Sources of Agricultural Limestone

When comparing limestone from different suppliers, be sure to ask for the following information:

1. Type of limestone: Is it either calcitic or dolomitic? Calcitic limestone consists mostly of calcium carbonate. Dolomitic limestone is a mixture of both calcium and magnesium carbonates. Dolomitic limestone should be used on soils with a magnesium soil test of 100 ppm or less. It is an excellent and inexpensive source of magnesium for acidic soils. On soils with a magnesium test greater than 100 ppm calcitic or dolomitic limestone may be used.

2. Guaranteed Minimum Specifications: This will provide the per cent calcium, percent magnesium, neutralizing value, fineness rating and Agriculture Index.

3. Neutralizing value (NV): NV compares the ability of the limestone to neutralize acidity relative to pure calcium carbonate. It is expressed as a percent of calcium carbonate's ability to neutralize acidity. Relative to calcium carbonate, a value less than 100 is less effective, while greater than 100 are more effective. The NV generally increases as the calcium and magnesium content increases.

4. Fineness rating: To be effective limestone must dissolve. A limestone's fineness rating is a measure of its particle size distribution and is determined using sieves. Any material passing through a #60 sieve is consisted to be fully effective. Material that passes through a #10 sieve but not #60 is considered only 40% effective. Materials that do not pass through #10 sieve are considered ineffective.

5. Agricultural Index (AI): AI is an indicator of a limestone's ability to neutralize acidity. It is calculated using the neutralizing value and fineness rating. It can be used to compare the ability of different limestones to neutralize soil acidity. The higher the AI the more effective the limestone on an equal weight basis. The average AI of limestone sold in Ontario has been about 75.

For more information about limestone, managing soil pH with lime, neutralizing value, fineness rating, calculating the Agriculture Index and determining the amount of lime to apply can be found in OMAFRA Publication 811 Agronomy Guide for Field Crops, Chapter 9.

Suppliers of Agricultural Limestone

This supplier list does not imply any endorsement or recommendation by the Ontario Ministry of Agriculture, Food and Rural Affairs.

For specific questions regarding the limestone analysis or specifications, please contact the appropriate company for their latest analysis information.

CBM Aggregates

546 Thomas St.
St Mary's, ON N0M 1V0
Telephone: 519-831-9492
Email 1:

Coloured Aggregates Inc.

158 Don Hillock Drive, Unit 12-13
Aurora, ON L4G 0G9
Telephone: 1-800-465-5066

Fax: 1-905-727-0060
Email 1:
Email 2:

Dufferin Aggregates

2300 Steeles Avenue West, 4th Floor
Concord, ON L4K 5X6
Telephone: 1-855-225-5332
Email 1:
Email 2:

E.C. King Contracting

2125 20th Ave. East
P.O. Box 457
Owen Sound, ON N4K 5P7
Telephone: 519-376-6140
Fax: 519-371-2783

Graymont (QC) Inc.

25. De Lauzon. bur. 206
Boucherville, QC J4B 1E7

Lafarge Canada

6509 Airport Road
Mississauga, ON L4V 1S7
Telephone: 905-738-7070

McLaughlin Haulage Limited

Haley Station, ON K0J 1Y0
Telephone: 613-432-5669

Miller Minerals

P.O. Box 248
New Liskeard, ON P0J 1P0
Telephone: 705-672-2282
Fax: 705-672-2746

Nelson Aggregate

3114 Burnside Line
Orillia, ON L3V 6H4
Telephone: 705-325-2264
Fax: 705-325-2265

Omya Canada Inc.

Box 245, 18595 Highway 7 W.
Perth, ON K7H 3E4
Telephone: 613-267-5367
Fax: 613-267-5408

R.W. Tomlinson Ltd

100 Citigate Dr, Ottawa On, K2J 6K7
Telephone: 613-690-3012
Fax: 613-822-6844
Website :

Setteringtons Fertilizer

601 County Road #14, R.R. # 5
Leamington, ON N8H 3V8
Telephone: 519-326-9093
Fax: 519-326-1667

Sudbury Lime Limited

300 Kukagami Road
Wahnapitae, ON P0M 3C0
Telephone: 1 (877) 682-2958

Walker Aggregates

P.O. Box 340
Collingwood, ON L9Y 3Z7
Telephone: 705-445-2300
Toll-free: 1-800-461-9193
Fax: 705-445-1776

Walker Brothers Quarries

P.O. Box 100
Thorold, ON L2V 3Y8
Telephone: 905-680-3755
Fax: 905-227-1034

For more information:
Toll Free: 1-877-424-1300