Vlll CONTENTS 



PAGES 



Alluvial soils, § 22 ; Character and distribution of 

 alluvial soils, § 23 ; Marine soils, § 24 ; Distribution 

 of marine soils, § 25 ; Lacustrine soils, § 26 ; Glacial 

 soils, § 27 ; ^Eolian soils, § 28. 



Questions on Chapter III ....... 28 



Laboratory Exercises ....... 29 



Classification of soils, I ; Use of soil auger in taking 

 samples, II. 



CHAPTER IV 



Texture and Structure op Soils .... 30-45 

 Shape of particles, § 29 ; Space occupied by parti- 

 cles, § 30 ; Mechanical analysis of soils, § 31 ; Me- 

 chanical analysis of some typical soils, § 32 ; Soil class, 

 § 33 ; Some properties of the separates, § 34 ; Chemi- 

 cal composition of soil separates, § 35 ; Soil structure . 

 § 36 ; Relation of structure to pore space, § 37 ; Re- 

 lation of structure to tilth, § 38 ; Conditions and 

 operations that affect structure, § 39 ; Relation of 

 texture to structure, § 40 ; Wetting and drying, § 41 ; 

 Freezing and thawing, § 42 ; Effect of organic matter 

 on structure, § 43 ; Roots and animals, § 44 ; Tillage 

 and structure, § 45 ; Structure as affected by lime, 

 § 46 ; The soil survey, § 47 ; Classification of soils, 

 § 48 ; Information furnished by a soil survey, § 49. 



Questions on Chapter IV . . . . . . . 45 



Laboratory Exercises 46-50 



Examination of soil particles, I ; Examination of 

 soil separates, II ; Simple mechanical analysis, III ; 

 Study of soil class and its determination by examina- 

 tion, IV ; Determination of soil class from a mechani- 

 cal analysis, V; Soil structure, VI; Determination 

 of apparent specific gravity of dry sand and clay, 

 VII ; Calculation of pore space, VIII ; A study of the 

 plow, IX. 



CHAPTER V 



Organic Matter 51-57 



Classes of organic matter, § 50 ; Beneficial effects 

 of organic matter, § 51 ; Porosity of organic matter, 



