CONTENTS 



PART I 

 GENERAL PRINCIPLES UNDERLYING PLANT CULTURE 



Chapter Page 



I. INTRODUCTION TO PLANTS .... 3 



II. ROOTS 9 



Uses of roots to plants g 



Habit of growth of roots . . . .11 

 Conditions necessary for root growth . 20 



III. SOILS 23 



Relation of soil to plants . . . .23 



Classification of soils 26 



How were soils made? . . . .30 

 Soil texture 37 



IV. RELATION OF SOILS TO WATER .... 

 Importance of water to plants . 



Sources of soil water 



Attitude of soils toward water : 



Percolation 



Absorption from below 



Power to hold water . . . .40 

 The effect of working soils when wet . 45 



V. FORMS OF SOIL WATER 48 



Free water 48 



Capillary water 49 



Film water 5 



xi 



