30 BULLETIN 339, U. S. DEPARTMENT OF AGRICULTURE. 
deficient or excessive water application have been eliminated, as have 
a few tracts on which a very large increase in water application was 
necessary to produce a small increase in the yield. The remaining 
data, some 50 per cent of the original data secured, have been grouped 
in Tables XIV and XV. 
TABLE XIV.—Average depths of water applied to 119 selected fields of grain and potatoes 
on medium clay and sandy loam soils, by months. 
[Altitudes ranging from 2,400 to 5,000 feet.] 
Depth of water applied. 
Season. Number l 
Of plats). Apr a | | Total for 
16-30 | May. June. | July. August. | Se 
| | Foot. Foot. | Foot. Foot. Foot. Feei. 
TEAL So) eke ge ae eee se a, ce Shik ee 0.32 0. 60 0.55 0.08 | 1.55 
z CY VER iG Sa Bu ey Dele goa Set = Bones 03 65 48 01 1.17 
LOPES RE Ne Set. chee ee 7 eee Seon pee [eee o eee 94 | .66 05 1.65 
Uy BRN Se eee anes ogee a 33 | 0. 04 | 21 54 59 23 1.61 
VORIEG 2 en eee ao 01 14 | 68 57 .09 | 1.50 
Percent Gf total =o. ==_jesese =. =e | 67 9. 28 45.91 38. 10 6. 06 | Seen e 
Table XIV shows that both the months and the seasons have - 
varied somewhat in their requirements and that the average annual 
requirement of water for this class of crop was 1.50 feet per acre. 
The results shown by the table are based upon the same data as 
are included in figures 5, 7, and 8, but were arrived at in a different 
manner. There is a very close agreement in that the requirement 
of water shown by the table is practically the same amount as that 
which the curves indicate will produce the maximum yield on both 
fertile and infertile soils. 
Table XV shows the average depths of water used on alfalfa, 
arrived at in the same way. 
TABLE X V.—Average depths of water applied to 52 selected fields of alfalfa and clover on 
medium clay and sandy loam soils. 
[Altitudes ranging from 2,400 to 5,000 feet.] 
Degth of water applied. 
Number z . 
Seon: of plots. April— Sep- | Total 
——_—_—— May. | June. | July. August.) tem- | for 
1-15. | 16-30. | | | | bee oa 
| Foot. | Foot. | Foot. | Foot. | Foot. | Foot. | Foot. | Feet. 
(1 0 Ree eee See ee ae 15 0.06 0.02 0.55 0. 74 0. 65 0.61 0.07 2.70 
NOD ae ee oe 1S ys eee 04 . 49 . 29 .91 | 7 - 25 2. 68 
1M ee A ee ea Wes, See eee | 49 . 00 . 62 | 61 . 04 2.26 
GTS ce ee ees - Be eee ee dR ju (eeeSoeee ee Se oS = 86 23. | 14 39 . 02 2.24 
AVORAIO == Fn 02 | . 02 | . 60 .44 ak 08 10 2.49 
Per cent of total. ....).-......-- ¥orises 24.1 17.7% | 29.3 23.3 4.02 Pee 
ee —— 
| 
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