Hi doulos jose there are actually several examples of exactly what you are describing already happening in India and in Africa :)

https://mkisan.gov.in/ussdapplication.aspx

http://disrupt-africa.com/2016/09/ugandan-startup-mobfit-uses-sms-to-connect-farmers-with-buyers/

https://techpoint.africa/2016/06/14/farmersng-is-connecting-farmers-to-customers/