Occurrence of azotobactor in Iowa soils and factors affecting thier distribution
Martin, W.P., Walker, R.H., Brown, P.E.
Occurrence of azotobactor in Iowa soils and factors affecting thier distribution - Ames 1937 - 227-256 p. - Iowa Agricultural Experiment .
Occurrence of azotobactor in Iowa soils and factors affecting thier distribution - Ames 1937 - 227-256 p. - Iowa Agricultural Experiment .