OSU Logo

OSU Nematode Testing Service - Sampling



  • A good sample is the best possible representation of the sample area in the required volume.
  • In fields with discreet areas of symptomatic plants, sample from the edge of the affected area.  Few plant-parasitic nematodes may remain where plant productivity has decreased, while more occur at or ahead of advancing symptoms.
  • 5 acres is the maximum area that should be represented by one sample.
  • Seal sample bags completely to prevent spillage, contamination, and abrasion.
  • Keep samples away from heat and at original moisture content; if adding ice packs for slow transit in hot weather, insulate between sample to prevent sample from freezing. Ship early in the week to avoid weekend delays in transit.


  • Prepare a composite soil sample from at least 20 locations within the sampling area from the top 12 inches or to the depth of root growth if shallower than 12 inches.  Use a soil sampling tube, a trowel, or a shovel.
  • Thoroughly mix the sample in a bucket or other large container.
  • Take several subsamples from the mixed composite soil sample to obtain about ONE PINT (500 cubic centimeters or one double handful) as the final sample.  A surcharge is assessed for excessively large samples.
  • Place this final sample in a soil sample bag or heavy plastic bag, such as a quart-size freezer bag.  Avoid sandwich bags (too thin).  Make sure that any paper bag you use has a waterproof lining. See below for how to label samples.


  • Dig subsamples of FINE absorptive* roots from at least 10 locations within the sampling area.  Mix subsamples as appropriate.
  • Take several subsamples from the composite root sample to obtain about ONE PINT (500 cubic centimeters or one double handful) of root material for the final sample. *NOTE: Woody portion of roots and mint rhizomes will be discarded during processing so estimate volume by looking at the amount of fine feeder roots.