DR. F. J. ALWAY, Univ. of Minnesota. Dr. M. W. BEIJERINCK, Technische-Hooge- PROF. A. W. BLAIR, Rutgers College. DR. P. E. BROWN, Iowa State College of Agri- DIRECTOR H. R. CHRISTENSEN, Staten Planteavls- DR. H. J. CONN, N. Y. State Exp. Station. DR. E. B. FRED, University of Wisconsin. DR. B. L. HARTWELL, Rhode Island Experiment DR. C. B. LIPMAN, Univ. of California. PROF. C. A. MOOERS, Tenn. Exp. Station. PROF. G. ROSSI, Royal Agricultural High School DR. E. J. RUSSELL, Rothamsted Experiment Sta- DR. O. SCHREINER, U. S. Dept. of Agriculture. PROF. CHAS. E. THORNE, Ohio Experiment Sta- DR. N. TULAIKOFF, Forest Institute, Petro- SOIL SCIENCE is published monthly at Rutgers College, the New Jersey State College for the Benefit of Agriculture and the Mechanic Arts, New Brunswick, N. J. Each issue consists of approximately 100 printed pages. The subscription price is $4.00 a year, payable in advance; the price of single copies is 50 cents. Postage will be prepaid by the publishers for all subscriptions in the United States and its dependencies. An additional charge of 25 cents is made for each yearly subscription in Canada, and 50 cents for subscriptions in foreign countries. Entered as Second-Class Matter, February 19, 1916, at the Post Office at PRINTED BY J. HEIDINGSFELD CO., NEW BRUNSWICK, N. J. 19-34 CONTENTS The Effect of Some Manganese Salts on Ammonification and Nitrification. P. E. Brown and G. A. Minges.......... Preliminary Investigations in Comparison of Field with Laboratory Experi- Some Bacteriological Studies on Agar Agar. Carl Raymond Fellers. The Organic Phosphorus of Soil. R. S. Potter and T. H. Benton.................... Does Vanadium Interfere with the Determination of Phosphorus in Soils when the Phosphorous is Weighed as Magnesium Pyrophosphate? Ross The Nitric Nitrogen Content of the Country Rock. Robert Stewart and Protozoa, as Affecting Bacterial Activities in the Soil. Selman A. Waksman. The Loess Soils of the Nebraska Portion of the Transition Region: V. The Water-Soluble Constituents. Fred W. Upson and J. W. Calvin........ On the Distribution of Phosphorus in a Vertical Section of Blue-grass Soil. |