Sampling Guide
Soil Sampling Instructions
A representative sample is the foundation of meaningful results. Follow these general guidelines to collect and submit soil for analysis.
Step-by-Step
- Divide the field into uniform areas. Sample areas with similar soil type, crop history, and management separately. Avoid mixing distinctly different areas in one sample.
- Collect multiple cores. Take 10–15 cores or slices from random locations across each area and combine them into a clean bucket to form one composite sample.
- Sample to a consistent depth. For most field crops, sample the surface 0–6 or 0–12 inches. Keep the depth uniform across all cores so results are comparable.
- Mix thoroughly. Break up clods and blend the cores well, then fill a clean sample bag with about 1–2 cups (roughly 1 pint) of the composite soil.
- Label clearly. Mark each bag with your sample ID and the area it represents, matching the names on your Chain of Custody form.
- Submit promptly. Deliver or ship samples as soon as possible. Keep them cool and out of direct sun until they reach the lab.
Good Practice
- Use clean, non-galvanized tools (stainless steel or plastic).
- Sample between irrigation or fertilizer applications.
- Keep cores at a uniform, consistent depth.
Avoid
- Unusual spots: fertilizer bands, manure piles, wet areas, or field edges.
- Galvanized or brass tools, which can contaminate micronutrient results.
- Mixing different soil types or depths into one sample.
Sampling depth, timing, and the number of cores can vary by crop and test.
Contact us for crop-specific protocols.