THE CHEMICAL EXAMINATION OF VARIOUS PEAT MATE¬ 
RIALS BY MEANS OF FOOD STUFF ANALYSES 1 
By A. P. Dachnowski, Physiologist, Soil Bacteriology Investigations , Bureau of 
Plant Industry , United States Department of Agriculture 
INTRODUCTION 
Several studies have been made in the 
past few years, and are still being 
conducted, with the object of accumu¬ 
lating information concerning funda¬ 
mental differences in peat lands and 
their relation to agriculture. Promi¬ 
nent among these studies are those 
dealing with type profiles of peat 
deposits; that is, with the number of 
different kinds of peat, their position 
and arrangement relative to one 
another, in deposits in different parts of 
the country. Results thus far secured 
lead to the conclusion that any ade¬ 
quate description of peat land and the 
several layers composing it must recog¬ 
nize three fundamental facts: (1) The 
differences in type of peat and the pro¬ 
file position of the materials; (2) the 
water level in its relation to the surface 
zone of oxidation and the lower zone of 
reducing action; (3) nature of the 
mineral subsoil and the water supply 
affecting the quantity and character 
of salts, such as lime, iron, sulphur, etc. 
CHEMICAL ANALYSES OF VARIOUS 
RINDS OF PEAT 
The following study was undertaken 
to obtain data on the differences in the 
principal groups of organic compounds 
of several types of peat layers and to 
establish, if possible, standards for 
grading types of peat as to stage of 
decomposition and relative agricul¬ 
tural value. In determining the rela¬ 
tive usefulness of different kinds of 
peat, for example, to microorganisms 
and higher plants, it is necessary to find 
adequate means of indicating the 
amount of different organic substances 
which the various layers of peat actu¬ 
ally contain. It is obviously impor¬ 
tant to know what variation may be 
expected in the layers of peat in dif¬ 
ferent regions of the country in varying 
stages of decomposition, and at differ¬ 
ent depths. Likewise it is evident that 
the composition of any layer of peat, 
whether stated in terms of calories, of 
soluble organic material, or of insoluble 
residue, contributes toward a basis for 
judgment and for securing standards 
of value for commercial peat products. 
The simplest means for compiling 
chemical composition records are analy¬ 
ses as made for crops and feeding stuffs, 
in accordance with official methods (l) 2 . 
The results obtained in regard to the 
amount of crude protein, crude fiber, 
nitrogen-free extract, and fat present in 
different peats can be readily compared 
with those derived from analyses of 
plants and feeding stuffs. 
The results reported here 3 indicate 
that data of tlyis kind are probably 
fully as important as those secured by 
other means for determining changes 
and losses of organic constituents in 
peat materials varying with composi¬ 
tion, stage of decay, and depth below 
the surface. In many particulars, 
however, the grouping under these 
terms of organic substances in different 
kinds of peat is unsatisfactory. The 
method does not give a sufficiently 
forceful illustration of the available 
organic compounds in plant remains 
now stored as layers of peat. It 
would, therefore, be preferable to 
differentiate between the several nitro¬ 
genous substances, carbohydrates and 
fats, and substitute a more accurate, 
though necessarily more complicated 
classification. 
Tables I and II represent the chemi¬ 
cal composition of samples from typical 
layers of peat obtained over a great 
portion of this country. A number of 
these types of peat have been illus¬ 
trated in a recent paper (9 ). 
1 Received for publication Apr. 9, 1924—issued January, 1925. 
2 Reference is made by number (italic) to “Literature cited,” p. 81-83. 
3 The analytical work' on this series of peat samples was done by G. L. Bidwell of the Cattle Food and 
Grain Investigation Laboratory, Bureau of Chemistry, U. S. Department of Agriculture. 
Journal of Agricultural Research, 
Washington, D. C. 
( 69 ) 
Vol. XXIX, No. 2 
July 15, 1924 
Key No. G-423 
