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