WHAT WATER DOES IN SOILS 41 



soil, and soon enlarge into deep gullies the furrows 

 which are formed at the start. 



How is water stored in the soil ? When the surface is 

 loose and spongy, and the soil easily penetrated by 

 water, as it is when covered by the natural growth 

 of grass, shrubs, or trees, or when it is well cultivated, 



FIG. 186. This was once pasture land like that shown in figure 18 a. It 

 has been ruined by washing and gullying because overstocked with cattle. 



most of the rain water soaks in. It then sinks to such 

 depths as will prevent its waste by run-off and evapora- 

 tion at the surface. The soil mass thus acts as a great 

 sponge or reservoir, storing the water for use during 

 the rainless summer. It then supplies water to springs 

 and streams and gives its moisture to field crops and 



