Growing potatoes on Martian soil was not an easy task. Even genetically modifying the tuber strains to better tolerate the basalt crust of the red planet was a stopgap measure – and bringing soil from earth was cost prohibitive.
The solution came, interestingly enough, from southern France. Mychorrihizal fungi introduced into the barren soil helped budding farm complexes on Mars thrive. Since then, genetically modified and selected companion fungi has been a staple in the farming toolbox of every colony.
The other option, if soil farming is not an option, is hydroponic farming. Hydroponics require a large amount of water commitment to maintain, but have the benefit of being able to run anywhere.
With either methodology, the Federation is able to turn any location with access to power and hydrogen into a working farm, capable of growing a variety of genetically enhanced crops at rapid speeds. These range from starchy potatoes and other tubers to luscious, exotic fruits. Some colonies have to priorities the calorie dense harvests to prioritize the small amount of arable land they have available.