38 IRRIGATION FARMING. 



with the loose wicking. Just so in the soils. The 

 close ones will raise the soil water from a greater 

 depth than will the loose, sandy ones, but the latter 

 will bring it up quicker to the full hight to which it 

 can rise. 



Soils Containing Alkali. — Alkali is always worse 

 in clay soils than in sandy ones. This is because it 

 rises to the surface from a greater depth. In the arid 

 country the rains often wet the soil only a few inches 

 deep, and the alkali forms at the bottom of the moist- 

 ure and makes hard cakes called hard-pan — for hard- 

 pan is only a soil full of alkali packed hard. We 

 rarely come in conta(5l with alkali in sandy soil, and if 

 it should prevail in such soils it would do no special 

 harm. The a<5lion of the weather for ages has caused 

 it to leach out as rapidly as it formed. 



The vineyards of the Hacienda de los Homos, in 

 Cohahuila, Mexico, are planted in stiff adobe soil 

 which by the alkaline efflorescence has become as white 

 as paper. A vineyard which has existed for several 

 years is marvelously vigorous, and there is no appear- 

 ance that this condition will change. At Viesca, Co- 

 hahuila, the clay soil of the public square seems as if 

 it were covered with snow. It produces, nevertheless, 

 magnificent trees and rose-bushes. From this it would 

 seem that the relation of alkali to soils is often misun- 

 derstood, and is considered more injurious than it really 

 is to the growth of vines, shrubbery, and trees. 



Effects of Alkali. — There are, however, many 

 tender garden and field crops that are badly injured 

 even -by the white alkalies that we have seen under 

 such peculiar conditions in Mexico. While the corro- 



