Soils, their formation, properties, composition, and relations to climate and plant growth in the humid and arid regionsNote 107 — Chapter XVIII · THE PHYSICO-CHEMICAL INVESTIGATION OF SOILS IN RELATION TO CROP PRODUCTION.Reading editionBull. 22, Bureau of Soils, U. S. Dept. of Agriculture.◇Copy noteReturn to CHAPTER XVIII. THE PHYSICO-CHEMICAL INVESTIGATION OF SOILS IN RELATION TO CROP PRODUCTION.