Soil Testing Tips

One of the most critical points in soil testing is to collect consistent soil cores. Remember: the results for several acres of land are determined by only a few ounces of soil. Make sure the soil samples you collect are representative of your field. Consistent samples yield better fertilizer recommendations.

Consistency is Important

  • Be consistent on depth of all cores. 1/2 inch variance in a core makes a big difference.
  • Mark your soil probes to sample the same depth every time.
  • Recommended soil sample depth for no-till is 4 inches, conventional till is 6 inches.
    Note: Let us know if you need to sample different depths.

Soil Sampling Equipment

  • You will need: a plastic bucket, a chrome soil probe, a permanent marker, a charging cable for your device, and your smartphone or tablet with Ag PhD Soils installed.
  • Use clean equipment, free of rust or carryover dirt to avoid contamination.
  • Use a chrome soil probe to collect samples. Do not use galvanized or other metal tools. They may contaminate soil samples with copper and/or zinc.
  • Use a clean, hard plastic bucket. Metal buckets may contaminate soil samples with zinc.
  • Be sure to bring your smartphone or tablet with Ag PhD Soils. REMEMBER the charging cable for the device!

Order Soil Sampling Supplies

Call us or log in to your Ag PhD Headquarters to order all the bags, boxes, and shipping labels you will need based on the grid size and the number of acres you intend to sample.

Timing is Everything

  • The best time to soil sample is when you need results. Whether you sample in fall or spring, try to do it the same season every year. Be consistent if you can.
  • Soil sample before a lime, fertilizer or manure application.
  • Soil sample when the soil conditions are favorable (not too dry, not too wet).

Grid Sampling

  • Choose a grid size that best represents your field. Try several. Adjust the grid as needed to fit your field.
  • Pull enough cores to reach the sample bag’s fill line. (approximately 8 plugs per grid point)
  • It works like this: Pull a core and place it in the bucket. Continue pulling cores until you have enough soil in the bucket to fill up the bag. Pour the entire contents of the bucket into the bag. Don’t worry about mixing; the lab will take care of that.

Avoid Irregular Locations

Avoid soil sampling in areas that may provide irregular results, such as:

  • Back furrows or dead furrows
  • Old fencerows
  • Areas used for manure or hay storage and livestock feeding
  • Areas where lime has been piled in the past
  • Waterways
  • Non-crop areas.

Shipping Soil Samples

  • Very Important: Remember to print and include your shipping sheet!
  • Keep your tracking numbers until the results are posted.
  • Remember, we will send you bags, boxes and prepaid shipping labels if you CALL US at 855.755.6933 in advance, or order online from your Ag PhD Soils Headquarters.

Brian Hefty and Darren Hefty explain the importance of soil sampling.