I'm not sure if this is a bug with the mod, information not documented in the Civilopedia, or an interaction (I have a lot of mods!). However, the Irrigation Farm says it gets +2 Gold for each two districts. This does not work at all in my game, I get no gold at all. I am playing Tokugawa. Could the alteration to the adjacency bonuses of Japan be responsible? I've never paid too much attention to the improvement, so I don't know if it's just this game or all the time.