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EPA’s Fertilizer Rules Earn My Seal of Approval

It’s about time lawn fertilizers were regulated; they’re waging chemical warfare on the Bay

Most of Maryland’s soils are acid. Unless they are limed every three to five years, they are generally too acid for optimum growth, so that any fertilizer applied is wasted and finds its way into the Bay. During the many lectures I give, I always ask who in the audience have had their soil tested in the last five years. I’m lucky to find even a few. Horticulture is a science, not a game for guessing or intuition.
    But that is how most homeowners and even many lawn companies apply fertilizer to their grasses.
    Which is why I applaud the Environmental Protection Agency’s decision to restrict fertilizer use in its 2010 strategy to restore the Bay.
    I strongly support new EPA’s efforts to remove phosphorus from lawn fertilizers. It is about time that measures are taken to minimize the sale of fertilizers to home gardeners. I only wish the guidelines were stronger, also banning the sale of ultra-high nitrogen fertilizers.
    All of the lawn fertilizers currently being sold contain nitrogen (N), phosphorus (P) and potassium (K).
    There is so much P in turf soils that it can almost be mined. Phosphorus has a very low solubility and simply accumulates. In over-abundance it can prevent certain essential trace elements from entering the roots of plants. Phosphorus also attaches to soil particles. When they wash into the Bay, it contributes to the high P levels responsible for.
    Some lawn fertilizer manufacturers have agreed to offer phosphorusfree fertilizers in the future. As far as I am concerned, that is not soon enough.
    Outlets selling fertilizer should require soil test results to assure proper use. None of the fertilizer instructions I have reviewed mention the need for soil testing. In my opinion, no one should be allowed to purchase fertilizers without having soil test results at hand.
    There is also some discussion on reducing the availability of fertilizers in the spring. Since most of our turf grasses are cool-season grasses, including bluegrass and fescues, the sale of lawn fertilizers for these grasses should be limited to August, September and October.
    Now is also the time to ban the sale of ultra-high nitrogen fertilizers. On a recent trip to a garden center, I was troubled to see lawn fertilizers containing 32 percent nitrogen. That is more nitrogen than the roots of grasses can absorb, even though half is in a slow release form.
    Having spent many years researching the effect of high levels of nitrogen on potassium uptake, I am not surprised that many of the lush lawns I see are affected by a disease called fusarium. True, nitrogen stimulates growth, but high levels of nitrogen create succulent plant growth that is susceptible to many problems.
    What also concerns me is that many of these high-nitrogen fertilizers are being applied at the same rate as low-nitrogen fertilizers such as 10-6-4. This means that three times more nitrogen is being applied than needed. This is further compounded by inaccurate fertilizer spreaders. Older spreaders apply more fertilizer at the same setting because the holes that it flows through enlarge with use.
    Some producers say that their fertilizers contain liming material to counter acidifying effects. Nonsense! There is too little liming material in these fertilizers to correct soils that are much too acid for efficient utilization of plant nutrients.
    People are quick to blame farmers for polluting the Bay. Yet turf is Maryland’s No. 1 crop, exceeding corn and gaining on all row crops combined. Excess lawn fertilizers flow into storm drains and nearby streams. Nitrogen not utilized by the roots leaches into the groundwater and wells and aquifers.
    Lawn-growers amateur and professional need to look at who’s calling the kettle black.


Ask Dr. Gouin your questions at frgouin@erols.com. All questions will appear in Bay Weekly. Please include your name and address.

I am writing to comment about the Bay Gardener article written by Dr. Francis Gouin, "EPA Fertilizer Rules Earn My Seal of Approval"

As a lawn care professional who analyzes more than 1000 soil tests every year, I would like to make the following statements about the following statements in Dr. Gouin’s article.

1.) “Most soils in Maryland should be limed once every 3-5 years because they are generally too acidic." This is not true. My 2010 report from our regional soil testing lab told me that only about 42% of my soil tests need lime, and most are only slightly acidic requiring a minimum application of lime. Usually, the soils that need the most are new development where the B horizon is excavated from the foundation and the sterile subsoil is spread across the property. Dr. Gouins statement encourages homeowners to over-lime. It is important to take a soil test before you lime to ensure you are doing the right thing. Soil testing should occur every 3 years according to Maryland Urban Nutrient Management Law.

2.)"If soil pH is not optimum, fertilizer is wasted and finds its way to the bay." Soil pH affects the ability of terrestrial plants to use nutrients available in the soil. It has nothing to do with the ability of the soil to hold nutrients. The cation exchange capacity of the soil is the measure of the ability of a soil to bind nutrients and other chemical ions to colodial soil particles. Good soil structure with ample cation exchange sites and thick roots from vegetation (or healthy turfgrass) will inhibit the movement and leaching of nutrients from proper fertilization. Only where the soil can move, and erosion is a problem is there a danger of nutrients finding their way into the bay.

3.) “All lawn fertilizers currently being sold contain Nitrogen, Phosphorus and Potassium” The lawn care industry has been using phosphorus free fertilizers for many years. Phosphorus is only added if it is deficient. If you look in the big box stores, you will find Scott’s fertilizer available with no P. Our lawn care program has been "P Free" for 22 years. P is only added if the soil test tells us so.

4.) “There is so much P in turf soils it can almost be mined.” I do find my share of soils with a lot of P, but they certainly are not the rule. I find just as many that need some P in the program. Dr. Gouin does talk about P being held tightly to soil particles and that it will move when the soil moves. P only enters the bay in silt and sediment from erosion caused by construction sites, not properly fertilized and maintained lawns.
5.)“Outlets selling fertilizer should require soil test results to assure proper use.” This statement does not make sense. Just because a person has a soil test in hand does not mean they will fertilize properly. Also, most lawn and garden centers do not have trained personel on staff to analyze soil sample results and recommend the proper fertilizer. You are opening up a big can of worms here.

6.) “Now is the time to ban the sale of ultra high nitrogen fertilizers.” High analysis fertilizers have their place in the professional arena. Higher analysis nitrogen fertilizers allow applicators to carry less material to cover the same area. If you want to take these out of the hands of homeowners, that would be OK with me. However, professionals in the agricultural business rely on these for efficiency. As long as these materials are applied at the right rate, there is no problem.

7.) “Having spent many years researching the effect of high levels of nitrogen on potassium uptake, I am not surprised that many of the lush lawns I see are affected by a disease called fusarium.” While I agree that over fertilization with nitrogen creates a plant that is over-succulent and susceptible to disease problems, I believe you may have your lawn diseases confused. Because the primary lawn grass cultivars are much less susceptible to this disease than they used to be, our seed mixtures are much more tolerant to disease pressure. Fusairum is not a major problem. Diseases that give us the most trouble these days are dollar spot in Kentucky bluegrass and brown patch in tall fescue. Proper fertilization is essential in helping turfgrass recover from disease damage.

8.) “Lawn-growers amateur and professional need to look at who’s calling the kettle black.” I think that this statement angers me the most. Ever since the enactment of Nutrient Management the agricultural community has been throwing the green industry under the bus while we have worked hard to support our Maryland Farmers. We are all in this together and it is everyone’s responsibility. The turf industry has shouldered its share of the responsibility. This comment does more to devide us rather than unite us.

In closing, while I have great respect for Dr. Gouin, I believe he may be a little out of touch and out of date. I wish that he would do more homework he writes his article and ensure he has his facts straight. Afterall, his readers take his word as Gospel.

Rick LaNore
MRW Lawns, Inc.
Maryland Turfgrass Council
Charles County Master Gardener, Class of 2004

Balanced and reasonable ... and a good reminder to all readers not to believe everything you read just because it is in the Bay Weekly, or the Capital, or the Sun or the Post ... the list goes on. Facts are hard to come by these days, while one-sided opinion is rampant. Thanks Mr. LaNore for some facts.