166 Mineral Nutrition of Plants 



65. Steward, F. C, and Preston, G., Plant Physiol., 15:23 (1940). 



66. Stiles, W., and Jorgensen, I., New Phytologist, 16:181 (191 7). 



67. Thomas, M. D., Soil Sci., 25:409 (1928). 



68. Trogdon, W. D. "The effect of acid and base forming nitrogenous 

 fertilizers on certain soil factors affecting soil productivity." Ph.D. 

 Diss., Ohio State Univ. ( 1949). 



69. Veihmeyer, F. J., and Hendrickson, A. H., Plant Physiol., 20:517 



( r 945)- 



70. , and Hendrickson, A. H., Soil Sci., 62:451 (1946). 



71. , and Hendrickson, A. H., Soil Sci., 65:487 (1948). 



72. , and Hendrickson, A. H., Soil Sci., 68:75 (1949). 



73. Vlamis, J., and Davis, A. R., Plant Physiol., 19:33 (1944). 



74. Weldon, Thomas A., and Hide, }. C, Soil Sci., 54:343 (1942). 



75. Went, F. W., Plant Physiol.. 18:51 (1943). 



