Farmers quite generally recognize that by applying farm manure to their land, they will secure increased crop yields. Few. however, have a very definite idea of the actual amount cf the increases secured. Nor do they realize that every ton of manure produced on their farms has a real money value which may be determined by calculating the value of the crop increases secured from its use.

The purpose of this bulletin is to show quite definitely the value of a ton of manure on various soil types in Iowa. The data presented have been secured on 43 of the cooperative soil experiment fields of the Soils Section, located on 16 of the more extensive soil types in the state.