4 The Colorado Experiment Station 
The areas involved varied greatly in size, some of them were very 
small. This was the case with both of the samples which might be 
considered as containing salt enough to be detrimental. The data 
at my command indicates that about 1.5 per cent of the soil is the 
superior limit which most plants can endure, though 1.8 per cent 
is given for some. The highest percentage for water soluble chlorin 
obtained from any soil is 1.025; the highest percentage of total 
chlorin is 1.887 P er cent. As the highest percentages of chlorin are 
scarcely above the maximum of tolerance for some plants and these 
have been obtained from two small spots only, the question of 
chlorin may be neglected in considering the bigger features of the 
subject even if applicable to these isolated examples. 
It is a fact recognized only by a few persons so far that we 
have in Colorado some very serious problems. On some of our soils 
the agricultural results, even under the best of practice, present 
surprises and disappointments. A well trained and experienced 
agriculturalist made the remark very recently that the results from 
an agricultural standpoint grew worse instead of better as the 
practice of the people approached more nearly to those standards 
which have been and are recognized as the best. This is no exag¬ 
geration but represents a real difficulty. Melon growers have no¬ 
ticed for several years that their old grounds have not been pro¬ 
ducing the same good grade of melons that they produced in former 
years. In some sections the quality of the sugar beets has shown 
a falling off. These are general effects the causes of which may or 
may not be difficult to trace out. It is in specific cases of injury, in 
exaggerated cases of the operation of such causes that we may best 
succeed in tracing them and such is the case in this matter. The 
diffused action over square miles is not intense enough to make 
definite recognition or a reasonable interpretation of the facts pos¬ 
sible. It is only by the aid of extreme cases that we acquire the 
data whereby to interpret the ordinary manifestation of the cause. 
In looking over a field in a high state of cultivation, especially a 
few days after irrigation, the appearance of broad brownish lines 
just at the outer edge of the irrigation furrows is not a striking 
feature and usually would be interpreted that the land had been 
heavily fertilized, or was rich in humus matter, but under no con¬ 
sideration that it might be indicative of danger. My attention was 
directed to a melon patch last season, 1909, which was sick, this is 
the term used. There was no rust, no insects, nothing visible lo 
indicate disease. The melon plants were, however, puny and un¬ 
thrifty. The soil was in fine condition and had been cultivated for 
several years and fertilized. A melon patch on adjoining land which 
had been in alfalfa was healthy and vigorous. These plots were 
separated by the usual wire fence; the soil was the same; the water 
