Economic value of farm manure as a fertilizer on Iowa soils
Stevenson, W.H., Brown, P.E., Forman, L.W.
Economic value of farm manure as a fertilizer on Iowa soils - Ames 1926 - 217-245 p. - Iowa Agricultural Experiment .
Economic value of farm manure as a fertilizer on Iowa soils - Ames 1926 - 217-245 p. - Iowa Agricultural Experiment .