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can not attain great depths in our prairie soils unless they 
have been opened by some preparatory crop or process. 
It is probable that the amount of ash constituents taken up 
by our alfalfa does not exceed ten, or at most, fifteen 
pounds per hundred, indicating an amount necessary for the 
perfect maturing of this plant, which only a rich soil can 
furnish or a most vigorous root system collect. 
We have no other series of soil samples so complete 
with the hay produced upon the same, but we have one 
sample from Rocky Ford, Otero county. The hay is a 
sample of the third cutting ; the yield for the year, three 
cuttings, was five tons. An analysis of the hay gave the 
following : water, 6.06 per cent.; ash, 9.87 percent.; fat, 1.29 
per cent.; crude fiber, 32.69 per cent.; protein, 13.69 per 
cent., and nitrogen free extract, 36.40 per cent. The fixed 
ash constituents amounted to 73.788 pounds for each 1,00c 
pounds of hay, as follows : silicic acid, .828 pound ; 
phosphoric acid, 3.258 pounds; sulphuric acid, 5.280 pounds; 
chlorine, 7.444 pounds ; lime, 23.684 pounds ; magnesia, 
3.033 pounds ; oxide of iron and alumina, .662 pound ; 
brown oxide of manganese, .153 pound ; potash, 27.197 
pounds; soda, 1.976 pounds ; or the total removed from the 
soil by the five-ton crop, supposing it all to have been as 
rich in ash as the third cutting was 737.88 pounds. 
The Weld county sample, already given, shows 677.88 
pounds ash constituents, based upon the first cutting and a 
yield of four and one-half tons. If we assume a five-ton 
yield, to make them more easily comparable, we have 
737.88 pounds of ash in Otero county, third cutting, as 
against 753.2 pounds in Weld county, first cutting ; a differ¬ 
ence of about 15 pounds, only three pounds for each ton, 
or only about two per cent, of the total ash constituents 
considered. This difference is less than that usually found 
between two samples cut at different times from the same 
plat. 
We fortunately have an analysis of the Otero county 
soil, also made by Mr. Ryan. The point at which this sample 
of soil was taken is not, as in the case of the Weld county 
sample, the one at which the hay sample was gathered; but, 
after examining the soil, I am satisfied that, owing to its 
uniformity, no error is introduced by the fact that the sam¬ 
ple is not the identical soil in which the plants had grown 
and there can be no doubt but that its value is as great as 
that of any chemical analysis which might be made of this 
soil. 
