18 IRRIGATION PRACTICE 



the soil until it is all absorbed by the lower drier soil or 

 until it communicates with the standing water-table. 



Soil moisture is the term used to designate the water 

 held in the capillary condition in soils. Soil water denotes 



FIG. 5. The moisture film surrounding a soil particle. The black part represents 

 a segment of the particle, (b) Hygroscopic coefficient; (c) wilting coeffi- 

 cient; (d) lento-capillary point; (e) point of maximum capillarity; (d-e) 

 freely moving capillary moisture. 



the free water, that beyond capillary saturation, which 

 may exist in soils. Many books on agriculture speak of 

 the maximum water capacity of soils, meaning the water 

 held in a volume of soil artificially confined in a funnel or 



