Nitrogen is a key nutrient for plant growth, and nitrogen fertilizer is one of the most common soil amendments used in the United States. In 2011, U.S. farmers applied approximately 12.8 million tons of nitrogen to their farmlands. However, the majority of applied nitrogen never actually reaches crops, but sits in the soil, leaches into groundwater, runs off into nearby surface waters, or is converted to nitrous oxide, a greenhouse gas 310 times more potent than carbon dioxide.
While it’s true that plants need nitrogen, feeding them inorganic fertilizer is like eating refined sugars—both provide an immediate burst of energy far in excess of what’s needed. In human beings, the excess is stored as fat, while in plants it goes to feed nitrogen-loving weeds. In contrast, organic fertilizers release their nutrients slowly, in sync with the growing plant’s needs, just as complex carbohydrates provide us with slow-release energy relative to sugars. Another advantage of organic fertilizers is that they provide a broader array of nutrients, including micronutrients, like a well-balanced diet. This is another reason why organic agriculture is healthier for your plants and for you. Rather than using refined, synthetic fertilizers, organic agriculture opts for complex and microbially diverse compost, manure, and nitrogen-fixing plants to provide the nitrogen needed for an abundant food supply without resorting to synthetic chemical fertilizers.