Lime and pH

1
Lime and pH

• Presented by
• Jim Lewis, Agricultural Agent
• Maryland Cooperative Extension

2
pH

• pH -log (H) log 1
• (H)
• (H) Hydrogen ion activity (concentration) in
  units of moles/liter, molarity (M)
  acidity

(H) pH 0.1 M 1 0.01 2 0.001 3 0.0001
4 0.00001 5 0.000001 6
3
pH

• pH of 5 is not 20 more
• acidic than pH of 6. It is
• 10 x more acidic than pH
• of 6!

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Very alkaline
Household lye
Bleach
Ammonia
Egg whites
Sea water
Pool water
Distilled water
Egg yolks
Pure rain
Beer
Orange juice
Pickle processing
vinegar
Lemon juice
Battery acid
Very acidic
5
Soil AcidityWhere does it come from?

• Organic matter decomposition
• Hydrolysis of aluminum
• Cation leaching or crop removal
• Acid rain
• Acid-forming fertilizers
• Acidic compounds released by roots and microbes
• Soil atmosphere carbon dioxide concentration

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Acidic RainfallQueen Annes County, MD2002 -
2003
Rainfall pH
2002
2003
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Effect of soil pH on plant nutrient availability
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Soil pH vs. Lime Requirement

• Soil pH Measure of the active acidity in a system
  that behaves like a weak acid (lots of
  potential acidity)
• Soil pH Gives no indication of the amount of lime
  needed for amending an acid soil.
• Lime Requirements Quantifies potential acidity
• Lime Requirements Incorporates soil pH, amount of
  clay, type of clay, amount of organic matter
  in the soil

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Quality of Liming Materials

• Calcium Carbonate Equivalent (CCE)
• Relative capacity of material to neutralize acid
• Pure calcium carbonate (CaCO3) 100 CCE
• Other liming materials ranked on a weight basis
• Based on molecular constitution

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Liming Materials
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Acid Neutralizing Values

• Liming Material CCE Lime ton equivalent
• Calcitic lime 100 2000 lbs.
• Burned lime 178 1120
• Hydrated lime (builders) 134 1490
• Magnesium carbonate 119 1680
• Dolomitic lime 95-109 1850-2100
• Ground shells 80-88 2200-2500
• Calcium silicate slag 71-80 2500-2800
• Basic slag 67-71 2800-3000
• Blast furnace slag 67-74 2700-3000
• Flue dust 96 2100
• Marl 40-90 2200-5000
• Wood ashes 40 5000
• Rock phosphate 7 29,000

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Only difference is a little moisture in wet
lime.

• Wet lime
• 5 moisture
• CCE 90
• Same mesh size
• .95 x 2000 1900 lbs.

• Dry lime
• 3 moisture
• CCE 90
• Same mesh size
• .97 x 2000 1940 lbs.

vs.
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Exercise 1 Using lime A with a recommended
application rate of 2,000 lbs. lime/acre, what
is the adjusted application rate after
correction for particle size analysis?

• Sieve Analysis or Mesh Size Analysis
• 95 passes through 8-mesh sieve
• 81 passes through 60-mesh sieve
• Fineness Factor
• Percent retained by 8-mesh sieve 100 - 95
  5
• Percent retained by 60-mesh sieve 95 - 81
  14
• Percent passing through 60-mesh sieve 100-5 -
  14 81
• 5 retained by 8-mesh X 0 effectiveness 0
• 14 retained by 60-mesh X 50 effectiveness 7
• 81 passes through 60-mesh X 100
  effectiveness 81
• Fineness Factor 0 7 81 88
• Corrected Application Rate
• 2,000 pounds lime 1/acre X 100 2,272 pounds
  lime 1 per acre
• 88 fineness factor

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Exercise 2 Calculate the EFFECTIVE NEUTRALIZING
VALUE (ENV) of an ag lime with the following
characteristics CCE 90 98 passes
8-mesh sieve, 76 passes 60-mesh sieve

• Fineness Factor
• Percent retained by 8-mesh sieve 100 - 98
  2
• Percent retained by 60-mesh sieve 98 - 76
  22
• Percent passing through 60-mesh sieve 100 - 2
  - 22 76
• 2 retained by 8-mesh X 0 effectiveness 0
• 22 retained by 60-mesh X 50 effectiveness 11
• 76 passes through 60-mesh X 100
  effectiveness 76
• Fineness Factor 0 11 76 87
• Effective Neutralizing Value (ENV) CCE x
  Fineness Factor
• ENV 90 X 87 78.3
• Application rate corrected for ENV
• 2,000 lbs./a lime rate X 100 2,554 lbs./a
  lime rate
• 78.3 ENV

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1 Ton CCE Recommendation

Northern Lime Co. 21.00/ton 72 CCE 2.5
K2O 3 SO2 60 mesh sieve 99

• Eastern Lime Co.
• 31.00/ton
• 179 CCE
• 20 mesh sieve
• 100
• 60 mesh sieve
• 99

Southern Lime Co. 18.00/ton 90 CCE 8 mesh
sieve 90 60 mesh sieve 50
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Eastern Lime Company 31.00/ton

• 179 CCE 20 mesh sieve .100 60
  mesh sieve .. 99
• 2,000
• 99 x 179
• 1,129
• 2,000

1,129 / acre
x 31.00 17.50 / acre
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Northern Lime Company 21.00/ton 72 CCE
2.5 K2O 3 SO2 60 mesh sieve ..99

• 2,000
• 72 x 99
• 2,806
• 2,000
• 50 K2O x 0.15 7.50
• 60 SO2 x 0.25 15.00
• 22.50

2,806 / acre
x 21.00 29.46 / acre
in other nutrients, if needed
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Southern Lime Company 18.00/ton

• 90 CCE 8 mesh sieve ..90 60 mesh
  sieve ..50
• 10 x 0 effectiveness 0
• 40 x 50 effectiveness 20
• 50 x 100 effectiveness 50
• 
  70
• 90 CCE x 70 63 effective neutralizing value
• 2,000
• 63
• 3,174
• 2,000

3174
x 18.00 28.56 / acre
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1 Ton CCE Recommendation

• Eastern Lime Co.
• 31.00/ton
• 1,129 / acre
• 17.50 / acre

Southern Lime Co. 18.00/ton 3,174 /
acre 28.56 / acre
Northern Lime Co. 21.00/ton 2,806 /
acre 29.46 / acre 7.50 K2O 15.00 SO2
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Size 60 mesh
Size 8 mesh
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Thanks!Do you have any questions?

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