I don`t want to rain on the parade. I`m not sure what organic agriculture is going to help run a grocery retailer - which is probably the most adept/scientific retailer out there.
Much as insurance companies and banks run non complex algorythms - so does the big grocer! The complexities of selling shelf space - direct vendor coupling/management - selling end of day data to know EXACTLY where they are in the market from day to day - setting price points - shelf layout science - tagging shelf science - and getting the extra rolls out of inventory FAR exceed ANY "general retail". There is a reason Milk is always on the back wall, and sugar/flour is always just inside of a turn - and childrens cereal is down low - and healthy cereal is up high - and they get paid by vendors for that too!
And that was the point from the beginning - it is VERY complex - and HIGHLY competitive. Just ask the grocers that had been around for a long time and THOUGHT THEY KNEW!
If you are looking to get in with little info - or with organic agriculture info - maybe start with a fruit/veggie stand. But you aren`t going to get the complexities of big grocery retail anywhere except big grocery retail. I got to study Kroger bit in my MBA program - and have studied Walmart for years. They understand and optimize cash flow (NPV, IRR, etc), they understand optimizing inventory turns - they understand vendor management. I know enough to know I don`t know enough.
If you want in with little/no relevant information - you are better off starting VERY SMALL. If you want to go big - better get big info first.
Business Optimization - www.businessoptimization.biz