Viii CONTENTS 



CHAPTER II 



PAGES 



PHYSICAL INTER-RELATIONS IN SOILS ..... 29-57 



Influence of Capillary Water on Other Physical Con- 

 ditions : Capillary water and soil structure, 46 ; Capil- 

 lary water and plowing, 46 ; Correct moisture condition 

 for plowing, 47 ; Effect of correct plowing on the later 

 preparation of the seed-bed, 48 ; Sources of soil heat, 

 49 ; Capillary water and soil temperature, 50 ; Specific 

 heat of soils, 51 ; Proper water content for agricultural 

 soils, 52 ; Effect of water on soil temperature, 53 ; Warm 

 and cold soils, 54 ; Over-wet soils are cold soils, 55 ; 

 Heat of vaporization, 56 ; A concrete example, 57 ; Cap- 

 illary water and ventilation, 58. Influence of Soil 

 Structure upon Other Physical Conditions: Agencies 

 active in soil ventilation, 69 ; Relation of soil structure 

 to soil ventilation, 60 ; Effects of life-forms, 61 ; Influ- 

 ence of soil structure on capillary water, 62 ; Influence 

 of soil structure on temperature, 63. Influence of Gravi- 

 tational Water on Other Physical Conditions : A replen- 

 isher of capillary water, 64 ; Assists in soil ventilation, 

 65 ; A cleanser of soils, 66 ; Standing water or gravita- 

 tional water in fields destroys soil structure, 67 ; Increased 

 labor required to fit puddled soils for crops, 68 ; Gravi- 

 tational water may interfere with ventilation, 69 ; Gravi- 

 tational water and food losses, 70 ; Gravitational water 

 and soil temperature, 71 ; Increased specific heat, 72 ; 

 Heat lost in the evaporation of gravitational water, 73 ; 

 The effects of gravitational water upon temperature 

 through bad soil structure, 74 ; The relations of capil- 

 lary water summarized, 75 ; The relations of gravita- 

 tional water summarized, 76. Drainage Effects : Effects 

 of the permanent removal of standing water, 77 ; The 

 way in which the changes take place, 78; Ventilation 

 plays a part, 79 ; Other agents, 80 ; Animal forms, 81 ; 

 Food-preparers, 82 ; The final results, 83. 



