What Happens If I Spread Urea on My Lawn?

Urea is a component of the urine of mammals. It's used in fertilizers, feed supplements and the manufacture of plastics and drugs. Because of urea's high nitrogen content, it's readily converted to ammonia in the soil, making it one of the most concentrated nitrogenous fertilizers. Lawns like receiving the right amount of nitrogen because it makes them healthy and green. Too much nitrogen, however, burns the lawn.

Urea contains 46 percent nitrogen and has almost completely replaced ammonium nitrate as a fertilizer in recent years. There are several advantages to urea fertilizer:

• Urea has very little chance of causing an explosion or becoming a fire hazard.
• The high amount of nitrogen in urea reduces handling, storage and transportation compared to other dry nitrogen-based fertilizers, which take up more space.
• It can be applied to soil as a solid or used as a spray.
• It releases few pollutants during manufacture.
• Urea can be very effective on both lawns and crops if used correctly.

Fertilizing with urea, or any fertilizer for that matter, must be done correctly or your lawn will end up unhealthy. A slow-release fertilizer is the best way to go so you don't bombard your grass with too much at once. Proper fertilization with urea will create a thick, healthy and green turf.

However, if you overdo it, the urea fertilizer can dry out or burn the lawn. Overfertilizing causes a buildup of salt in the soil, which is drying and can turn your lawn yellow or even brown in spots.

It's easy to make mistakes when fertilizing your lawn. Here are four pieces of solid advice:

1. Test your soil first: Most lawn owners never do this, but it can be extremely helpful, especially if your lawn is having issues. Gather 10 or 12 soil samples from different areas of your lawn and have them sent off for professional testing. You should do this in early spring before you do any fertilizing. A professional test will let you know the pH of the soil and also what nutrients might be lacking or overabundant.
2. Don't overfertilize: A common problem is too much fertilizer, which can harm the grass and the environment. Most lawns can get by with fertilizer being applied twice a year, even though many retailers suggest four times a year.
3. Fertilize at the right time(s) of year: Consult your local cooperative extension service staff to find out the best time to fertilize your lawn, depending on the type of grass you're growing (cool-season vs. warm-season types).
4. Spread the fertilizer carefully: Don't be careless with fertilizer around streams, ponds or other bodies of water. The fertilizer will seep in and create excessive algae blooms. Sweep up any fertilizer that gets on your driveway or sidewalk. If you wait for the rain to wash it away, it will go down the drain and into the water system.