When the Mongols left from their Jurched campaign, they churned up the land behind them by having their horses trample the farmland with their hooves and prepare it to return to open pasture. They wanted to ensure that the peasants never returned to their villages and fields. In this way, Inner Mongolia remained a grazing land, and the Mongols created a large buffer zone of pastures and forests between the tribal lands and the fields of the sedentary farmers.
