OFFICE OF EXPEKIMENT STATIONS. 205 



also save other large areas wliicli the escaping water now ruins by 

 saturation. It often happens that this percolating water, when it 

 reappears on lands below, is charged with soluble salts dissolved from 

 the subsoil passed through. 



This accumulation of alkali renders the soil unfit for cultivation 

 where the amount of seepage water does not render such cultivation 

 impossible. The injurj'^ Avhicli is being wrought through this action is 

 shown in nearly every one of the older irrigation districts in Colorado, 

 Utah, and California, where extensive marshes covered with flags 

 and rushes have taken the place of what were once fertile and pro- 

 ductive fields. It is believed that a better undei'standing by ditch 

 owners of the extent of this loss will result in measures to lessen it. 

 Investigations in this line are being carried on by a number of the 

 agents above named, and, in addition, Mr. Clarence T. Johnston, 

 assistant in irrigation investigations, is making a series of detailed 

 tests on important canals in Wyoming, Colorado, and Utah to deter- 

 mine more accurately the rate of this loss and to discover, if possible, 

 the best means of lessening it. 



SEDIMENT INVESTIGATIONS. 



The quality of the water used in irrigation has an important influ- 

 ence on the enduring success of farming along any stream. In some 

 cases the sediment it carries has a manurial value. In others, the 

 streams are so impregnated with alkaline salts as to make their use a 

 source of increasing injury to the soil, and sometimes to vegetation 

 at the time applied. The continuous operation of some canals through 

 the season is a matter of extreme ditficulty because of the rapid 

 deposit of sand and silt, and the enduring value of storage basins 

 depends upon the percentage of sediment in the water which fills 

 them and the means which can be employed for its removal. A num- 

 ber of the AV'estern experiment stations are investigating this matter 

 and have already made important contributions to our knoAvledge of 

 this subject. 



Some investigations regarding the amount and character of this 

 sediment were carried on last year in cooperation with the W^'oming, 

 Arizona, and New Mexico experiment stations, and this year special 

 work in this line is being done by Prof. J. C. Nagie, of the Texas 

 Agricultural College. 



INVESTIGATIONS IN THE HUMID REGIONS. 



Interest in the use of irrigation to supplement rainfall in the humid 

 regions of the United States is constantly growing. In a number of 

 regions this has been greatly stimulated during the past season by 

 long-continued drought. Scarcely a season passes in anj'^ section of 

 tlie country in which there are not periods when the unequal distri- 

 bution of rainfall produces a temporary scarcity of water at critical 

 periods in the life of certain crops and a resultant diminished yield, 

 which the ability to supply water when needed Avould have prevented. 



During the past year Prof. E. B. Yoorhees, of the New Jersey agri- 

 cultural experiment stations, who had alreadj' made preliminary 

 investigations regarding the possibilities of irrigation in that State, 

 an account of which was published in Bulletin No. 30 of this Office, 

 undertook to continue these investigations in cooi)eration with this 

 Office. In this work he collected data showing the area of land irri- 

 gated in New Jersey, the methods employed, the duty of water 



