xiv TABLE OF CONTENTS 



CHAPTER V 



SOIL MOISTURE AND DRY FARMING 



Page 



1. How WATER OCCURS ix SEMI-ARID SOILS 80 



(a) As. free water. 



(b) As capillary water. 



(c) As hygroscopic water. 



(d) As run-off water. 



2. THE FUNCTIONS OF WATER IN SOILS 84 



(a) To dissolve plant food in the soil. 



(b) To transport food solutions to the plant. 

 . (c) To maintain proper growth in the plant. 



3. How SOIL MOISTURE MAY BE LOST 85 



(a) By evaporation at the surface. 



(b) By transpiration through plant growth. 



(c) By leaching out of the subsoil. 



4. Loss OF MOISTURE BY EVAPORATION 87 



(a) How moisture is lost by evaporation. 



(b) The extent of such loss. 



(c) How such loss may be reduced. 



5. Loss OF MOISTURE BY TRANSPIRATION 92 



(a) How moisture is lost by transpiration. 



(b) The extent of such loss. 



(c) How such loss may be reduced. 



(d) Transpiration and hot winds. 



6. OTHER INFLUENCES THAT AFFECT EVAPORATION 95 



(a) Evaporation as affected by latitude. 



(b) Evaporation as affected by altitude. 



(c) Evaporation as affected by the humus supply. 



7. THE IMPORTANCE OF SUBSOIL MOISTURE 96 



(a) The function of moisture in the subsoil. 



(b) How to secure moisture in the subsoil. 



(c) How to retain moisture in the subsoil. 



8. THE UTILIZATION OF SUBSOIL MOISTURE 99 



(a) The extent to which it may be drawn upon. 



(b) Drawing upon it to no good purpose. 



(c) When a reserve of moisture is specially helpful. 



CHAPTER VI 

 PLANT GROWTH IN^DRY AREAS 



1. SOME FEATURES PECULIAR TO SUCH GROWTH 103 



(a) It is more sparse than in humid areas. 



(b) It is more or less dwarfish. 



(c) It tends to an abundant fruitage. 



(d) It is made chiefly in the early season. 



