IRRIGATION BY MEANS OF UNDER¬ 
GROUND POROUS PIPE 
By E. B. HOUSE 
Alany inquiries come to the Colorado Experiment Station from 
farmers of the State, concerning the installation of underground pipes 
for the purpose of snb-irrigation. This agitation on the part of the 
farmers is largely due to articles and advertisements published by our 
farm journals, daily papers, and weekly press, concerning this method 
of irrigation and the possibilities of tremendous crops whenever this 
system is installed. In order that these inquiries may be fully answered 
as far as certain sections and certain soils of the State are concerned, 
this bulletin is written. 
In 1913 a business firm in the State of Colorado requested the 
State Agricultural College to allow them to install, on land to be 
chosen by the college, a subirrigation system. The Station in return 
was to furnish them with these data collected, and also with the con-- 
elusions to be drawn from these data. It was also agreed by both parties 
that a bulletin was to be published after the experiment had been run¬ 
ning a sufficient time to give fairly reliable results. 
A piece of land satisfactory to all parties was selected on the West 
College Farm. The area of this piece of ground was approximately 2V'2 
acres. There was growing on the land selected for the experiment (i) 
an apple orchard, covering about one-third of an acre, (2) an alfalfa 
field of .7 acres, one vear old at the time the subirrigation system was 
installed, (3) across the road to the north a tract of ground having an 
area of 1.6 acres. This land had just been plowed and upon this tract, 
it was planned to trv out different cereal crops. 
WATER SUPPLY 
The water foi the subirrigation system was supplied by a drain 
the outlet of which entered an irrigation ditch on the College farm, 
some 250 feet west of the tract chosen for subirrigation work. This 
drain furnishes an ample supply of water throughout the vear for the 
purpose of subirrigation, but the quantity varied somewhat at diff erent 
seasons. At no time, however, did the supply drop to so small a quanti- 
tv as to make it impossible to keep the subirrigation pipes full. 
INSTALLATION 
The company sent their expert to plan and supervise the construc¬ 
tion of the svstem. Figure i shows the plan of the suhirrigation sys¬ 
tem as laid out by this expert. 
lender his direction a careful survev was made and the pipe lines 
staked. These ]fipe lir.es coincided approxdmately with the contour 
of the ground. It should be stated that the orchard is p-acticrlly level 
north and soutli, with a slight fall as one ]'asscs ti the c:'^t. d'h ' 
