In this article, I want to discuss the impacts of fertilizers and some things that homeowners can do to prevent pollution.
First lets talk about the basics. The most used substance in fertilizer is Nitrogen (N), while Phosphorus (P), and Potassium(K) are less widely used. These can be naturally occuring (cow dung has lots of nitrogen) or unnaturally occuring. Fertilizers contain the food plants need to grow. If we create healthy soils, there is no need for chemcial fertilizers. We have a very healthy lawn that has not been fertilized for atleast 15 years.
Another substance is being sprayed on our lawns (and crops). It is herbicide, developed to kill all or specific plants, and is harmful to humans. When weeds come onto a lawn, this is the common solution applied by lawn care companies. But there are many side effects, and you can do your research: pollution, birth defects, mental health issues, allergies. The best way to fight invasion of unwanted species is 1) to have a healthy crop that can crowd out other species, and 2) have some biodiversity to have a complete ecosystem in which all the species and elements are in balance.
So we see that fertilizers can make the grass greener, but at what price? When the fertilizers run off into the waterways, they can cause alot of problems. In the bay, the algaes feed off the nitrogen and reproduce rapidly. Since they grow rapidly they also die off rapidly. This causes a lack of oxygen in the water and can large numbers of fish, crabs, clams, etc... Signs are crabs being $120/ bushel. Clams, menhaden, flounder, oyster, and rockfish to name a few are on a serious decline. For what? The grass to be greener? Is it really greener?
Lets look at some factors that cause grass not to do well, and require fertilizer to look nice. First the soil is very important. Organic compost, leaves, and other organic ammendments must be added to most soils in the area. The ideal pH should be 6.2-6.8. Organic matter % should be over 5%. However a soil regularly doused with chemcials can not be healthy! To measure these we can get a soil analysis done for you. Secondly, the grass strain must be the correct type for your climate. Do you have lots of shade? Fine fescue will do better for you. Do you have plenty of sun tall fescue is best for maryland. Do you want a nice soft lawn? Zoysia may be right for you. Thirdly, overwatering can cause the grass to develop shallow and weak roots. Grass should be establsihed with deep watering, so that the roots are trained to go deep for water. Lastly, cutting the grass too low can cause alot of problems. This is a common practice of most lawn care companies and lets examine the effects of this practice.
Most lawn care companies cut the grass from 2-3.5 inches. When grass is cut too low it puts all its energy into growing above ground, so the roots are not healthy. Also there are alot of microbes in health grass that break down thatch and organic matter. When the grass is cut too low their microclimate is destroyed. Then the unhealthy level of thatch builds up. The grass is not drough resistant and requires more water and more chemical fertilizers to look nice.
Actully 4.5-5 inches is ideal. Lets look at the benefits. Deep, healthy roots develop. The turf is more disease resistant and highly drough tolerant. Microbes have a good climate and flourish, breaking down thatch and enriching the soil. A healthy lawn can capture pollutants from running off, help prevent erosion, and cool the area up to 10 degrees compared to bare earth.
Another health practice is grass-cycling, or mulching. This means mowing the grass with a mower that cuts the blades up very finely and distributes them into the yard. This is a natural nitrogen and organic matter source.
So lets just look again at the things we can do to prevent pollution of our local ecosystem as well as the Chesapeake Bay.
1) Choose the right species of grass for your climate. This will allow the grass to out-compete weeds (no herbicide needed). This will allow the grass to be more self- sufficent meaning no fertilizer is needed.
2) If you have to water, do it only as needed and water 6 inches deep. This will encourage deep root growth with leads to drough resistance.
3) Mow 4.5-5" high and leave the clippings in the lawn. This will create healthy soil, reduce thatch, add organic nitrogen and organic matter to the soil, increase the microbe population and decrease your lawn care bill.
4) If you insist on adding fertilizers, follow the application instructions on the package. For nitrogen add 2-3LB for 1000 square feet MAXIMUM. Apply 15 feet away from water(streams, rivers, ponds, etc...), and do not spill on the road, sidewalk, driveway, etc...
All of these healthy practices combined will lead to a healthier ecosystem, a healthier population of seafood in the bay, and hopefully healthier people. Please contact us if you have any questions or comments. Thank you very much for making conscious decisions for you, your family and your property.