6 BULLETIN 1301, U. S. DEPARTMENT OF AGRICULTURE 
The color of the soils on the uplands, as well as that of the medium 
and heavier soils of the experiment plats, is best described as a strong 
dark brown, almost black. The dark-colored horizon in the. virgin 
soil is about 8 inches thick, underlain by a brown horizon extending 
to a depth of about 2 feet. Below this hes the usual zone of accumu- 
lated carbonate of lime. 
This soil lies on or near the western border of the true black 
earth of the United States. The color of the surface soil is dark 
enough to be placed in that group, but the 16-inch to 18-inch horizon 
of brown loam between the dark-colored surface horizon and the 
carbonate zone does not permit its correlation as a typical member 
of that group. It is also somewhat too dark to be placed in the 
zone of chestnut-colored soils. So far as existing knowledge of its 
characteristics will permit any decision as to its place in the general 
scheme of dry-land soils, it must be considered as a nontypical 
chernozem. In the scheme of classification used by the Bureau of 
Soils it is a member of the Williams series. 
The composition of a sample taken from the plateau, locally 
known as the Custer Flats, 2 miles south of the station buildings, is 
shown in Table 4. The figures in this table show the total quantities 
of the constituents present. 
The chemical analysis confirms the statement made above that 
the ‘‘good clay subsoil,’ universally present in the mature soils of 
the humid part of the United States and recognized by the farmers, 
is absent here. The analysis shows no concentration of either iron 
oxide or alumina in the subsurface, whereas the composition of the 
mature soils in the humid region invariably shows more or less con- 
centration of this kind. 
The content of lime, potash, and nitrogen is all good to high, and 
that of phosphoric acid is high. 
TaBLE 4.—Chemical analysis of soil collected at the Northern Great Plains Field 
Station . 
Depth 
Analysis for— 
0 to7 7 to 24 | 24 to 36 
inches | inches inches 
Silieare SO seks terse CORN soe) ats Sees tc 2) ee ee ee per cent__} 70.31 70. 74 60. 71 
ibaMiiTMECdOXdG CSO pee otek eee ae ee doz c= BO . 66 . 55 
HCLEICOMGGwie3 Og eee eae Oe RES. ok. SSR ees Be doz 3.47 4.03 3.91 
PAC TITAN BAU TO 3a ee ea oe ee Ss Se do 12. 47 13.18 12. 97 
INTE SANESeOxIG ean @ Se eee ee a ee ee ee 6 aa . 087 | . 079 . 055 
IFN CAO Ree eee een HELE S Fa ee Rae re douzs 12 1. 08 6. 69 
Miaeiresia Vig © Brera ao eae ae tres ee ee Cosas .76 1. 53 2. 69 
IB OLAS MK) © erat abe cnr saad REN ab oe ae el ee ee ee ee doe== 2. 52 2. 34 2. 28 
SOd areas Oe Sana ecw ME ek 2 2 ae ee dos=as 1. 05 1.10 -91 
IPHOSDHORUS pentoxMd ew basse eee as Ce a eee eee doe== sah elle alr 
SulphurttrioxidesS Oss et oie 2 eas 2 ee eee ee do k= sail! . 09 . 09 
SIG ON OSS Wee ee ap ee ee ee RT ns 2 Ne eer ea ee dome: 7. 64 4,89 9.16 
INGIGNOS CTS NGS eee ern Sete VR et ee ee dou . 244 SPEs-| . 065 
Carbonidioxide; ©O2 Grom: carbonates) 225-2 2 6 ee ee ee dos 0 0 5. 65 
Vater amelie Oat rll ce Hye Roles sn kee eases nt ee oe OE, do2= 2. 33 2. 30 2. 50 
1 Nitrogen, carbon dioxide, and water are included in ignition loss and should not beadded again in com- 
puting the totals, which approximate 100 per cent and are within the limits of error of the analyses. 
