Coefficient of uniformity for sand rootzoone material

In the 2018 revisions to the USGA Recommendations for a Method of Putting Green Construction, one of the updates was the addition of a recommended range for coefficient of uniformity (Cu). Brian Whitlark wrote about this in an article for GCM that listed the changes:

"Root-zone stability and putting green firmness. A Cu range (coefficient of uniformity) has been included. The Cu should range from 1.8 to 3.5 for mixtures containing peat, and from 2 to 3.5 for mixes with…