Contents xv 



PAGES 



The Value of Turbid Water in Irrigation. Eio Grande 



Po Nile Durance 259, 260 



Improvement of Land by Silting. Warping or colmatage 



Silting of gravelly soils 261-264 



Opportunities for Silting in Eastern United States. In Wis- 

 consin and Michigan In New York and New Jersey 

 In the South 264-266 



Alkali Waters not Suitable for Irrigation. Safe and unsafe 



alkali waters 266-268 



CHAPTER VIII 



ALKALI LANDS (pages 269-289) 



Characteristics of Alkali Lands 269, 270 



Causes of Injuries by Alkalies. Plasmolytic effects Toxic 



effects 270, 271 



How Alkalies Accumulate in the Soil. By capillarity In 



marsh soils by underflow 272-274 



Intensive Farming may Tend to the Accumulation of Alkalies. 274, 275 



Amount of Soluble Salts which are Injurious in Soils. Con- 

 clusions of Plagniol Of Dehe"rain Of Gasparin Of 

 Hilgard Plasmolytic action 275-278 



Composition of Alkali Salts. In California In Washington. 278-280 



Appearance of Vegetation on Alkali Lands. In arid regions 



In humid regions 281-283 



Conditions which Modify the Distribution of Alkalies in Soil. 



Tillage Shading Action of roots 283, 284 



Use of Land Plaster to Destroy Black Alkali. Hilgard's 



conclusions 284, 285 



Kinds of Soil which Soonest Develop Alkali 286 



Correction of Alkali Water before Use in Irrigation 287 



Drainage Must be Ultimate Remedy for Alkali Lands 287-289 



