INVESTIGATIONS RELATIVE TO THE USE OF 

 NITROGENOUS FERTILIZER MATERIALS, 

 1898-1907. 



Official Abstract of a Paper read by Professor E. B. 

 Voorhees, before The International Congress of 

 Applied Chemistry held in London, June, 1909. 



By Edward B. Voorhees, Sc.D. (Director), and Jacob G. 

 Lipman, Ph.D. (Soil Chemist and Bacteriologist), 

 Agricultural Experiment Station, New Jersey, U.S.A. 



Ten years ago denitrification was believed to pos- 

 sess an economic significance. A considerable num- 

 ber of agricultural chemists thought that the destruc- 

 tion of Nitrate by denitrifying bacteria involved losses 

 of nitrogen in all cases where Nitrate and animal 

 manures were used together. The experiments re- 

 corded here were planned, primarily, to determine 

 whether such losses of Nitrogen really occur in field 

 practice. The data collected in the course of ten 

 years supply some definite information in this con- 

 nection; and furnish, moreover, much important in- 

 formation bearing on other phases of the nitrogen 

 question. 



The experiments have been carried on in large 

 galvanized iron cylinders 4 feet long, 23.5 inches in 

 diameter, and open at both ends. The cylinders were 

 sunk in the ground until only about 2 inches of the 

 upper portion projected above the level of the sur- 

 rounding soil. Uniform amounts of gravelly subsoil 

 were placed in the cylinders and firmly tramped down. 

 Weighed quantities of surface soil were then placed 

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