Fertilizer and the Bay

Do You Contribute to the Polluting of the Chesapeake Bay?

by Sandy Curry

No, not I!! Agriculture and industrial runoff are responsible for of the nitrogen pollution washing into the Bay!! But, not me! I simply do not add to the pollution of the Chesapeake Bay.

It is certainly true that excess nutrients, such as nitrogen and phosphorus, are a major factor in the poor water quality of the Chesapeake Bay. Sources of this pollution do include sewage and industrial discharges and farm runoff. However, homeowners also contribute to the serious problem of nutrient enrichment. 

Americans apply millions of tons of fertilizers, which contain nitrogen and phosphorus to gardens and lawns year each year. When improperly applied, water runoff from our property carries these pollutants into storm drains which flow into the Chesapeake Bay. 

Join the local Sierra Club as we examine the nutrient problem, consider what we can do in our own back yards to limit nutrient flow, and suggest resources that help with future plans to make our actions more effective.

Now is the time to act, for we have a long way to go before we can remove the Chesapeake Bay from the federal “Dirty Waters List.” 

The Problem with Excess Nutrients 

It seems strange that nutrients, which are essential to the growth of all living things, can be the source of “dirty water.” However when nutrients such as nitrogen and phosphorus are washed into the bay in excessive amounts, they actually degrade the quality of the water and the life it sustains. These nutrients do enhance growth, the growth of algae that multiply, or bloom to unbelievable numbers. The algae, in turn, keep light from filtering through the water to the submerged aquatic vegetation, which forms habitat and food for bay creatures. 

In addition, the decomposition of the algae consumes oxygen so necessary to aquatic life. These events resulted in the largest “dead zone” in the history of the bay during the summer of 2003. Apparently the spring rains increased the nutrient flow, which led to severe algae blooms and the greatest area of water of low-oxygen content that has been observed in the 20-year history of monitoring water quality (Bay Journal, September 2003). 

Roughly 300 million pounds of nitrogen, the most serious pollutant, reaches the Chesapeake Bay each year. State and Federal agencies and the local Chesapeake Bay Foundation are calling for us to reduce the nitrogen levels by half, to 150 million pounds, by the year 2010. We can do our part in realizing this goal. 

The Problem in our Yards

Most of us live within a short distance of a storm water drain or a river or tributary, which leads into the bay. There are 64,000 miles of shoreline along the bay, many of these miles in Anne Arundel County, and this does not cover the homes located on tributary streams that flow into the bay. Formerly, the shorelines were forested or covered with wetlands that helped to filter excess nutrients before they reached the bay. Now, cities and homes with impervious services increase storm water flow, a major source of nutrient runoff. 

We contribute to the problem by using fertilizers to maintain our lawns and gardens. Fertilizers contain nitrogen, phosphorus and potassium, and these flow into the bay as part of the runoff. We can work in our yards to improve the water quality of the Chesapeake Bay. 

What Can You Do Improve Water Quality in Our Chesapeake Bay 

Obviously, our most effective strategy in diminishing nutrient pollution would be to stop using fertilizers and to engage in “bayscaping” practices, which help to prevent storm water runoff. There is a growing attraction to Bay-friendly landscaping in the Chesapeake Watershed Area. 

Some homeowners have plans to reduce or eliminate lawns, for an expansive turf requires unusually high amounts of chemicals, precious water, and continual maintenance. Instead, groundcovers, plants, vines, shrubs and trees that are native to the area are used because, while equally beautiful, they generally require less water and chemical additives, they are hardier, and they increase the habitat for wildlife such as birds and butterflies indigenous to this area. In this Bay-friendly design, plants are naturalized in arrangements that help to control storm runoff, such as rain gardens and buffer zones around impervious services to conserve water and soak up extra nutrients. 

If this is an attractive alternative to you, check the links listed below, for we are lucky to have some good resources in planning Bay-friendly landscapes.

Use Fertilizers Wisely

However, most of us will probably continue to use fertilizers this year. We can use fertilizers wisely. A few simple steps will help to improve the health of the Bay. 

1. Create a compost pile. Using compost can decrease the need for fertilizer. Grass clippings, leaves, yard trimmings, and organic kitchen scraps, vegetable and fruit peelings, egg shells and tea and coffee grounds can be recycled. Composting improves the condition of the soil, retains water, and makes a great fertilizer. www.mde.state.md.us >> composting.

2. Have your soil tested every 3 to 5 years. When applied at the wrong time or over-applied, fertilizers can create salt problems in the soil, affect winter hardiness, exaggerate pest problems and make plants grow excessively. Excess nitrogen and phosphorus can leach out of the soil and pollute ground water or wash off landscapes to pollute the Bay.

3. Fertilize only when necessary, using the right type of fertilizer. *The University of Maryland recommends using no more than 1 pound of actual Nitrogen per 1,000 square feet of lawn per application and no more than 2 to 3 applications per year. *The three numbers on the fertilizer bag, 3-1-1 for example, represent the percent of nitrogen, phosphorus, and potassium, respectively, in 100 pounds of the fertilizer. Landscape plants require a different balance of these nutrients, with lawns usually needing a fertilizer high in nitrogen, low in phosphorus, and moderate in potassium. Flowering plants need a higher amount of Phosphorus than Nitrogen and Potassium. *When fertilizing lawns and trees, look for products that contain water insoluble nitrogen. This means that nitrogen will release slowly over time. This is complicated, so look for the following words on the fertilizer bag: water insoluble nitrogen (WIN), controlled release nitrogen, sulfur coated urea (SCU), IBDU, ureaformaldehyde (UF), or resin-coated urea to indicate slow release forms (www.agnr.umd.edu).

4. Do not apply fertilizers when there is a chance of high winds and heavy precipitation. Fertilizer scattered on pavement or water-soaked soil is carried by storm runoff to the Bay. 

5. Use a “drop” spreader to apply fertilizer. This type of spreader, rather than a rotary spreader, enhances the controlled application of fertilizer, keeping it where you want it, not broadcasting it wildly. 

6. Mow the lawn at the proper height. Set you lawn mower to a blade height of 3 inches. At this height, grass will shade out many weeds and develop healthy roots. Remove no more than 1/3 of the grass blade when you mow. 

7. Use a lawn care service certified by the Maryland Department of Agriculture’s Pesticide Regulation Section, 410-841-5710. The Water Quality Improvement Act of 1998 requires commercial applicators to apply nutrients in accordance with the most recent Maryland Cooperative Extension recommendation. Ask questions and request least toxic controls and environmentally friendly lawn care products. To check you lawn care service, call Maryland Department of Agriculture’s Nutrient Management Program, 410-841-5959. 

Important links to a Healthy Bay. 

Alliance for the Chesapeake Bay. Bayscapes. Coverage of Bay Issues as well as landscaping for a healthy Bay. 

Arlington Echo. Excellent information on constructing rain barrels and rain/bog gardens. 

Chesapeake Bay Foundation. Largest conservation organization dedicated to saving the Chesapeake Bay Watershed. 

Maryland Native Plant Society. Extensive information on the use and culture of native plants in Maryland. 

Maryland Cooperative Extension Home and Garden Center. Publication, Landscapes that Help the Chesapeake Bay. Master gardeners help staff this site and will answer or direct questions to the proper person. 

Maryland Department of the Environment. Composting. Maryland Environmental Issues, including composting.