When Fertilizer “Leaks,” Water Pollution Peaks

Fertilizers can run off into streams and lakes, so, word to the wise—less is more. Listen up:

Nitrate shower, anyone? Didn’t think so. (D. Arlotta/CDC)

You might think the more fertilizer on your garden, the better—but using too much may do more harm than good when it comes to clean water.

This is in large part because nitrate in fertilizer can leach into water, posing a health risk—or make its way to the coast, causing excessive and often toxic algae growth.

“Nitrate is a very leaky nutrient,” explains Carl Rosen, soil scientist at the University of Minnesota. “It’s difficult to keep it in place, so when you apply nitrogen fertilizer, there is the potential if you get excessive rainfall, for it to move out of the system.”

He suggests minimizing the problem by getting your soil tested so that you choose the appropriate fertilizer. Then apply it in smaller batches.

The key? Use only what your plants need, and not a bit more.