03/18/08 Idaho lab's PNC analysis, part 2

A five pound soil sample arrives at the Idaho Quality Assurance Lab in Twin Falls where it's checked in, dried out and then weighed. Manager Mike Becerra says the sample in its entirety is poured into what's called a Fenwick can. BECERRA "And at that time water is running out of the can from the bottom there's' a fitting down there and that causes all the dirt material too basically to float up or to be suspended. The lighter material will come up it goes off a spillway through a series of screens. The big screen takes out the big chunks basically. The smaller screen below will catch anything that's of cyst size or larger. Very simply that's what it's done. Gravity type separation and then there's a size exclusion separation." The lighter screen material is then transferred into a beaker and allowed to sit for an hour or so. BECERRA "And during that time a whole bunch of the material will sink and the stuff that floating will include any cysts that might be present." Then trained operators take that final material and put it under a microscope and look for nematodes. They've gone through 45 thousand samples and have found very few nematodes. So what happens to the dirt after testing and who are the people who spend hours looking at dirt? Some answers tomorrow. Today's Idaho Ag News Bill Scott