40 IRRIGATION IfARMING. 



In irrigating light soils very small streams of water 

 should be used ; otherwise, if the drainage is good 

 there is danger of washing out the soluble fertilizing 

 elements, leaving only the coarse mineral constituents, 

 and rendering the soil less fertile and produc5tive. This 

 precaution is especially necessary when using the clear, 

 pure water from springs or artesian wells, which car- 

 ries ordinarily little of the rich fertilizing sediment 

 characfleristic of streams which flow for long distances 

 through alluvial regions. In the employment of the 

 latter, if well charged with sediment, the use of a large 

 irrigating head is frequently advantageous, as it gives 

 an opportunity for a uniform settlement of the sedi- 

 ment while the water is entering the soil. 



Remedies for Alkali. — The remedies for the im- 

 provement of soils surcharged with the neutral alka- 

 line salts, the texture of which is very compadl and ad- 

 hesive, are thorough tillage, the leaching out of the 

 alkali by irrigations combined with either natural or 

 artificial drainage, and frequent irrigation of the soil, 

 assuring the intermixture of the surface deposit of 

 alkali with the lower strata of soil, and thus diluting 

 it and partially neutralizing its injurious presence. As 

 shown in the preceding chapter, cultivation also checks 

 evaporation, and hence currently lessens the deposits 

 of alkali on the surface. A loose, dry top soil adls as a 

 cushion of earth and air, intercepting the continuity of 

 the upward passage of moisture along the lower plane 

 of cultivation. 



The writer has more recently been asked by a num- 

 ber of correspondents to give an opinion regarding the 

 suitability of stable manure and other fertilizers as 



