganisms to digest into a variety of nutrients. Food grown on soil amended with organic fertilizer has been shown to have higher levels of flavonoids, according to a 2007 University of California at Davis study. Flavonoids are part of the process of creating antioxidants important for immune strength.