44 



for Huron, which is centrally situated and representative of the con- 

 ditions throughout the valley : 



Precipitation at Huron, S. Dak., from 1S9G to 1903. 



While reports from all parts of the valley mention the abundant 

 rainfall, during the more recent years a study of the precipitation 

 records shows that there has been little change in the total precipita- 

 tion, the very favorable conditions being due more to better distribu- 

 tion than to a greater amount. 



CONCLUSIONS. 



As a result of this series of investigations the following conclusions 

 are established: 



(1) Irrigation can be practiced to advantage during most of the 

 years, though there is occasionally a year when the moisture is suffi- 

 cient and ijroperly distributed. 



(2) The wells are not called upon to furnish all tlie water needed 

 for crops, but merely to supplement rainfall. 



(3) Care must be taken that the soil does not become too wet. 



(4) The salts in the waters and those drawn from the land have 

 not thus far had any detrimental eflEect, nor do they give indications 

 that they will have in the future. All cases of deterioration of the 

 soil are directly traceable to an oversupply of water. 



(5) Under irrigation the farmer is practically sure of a crop each 

 year. 



((J) In ordinary or extra dry years the crop is increased two and 

 sometimes three fold. 



(7) 'J'he crops are alwaj^s of superior quality, grading Ko. 1 when 

 unirrigated crops grade No. 3 or are even rejected. 



(8) A good 2-inch well supplemented by a reservoir will furnish 

 water for a half section of land. 



(•)) The main di-awbacks are the lack of knowledge regarding the 

 in-actical handling of water in the field and the too lavish applica- 

 tion, especially if soon followed by rain. 



