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Show The Duty of Water in Cache Valley, Utah 11 102. 96 92 ? 84 A ^ / \ / / ""^ N • ' ' \ ../ s 0 0 78 « 72 Q. j » 66 Q • S " -°> 54 c c* 8 ° « - S 36 24 18 IS 6 " v ' "^ x / > "- ^ s ' ^' » '' V Dor n ?'' Ir ob « S 0 f V* otei Of pllf d: 1 4 8 12. 16 EO 24 28 32 36 40 44 48 Fig. 6.- Yield of corn with various quantities of irrigation water. The diagram represents 17 years' work with a total of 118 tests. An examination of the results with corn shows the highest yield with 25 acre- inches of water, although yields are almost the same for all quantities of water between 15 and 30 inches. While the yields were somewhat reduced by excessively large irrigation applications, this was not nearly so much the case as with potatoes and sugar- beets. RESULTS WITH WHEAT* In the experiment with wheat as reported in Table VI and Figure 7 it will be seen that the yield was not nearly so much affected by irrigation as was the case with alfalfa, sugar- beets, and potatoes. Fifteen inches of water gave almost as high a yield as any treatment and yet the yield kept up fairly well with the very high irrigations. It will be noted that where no irrigation water was applied the yields of wheat were fairly satisfactory. Therefore, in practice it is doubtful whether more than 15 inches of water would pay for the extra quantity. Were it not for the fact that wheat can use water to advantage early in the season during the period of flood water, it is questionable that * For more complete discussion see Utah Station Bulletin No. 146. |