Fertilizer
Soil
color is deceiving and does not indicate the
fertility; and the darkest may be poorest in nutrients. While grasses
will survive without fertilization, they will not do so and look and
perform to the standards we set for them today. A healthy, green,
lush lawn is generally a result of a correct fertilization program.
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A minimum
lawn fertilization program--one that will produce acceptable home
turf for most people--is to fertilize warm season grasses twice a
year, and cool season grasses three times a year. Warm season grasses
like bermudagrass and St. Augustine grass should be fertilized in
May-June, and again in September-October. Cool season grasses such
as tall fescue, Kentucky bluegrass and perennial ryegrass should be
fertilized in March, in May and again in September-October.
There are many different
lawn fertilizers available on the market. A fertilizer containing
nitrogen, phosphorus and potassium, in that order, is often referred
to as a complete fertilizer. An example might be 16-8-8, a turf fertilizer
which contains 16 percent nitrogen, 8 percent phosphorus and 8 percent
potassium. Regardless of the mix of elements, nitrogen is the most
important element in the bag for turfgrass fertilization. For that
reason, the amount of fertilizer to apply to your lawn is based on
nitrogen.
For established lawns,
generally a maximum of 1 pound of actual nitrogen per 1,000 square
feet of lawn should be applied at one time. To find out how much of
a particular fertilizer you need to apply to get 1 pound of actual
nitrogen, simply divide 1 by the first number of the analysis shown
on the bag and then move the decimal point two places to the right.
This will give you the number of pounds of the fertilizer you need
to apply to 1,000 square feet of lawn area to supply 1 pound of actual
nitrogen. For example, for a 16-8-8 fertilizer, 1/16 = 0.063. Move
the decimal point and you have 6.3. Therefore, with a 16-8-8 fertilizer
you will need about 6 pounds of the fertilizer per 1,000 square feet
of turfgrass to supply 1 pound of actual nitroge
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Besides their nutrient
analyses, fertilizers differ in how they make their nitrogen available
to grass roots. Fast release of soluble fertilizers are usually the
lest expensive. They can provide a quick greening response for a relatively
small amount of product applied. However, they can burn your lawn
if you apply them improperly, and they are used up more rapidly than
some other types of fertilizers. Ammonium sulfate and ammonium nitrate
are examples of fast release or soluble fertilizers.
Slow release chemical fertilizers
allow nitrogen to become available over longer periods of time than
do soluble fertilizers, and they won't burn the lawn even when applied
at relatively high rates. However, slow release fertilizers are comparatively
expensive, and their release rates can vary depending on the amount
of water you apply, the temperature, or the activity of soil microorganisms.
Natural organic materials
may also be used a s lawn fertilizers. Examples are animal manures
and compost. Although safer because they aren't as likely to burn
turf, you have to apply relatively large amounts of them to obtain
the required amount of nitrogen needed. Some of the manures may contain
weed seeds and harmful salts, and some may have unpleasant odors.
They do release nutrients over an extended period of time.
Fertilizing by hand can
be effective, but a mechanical spreader is easier, safer an more accurate
for most home gardeners. The two general types of mechanical spreaders
available are the broadcast (cyclone or rotary type) spreader, and
the drop spreader. To achieve the most even distribution, spread half
the fertilizer in one direction, and the other at right angles to
the first.
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