The captured Farm page is essentially only the upgrade-requirements table plus building-guide navigation; it gives no descriptive text about food production or upkeep. From the table: the Farm is the food field whose own upgrade cost is paid in Lumber/Stone/Ore -- the Food column is blank at every level (it never costs food to upgrade). Stone enters at Lv7, Ore at Lv12; late-game amounts are large and roughly balanced (Ore often largest). Every Farm level is Keep-gated, requiring the matching Keep level (Keep n per Farm n) as its only listed requirement, so Farm level can never exceed current Keep level. The Speed column is a construction-speed example climbing +0% (through Lv17) to +610% at Lv50. No duty-officer slot or milestone unlocks are documented on this page. Whether food output is neutralized by troop upkeep is not addressed here -- that mechanic is covered on the Warehouse page (protected/non-consumed food). Actionable for base_dev: Farm upgrades are cheap early, explode in cost late, never consume food, and are strictly Keep-gated; treat resource fields as low priority, raising them only to the Keep minimum needed to unlock/advance the Keep.
Original research source: Evony Guide Wiki