
- ground limestone - 100 lbs. per 1000 sq. feet
- complete fertilizer (6-12-12) - 20 lbs. per 1000 sq. feet. (till into top layer)
- peat - 3 six cubic foot bales per 1000 sq. feet
- grass seed - 2 lbs. per 500 sq. feet
Nearly
every homeowner desires an attractive lawn because this is one
feature which most enhances the appearance of the average home
grounds. Healthy, attractive lawns are not an accident but the
result of a regularly and carefully executed maintenance program.
This applies to the soil as well as to the turf grass itself.
Turf grasses will not grow well in highly acid
soils, and since most soils in West Virginia are acid by nature,
well established lawns will require applications of lime. Acid
conditions of soils can be brought about by the leaching out of
calcium and magnesium, the alkaline constituents, from the soil;
yearly applications of nitrogenous fertilizers; the use of
organic materials, such as compost or peat moss, used to
condition the soil or as a top dressing; and the washing of
sulfur from the air by rains into the soil.
Acid soils are commonly referred to as
"sour," whereas alkaline soils are called
"sweet." The reaction of soils is measured by the
quantity of hydrogen (-H) ions in the soil which is
expressed by numerical units numbered between 1 and 14, with 7
being neutral. In West Virginia, soil reactions may vary between
pH 4.0 and pH 7.0. Soils with a reaction of less than pH 7.0 are
acid and those with a reaction greater than pH 7.0 are alkaline.
Most lawn grasses perform best at a reaction between pH 6.5 and
pH 7.0.
Acid soils are not necessarily infertile but an
indication that the supply of calcium and magnesium is low and
needs replenishing. More importantly, high acidity or low pH
levels may also cause other nutrients to be unavailable to
plants. The greater the acidity of the soil, the greater the need
for lime.
What is Lime?
"Agricultural lime" or "ground
limestone" are terms used quite loosely and include all
types of lime. Lime is a compound of calcium or calcium and
magnesium capable of counteracting the harmful effects of an acid
soil on lawn grasses.
There are three major types of lime and each
has its advantages.
- 1. Ground limestone and calcic
limestoneCalcium Carbonate (CaCO3 )almost pure
calcium carbonate, finely ground. Ninety-five percent of
all lime used in the United States is calcium carbonate
because it is the most abundant and cheapest form of
lime. Also, it is not caustic or disagreeable to handle
as is burnt or hydrated lime. It may also contain varying
amounts of magnesium carbonate. Limestones containing
significant amounts of magnesium carbonate are called
dolomitic limestones. Dolomitic limestone contains about
equal parts of magnesium and calcium carbonate.
- 2. Burnt lime (CaO)quick lime,
caustic limeacts more quickly than calcium
carbonate. Gloves should be worn when using burnt or
hydrated lime. Only ½ the rate of ground limestone is
needed since burnt lime is twice as effective in
neutralizing.
- 3. Hydrated lime [Ca(OH)2]or slaked
limepound for pound is about 1½ times more
effective and quicker to react than ground limestone
(calcium carbonate).
Functions of Lime
Lime is primarily a soil amendment or
conditioner and not a fertilizer, as is commonly thought. Lime
performs several important functions:
- 1. Corrects soil acidity
- 2. Furnishes important plant
nutrientscalcium and magnesium
- 3. Reduces the solubility and toxicity of
certain elements in the soil such as aluminum, manganese,
and iron. This toxicity could reduce plant growth under
acid conditions.
- 4. It promotes availability of major plant
nutrients. Calcium acts as a regulator and aids in
bringing about the desirable range of availability of
many plant nutrients. Some elements which lime aids in
regulating are zinc, copper, and especially phosphorus.
- 5. It increases bacterial activity and
hence induces favorable soil structure and relationships.
Soil structure is also improved by the addition of
decayed organic matter or compost. The soil becomes more
porous, increasing air circulation and the ability of the
soil to absorb and hold moisture.
Time of Application
To obtain maximum
efficiency and faster action, the best time to apply lime to the
lawn is when the soil is being prepared for planting. This
applies to the sub-soil as well as the topsoil because lime moves
very slowly through the soil. Research has shown that it it takes
up to two years for lime to move two two inches through the soil.
Applications of lime on established lawns may
be made at any time of the year, the most favorable time of the
year being fall, winter, or early spring, in that order. If
applied when the soil is too wet, it is difficult to obtain an
even distribution. If heavy equipment is needed to spread the
lime, make the application on level areas when the ground is
frozen. Less damage is made to the soil and grass under these
conditions. Alternate freezing and thawing and early spring
showers hasten its penetration into the soil.
Lime must be spread evenly over the entire area
because it does not move horizontally. The use of a spreader
insures a better distribution and permits the lime to be placed
next to flower beds or in close proximity to acid-loving plants.
Pelleted lime is now available at most garden
centers. Pelleted lime costs a little more but has several
advantages in that it goes through a spreader more easily; may be
spread by hand without being covered by dust; dust does not drift
or blow into areas where lime is not wanted; eliminates such
problems as tracking lime onto patios, etc. or into the house;
and is easier to clean up if the bag is broken.
Rate of Application
The amount of lime required will vary with the
degree of acidity, the soil type and the kind of lime material.
Light, sandy soils require less lime than soils high in silt and
clay. It is always a good practice to have the soil tested to
determine the amount and kind of lime required. Soil test mailers
and sampling instructions are available from County Extension
offices.
Liming the lawn is an important part of good
maintenance and should be included in the schedule. However, many
enthusiastic gardeners are apt to over-lime. Generally,
applications of lime should only be made every three to five
years. Soil tests will aid the homeowner in determining the exact
applications to be made. Single applications of over 150 pounds
of lime per 1,000 square feet (three tons per acre) are not
recommended. If over 150 pounds per 1,000 square feet are needed,
apply half one year and the remaining half two to three years
later, after rechecking the soil pH.
It should be remembered that too much lime can
be as damaging to lawn grasses as the lack of lime. Also, lime is
not a cure-all to all lawn maladies but an ingredient which can
correct soil acidity, thus creating favorable conditions for
other factors to occur which develop favorable conditions in soil
for lawn grasses. It is important that homeowners know that lime
is necessary and how much is needed so that they can make the
proper application for the first step toward a healthy lawn.