178 AGRICULTURE. 



ft., or 235,905,678.7 gal., sufficient to cover 723^^1 acres to a 

 depth of I ft. 



The sub-humid region is the strip of country running 

 north and south between the arid region, where irrigation 

 is absolutely necessary to the successful prosecution of 

 agriculture, and those portions of the United States in 

 which the rainfall is usually sufficient for agricultural pur- 

 poses. It includes portions of North Dakota, South Da- 

 kota, Nebraska, Kansas, and Texas, and may be described 

 as a region where irrigation is not always necessary, but 

 where agricultural operations cannot, with any assurance 

 of success, be undertaken without it. 



The average value of the irrigated land in farms in the 

 United States was ascertained by the census of i8go to be 

 $83.28 per acre, and that of the non-irrigated land in farms 

 $20.95 per acre. 



The average annual value of the agricultural products of 

 the irrigated land was ascertained to be $14.89 per acre irri- 

 gated, and that of those of the non-irrigated land $6.80 for 

 each acre improved. 



The average first cost of the irrigated land, including 

 purchase money, water rights, etc., was ascertained to 

 have been $8.15 per acre, and the average annual cost of 

 the water supply $1.07 per acre. 



The total value of the irrigated farms of the United 

 States, as reported by the farmers themselves, was, in round 

 figures, $296,850,000, an increase of $219,360,000, or 283 per 

 cent, upon their cost, including land, water right, fences, 

 and preparation for cultivation. 



The total value of the productive irrigating systems was 

 found to be $94,412,000, an increase of $64,801,000, c^ 2ig 

 per cent, upon their cost. 



