The vines have scarcely ever been manured in the Cognac region. What manure is produced is usually reserved for the cereals or meadows. This is not considered an economical process, since it is proved by experiment that generous fertilization produces much more abundant growth of grapes. Not only is stable manure valuable in the vineyard, but also chemical fertilizers. Organic manures are preferred to the mineral manures, when they can be procured, especially for furnishing nitrogen to the growing plant. These organic compounds decompose more slowly and thus produce their plant food as it is needed for the growth of the grape.