4 
The Colorado Experiment Station 
turn reddish-brown, while the central portion assumes a pale yel¬ 
low, greenish color. When the nitre is present in large quanti¬ 
ties, the whole leaf turns reddish brown, and, in severe cases, the 
nitre may even attack the branches and the whole tree. In many 
instances, only a portion of the tree is affected. This is due to 
the fact that nitre may be present only in small spots, and the 
roots, feeding in these, become poisoned, and the branches which 
receive food from the roots in these areas show the presence of 
the poison. Often, a half tree will die, while the remainder of 
the tree appears to be perfectly healthy. 
Several thousand acres of land in Grand Valley that have 
been made unproductive by nitre poisoning, could have been 
saved, and could yet be saved if the growers practiced rational 
methods of soil management. 
The object of this investigation was to determine the quickest 
and most economical method of correcting and reclaiming nitre 
land in the Grand Valley. Particular attention was paid to land 
occupied by fruit trees, or lands that had been occupied by fruit 
trees which had been killed b}" excessive nitre in the soil. 
The work was started in June, 1914, and has been carried on 
for the last three seasons on a farm west of Grand Junction. 
Arrangements were made to take over two acres of land on 
which an apple orchard had been killed and the trees removed 
several years previous. This piece of land, at the beginning of 
the experiment, was entirely barren of vegetation. Even the 
hardiest and most resistant Aveeds failed to grow on it. Samples 
of the soil analyzed by Dr. Pleadden, Station Chemist, showed ex¬ 
cessive amounts of nitrates. The condition of barrenness had 
existed for several years without any apparent change in the char¬ 
acter of the soil, so far as sustaining plant life was concerned. 
The water table of this plat of land during the irrigating season 
came to about four feet of the surface and in no way interfered 
with the growth or ripening of the ordinary farm crops. The 
land is nearly level, but with a slight fall toward the south. The 
soil is heavy and does not permit the water to percolate freely. 
METHODS EMPLOYED 
The land was well plowed, harrowed and prepared in the usual 
manner for seeding grain crops. A portion of the land, about 
one-fourth acre, running the whole length of the field, was enclosed 
with an embankment of earth, and water was led into this en¬ 
closure so that the whole strip was covered to the depth of sev¬ 
eral inches. The land was kept covered for ten days, permitting 
the water to gradually work its way thru the soil and drain off 
