Does Your Lawn Need Phosphorous?

Phosphorous is a contaminant. Before using phosphorous on a lawn, it's best to take a soil sample to a local agricultural co-op, or college extension for analysis. More is definitely not better when applied to fertilizer. Excess fertilizer is merely washed down the street or leached from the soil and possibly finding its way to surface water.

The largest contributor of phosphorus to surface water comes from the use of lawn fertilizer. Phosphorous can make its way to surface water by soil leaching. Phosphorous is also attached to leaves and grass clippings and when moved to another location, can run into waterways.

Grass and flowers need phosphorous in order to grow. The region you live in will dictate if your lawn needs phosphorous or if it's legal to apply the nutrient. Some areas of the United States are phosphorous rich. That is the reason for soil testing. A soil test will show the amount of nitrogen, potassium and phosphorous levels in the soil. An additional benefit of soil testing is economic. There is no point in spending money for a nutrient that the soil doesn't need.

How to tell the phosphorus ratio in your fertilizer.

The nutrient ratio is listed on the bag front. Fertilizer analysis refers to the percentage by weight of the nutrients. You will see three numbers in a row, such as these, 46-0-0. The first number is nitrogen, then phosphorous and the last number is potassium.

Some municipalities or states have banned phosphorus fertilizers because of water quality concerns. If a homeowner lives in a city that controls or bans the application of phosphorus it will be necessary to shop for fertilizer online or learn how to make it. Compost is probably the easiest method of making soil nutrients. It's difficult to buy phosphorus free fertilizer from retail outlets.

It's possible to find quick release nitrogen fertilizer in a 46-0-0 ratio, but it has dangers for the inexperienced homeowner. Quick dissolve nitrogen in high levels can easily burn a lawn. Improperly applied fertilizer can make an absolute mess of an otherwise beautiful lawn

Phosphorus fertilization tips.

Perform a soil test to determine if phosphorus is even needed for your soil. After fertilizer is applied to the lawn, it's important to sweep any fertilizer particles off the sidewalk onto the lawn. Fertilizer left on non-porous materials can be washed into storm drains. Keep a five to ten-foot fertilizer free zone around surface water.

Sources
turf.msu.edu/docs/E0021TURF.pdf