PREFACE 



THE study of soil alkali is by no means simple, nor have 

 all the problems relating to it been solved. The many 

 different salts involved, each with its own properties; 

 the various types of soils in which these salts occur, all 

 with different textures and composition; the complex 

 relations between the soluble salts of the soil and the plants 

 growing on it; and the several economic factors involved 

 in the reclamation of alkali land: these and numerous 

 other considerations make the problems connected with 

 soil alkali as difficult to solve as any found in agricultural 

 science. 



The excuse for writing a book on a problem that is so 

 far from solution is found in the great demand that exists 

 for one volume containing the important information 

 concerning alkali. At present, the literature of the sub- 

 ject is very much scattered and is largely unavailable to 

 the average student of soils. 



There are hundreds of millions of acres of land in the 

 world that are at present not used for agriculture but which 

 might become productive if the alkali could be eliminated. 

 The need for more land to supply food for the world's 

 increasing population is making a very insistent demand 

 that some of these alkali lands be made available. The 

 response to this demand will depend on a better under- 

 standing of the nature of alkali and methods of reclaiming 

 land impregnated with it. This accounts for the new in- 

 terest that is being shown in the study of soil alkali. 



