Fertilizer

This page is for Master Watershed Stewards considering a Behavior Change campaign in their community. To learn more about what you can do as an individual click here.

A major source of pollution for Chesapeake Bay waterways is nutrient pollution. When it rains after fertilizer has been applied to a lawn, much of the fertilizer gets washed down storm drains and into local waterways. Excess nutrients, such as, Nitrogen and Phosphorous cause an increase in algal blooms. The algae generates clouds at the water’s surface which block sunlight from bay grasses. When the algae dies, it is decomposed by bacteria which use lots of oxygen in the process. This depletes the oxygen available for fish and other aquatic life, creating dead zones in the Bay. Being conscientious about what we put on our lawns and when can help to defray the problems associated with nutrient runoff.

Maryland Law requires that no more than 0.9 pounds of total Nitrogen per 1,000 square feet be applied in any single application of fertilizer. It is also prohibited to apply fertilizer between November 15 and March 1. For more information visit the Maryland Department of Agriculture’s website: http://mda.maryland.gov/Pages/fertilizer.aspx.

(Note: Some of the behaviors below are general. You may want to be more specific before designing a Behavior Change campaign.) 

Behavior: Do not fertilize at all.

Some of the common perceived or actual barriers to not fertilizing include: 

Some of the common perceived or actual benefits of not fertilizing include:

1.      Not having to mow as often

2.      A healthier lawn without the problems associated with overfertilization: thatch            buildup, susceptibility to drought damage and rapid leaf growth     at the                      expense of roots

3.      Money savings

4.      Time savings

5.      Reduced nutrient runoff and waterway pollution 

Behavior: Only apply fertilizer during the Fall.

Fall fertilizing promotes root growth that creates strong, hardy turf that can last throughout the winter. Spring fertilization promotes blade growth that may necessitate more frequent mowing, and weed growth that will compete with turf.

Some of the common perceived or actual barriers keeping people from fertilizing in Fall only include:

Some of the common perceived or actual benefits of people fertilizing in Fall only include:

1.      Excess fertilizer won’t wash off into waterways

2.      Saves time from applying fertilizer

3.      Saves time from mowing

4.      Saves money

Behavior: Use fertilizer as directed by law or on the bag.

The optimal fertilization for lawns and fertilization with minimal negative environmental impacts have been the subject of many studies. Acceptable environmental impact has been incorporated into laws about when, how and how much someone should fertilize their lawns. Failure to abide by these laws can incur significant monetary fines. Fertilization instructions listed on fertilizer bags will reflect these laws and also reflect years of study about the most effective way to fertilize your lawn. Following these directives will help prevent people from overfertilizing and causing excess fertilizer to runoff into local creeks and rivers.

Some of the common perceived or actual barriers to people using fertilizer as directed include:

Some of the common perceived or actual benefits for people using fertilizer as directed include:

1.      Following the law

2.      Get best results as researched by fertilizer company

3.      Won’t accidentally over-fertilize

Behavior: Leave a fertilizer-free buffer zone.

For homeowners who live on or near the water, it is beneficial to leave a buffer between lawn and water with no fertilizer. If a lawn is fertilized right up to the water’s edge, even a small amount of water could wash the fertilizer directly into the creek or river. Leaving a buffer zone (the bigger the better) can help prevent this problem.

Some of the common perceived or actual barriers to people leaving a fertilizer-free buffer zone include:

Some of the  common perceived or actual benefits for people leaving a fertilizer-free buffer zone include:

1.      Excess fertilizer won’t wash into waterways as easily

2.      Other plantings may increase privacy

3.      A planted buffer will help absorb polluted runoff

See what others have done!

Tools:

Clear Choices Clean Water Pledge

Case Studies:

Bert the Salmon: Promoting Natural Lawn Care in the Seattle Area