Soil Acidity and Liming

• Pellet Lime – Finely ground limestone– Glued together into water soluble pellets– Advantage: Handling, spreading, speed of

reaction– Disadvantage: Cost

100-200 mesh

Soil Acidity and Liming

• Fluid Lime – Finely ground limestone

– Suspended in water with clay

– Approx. 1000 lb CCE/ton material

– Advantage: Spreading, speed of reaction

– Disadvantage: Cost

Less than recommended very fine limestone applied compared to normal

liming program

7

6

5

4

pH

0 3 6 9Reaction Time (years)

3

Less than recommended very fine limestone applied annually but

similar rate over time.

7

6

5

4

pH

0 3 6 9Reaction Time (years)

Soil Acidity and Liming

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

Start 1994 1995 1996 1997Ch

ange

in p

H

Pellet Lime @500lb/A/yrPulverized Lime @8000 lb/A

Effect of Pellet Lime on Soil pH

Soil Acidity and Liming

• Calcium and Magesium – Normal liming practices will also supply required

calcium and magnesium• At normal rates usually adequate Ca will be supplied

for most crops• Magnesium will depend on the type of limestone

used– If Mg is required use a Mg containing limestone (dolomitic)– Mg recommendations

» pounds Mg/A» % Mg in recommended limestone

Calcium and Magnesium

• Management Recommendations– Maintain optimum pH – Maintain at least optimum levels of Mg (60

ppm) and K (100 ppm)– Don’t worry about ratios until they are way

out of balance• eg. Mg:Ca >1, K:Mg>1• Rare

By-product Liming Materials

• Quality–Liming value

–Undesirable components

Example: Liming Value

Material sold in western PA for $2/ton

CCE = 5.38%

For 1 ton of neutralizing value:

2000 X 100 ÷ 5.38 = 37,174 lbs. or 18.6 tons ($37.20)

Fineness:

Through 20 Mesh = 98.8% (90%)

Through 60 Mesh = 78.2 % (60%)

Through 100 Mesh = 63.2% (50%)

Gypsum

• CaSO4

• Excellent source of Ca and S– 33% Ca & 27% S

• No neutralizing value

• Not a liming material

Limestone vs Gypsum

• Limestone changes pH Gypsum doesn’t

• Both are good sources of Ca

– Lime to recommended pH . . . no need for additional Ca for the

soil or for agronomic crops in PA

– High pH but low calcium soils (Sodic Soils) use gypsum as a

source of Ca for the soil and the crop (Western US)

• Improves physical properties Relieves chemical compaction

– Low pH, acid loving crops or highly weathered soils, use

gypsum as a source of Ca for the soil and the crop (Tropics)

• Minimal lime to reduce Al toxicity

Byproduct Materials Undesirable components

• Should be registered (PDA)• Must be approved for land application by DEP

– May limit lifetime application• Problem with unregistered materials and

materials from out of state– May be little or no checking of quality

• Determine the source– Dust, screenings– Stainless steel slag

• Ask what contaminants might be present • If in doubt . . . get it analyzed OR don’t use it

Example: Undesirable components - Metals in Aglime

Material

Cu Zn Pb Cr Ni Cd

Aglime .02 .03 .05 .02 .04 .00

Aglime .02 .02 .05 .02 .04 .00

Aglime .03 .02 .04 .02 .04 .00

Aglime .01 .05 .07 .02 .04 .00

Aglime .01 .05 .07 .02 .04 .00

Ind. Byprod. .04 .05 .10 .03 .07 .00

Ind. Byprod. .04 .08 .20 .04 .05 .00

Ind. Byprod. .03 .00 .07 .03 .05 .00

Ind. Byprod. .03 .27 .09 .04 .08 .00

Ind. Byprod. .02 5.62 .08 .02 .06 .01

Ind. Byprod. 68 160 19 2037 435 5

Other Materials

• Biosolids and Water Treatment Sludges– Often have significant neutralizing value

– Must be clean

– Must be registered if sold as liming materials

Other MaterialsOrganic Calcium Compounds

• Promesol 30, Liquid Lime– Trihydroxy glutaric acid 25%

Ca– 1 gallon = 500-750 lb CCE?

• Liqui-Til– Trihydroxy glutaric acid– Neutralizes pH in alkaline

soil?

• KK Organic Soil Builder– Neutralizes both acidic and

alkaline soils?

• Liqui-Cal– 8% Ca– 1 gallon = 500 lb CaCO3?

• Liquid Calcium– 1 gallon = Ca in 500 lb CaCO3?– Suggest it is a lime substitute

• Golden Cal– Glucoheptomic acid– 1 gallon = 500 lb CCE?

• pH Plus– 1 gallon = 500-750 lb CCE?

Other Materials

• Remember: 1 Eq. of base is required to neutralize 1 Eq. of acid

• Watch out for materials that contain Ca with unwritten or suggestive claims for liming value

Soil Acidity and Liming

• Limestone Application– Apply limestone far enough ahead of time to be

effective– Spread limestone uniformly

• Spinner spreaders• Boom spreaders• Damp lime• Dust

– Spit high rates of limestone (>4 ton/A)– Time of year is not too critical

• Consider soil quality issues – compaction

– Mix limestone as much as practical• Adjust for depth of mixing - 6 2/3 in. standard depth• No till – Correct pH before going to no-till

Soil Acidity and Liming

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

85 86 87 88 89 90 91 92 93 94 95 96 97

0-2"

2-4"

4-6"

Time (years)

Soil pH vs No-Till With 6000 lbs/A of Lime Applied Every 3rd Year