Future of Ponds Brightens As Organic Fertilizers Become Popular

 

            When you walk into Mahoney’s Garden Store in East Falmouth, you see two large sections of lawn care supplies that seem to be battling it out for your attention. On one side are the traditional synthetic fertilizers and insecticides, and on the other are the organic fertilizers and insecticides. In recent years, more and more people have been shifting to the organic option.

 

            This shift is promising for the health of Great, Green, and Bournes Ponds in particular, but also for every one of Falmouth’s coastal ponds and harbors.

 

            Water quality in these ponds has deteriorated steadily over the past twenty-five years, and lawn fertilizers have played a role in the decline. Fertilizers work because they contain nitrogen, a nutrient that grass needs to grow. However, much of the nitrogen in fertilizers never makes it into the plants; rather, the nitrogen leaches down into the groundwater and eventually out into the coastal ponds. Once in the ponds, the excess nitrogen stimulates the growth of algae, which in turn shades out native vegetation, destroys fish habitat, and occasionally drives oxygen out of the water, suffocating the animals (fish and shellfish) that live there.

 

            Synthetic chemical fertilizers pose much more of a leaching problem than organic fertilizers. Synthetic fertilizers contain nitrogen in its most simple, inorganic forms. The nitrogen dissolves in water and is easy for grasses to take up from the soil. This may seem great when the fertilizer is first applied: the grasses get inundated with food. But just as you cannot eat fifty pizzas in one sitting, the grass cannot absorb all that nitrogen at once. Most of the nitrogen leaches out in the groundwater.

 

            In contrast, organic fertilizers release nitrogen slowly, over many days, allowing the grasses to absorb much more of the total nitrogen in the fertilizer. Only a small fraction of the nitrogen makes it out into the ponds.

 

            The central difference between organic and inorganic fertilizers is that organic fertilizers contain a higher percentage of water insoluble nitrogen (WIN). While synthetic fertilizer contain very little WIN, WIN ranges from 30-95% for organic fertilizers. Water insolubility ensures that the nitrogen in the fertilizers will not simply dissolve into water with the first rain and rush down into the groundwater. Some organic fertilizers are better than others: those with 90-95% WIN are the best.

 

            Fertilizers are the second largest source of nitrogen to the ponds, dumping more than 18,000 pounds of nitrogen a year into the three East Falmouth ponds from lawns in their watersheds. This accounts for more than 15% of the total nitrogen loading to the ponds. So if the recent trend toward organic gardening continues, the effect on the ponds could be quite significant.

 

            At Mahoney’s, the shift towards organic fertilizers has been remarkable. Just a few years ago, sales of organic fertilizers and insecticides made up only a small fraction of total fertilizer and insecticides sales. Last year, they reached 15%. This year, they are up to 40-50%. In fact, the demand for organic products is so high that suppliers can barely deliver enough to keep the shelves stocked.

 

            James Redding, a sales manager at Mahoney’s, believes that one of the reasons that organic fertilizers have become so popular is that local citizens groups have actively promoted them.  In Falmouth, The League of Women Voters, The Garden Club, FACES (Falmouth Associations Concerned with Estuaries and Saltpond) and the Ashumet Plume Citizens Committee have conducted workshops to let people know about lawn care practices that reduce nitrogen run-off to the ponds.  A central theme in these workshops is that the best option is not to use any fertilizers at all; just take advantage of nitrogen from rainfall and grass clippings left on lawns to feed them.  But, if that seems too radical a first step, then spring and fall applications of organics is the way to go. A FACES poster advocating organic fertilizers greets customers as they come into Mahoney’s gardening section.

 

            Several other factors have also spurred the shift towards organics, according to Mr. Redding. First, the number of organic products available to customers has exploded over the past couple of years. There is ground seaweed to feed your grass, corn gluten to prevent weeds from emerging, and the list goes on. Families are also turning to organic alternatives in order to keep their lawns safe for their children. 

 

            Finally, more and more people see the real benefits of organic fertilizers to the lawns themselves. Organic fertilizers provide a much fuller suite of nutrients than the synthetic ones, and they release those nutrients slowly as the plants need them. The result is a fuller and hardier lawn, more resistant to insect and fungal attacks. Of course, many people who keep home compost or manure piles for their lawns have known these benefits for a long time.

 

            But organic fever has not caught on everywhere. At the Cataumet Garden Center, sales of organic fertilizers have increased over the past several years, but those increases have been fairly small. Seth Andrews, manager of the Center’s nursery, says that their customers are now, more than ever, “exploring options of responsible lawn care”, which includes organic gardening. But people are, for the most part, sticking to the synthetic options.

 

            Synthetic fertilizers have two things going for them: they are cheap, and they work quickly. They cost 3-5 times less than the organic alternative. And, because they contain nitrogen in a form that is easy for plants to take up from the soil, results are immediate. Fertilize one day, the grass is greener the next.

 

            In the long-run, Seth believes, the slow releasing organic fertilizers are better for the lawn. But the lure of a quick fix often tempts people. He says the “biggest hurdle” for getting customers to switch to organic gardening” has been “people’s need for fast results, versus long-term benefit.”

 

            Professional lawn care companies typically are among the most eager for “fast results”, according to Seth. Most customers want their lawn care company to give them green lawns, the quicker the better. For a lawn care service provider, the easiest way to do this is to buy a large stock of synthetic fertilizer, throw it into the back of a truck or into spray packs, and go to it. Not until customers insist on organic lawn services, both with their voices and their pocketbooks, will this sector of lawn care join in with the recent trend towards organic practices.

 

            While organic gardening certainly has not caught on everywhere, it has gained momentum. You can help accelerate that momentum by curbing your own use of nitrogen chemicals and by urging more of your neighbors to give organics a try.  Those are simple steps every homeowner can take to start reversing the nitrogen pollution that’s ruining Falmouth’s coastal ponds.