36 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



a mulch of dry soil iniinediately after irrigation ceases. To avoid 

 the uncertainties due to seepage losses, these experiments were car- 

 ried on in tanks 3 feet deep. It is found that in some instances the 

 losses would be decreased as much as 50 per cent, the saving being 

 equal to 10 to 20 per cent of the quantity applied. If these results 

 could be duplicated in field practice the}^ would make it possible to 

 increase the area irrigated by an equal percentage, and it is believed 

 they can be in the irrigation of orchards. Tlie principles underlying 

 this saving can be applied in modifying the methods of irrigating 

 grain and hay. The corrugated system of irrigation applied to the 

 irrigation of grain and hay fields in AVashington, for example, 

 requires less water and produces larger yields than the plan of 

 flooding the entire surface. 



At Canyon City and Rockj^ford, Colo., demonstrations of the value 

 of irrigation through deep furrows and immediate covering of the 

 wetted surface after irrigation, added to clean and frequent cultiva- 

 tions of the soil, was carried on, the results being ver^^ favorable to 

 the decrease of water and the increase of cultivation. 



Great activity in the settlement of the semiarid region withiji the 

 last few years and the repeated failure of similar earlier attempts at 

 settlement have made necessary a study of the irrigation possibilities 

 of this region. It is believed that onl}^ by making use of ;ill the 

 water Avhich can be secured by storing storm water and pumping 

 from wells for irrigation can a repetition of the earlier experiences 

 be prevented. We have, therefore, devoted a considerable part of our 

 funds to what has been termed " irrigation extension " work. A 

 farm was established at Cheyenne, Wyo., part of which has been irri- 

 gated only in the previous autumn when flood Avater was available, 

 and part irrigated during the summer with water pumped from wells, 

 and a part farmed without any irrigation. On this sijigle farm it 

 is possible therefore to compare the possibilities of flood-water irri- 

 gation, summer irrigation from wells, and intensive cidtivation to 

 conserve rainfall. The results in 1906 were most encouraging, large 

 crops being harvested from both the flood-irrigated and the sunnner- 

 irrigated fields and good crops from lands not irrigated. A similar 

 farm where all the water used was pumped from wells was estab- 

 lished in Chase County, Nebr., and farms were also maintained at 

 "Wichita Falls and Quanah, Tex. In addition to conducting these 

 farms information was collected as to wh:ii Ims already been done 

 in the way of irrigation from small water supplies throughout east- 

 ern Colorado. This study consisted in a mere collection of informa- 

 tion as to equipment, cost, and areas irrigated. In Wyoming, South 

 Dakota, and Montana a more thorough study of small storage was 

 made. In that section a number of small reservoirs have been made. 



