es of roots to plants 9
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 39
Importance of water to plants 39
Sources of soil water 40
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 50

VI.--LOSS OF SOIL WATER
By surface wash
By percolation and leaching
By evaporation
By transpiration
How to check these losses 53

VII.--SOIL TEMPERATURE 57
How soils are warmed 58
How soils lose heat
How to check loss of heat 59
Conditions which influence soil temperature 60
Value of organic matter 61

VIII.--PLANT FOOD IN THE SOIL 63

IX.--SEEDS 70
Conditions necessary for sprouting 70
Seed testing 75
How the seeds come up 77
Use of cotyledons and endosperm 79

X.--SEED PLANTING 81
Depth of planting:
Operation of planting
Planting machines 81
Seed classification 85
Transplanting