OATS IN THE GREAT PLAINS AREA. 7 
The plats hero, as in all of the work, arc one-tenth acre in size. Their 
dimensions are 2 by 8 rods. Along their larger dimension the plats 
are separated by bare alleys 4 feet in width. Along the ends of the 
plats they are separated by roads 20 feet wide. 
At this station five crops are represented in a scries of continuously 
cropped plats lettered from A to F. In this group, plats C and D 
are alternately cropped and summer tilled, so that each year a crop 
is grown on land that was summer tilled the previous year, and a plat 
is summer tilled for cropping the next year. 
The remainder of the field is in rotations in which each plat is 
known by a rotation number and letter. On the field diagram the 
separation of rotations is indicated by heavy lines. 
The movement of the crops is in the direction from Z to A and 
from A back to the letter that marks the other end of the rotation. 
P*t/o>v. 
* 
Com, PP. 
p 
Corn, fP 
Corn, f.P. 
ft 
Corn, SP 
Com, S.P. 
P 
fallow. 
./7 
Corn, f.P. 
tj 
Corn, PP. 
n . 
Oats, rat. 
a a 
a ° 3 ' s - " 4 
Bar/ay, O. 
a 6 
oats, sp. 
B 7 
oats, Sfi 
Wheat, SP 
8 ' Z 
WUat, fat 
Wheat, O. 
Wheat, P.P. 
a 3 
Wheat. PP 
meat, pp 
oats, pp 
c 
Barley, S.P 
Wheat, S.P. 
Oafs t sp. 
Oats, f.P. 
f 
c Oats, PP 
Oats, Pfi. 
c 
Carn, SP 
Com, Sfi. 
Com, Sfi 
Sorn, S.P. 
Corn, S.P 
meat, S.P. 
Oats, st>. 
Sar/ey, Sfi 
WinterWnzat, 
Wneat, D. 
a /4 
mist. />. 
8 'f 
wheat A 
p /a 
JVheaf, />■ 
\ g Ccrn, P.fi 
meat pp. 
a ' 
Oat j, p.p. 
<£ . , ■ - - j 
Ser/ey, ffl. 
Ig. Wheat, fifi 
e *y: e* 
Peas, PP. 
c 
/*'">"• 
SC/o/tr. 
c 
Com, Pat 
c 
Wheat, Pat. 
Oafs, fat. 
Sar/ey, Pal. 
W Wheat, rot 
c 
o 0ats, c-v 
oars, G/ii- 
Oars' fa/. 
° i, ,1,,. 
Oats, Grl. 
fjllov/. 
-fa/fov. ' 
fa/low. 
fa How. 
fa/'ofi. 
o 
Corn, Sfi. 
P 
Corn JP 
Corn, Sfi. 
p 
Torn, S.P. 
P 
Corn, SS. 
£ 
Wheat, Si. 
Oafs, SS. 
Bar/ey, SS. 
WWheat, SS. 
g oars, o. /s 
Oats, />. 
Oats, o. 
a ' /e 
Oafs, 0. 
a '32 
Corn, l. 
fir . mi ii • i 
Wheaf, ' 
Oats, I . 
f 
Sar/e/ t I. 
w Wheat, i. 
c r?yc, P.fi. 
Peas, PP 
c 
fial/ow. 
( 
SCU/en. 
Arome. 
/?i fat fa, pp. 
n ™ m °- 
C/oVer. 
Po fa foes. SP. 
W/itaf, CM. 

Wh*af, GM 
meat, m 
Wheat, GM- 
£rom e . 
6 
4/fialfia. 
Oafs Sod. 
Oafs Sod. 
a 
Oats. IT. 
a 7S 
Sorghum, Sfi 
yfrjCif 
Jordhvm, Sfi. 
Corn, SP 
■?■/<?/. Sod^ z 
Alfalfa. 
Com, SP 
Corn, S.P' 
c // 
Pa//oW._ 
tv/>:at. D. 
[ Wheat, /> 
\e 7/ 
Oals, />. 
a . J4 
B om t o. 7z 
Oafs, PA 
Oats Sod. 
D 
Wheat i>. 
. Wh.eaf, O. 
Wheat, fa/. 
S. C/over 
c 
j fa//&w, m 
S.C/o/en 
c 
/allow, M- 
Corn, Sfi. 
Corn, Sfi 
firome. - 
C/ot'er. 
Potatoes, Sfi' 
P 
Oafs, GM. 
D 
Oafs, fie/. 
Wheal. G.M. 
Q Wheat fa/. 
■ Wbt&t O. 
Wheat, D. 
Oafs, faf 
t> ' 76 
$ WAeaf, D. 7i 
Paf/otv, M. 
Fig. 2.— Diagram of the dry-land rotation field at the Belle Fourche Field Station. The lettering shows 
the cropping practiced hi 1914. The explanation of abbreviations used after the name of a crop is as 
follows: D.=Disked, Fci.=summer tilled, F. P.=fall plowed, G. 3f. = green manured, i.=listed, M .= 
manured, S. P.=spring plowed, S. (S^subsoiled. 
In figure 2 the diagram is filled out to show the cropping in 1914. 
The letters following the crop indicate the treatment given the 
ground in preparation for it, S. P. standing for spring plowed, F. P. 
for fall plowed, Fal. for summer tilled, G. M. for green manured, 
and D. for disked. The addition of the letter M. indicates the use of 
manure. 
To illustrate: In 1914 plat A of the 4-year rotation No. 14 was in 
corn on spring-plowed ground, plat B was in wheat on disked corn 
ground, and plat C was in winter rye on fall-plowed land. This 
would be plowed under for green manure. Plat D was in oats where 
winter rye had been turned under the year before. In 1915 A will 
be in wheat, B in whiter rye, C in oats, and D in corn. 
Some of the rotations are calculated to conserve or increase the 
fertility of the soil, while others may perhaps deplete it. In the 
present stage of the work the effects of rotations as units are greatly 
87674°— Bull. 218—15—2 
