"Villagers gather Food from Mills faster."
In-game description

Artificial Fertilizer is a technology in Age of Empires III that can be researched at the Mill once the Fortress Age is reached and Seed Drill is researched. Once researched, it allows Settlers, Coureurs des Bois, and Settler Wagons to gather food from Mills, Farms and Rice Paddies 30% faster.

Should the faster food sources are depleted or difficult to get to, researching Artificial Fertilizer is important to keep the player's food stocks high in the mid/late game.

Community content is available under CC-BY-SA unless otherwise noted.