Most of what is farmed in Mississippi and the rest of the country isn’t food that goes on Americans’ tables. It is soybeans grown for animal feed, corn grown for ethanol, rice grown to export to Central America and so on. The fruits and vegetables that Mississippians eat are probably grown in California or in other countries.
The rice shortage is made significantly worse by Japanese rice-based nationalism and widespread refusal to eat imported rice. They could easily import more foreign rice for cheaper than domestic rice, but of course that isn’t happening.