Cereal grains provide more than one half of the total calories consumed by man.
Not only humans, but also domestic animals are fed primarily by cereal grains. Society as we know it could not exist without cereal grains. The only places that cereal grains are not too important is in a few areas of the lowland tropics, and in high Andean areas. Grasses also are among the oldest of cultivated crops. They were used long before that.