Hi all I came across this site and wanted to share this great research. at this link:
cover crop chart, you will find a cover crop chart and you'll see the link to donwnload the whole chart, 65 pages if I'm not mistaken.
The idea they had was design the chart, patterned after the periodic table of elements, includes information on 58 crop species that may be planted individually or in cocktail mixtures.
And it really is nice to look through.
Hope you enjoy!