38 
Colorado Experiment Station 
chard set in a soil so thin that it scarcely covers the underlying 
calcareous shale and I could find none of this bleeding in these trees. 
The orchard is young and fairly thrifty. It is further true that this 
bleeding is not universal throughout the fruit growing sections of 
the state while the presence of lime in relatively large quantities is 
certainly the rule with only a few exceptions. 
In Bulletin 131 I stated that the question is: Are these trees 
suffering from systemic arsenical poisoning, lime poisoning, or both? 
Again I Jiave repeatedly expressed my opinion that it is doubtful 
whether we can distinguish the part which each plays in the case. 
There can be no doubt, and there is no doubt in the minds of thought¬ 
ful men conversant with the facts, but that something is the matter 
with these orchards. This does not mean that the trees are dead or 
that the orchards may not continue to give very handsome returns 
for years to come, but simply that the trees are not healthy and that 
the bad condition of some trees is possibly due to this cause. Arsenite 
of lime was at one time our generally used spray material and it is 
possible that soil conditions may have been such that this in some cases 
caused the injury. 
The lime and arsenic may have been taken up together, that is, in 
combination, or taken up at the same time but not in combination 
and we are not able to distinguish the,ir separate action. I would 
make no mention of this matter if I did not believe it to be of such 
importance as to demand mention. 
I have studied these marly soils to see if I could find anything 
indicative of an explanation for this condition. Orchards do quite 
well on some of these lands, especially if the surface soil is twenty 
inches or more deep and not too rich in lime. The following analysis 
will give an idea of their composition : 
ANALYSIS OF MARLY SOIL. 
Insoluble . 4S.5S9 
Soluble Silica. 17.071 
Chlorin . 0.008 
Phosphoric Acid. 0.036 
Carbonic Acid . 8.532 
Lime . 11.695 
Magnesia . 1.674 
Sodic oxid . 0.374 
Potassic oxid . 0.5S9 
Ferric oxid . 4.890 
Aluminic oxid. 4.554 
Manganic oxide (br) . 0.179 
Ignition (loss) . (1.776) 
Sum .. 100.002 
O Equiv to Cl . .002 
Total ... 100.000 
Total Nitrogen . 0.386 
