U. S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF PLANT INDUSTRY— BULLETIN NO. 173. 



B. T. GALLOWAY, Chief of Bureau. 



SEASONAL NITRIFICATION AS INFLUENCED 

 BY CROPS AND TILLAGE. 



BY 



C. A. JENSEN, Agriculturist. 



Issued April 18, 1910. 



" WASHINGTON: 



GOVERNMENT PRINTING OFFICE, 



1910. 



