Table of Contents 



MINERAL NUTRITION OF PLANTS 



World Food Possibilities and Fertility Status of Our Soils 



Charles E. Kellogg and A. C. Orvedal, U. S. De- 

 partment of Agriculture, Beltsville, Maryland 



PHYSICO-CHEMICAL AND BIOLOGICAL FACTORS 

 AFFECTING NUTRIENT AVAILABILITY IN SOILS 



Soil as a Medium for Plant Growth 23 



Emil Truog, University of Wisconsin 



The Activities of Cations Held by Soil Colloids and the Chemi- 

 cal Environment of Plant Roots 57 



C. Edmund Marshall, University of Missouri 



The Availability of Soil Anions 79 



Roy Overstreet, University of California, and L. A. 

 Dean, U. S. Department of Agriculture, Beltsville, 

 Maryland 



Contact Phenomena between Adsorbents and Their Signifi- 

 cance in Plant Nutrition 107 



Hans Jenny, University of California 



The Effect of Soil Physical Properties on Nutrient Availability 133 



J. B. Page, Ohio State University, and G. B. Bod- 

 man, University of California 



Role of Soil Microorganisms in Nutrient Availability 167 



A. G. Norman, Chemical Corps, Camp Dietrick, 

 Frederick, Maryland 



66757 



