Dr. Bob Cross, from Clemson University, was on site Monday to collect more data on the PG trials. You will notice the 3/4" holes spaced out around that 1,000ft2 portion of the putting green. He is not analyzing nutrients, rather root mass. He will take the plus back to his Clemson lab, where he puts them in a very hot oven. Samples are weighed prior to and after going in the oven. While in the oven, the organic matter is "burned off" in a process known as, "ashing." The difference in weight from before and after is directly related to the quantity of roots. Basically:
weight of roots and sand (before oven) - weight of sand (roots burned off) = weight of roots
This data can then be compared along the other trials to see if any of the products being applied produce a great root mass than the others.