Buy shares in farms, farm equipment, fertilizer and seed companies that trade on exchanges around the world. Stock markets in agriculture-producing countries should do better than those in agriculture-importing ones. Retailers, restaurants, banks in agricultural areas will do well.
This is the first time that I know of, in recorded history, when every major central bank is printing money at the same time and trying to debase their currency. In the thirties, we had beggar-thy-neighbor policies but those were mainly tariffs and controls.