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Nitrogen (N)
Low req1
High req2
Phosphorus (P)
Potassium (K)
Calcium (Ca)
Magnesium (Mg)
Sulfur (S)
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 --
1.75-2.00
2.00-2.25
0.20-0.30
1.25-1.75
1.20-1.60
0.25-0.40
--
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2.20-2.80
--
--
0.11-0.25
1.00-2.00
1.00-1.50
0.25-0.50
0.20-0.40
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3.25-4.00
--
--
0.20-0.40
1.50-2.00
1.50-2.25
0.30-0.60
--
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2.00-2.50
--
--
0.13-0.35
2.50-3.00
1.60-2.50
0.30-1.20
--
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2.40-3.00
--
--
0.14-0.25
1.60-3.00
1.50-3.00
0.30-0.80
--
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2.60-3.00
--
--
0.16-0.22
1.60-2.10
1.50-2.60
0.30-0.75
--
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2.10-3.00
--
--
0.16-0.50
2.50-3.00
2.00-3.00
0.30-0.80
--
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1Stayman, Turley, McIntosh, Jerseyred, Gravenstein, Starr, Summer Pippin, and Britemac have low nitrogen requirements.
2 Red Delicious, Rome Beauty, Golden Delicious, and Jonathan have high nitrogen requirements.
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Soil samples.Soil samples should be taken in the
fall months following the harvest season and sent to the
laboratory for analysis so that the information provided by
the test is available for decision making before the spring
rush. The fall and winter months are often the best and
most convenient times to apply needed lime applications
in fruit orchards. Fertilizer applications are generally more
effective if made 1 to 2 months prior to tree bloom than at
other times of the year. Growers that wait until the spring
months to take soil samples may not get the results of the
tests back from the laboratory in time to make effective
use of them.
Most soils in the Mid-Atlantic region are naturally
acid or became acid under crop production systems. A
regular liming program is required to neutralize soil
acidity and to supply crops with calcium and magnesium.
The first step in a liming program is knowing the
optimum or target pH value of the crop to be grown.
Many crops will grow over a wide range of soil pH but
most tree fruit crops perform best when soils are limed to
pH 6.5. The soil pH in orchards should not be allowed to
fall below pH 6.
Soil pH alone cannot be used to determine the
amount of liming material to apply to correct soil acidity.
The second step in a liming program, therefore, is to have
a soil fertility test performed. The soil test results provide
the data needed to determine the lime requirement and the
type of lime to use.
Lime Requirement.A soil's lime requirement
depends on total acidity that must be neutralized to raise
pH to the desired level. It is important to understand that
a soil pH measurement only indicates the concentration of
active acidity in soil solution. Total acidity represents
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the active acidity in solution plus the amount of
exchangeable acid cations held on clay and organic matter.
For the purpose of lime recommendations, total acidity is
estimated from soil texture plus soil pH or it is measured
directly by titration (which is referred to as buffer pH).
Buffer pH measurements that appear on soil test reports
from some laboratories are a measurement that can be used
to determine lime requirement and should not be confused
with soil pH. The interpretation of buffer pH is specific to
the buffer method employed by the laboratory and the
properties of the soils in the region.
Soil pH measurement and soil texture are commonly
used to determine lime requirement. Soil texture
classifications (i.e. loamy sand, sandy loam, loam, or silt
loam) may be considered a fixed property of a soil because
it is not readily changed. Thus, once soil texture is
known and soil pH is measured, a soil's lime requirement
can be determined by referring to the appropriate table for
the crop to be grown without any reevaluation of soil
texture. Once growers know the soil texture, they may
find portable pH meters to be helpful in the evaluation of
their liming program.
The lime requirement for a given soil also depends
on the target soil pH. Most tree fruit crops have a target
pH of 6.5. The lime requirements for various initial soil
pH's and soil textures are shown in Table 1. Be careful to
avoid over application of lime because excessively high
soil pH's may induce nutrient deficiencies.
Calcium Carbonate Equivalent.Soil test
recommendations for liming soils should be given in
pounds of calcium carbonate equivalent per acre (lbs.
CCE/acre). Pure calcium carbonate (CaCO3) has a CCE
of 100% and is the standard against which all liming
materials are measured. Since the CCE of liming
materials available in the state may vary from 40 to
179%, the amount of liming material needed to supply a
given quantity of CCE will vary considerably. The CCE
of a liming material must be stated on the product label.
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