If a grower simply wants to sample a field to check for the presence of SCN, I'd recommend sampling the field after soybean harvest. The chances of finding SCN after a soybean crop are greater than sampling after a corn crop because soybeans are a host for SCN. Of course, if the grower discovers SCN in a soil sample taken from a field in which soybeans were just harvested and corn will be grown the next year, he or she also should collect another sample after the corn harvest in those fields if soybeans will be grown again following the corn crop. Knowledge of the SCN population densities (numbers) in a field is important in making management decision. Detailed information on the proper way to collect good soil samples can be found on the back of the ISU Plant Nematode Sample Submission Form (publication PD-32).