There is a crop rotation diversity index, developed by Dr. Dwayne Beck of Dakota Lakes Research Farm (near Pierre, SD) that can help in assessing your crop rotation plant diversity. The index and method of calculation are described in detail at Dakota Lakes Research Farms website http://www.dakotalakes.com/. A spreadsheet calculator of the index that I developed some years ago is available at the North Dakota State University Dickinson Research and Extension Center website https://www.ag.ndsu.edu/archive/dickinso/agronomy/jons%20worksheet.htm
