What You Need to Know About Fertilizing and Watering - Southwest ...

How did this happen?
While proper fertilization and watering practices are safe for plants
and the environment, improper practices can damage plants and can
contribute to surface and groundwater pollution. Research suggests that
excess nutrients such as nitrates (formed from nitrogen in fertilizer) and
phosphorus (also called phosphate) are entering ground and surface
waters and degrading our springs and spring runs, as shown in the
bottom photo on the cover page. If more nitrogen is applied than can
be used in the root zone of the plant, or if too much water is applied,
nitrates will be washed below the root zone and into ground water. This
is called “leaching.”
Once out of the root zone, nitrates in ground water can move freely,
show up in wells and flow back to the surface in springs.
Phosphorus does not move as freely in ground water as nitrates.
Phosphorus binds to limestone in the aquifer, where our water is stored,
and becomes trapped. However, springs are found in areas where there
are many sinkholes, cracks, caves and channels in the limestone in the
Floridan aquifer. These areas are shown in blue on the map on the first
page (page i).
Phosphorus passing through sinkholes and cracks in the aquifer is not
exposed to as much limestone and can travel on to springs.
Phosphorus usually enters a spring or spring run through surface
runoff from yards, parking lots and streets.
Native soils in spring basins and spring ecosystems are generally
naturally low in nutrients. The addition of nutrients to springs and
spring runs through ground and surface water can cause excessive
aquatic weed and algae growth and can degrade water quality and
clarity in our springs.
Other sources of excess nutrients
causing degradation of our
springs are animal wastes and
poorly functioning septic tanks.
iv