OCR Text |
Show The Duty of Water in Cache Valley, Utah 7 inches and that it then declines gradually with the addition of more water. The increase in yield is seen to be more rapid with the smaller applications of water than it is with larger quantities. There is quite a range of water application where the yield is not greatly affected by a little more or less water. This is doubtless due to the difference in the climate during various years. For example, during one year the yield would be highest with 25 inches of water, whereas during a very dry year a higher yield could be obtained with a larger quantity. i- 0 I* 1i Q- 24 to g 22 C to 0 ca i6 s- a- 14 D o - o 10 o> 5- 8 6 4 2 j Sqqar Be et5 , j •"" y " TiT**" <^ -^ | ••' S? Y\ / v- jy '•• \^^ Q~ > vf 1 1 ; \ ^^ s*^ i ~"\ i ;' , 1 ^ ! ! i ~-£- ^ si y I 1 1 1 I ! i ! i I- j • ! ! ! ! 1 _ ir,: ! ii in 3 16 2+ 32 40 48 56 64 72 BO BB 96 Inches of wafer applied. Fig. 3.- Yield of Sugar- beets with various quantities of irrigation water. The diagram represents 17 years' work with a total of 200 tests. RESULTS WITH POTATOES* Experiments with potatoes extended over 14 years and included a total of 216 trials. The results are shown in Table III and Figure 4. The highest average yield for any treatment was secured for 32 V2 inches of water. The 4- year average for this treatment was 377 bushels of tubers to the acre. The average of 12 years' results with no irrigation was 117 bushels per acre. While considerable variation is noted in the trials during different years, the general tendencies are distinct. The most * For more complete discussion see Utah Station Bulletin No. 157. |