X TABLE OF CONTENTS 



PAGES 



124 — Addition of organic matter, 125 — Action of plant 

 roots and animals, 126 — Addition of lime, 127 — Til- 

 lage, 128 — The action of the plow, 129 — Resume^ 130. 



CHAPTER XI 

 The Forms or Soil Water and their Movement . . 198-242 

 Methods of expressing soil moisture, 131 — Kinds of 

 water in the soil, 132 — Hygroscopic water, 133 — Effects 

 of texture and humus on hygroscopicity, 134 — Nature 

 of the film, 135 — Effect of humidity and temperature 

 on hygroscopic water, 136 — Determination of hygro- 

 scopicity, 137 — Heat of condensation, 138 — Capillary 

 water, 139 — Surface tension and the force developed 

 thereby, 140 — The form of water surfaces between soil 

 particles, 141 — Factors affecting capillary water, 142 — 

 Surface tension and the amount of capillary water, 143 



— Texture and the amount of capillary water, 144 — 

 Effect of structure on the amount of capillary moisture, 

 145 — Organic matter and the amount of capillary mois- 

 ture, 146 — Determination of capillary water, 147 — The 

 moisture equivalent of soils, 148 — The maximum re- 

 tentive power of soils, 149 — Capillary movement, 150 



— Factors affecting rate and height of capillary move- 

 ment, 151 — Effect of thickness of film on capillary 

 movement, 152 — Surface tension and capillary move- 

 ment, 153 — Effect of texture on capillary movement, 

 154 — Texture and capillary pull of soils, 155 — Effect 

 of structure on capillary movement, 156 — Gravitational 

 water, 157 — Pressure and the movement of gravity 

 water, 158 — Effect of temperature on the flow of grav- 

 ity water, 159 — Effect of texture and structure on the 

 flow of gravity water, 160 — Determination of the quan- 

 tity of free water that a soil will hold, 161 — The calcu- 

 lation of the free water of a soil, 162 — Value of studying 

 flow and composition of gravitational water, 163 — The 

 study of gravity water by means of tile drains, 164 — 

 The lysimeter method of studying gravitational water, 

 165 — Thermal movement of water, 166. 



