Nitrogen Feeds the Planet
The primary ingredient in most of the world’s crop-growing fertilizers is nitrogen. The natural supply of nitrogen was scarce until Fritz Haber invented a nitrogen-fixation process in 1908 that was later adapted to an industrial scale by Carl Bosch. In terms of food, this newly-available reactive nitrogen allowed the number of people supported per hectare of arable land to increase from 1.9 in 1908 to 4.3 in 2008. Scientists now estimate that virtually half of humanity is fed by Haber-Bosch nitrogen fertilizers! But, not all of that nitrogen makes it into our food – excess nitrogen from fertilizers and other sources can be washed away from our yards and farmlands and into aquatic ecosystems. The extra nutrients in the water can feed an explosion of algae growth that degrades water quality, food resources and habitats.
Viewer Tip: Luckily, we don’t have to stop using fertilizers to avoid these unintended consequences. We just have to be a bit smarter about how we use and control these nutrients by following some best management practices:
- On Your Property: Use rain barrels or grow a rain garden to reduce stormwater runoff from your home and lawn. Use fertilizer according to directions and don’t apply it at all on rainy days or during seasons when your grass isn’t growing.
- On the Farm: Many farmers already use landscaping techniques to trap nutrients, just on much larger scales. In addition, the USDA released a new set of national nutrient management standards to help farmers use the right fertilizers, in the right amount, with the right application techniques, at the right time. Learn more at www.nrcs.usda.gov/wps/portal/nrcs/detail/national/landuse/?cid=STELPRDB1046217.
There are many steps you can take to protect habitat and water quality along stream banks and lake shores.
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(Sources: J.W. Erisman et al., 2008. “How a century of ammonia synthesis changed the world.” Nature Geoscience, 1, 636-639; U.S. Environmental Protection Agency. “Act.” Accessed Online May 31, 2012. http://www.epa.gov/nutrientpollution/whatyoucando/index.html; U.S. Department of Agriculture, Natural Resources Conservation Service. “NRCS Announces Nutrient Management Standard Update.” Accessed Online May 31, 2012. www.nrcs.usda.gov/wps/portal/nrcs/detail/national/landuse/?cid=STELPRDB1046217)