Fast Casual, KY 01-19-07 Chipotle calendar sales to support sustainable agriculture DENVER – Chipotle Mexican Grill has started to sell whimsical calendars in its stores for $5 apiece. The calendars, featuring foil-wrapped burritos in different seasonal poses, are being sold to support The Land Institute and the Leopold Center for Sustainable Agriculture. Chipotle hopes to raise about $100,000 for the charities. Salina, Kan.-based The Land Institute is an organization working to develop an agricultural system called Natural Systems Agriculture. The system is designed to respect the sustainability of the native prairie and produce annual crops such as wheat and corn. The Leopold Center, based in Ames, Iowa, is a research and education center at Iowa State University with programs intended to develop sustainable agricultural practices that are both profitable and conserve natural resources.