2 9 
A Study oe Colorado Wheat 
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there are factors profoundly influencing the growth of plants 
beyond the ordinary range of observation." Later Professor 
Montgomery adds, “A number of interesting problems are sug¬ 
gested. Why should one plant, growing under practically the 
same environment as another, collect from the soil two or three 
times as much nitrogen." Again, “The three plants * * * 
are from the same mother growing in the same centgener, probably 
less than two feet apart, yet the actual grams of nitrogen gathered 
differ more than ioo percent. This difference is not inherited, as 
these plants rarely transmit this quality." Professor Montgomery 
does not ascribe this difference to the soil, and the quotations are 
not made for the purpose of intimating that he does, but simply 
to show that variations in the composition O'f individual plants, 
growing, as is here asserted, within two feet of one another, may 
be very great, and that the difference in their nitrogen content can¬ 
not be attributed to heredity. The inference that I draw from the 
facts given is that there was a relation between the soil and these 
variations, but we shall find occasion to come back to this subject 
at another time. 
SOME SURFACE SAMPLES OF SOIL AND THEIR BACTERIAL 
CONTENT. 
It was proposed to study the relation between the moisture, 
the number of bacteria, the total nitrogen and the nitric nitrogen 
present from time to time. Our plan proved to be more generous 
in scope than our ability to perform. In addition to this Professor 
Sackett did not encourage me with the promise of any easily 
interpreted results, as the bacterial counts do not include all of 
the bacteria, one or more important classes being eliminated by the 
character of the culture medium used. 
In this connection it may be well to note one of the effects of 
turnipg the land to such a depth as I did, twelve inches in two cases 
and nine inches in one case, whereby I put several inches of the 
subsoil on the surface, at least two inches by the shallower and five 
or six inches by the deeper plowing. This plowing was done in 
the spring immediately before seeding. I appreciated the disad¬ 
vantages of the procedure, but as previously explained, I had, 
owing to circumstances over which I had no control, no choice if 
I wished to give the land a deep plowing. The result was that the 
surface of my plots represented unweathered subsoil with a com¬ 
paratively meager bacterial population. We united twenty samples 
of this subsoil to form a composite one taking care that the samples 
should not be inoculated by admixture of surface soil or by other 
means. Professor Sackett kindly made the bacterial count which 
he reported to us as—bacteria 911,875, moulds 97,975 P er gram 
