Soil Sampling

What to bring

Sample Bags

8 oz soil sample bags. Polylined bags recommended. One bag per sampling location.

Brushes or Wipes

Clean the probe between each sampling location to avoid cross-contamination.

Soil Probe or Auger

¾" or 1" diameter. Avoid shovels — they don't collect consistent cores.

Cooler with ice packs

Required if testing for biology. Keep samples below 40°F / 4°C from collection through shipping.

Collecting your samples

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Navigate to the location

Label your bag: Write the location point number on the bag before you collect anything

Set your depth: All cores must be taken at 0–6 inches from the surface.

Collect cores: Take 12 cores within a ~30 ft radius* of the location point. Combine all cores from that location into one bag.

  • Fill to ¾ full: Each bag should be about ¾ full before sealing. If it's short, take an extra core or two.

Store immediately: Ship your samples as soon as possible.

  • Chemistry only? No temperature control needed

  • Testing for biology? Seal the bag and place it in your cooler with ice packs right away. Don't leave samples in a hot vehicle as heat allows microbes that weren't in your field to grow in the bag, skewing your results. Avoid freeze/thaw cycles — they degrade microbial DNA.

* Consult your agrononomist for a tailored plan

Timing and Conditions

Sample Consistently

Try to sample at the same time each year under similar field conditions. Consistency makes year-over-year comparisons meaningful.

Monitor Moisture

Avoid very wet or very dry soils.

Ideal soil moisture is roughly 4–25%.

If soil is powder-dry, delay sampling or let the lab know — dry samples carry a higher risk of failure for biological analysis.

Bulk Density Samples

Bulk Density (BD) provides information on the suitability for root growth and soil permeability. It’s the weight of dry soil in a known volume.

Collect between plants or near enough to plants that there hasn’t been compaction. Avoid waterlogged, over-dried areas as well as where a tractor has driven.

• Use a bulk density sampler like one from AMS or contact us for alternatives (Standard sampling probes will not work as they compact the soil)

Parameters

  • 1.5-2" diameter, 30cm depth

  • Approximate weight

• 1.5" diameter: 400-800g

• 1.75" diameter: 500-1100g

• 2" diameter: 700-1400g

Let us know

  • Inner diameter of probe

  • Actual depth

  • Core depth