CONTENTS 



XIU 



Extent of Roots 84 



Depth of Root Penetration 86 



CHAPTER VII 

 Stoking Water in the Soil 



94-129 



Alway's Demonstration 95 



What becomes of tlie Rainfall ? 97 



The Run-off 98 



The Structure of Soils 99 



Pore-space of Soils 101 



Hygroscopic Soil- water 102 



Gravitational Water 104 



Capillary Soil-water 106 



Field Capacity of Soils for Capillary Water .... 107 



Downward Movement of Soil-moisture Ill 



Importance of a Moist Subsoil 116 



To what extent is the Rainfall stored in Soils 1 . . . 119 



The Fallow 122 



Deep Plowing for Water Storage 125 



Fall Plowing for Water Storage 126 



CHAPTER VIII 



Regdlating the Evaporation 



The Formation of Water Vapor . 

 Conditions of Evaporation from Soils . 

 Loss by Evaporation chiefly at the Surface 

 How Soil- water reaches the Surface 

 The Effect of Rapid Top-drying of Soils 

 The Effect of Shading .... 

 The Effect of Tillage .... 

 Depth of Cultivation .... 

 When to Cultivate or Till 



130-164 



132 

 136 

 139 

 141 

 147 

 150 

 152 

 157 

 158 



