Avoiding Algae Blooms from Fertilizer Runoff
It’s an all-too-common occurrence--irrigation or rain water causing fertilizer to run off into nearby ponds and lakes. The turf is no greener, the plants no more lush, and fertilizer (and money) is wasted. And to top it all off, nearby ponds are polluted, leading to unsightly algae blooms. This pollution process has a long name: eutrophication.
A Closer Look at the Problem of Eutrophication
Eutrophication happens whenever a body of water becomes overfilled with nutrients thanks to runoff from the surrounding land, and it has become a hot topic in recent decades. The nutrients may come from several sources, including intentional fertilization, manure from animal operations, sewage sludge, and natural phenomenon such as falling autumn leaves.
While on land, these nutrients can be a resource. Displaced to the water, however, they quickly become a liability. The increased nutrients can cause algae blooms, leading the water to turn an unsightly pea soup color. The growth in algae leads to unsafe drinking water, fish kills, and even dead zones.
This topic made the news in summer 2014 when residents of Toledo, Ohio were banned from drinking tap water. This was due to the toxic algae bloom in Lake Erie. Growers and landscape professionals have been urged to reduce the amount of phosphorus they use and to undergo training in applying commercial fertilizers. What is your company doing to prevent and remedy such problems?
Simple Solutions for Eutrophication
Some very simple strategies can help make your business part of the solution, rather than the problem.
- 1- Think ahead. Take care to put nutrient sources, such as fields that will be fertilized, as far away as possible from bodies of water.
- 2- Reduce runoff. Water that flows unimpeded downhill will tend to take soil and nutrients with it. Careful contouring of the land can help prevent this by slowing and spreading the flow of water, giving it time to soak in before it runs downhill. Terraces, swales and buffer zones can be used to keep fertilizer from entering ponds and other waterways.
- Over time, the water retained in the landscape will filter down and replenish the groundwater. Nearby ponds, lakes and springs will benefit from receiving a steady and filtered flow of water, rather than occasional and polluted surface flooding.
- 3- Reduce nutrients in runoff. Use slow-release fertilizers that provide a gradual and steady feeding for plants, rather than a sudden burst of fertilizer. It’s better for plants, and if some of it runs off into nearby water, it may do less damage.
- Soil Tech’s TurfTech Bio is one such product. It supplies free nitrogen from biological nitrogen fixation, promoting higher quality turfgrass with a reduced need for synthetic fertilizers. In addition, the organisms in TurfTech Bio can improve the soil’s crumb structure, allowing it to better retain moisture and resist compaction. Compacted soils contribute to runoff, while a good soil crumb structure absorbs water more quickly. And TurfTech Bio also provides several strains of rhyzobacteria, proven fungal antagonists that may inhibit turf disease.
- 4- Digest nutrients quickly. Finally, if excess nutrients do reach nearby lakes and ponds, accelerate their digestion so that they do not become a problem. Whatever the source of excess nutrients--an abundance of autumn leaves, fertilizer or manure runoff--Soil Tech’s Lagoon Kleen and Pond Kleen can help. These products provide digestive bacteria and enzymes to rapidly degrade organic matter in pond systems and reduce the availability of nutrients which feed eutrophication.
With a bit of thoughtful planning and careful choice of products, landscapers and land owners can do quite a lot to prevent eutrophication and keep nearby waterways healthy and beautiful.