Turf

fertilizers By Dr. Bryan G. Hopkins Fertilizer Bans Coming to a City Near You? Simple solutions can prevent this drastic step All turfgrass managers must be good environmental stewards so fertilizer bans are not initiated Good intentions are not always good. Recent policy trends have banned the use of fertilizers in the landscape due to growing pollution concerns in a variety of locations, including communities in Washington, Florida, Connecticut, New York, etc. It is true that the number one water quality problem in the United States is pollution of nitrogen and phosphorus that lead to eutrophication—excessive algal growth resulting in hypoxia and leading to death of fish and other aquatic life. As a City Council member in Tampa, Fla., put it, "Tourists don't want to come to a place where there's no fish, and people don't want to live in a place where the water is polluted." In New York, studies have shown that phosphorus from erosion and runoff has a significant negative impact in lakes and reservoirs. About 50 percent of phosphorus found in storm runoff comes from lawn fertilizers. The runoff of fertilizer into waterways also increases the amount of water treatment and purification necessary, which in turn increases costs. Nitrogen can also be lost to the atmo20  www.westernturfmag.com sphere and impact sensitive ecosystems with reactive nitrogen (ammonia) and as a potent greenhouse gas (nitrous oxide). Nitrogen lost to the atmosphere occurs through natural soil chemical and biological processes that are increased with the addition of fertilizers. With 78 percent of nitrous oxide emissions coming from fertilization, there is a need to find a solution. Banning fertilizer sounds like a viable solution, but eliminating fertilizers would create disaster in terms of food, fuel, and fiber production for the 7 billion people on Earth. Nutrients are necessary, and eliminating fertilization is not an option unless we want to reverse the green revolution, which has resulted in vast improvements in quality of life in the last century. Nutrients are essential for plant growth and development. Without them plants are unable to complete their life cycle. When crops are harvested the soil nutrients are removed. If not replaced, soil quality suffers. Such is the case in history with "the fertile crescent" in the Middle East, which is no longer fertile in most areas due to ancient soil mismanagement. Some would say, "Let's keep the fertilizer on the crops but we don't need to fertilize urban environments." This may be a good intention, but without fertilizers the green spaces that provide recreation, aesthetics, temperature mitigation and biodiversity would be lost. The Biophysical Chemistry Lab in the Brigham Young University Plant and Wildlife Sciences Department is focused on researching environmental solutions that are socially acceptable as well as economically viable. We propose three simple solutions as alternatives to fertilizer bans: 1) Vegetate the soil to minimize water and solute runoff. 2) Fertilize based on soil testing to avoid nutrient excesses, and 3) Apply newly developed, sophisticated fertilizer products engineered to enhance nutrientuse efficiency. Plant cover on soil reduces water runoff, which in turn reduces the movement of soil, nutrients, and other solutes best left on the land and not in the water. Having a soil covered with plant material also effectively utilizes nitrate and other nutrients—reducing the likelihood of them leaching to groundwater. Another related benefit of plants growing in soil is that soil water is utilized and, thus, is less likely to move downward to groundwater or overland to surface waters and carry potential pollutants with it. Fertilizer is an important key to having a healthy plant canopy to cover the soil. In addition to reducing runoff and leaching problems, plants also provide a moderating temperature effect to the environment (which can reduce heating/cooling costs). Also, a healthy plant canopy is aesthetically pleasing and helps clean the air—thus giving a boost to quality of life. All plants need nutrients, and soil testing provides a guide to applying only what is needed—minimizing risk of nutrient pollution. Farmers have thin profit margins and, as such, have learned the value of applying nutrients on an as-needed basis—as determined by soil testing. Homeowners and urban land managers are often less focused on the economic bottom line and tend to apply

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