The PIDC provides soybean cyst nematode egg counts, information about thresholds and rotation information. We also provide complete nematode counts for corn, turf, and other grassy plants.
Nematode Soil Samples
Soil samples should NOT be collected when the soil is wet or frozen.
Soybean cyst nematode (SCN) egg count
WHEN: In fall: after harvest and before the soil freezes. In spring: before planting, after the ground has thawed and drained. During growing season: from near stunted and/or yellow soybeans.
HOW: Collect a soil core or 1/4 cup of soil (a subsample) from ten to twenty different locations within an area no larger than 10 to 20 acres using a soil sampling probe, hand trowel, or shovel. Define the sampling areas within a field by agronomic, cropping history, or other logical features (see figure) or divide the field to be sampled into evenly sized areas if conditions are similar throughout the field. Take care not to sample only from “hot spots” or areas of severely damaged plants. Collect soil from the top 8 inches, directly in the root zone (if in season and soybeans are being grown).
Combine all of the subsamples in a bucket and mix the soil thoroughly. From the mixed soil sample, place approximately 1 to 2 cups of soil into a plastic bag or paper soil test bag.
Nematode soil sampling patterns for crop fields with unique features.
Complete nematode counts
Complete nematode counts consist of counts of the common grass feeding nematodes. We provide genera level identification and how many of each genera are in your sample. We also provide information on thresholds and if management is warranted.
Please see our video with information on sampling for neamtodes on golf greens: https://www.youtube.com/watch?v=xb4_3lWVhUo
•Take samples with a soil probe not a cup cutter
•10-20 soil cores
•Depth of about 4-6 inches – as deep as the grass roots
•Place cores from green into a sealable plastic bag
•Be sure to keep sample out of sun and cool prior to shipping (refrigerator)
•Ship in a box with newspaper or other packing materials to prevent too much shaking
•If weather is very hot ship overnight.
Form and fee, do not send payment with your sample. You will receive a statement from Iowa State University.
Soybean Cyst Nematode egg count $20.00 Form: PIDC 32 Plant Nematode Sample Submission
Complete nematode counts $35.00 Form: PIDC 32 Plant Nematode Sample Submission
- Place each soil sample in a separate, sealed plastic or paper soil sample bag.
- If roots are being collected, place in a separate plastic bag.
- Use a permanent marker to label each bag with grower’s name and either a field name or sample number that corresponds to the information on the front of this form.
- Protect the samples from temperatures above 80 degrees.
- Do not be physically rough with the samples (by dropping or throwing them into a box or cooler, for example).
- Deliver or send the samples for processing as quickly as possible; avoid shipping samples on Thursdays and Fridays so that samples do not sit in delivery trucks over the weekend.
If your sample is from outside of Iowa do not submit it without contacting us we have strict limitations on soil movement.