Another heuristic to apply might be the number of LACs with student-run farms, especially in the northeast where the growing season is shorter than the rest of the country:
http://newsletter.blogs.wesleyan.edu/2018/07/11/fresh-organic-produce-grown-sold-by-wesleyan-students/
https://www.amherst.edu/campuslife/housing-dining/dining/sustainability/book-plow-farm