WINTER IRRIGATION. 465 



There are successive winters when there is not 

 enough rain or snow to wet the subsoil, hence the 

 spring and summer rains fall on a soil unfavorable by 

 its dryness to make proper use of the water, and 

 instead of soaking into the earth to any depth it runs 

 off rapidly or evaporates. Enough rain may fall in the 

 spring to mature a fair crop, provided the subsoil is 

 sufficiently wet from winter irrigation. Many fruit 

 and forest trees die from the lack of moisture in the 

 subsoil in winter. Rain may keep the surface soil in 

 moist condition, sufficiently so to produce growth, but 

 the feeding rootlets having penetrated the dry subsoil, 

 cannot obtain enough moisture to equaHze the evapo- 

 ration going on through the leaves, thus starving the 

 tree to death. 



Some Valuable Experiments.— The value of 

 conserving moisture on fruit lands by mulches through 

 the winter has long been understood and is widely prac- 

 ticed by many farmers, and the value of winter irri- 

 gation for orchards is no longer questioned. As we have 

 said, the winters are long and dry in the arid region, 

 there is no continuous mulch of snow, and the orchard- 

 ist who cannot irrigate late in the fall or occasionally 

 through the winter is unfortunate. The value of irri- 

 gating alfalfa in the fall has been tested by a friend of the 

 writer. Alfalfa irrigated late in the season, 0(5lober 2d 

 and 3d, did not winter-kill as badly as that not irri- 

 gated. The quantity applied cannot be estimated 

 accurately, but as nearly as can be estimated enough 

 was used to cover the land six inches deep. The 

 plants which were fall irrigated started earlier in the 

 spring and made better growth, at one time being four 



