4 
Colorado Experiment Station 
stances, in the application of sub-irrigation, the water-plane is 
raised to within 12 inches of the surface, while in the most con¬ 
servative cases the aim is to raise it within 22 inches. It is not 
our intention to consider the conditions under which these results 
may be obtained or to discuss methods of irrigation, but simply to 
present the facts. One result has been the seeping of that sec¬ 
tion of the valley lying to the north of the Rio Grande and east 
of Center. This fact has called into existence the Gibson and Syl¬ 
vester ditches for the purpose of drainage. The conviction is very 
general that drainage will remedy conditions in this section of 
the valley. It does not matter whether this conviction is wholly 
or only partially correct, it establishes the prevalence of this 
seeped condition. 
SOIL IS NOT EXHAUSTED 
Another cause of failure might be exhaustion of the soil. This 
probably plays only a small part, if any, in the present unfavor¬ 
able condition of this section. How unfavorable this general con¬ 
dition is, is not appreciated by any except those who have an inti¬ 
mate knowledge of the country. The practice of the ranchmen 
in farming this land may have been bad, but exhaustion of the soil 
is not at all a contributing factor. 
An ordinary agricultural analysis of a soil from Hooper gave 
the following results: 
ANALYSIS OF SOIL. HOOPER. COLORADO 
Percent 
Sand* . 62.241 
Soluble silica . 15.229 
Sulfuric acid . 0.363 
Phosphoric acid . 0.320 
Carbonic acid . 2.629 
Chlorin .. 0.081 
Lime (calcic oxid). 4.295 
Magnesia . 1.595 
Potash . 1.383 
Soda . 1.326 
Ferric oxid . 3.930 
Aluminic oxid . 4.259 
Manganic oxid (br.). 0.175 
Ignition . 2.260 
Sum . 100.085 
Oxygen equal to chlorin.. 0.018 
Total . 100.067 
* This sand consists of particles of igneous and other rocks rich in felspar 
and has, comparatively, a small amount of quartz particles. 
This soil is quite typical of by far the larger part of the soils 
found in the valley and, so far as this kind of an analysis is reliable 
as an indication of the supply of plant food, the soil is excellent 
