The Myakka River gently flows as it meanders through Myakka River State Park. [credit: sarasota county government]

BAY-FRIENDLY FERTILIZING IN RESIDENTIAL COMMUNITIES

We can all reduce our nitrogen input to help save the bay. Reclaimed water is a must to ensure the sustainable use of our freshwater resources.

As there is a certain amount of nitrogen (N) and phosphorus (P) found in reclaimed water, plans should be made to reduce fertilizer.

Overapplication of nitrogen-based fertilizer can lead to undesirable physical changes in the plant, such as shallow root growth, making the plant less stress-tolerant. Nitrate leaching occurs when too much nitrogen is applied to our county's sandy soils. As a result, the nitrogen that does not get absorbed can find its way into our waterways and bays.

You can avoid over-fertilizing by including your reclaimed water's nutrients in your fertilizer calculations.

Follow these two easy steps to see just how much fertilizer you could save irrigating with reclaimed water:

Find out where you get your reclaimed water.
Find out how much fertilizer you could save based on your reclaimed water use.

Step 1. Find out where you get your reclaimed water.

Depending on where you get your reclaimed water, you will likely have a different concentration of nitrogen in your irrigation water. In unincorporated Sarasota County, there are three water reclamation facilities that provide reclaimed water to our residents: the Bee Ridge Water Reclamation Facility, the Central County Water Reclamation Facility, and the Venice Gardens Water Reclamation Facility.

Type your address in the top left corner of the map below to figure out your reclaimed water service area*.

*Some reclaimed water service areas may not be available in this dataset.

Step 2. Find out how much fertilizer you could save based on your reclaimed water use.

Keep the Bay Blue, Not Green.

Nitrogen fertilizer must contain at least 50 percent slow-release nitrogen, and no more than 4 pounds of nitrogen per 1,000 square feet may be applied to turf or landscape plants each year.

Per application, the University of Florida recommends no more than 1 pound of nitrogen per 1,000 square feet of turfgrass. And, remember, your reclaimed water is already delivering a portion of that amount.

See total nitrogen (TN) trends in your reclaimed water

Values are calculated from the 2022 and 2023 total nitrogen (TN) data of the Bee Ridge, Central County, and Venice Gardens Water Reclamation Facilities. The TN values were converted from mg/L to lbs./1,000 sq. ft. using a conversion formula from Accounting for the Nutrients in Reclaimed Water for Landscape Irrigation by Martinez et al.

Cumulative Total Nitrogen (2023)

These values are based on weekly, 3/4-inch irrigation applications through May.

Water Reclamation Facility	Total Nitrogen (lbs./1,000 sq. ft.)
Bee Ridge	1.04
Central County	1.53
Venice Gardens	2.61

SOURCE: Sarasota County Utilities

Average Total Nitrogen (2023)

This line graph shows monthly fluctuations in the average TN concentration (mg/L) in 2023.

Cumulative Total Nitrogen (2022)

These values are based on weekly, 3/4-inch irrigation applications for 52 weeks. You can use this information to determine your fertilizer amendments for 2023.

Water Reclamation Facility	Total Nitrogen (lbs./1,000 sq. ft)
Bee Ridge	1.75
Central County	1.43
Venice Gardens	3.23

SOURCE: Sarasota County Utilities

FERTILIZER RESTRICTION PERIOD! Do not use nitrogen-based fertilizer from June 1 through Sept. 30, during Sarasota County's rainy season.

Disclaimer:

Natural cycling of nitrogen and phosphorus may slightly alter the forms and concentrations of nutrients in the final irrigation water. Also, a small fraction of the nutrients in reclaimed water may be in forms that plants are not able to use. While these caveats mean that the nutrient values seen here may be slightly different than what is actually applied via irrigation, the differences are likely small, and reclaimed water should still be used wisely with the understanding that it can contain appreciable levels of plant available nutrients.

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