Can Fertilizers Get in Bodies of Water?

Fertilizers

• Organic fertilizers such as animal manure have been used for centuries to improve plant growth and crop yields. They're generally benign to the overall ecology, though, and are diluted greatly as they run off from fields whenever it rains. Inorganic, or chemical-based, fertilizers have a history that dates only back to the Industrial Revolution, when they were first synthesized in laboratories. An example of an inorganic fertilizer is ammonium nitrate, which is also rich in organic nitrogen.

Runoff

• Runoff from the soil in a lawn or garden or any plot of land occurs whenever the ground receives more water than it can absorb. That water has to go somewhere, and it tends to seek the path of least resistance. Because land predominantly sits above the local waterline, that excess water runs off from the land, gradually making its way towards bodies of water. Fertilizers applied to the soil tend to be carried away as well.

Effects

• When bodies of water end up being contaminated with excess nitrogen left over from chemical fertilizers, a number of issues can result. These include algae blooms and an overabundance of weeds. Both benefit greatly from that nitrogen, and they can choke off the available oxygen in the water, killing off fish and other marine life. Vast dead zones in bodies of water, including the Gulf of Mexico and Chesapeake Bay, have been noted due to that runoff, notes Scientific American.

Prevention

• If you prefer to use chemical-based fertilizers, which do come with many benefits, try to find one containing slow-release nitrogen. This limits the amount of nitrogen making its way to bodies of water. Also, iron is a good substitute for nitrogen and makes lawns just as green as nitrogen does. And never apply fast-acting fertilizers if you know it's going to rain heavily. Lastly, try to avoid applying fertilizer on any sloping lawns or gardens.