It can be done to completely omit "einkaufen" and it might continue to be a superbly accurate sentence (however it would go away us guessing just what the speaker is planning to do within the farmer's market): "Ich gehe auf den Bauermarkt." So as to add entries to your own https://magazin-welt.de/die-vorteile-eines-massivholzbetts-haltbarkeit-stil-und-nachhaltigkeit/