'Fallow' in the Bible

but the seventh year you shall let it rest and lie uncultivated, so that the poor among your people may eat [what the land grows naturally]; whatever they leave the animals of the field may eat. You shall do the same with your vineyard and olive grove.

As for the peoples of the land who bring merchandise or any grain on the Sabbath day to sell, we will not buy from them on the Sabbath or on a holy day; and we will give up raising crops during the seventh year [leaving the land uncultivated], and forgive every debt.