OMAFRA-Accredited Soil Testing Labs in Ontario
Ontario nutrient recommendations are only valid when they come from an OMAFRA-accredited laboratory using the accredited extraction methods. These are the 8 accredited labs, with current contact details.
The 8 accredited labs
| Laboratory | Location | Phone | Services | Web |
|---|---|---|---|---|
| A & L Canada Laboratories Inc. | London, ON | 519-457-2575 1-855-837-8347 | Soil, tissue, manure, water, nematode | Website |
| Stratford Agri Analysis | Stratford, ON | 519-273-4411 1-800-323-9089 | Soil, plant tissue, manure, feed, water | Website |
| SGS Canada Inc. – Crop Science | Guelph, ON | 519-837-1600 1-800-265-7175 | Soil fertility, tissue, nutrient management | Website |
| Agriculture & Food Laboratory, U. of Guelph | Guelph, ON | 519-767-6299 1-877-863-4235 | Soil, plant, water, accredited research lab | Website |
| Activation Laboratories Ltd. (Actlabs) | Ancaster, ON | 905-648-9611 1-888-228-5227 | Soil & agronomic analysis | Website |
| Honeyland Ag Services | Ailsa Craig, ON | 226-377-8485 | Soil sampling & analysis | Website |
| Eurofins Environment Testing Canada | Ottawa, ON | 613-727-5692 | Soil & environmental testing | Website |
| Brookside Laboratories Inc. | New Bremen, OH (serves ON) | 419-977-2766 | Soil fertility & plant analysis | Website |
What to ask for when you submit a sample
- Olsen P (sodium bicarbonate) — not Mehlich-3 or Bray-P1
- Ammonium-acetate K — reported in ppm
- Soil pH and buffer pH — drives lime requirement
- Organic matter % — informs nitrogen mineralisation
- Magnesium and zinc — zinc matters for corn, manganese for soybeans
How often should you sample?
OMAFRA guidance is a soil test every three years per field or management zone, sampled at the same time of year each cycle so results stay comparable. Sample to a consistent 15 cm (6 in.) depth, take 15–20 cores per composite sample, and avoid headlands, old manure piles and fence lines.
Turning your results into a fertilizer rate
Once you have Olsen P and K in ppm, the OMAFRA sufficiency tables give a phosphate and potash rate directly. Our soil test interpretation guide reproduces those tables, or the calculator will do it for you.
Related guides
Build your own nutrient plan
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