Hypoxia and the Role of Fertilizers
During the last thirty years scientists have observed hypoxic zones, or “dead zones,” in various water bodies throughout the world. Hypoxia occurs when excess nutrients pollute water by promoting an overgrowth of algae. When the algae eventually die, they are consumed by bacteria that choke water of oxygen and result in areas that are so oxygen-deprived they cannot support aquatic life.
Agriculture and the fertilizer industry are frequently cited as the principal sources of excess nutrients in hypoxic zones. As an example, the Environmental Protection Agency says that agriculture is responsible for 44 percent of the nitrogen and phosphorus being delivered to the nation’s largest estuary, the Chesapeake Bay. Because nutrients can come from many other environmental sources, estimates of fertilizers’ role in hypoxia are often questioned. Additionally, studies have shown that weather patterns are often a larger contributing factor than was first believed.
What is the Fertilizer Industry Doing to Address Hypoxia?
Agricultural researchers, nutrient providers, farmers and retailers have researched and developed a number of programs and practices known collectively as Best Management Practices (BMPs). These practices prevent or reduce the movement of sediment, nutrients and other pollutants from the land to surface or ground water or protect the environment from potential adverse effects of agricultural activities in other ways.