Historic, archived document

Do not assume content reflects current
scientific knowledge, policies, or practices.

UNITED STATES
DEPARTMENT OF AGRICULTURE
~ CIRCULAR No. 421

Washington, D. C. January 1937

| RESULTS OF FIELD CROP,
-|. SHELTERBELT, AND ORCHARD INVES-
_ TIGATIONS AT THE UNITED STATES
DRY LAND FIELD STATION,
- ARDMORE, 8. DAK., 1911-32

By
OSCAR R. MATHEWS
Senior Agronomist
and
VERNER I. CLARK
Former Scientific Aide

Division of Dry Land Agriculture
Bureau of Piant Industry

Price 10 cents

CIRCULAR No. 421 JANUARY 1937
UNITED STATES DEPARTMENT OF AGRICULTURE
WASHINGTON, D.C.

RESULTS OF FIELD CROP, SHELTERBELT, AND OR-
CHARD INVESTIGATIONS AT THE UNITED
STATES DRY LAND FIELD STATION,
ARDMORE, 5. DAK., 1911-32

By Oscar R. MATHEWS, senior agronomist, and VERNER I. CLARK, former
scientific aide, Division of Dry Land Agriculture, Bureau of Plant Industry

CONTENTS
Page Page
Introduction see ee ee ee ee eee 1 | Shelterbelt investigations—Continued.
Agricultural history of the section _________- 2 Comparison of cultivation, mulching, and
Typo of agriculture practiced______________- 2 lacksof-cultivationsee. os eee 4]
Soiliconditionsis 23th tf: Wee Lees eee ak 3 Speciestblocks? (4/232 378 ee ad 41
Climaticiconditions== =) es eee eee 3 Hog-house shelterbelt____-__________________ 42
Field crop investigations____________-________- 4 Conclusions from shelterbelt investigations_ 42
Crop rotations and cultural methods_______ 4] Farm orchard investigations._________________ 43
Mieldgtrial se ee ae a gee ee 21 IAD DICMEVATICLICS eee ol unite Ure ae pear enipune mele 44
Warietalatests ies: Peaiis 2a Ne ee Une ee 27 Plimvanrieties! 3 sss Obs 44
Shelterbelt investigations_.___________________ 38 ETUitsproguchiones— 622 eee 45
Pruning and spacing experiment___-____-___- As SUumMMAany eee sas ee ee eee 45
INTRODUCTION

The United States Dry Land Field Station at Ardmore, S. Dak.,
was established for the purpose of studying the possibilities and the
limitations of crop production in the area that it represented. This
area includes southwestern South Dakota, northwestern Nebraska,
and east-central Wyoming. Ardmore is one of a group of 24 sta-
tions at which the Division of Dry Land Agriculture of the Bureau
of Plant Industry has studied crop production in the Great Plains.

Work started at the station in 1911 with the breaking of prairie
sod. Crop-rotation work was continuous from 1912 to 19382, inclusive.
Work with dairy cattle, beef cattle, and hogs was inaugurated in 1917
for the purpose of determining the best methods of utilizing home-
grown feeds. Shelterbelt investigations for the purpose of determin-
ing the species of trees and methods of planting and care suitable for
the section were started in 1917. Fruit trees were planted at different
times from 1917 on, to determine varieties that were suited to the
conditions they must endure.. Cooperative work with other divisions
of the Bureau of Plant Industry was carried on for the purpose of
determining the varieties of grains and forage crops best adapted to
the section.

The results of all the work at the station to and including the year
1925 appear in an earlier publication.*

1CoLE, J. S., Ketso, F. L., RUSSELL, E. Z., SHEPHERD, J. B., STUART, D., and GRAVES,

. R. WORK OF THE UNITED STATES DRY-LAND FIELD STATION, ARDMORE, 8. DAK., 1912 TO
1925. U.S. Dept. Agr. Tech. Bull. 17. 68 p., illus. 1927. For sale by Superintendent
of Documents, Washington, D. C., price 15 cents.

103768°—36 1 i!

Zz CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Reduced appropriations compelled the Bureaus of Plant Industry
and Dairy Industry to close their work at the station in 1932. The
present circular gives the results of the investigations of the Bureau
of Plant Industry from the time they began in 1912, to the time they
were discontinued in 1982.

AGRICULTURAL HISTORY OF THE SECTION

This section was first settled by large cattle companies whose busi-
ness was growing beef cattle on the open range. Later, settlers and
squatters took up favored locations along streams and watercourses.
Some of these settlers produced crops in a small way, but cattle pro-
duction on the open range remained the chief source of income.

The building of railroads into the section in the eighties brought |
about a great increase in homesteading and resulted in the breaking
up of the large cattle companies. Many of the original homesteaders
had no intention of remaining permanently in the country and con-
fined their cultivation to the acreage necessary to obtain title to the
land. Many of those who intended to remain were unfitted both by
temperament and training for the life of a homesteader. As a result,
much land passed into the hands of loan companies and nonresident
owners. Settlement of the country was greatly stimulated during
a series of years of good production. A series of bad years had the
effect of depopulating the section, as very few of the settlers were
financially situated to withstand successive years of crop failure.
The last great wave of settlement was in the years 1905-12. During
this period practically all the remaining land fitted for cultivation
was settled and taken out of the public domain.

Crop production on a large scale was not practiced before 1912.
During the period 1911-15 acreages under the plow were gradually
increased. ‘The stimulation of wartime prices greatly increased pro-
duction during the next few years. The acreage continued to in-
crease during the period 1918-29. The improvement of the farm
tractor and other implements adapted to large-scale production was
responsible for much of the increase. From 1929 to 1932 the acreage
of land under cultivation remained almost stationary. Very little
new land was brought under cultivation, but practically all that had
been broken was planted to crops.

TYPE OF AGRICULTURE PRACTICED

The past 25 years have witnessed a change from livestock produc-
tion on the open range, with a minimum amount of farming, to a
type of farming wherein crop production plays an important part
both as a method of providing feed for livestock and as a source of
cash income. Beef cattle remain the principal item of livestock
production, but hogs and sheep are grown to a lesser extent, and
the majority of farmers milk cows. Dairying as a specialized in-
dustry is carried on by very few individuals.

The present tendency appears to be the consolidation of small
holdings into relatively large farm units, with pasture land and plow
land both contributing to the production of livestock. On nearly all
farms wheat is grown as a cash crop, and in good years an important
part of the farm income is obtained from it,

INVESTIGATIONS AT ARDMORE, S. DAK. a
SOIL CONDITIONS

The soil at the Ardmore station is a heavy clay loam that remains
fairly uniform to a depth of about 15 inches. Below that depth there
is a zone of lime carbonate accumulation that extends to a depth of
about 2 feet. Below that depth the soil remains fairly uniform clay
or gravelly clay until the undecomposed shale is reached, except
where sand or gravel deposits occur. The crop-rotation field is
underlain with a layer of sand and gravel that generally lies at a
depth of between 4 and 5 feet but comes closer to the surface in a
few places. Where the layer of sand is within 2 feet of the surface,
the producing capacity of the soil is drastically lowered. The color
and profile correspond closely to that of the Rosebud series as

mapped by the Bureau of Soils, and so far as essential character-

istics are concerned it can be designated the Rosebud clay loam.

_The experimental plots are located on an upland terrace on which

the soil material had accumulated by deposition from river water.
The terrace is more than 100 feet above the level of Hat Creek.
There is no ground water. The plots do not receive run-off from
adjoining areas, and the nearly level surface does not especially
favor run-off.

The surface soil is tenacious when wet, and when wet or dry,
requires considerable power for cultural operations. The expense of
working the soil makes it necessary to restrict the number of field
operations as much as possible without sacrificing the crop.

CLIMATIC CONDITIONS

The average annual precipitation at Ardmore during the period
covered by these investigations was 15.90 inches (table 1). Of this
amount, 9.81 inches fell during the 4 months April—July and 12.44
inches during the 6 months April-September.

TABLE 1—Precipitation* at the Ardmore station for the 21 years, 1912-32

1
zs
5 a be

Year » | 2 ee el Seer re

Fie ee is a 4 gi 3 E Best isieh ks

| = = > 2 > = me) ° Ke 2 So =

Atos eis Ss 5 pies No silat ae As

Ss cy = < = 5 5 < DM oe) PL, A Ty <

In: \ In. \ En. In. In. In. In In In. In. In In In In
POLO se ee eet |OssOnmelaopur 2.15) ) 0880) }) 1287 -| 1-97 | O883).) 1568) | 0255 | 0! 27 Aly 9.30 | 12.89
HOlG2 es ee .03 | .40 soO a 1252) ) 25045) 159) 4) P578) |) 1523: |) 1450) |) 1:59 .15 | 0.90 9.66 | 13. 23
TIDY, Lag Sele Secor . 02 45 SAA BY GE NAG 2E [PR pm! .49 | 1.79 70.) 4.51 AR -43 | 10.78 | 13.47
RG ee eee . 50 64 .86 | 4.26 | 3.40 | 6.67 | 6.01 | 1.37 | 4.70 . 81 -11 | 1.08 | 26.41 | 30.41
BOGS aoe PAT ABH) .54 | 1.04 | 3.61 | 2.58 | 1.80 | 1.90 02 . 85 . 39 .20 | 10.95 | 13.53
MOU (te Bie Fe ee TaeOOr be OZ a ez e740. O4) akg ek: .47 | 1.99 43 . 67 .18 .70 | 12.68 | 15.81
112 Ae a ly ae 48 | .29 .60 | 2.85 | 5.99 | 1.75 | 3.49 .44 | 3.01 . 45 eb .66 | 17.53 | 20. 26
TG AS tak Spa a ee fe ea {} SOS E2eb 2a 250001 11-50) eo.05 .47 . 38 | 2.10 .78 . 14 | 10.57 | 15. 28
ss tt iS ANE eas} 92 | 3.78 | 5.20 | 3.10 “i | 1.59 .29 | 1.48 .29 31 | 14. 73 | 18.43
TTS ces ok Bie 0 am SS La 07 52 | 241) 4.54 | 1.26 30D . 46 66 . 68 30 9.74 | 12.78
Op) See ara 55 | .14 T | 3:23 | 2.56 | 259 | 4.07 .78 awh 83 | 2.19 41 | 13.38 | 17.50
RG Zo == eee 05 | .30 40 98 | 3.80] 5.93 67 | 32.09) | 1.52") 1.48 .13 .25 | 15.99 | 18.60
HOQAL rs Fee are 02 | .75 70 69 .75 | 1.95 | 2.61 C230 Melee lac . 57 . 44 7.47 | 11.74
HOQ Ge = ee = 29 | .45 42) 1.34 | 2.02 | 4702 | 2.55 SUP- . 70 | 2.45 .32 66 | 11.35 | 15.93
HOJG_ 2 wie. 69 | .12 40 49 | 2.53 | 1.80 | 3:55 | 2.94 | 1.09 | 1.26 | 1.70 09 | 12.40 | 16. 66
IN ( See 22 Seu l14, PAs OGuiSecor loeZzoninascs:. | 2.20) | tel) 1216 515 DAL GWE IRDA PAL
ip a a es 28 28 49 SOT elo2) o100 | o.00 76 . 30 55 14 RIG eLOStonte205
RODS SoS er & 09 Les ote esta 18 eee |) 2390} 149) Qe 74 . 20 .05 | 12.90 | 15.46
OSU Soisae ce 36 18 CST eos h2389) 0 15 24 70),) 8501) | Le10) 193: 68 34 OL LOSS7 | 15571
LOUSY be Se ae Se 02) .36 73 LO ele 13) 89 a0Q| 1. 34 44 | 1.71 .3l 883 Bef O24
LER eee 39 07 (oleae strates to 69 | 1.01 | 2.63 19 95 09 st alee a Se 7/7/
Average____| .34 |: 34 E66 | anOsise- Toll escD | 2e2dt 1 5OFf 13) | e208 47 . 36 | 12. 44 15. 90

1 T=trace.

4 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

The highest. precipitation was 30.41 inches in 1915; the lowest was
9.24 inches in 1931. In only one year, 1915, was the moisture supply
sufficient to mature all crops without drought damage. In several
other years the damage was small, but in the majority of years yields
were sharply reduced by drought, and in a number near failure re-
sulted from severe drought. The ‘normal expectation is for drought
injury at some time during the er owing season.

The fact that the average precipitation is 15.90 inches does not
mean that this is the most “probable amount. In 13 out of 21 years
the rainfall was below the average. In other words, the normal ex-
pectation is for a less-than-average precipitation approximately 60
percent of the time.

Hail played an important part in determining crop yields. Hail-
storms are frequent, but the injured areas are not usually large, and
it is likely that the 15-percent. average hail damage at the station is
not far from the average for the section as a whole. At any rate, the
probability of hail damage 1 is a factor that must be taken into con-
sideration in farming operations in this section.

The average ev aporation for the 6 summer months April-Septem-
ber, was 38.206 inches during the 20 years. that observations were
taken. The highest evaporation was 51.760 inches in 1931, the year
with the lowest precipitation. The lowest evaporation was 28,908
inches in 1915, the year with the highest precipitation. In general,
low precipitation is associated with high evaporation, and high pre-
cipitation with low evaporation.

The temperature at Ardmore is characteristic of the northern Great
Plains. Extremes of temperature are reached, both in summer and
in winter. The lowest temperature recorded at the field station was
—34° F. on January 17, 1916. The highest was 109° on July 25,
1931. In most winters temper atures of —90° or lower are recorded,
but the minimum temperature reached —80° only seven times in
20 years. Temperatures of 100° are reached nearly every year, but
temperatures of 105° or more were recorded on only 18 days in 20
years. Hight of these days were in the exceedingly hot and dry year
of 1931.

In the 21-year period, 1912-32, the average date of the last killing
- frost in spring was May 10 and of the first in autumn September
27. The average frost-free period was 140 days. Frost-free periods
in individual years ranged from 120 days in 1916 to 179 days in
1930.

FIELD CROP INVESTIGATIONS

Crop investigations at Ardmore were divided into three principal
lines: (1) The | production of crops in rotation plots for the purpose
of determining the sequences and cultural methods under which the
staple crops of the section should be grown; (2) growth of crops on
a field scale as a feed-producing enterprise ; and (3) tests of varieties
of grain and forage crops. These three lines of endeavor will be
discussed separately.

CROP ROTATIONS AND CULTURAL METHODS

The crop rotations comprise a study of the effects of different
cultural methods and sequences on the yields of crops. They also

INVESTIGATIONS AT ARDMORE, S. DAK. 4

show the effect of hay crops in rotations and the results that may
be expected from the use of summer-fallow and green-manure crops.
Most of the rotations have been carried on continuously from 1912,
but some rotations were added as the need of studying particular
problems became evident. A few rotations were discontinued after
time had demonstrated their lack of adaptation to the locality. In
1932 there were in operation twelve 2-year, fifteen 3-year, nineteen
4-year, three 5-year, and three 6-year rotations. In addition there
were continuously cropped plots of spring wheat, winter wheat, oats,
barley, corn, and sorgo grown under widely different methods of
soil preparation. Alternately fallowed and cropped plots were also
_ devoted to these same crops. On one set of six plots the effect of
_ delayed seeding of wheat as a means of weed control was studied.
Eight plots were devoted to a study of the effects of different methods
of fallowing. Two plots, one each of spring wheat and winter
- wheat, showed the results from continuous disking.

AVERAGE YIELDS

While the results from crop rotations are intended primarily to
show yields of given crops under given cultural methods, the aver-
age yields of all plots of each crop grown each year give useful
information on the adaptation of the several crops to the section.
Exact comparisons cannot be made with such averages, because the
relative numbers of good and poor methods of production that enter
into them are not the same with all crops. With crops like wheat,
oats, corn, and winter wheat the number of plots is large enough
so that the average yields are fairly accurate measures of the pro-
duction that may be expected. With crops occupying a smaller num-
ber of plots the measure is not so accurate, but in most cases they
occupied a smaller number of plots because they were thought to
be relatively less important, at least in rotations. In some cases,
however, crops occupying a lesser number of plots are important.

The number of plots of the different crops grown in 1932 was as
follows: Spring wheat, 50; delayed-seeding spring wheat, 5; winter
wheat, 17; oats, 40; barley, 10; flax, 4; corn, 44; sorgo, 8; alfalfa, 3;
bromegrass, 5; sweetclover, 4; winter rye, 6; peas, 4; potatoes, 2;
and beans, 2. Twenty-seven plots were fallowed.

The 20-year average yields of the different crops are shown in
table 2. With most crops all the plots are included in the average.
Only one plot of winter rye was harvested for grain. The other
plots do not appear in the average. No peas were harvested. With
hay crops the yield does not include the first year. For example,
with alfalfa the yield given is for second-year and third-year plots,
and does not include the year in which the plot was planted. Only
one plot of sweetclover appears in the average yields, as there was
only one rotation in which a second-year hay crop of sweetclover
was harvested.

5
H
=|
5)
:
gi
rey ‘TIey 0} ONP SeM ZZ6T PUS FIGT UI Sdo1d UreIZ Jo oIM[Ie} ONL, 1
e)
a ZS €°8 8% 1 68 8e9 ‘T CLOT 6LF ‘T Lig ‘T 61 ‘F 928 ‘T € FI 6° 91% 8 ‘Te 0 ‘&I POT conan OG 10 AGU:
A 0 9°8 G% 0 0 COCANT cri aan eee as cL 082 608 GOL 6° e871 08ST 8'F SEOLES Sipsecse= pn ae eas ZR61
0 po 0 r 08 096 | LIE oe me ell OG 089 1 G€6 | Ce 0 gg 0°¢ an 6% Se egeeee pans TS TERE
= 9°9 SL 6° ob ose ‘S VOOLGt ea ae ae 00F 00F “8 GOL ‘T 9g eT L 8&8 I 8% 16 ram yf ae aa monies To OS6I
a) eee ae Cue 6° 6°L11 009 ‘T (N00) ol See gce ‘I 09S ‘% 299 ‘SZ LOL Cal 6 LT I GZ r6 rel oa ee fee 6261
Ce Ue se 8°8 6°L evEl | 006'% | 00L ee OOF ‘T | OFZ‘ | O&6‘T | F 02 8h L ‘16 I ‘OF G06 I GaoRe 4 | Secs ere se en iumeascol
“i eeoriegcea| aso | te ae 9 061 00€ ‘8 WRG co '| Sana ee G2g ‘E ose ‘6 GPF ‘S G98 G6 80g 8 99 9°81 9% Chee SoRseee ek mnaLCOl
Spi, a ee ee ce 9 SLT 0 COCe teoalin ss sean 002 006 ‘ 126 ‘T CTL oT 9 “ST 8 FS VP Cilitse NIGEE Ree SS a nOCOl
ra ERS a kno ae aaa aes Cen Om OSS: 4 pease ae OSF OF6 ‘E £10 ‘% 0'eL a €°ZE 9 Ee Z 01 TL Gresaceey oa SARE
ies aera <a ese eal See O37 00 @ OPP pa aa 00g 060% 826 ‘T vZ 0 IL €€1 £6 Ge: 2 eee ee rege SNE COL
oS Sree | ee ea Te cee OI, OSP ‘ OCT alse tes 092 ‘% OSI ‘2 109 G 62 I ‘I Go EP I 69 PLL PFS 7a eee 8 aRaeECCOl
ger ae aaa er a|p eon S(ERuCS Oe SEOh i =| semen | OOChI 008 ‘F 988 ‘T 8 FI 0 0 0 0 Or pees e te ee COOL
° eee ba[ gee el: ee ae | LOR 004 ‘F OS ‘TE = |7777==-77] 006 ‘T 062 ‘F 916 ‘T 6° 89 PPL QGP 091 9°81 SCS See. eee 1261
re) Po ae eS |e ae | ae Se) Omer (PEEES = liacteerse| Sores OF0 ‘F 099 ‘T € 61 8°9 I Ge 8°99 LG 1 82 fee aed SES Tree 0AB1
pemereeragrr | cae eect ey a Ohabe =|" " or ee Ser ‘T 098 SCI ‘T 796 ‘8 FOS ‘T 6 D6 9°8 £°GS € 81 Qsileeal)s: sec ese SE 6161
= ial Side | ee spe OGL. |e ans ae £80 ‘% 004 ‘F Ost ‘F 002 ‘9 OL ‘% OEE 19 6 68 199 P'6r ONO Sea Sas eS ae ere ee SI6L
On aaa Sale |: sa Me |, ONCOT ss ae ae E8F ‘T 0 006 ‘T OOT ‘8 OF ‘T 6 ‘SI 0's 9 2 SI 6 ClO alee eS ae aE L161
H ce 2g>. tee <a Se | ig GAG “lage ames 196 ‘% 002 ‘2 GZS % OFZ ‘9 G20 ‘E Lice 9 Pb & 8 68 € 18 Teal’ pas eae yo eae 916
Mere: a= % pers pe Seale cer6 Ter aa al OO 9 OOL ‘% OCS | emma --"! 699 ‘8 8°88 881 6 29 GL zee Ope vas Seaee oe a eee ---GT6L
a ey cee | imal: ee ee |r OS0G ena ECT. 0 Sk 3S Seal SLM 0 0 0 0 0 On eee ge FI6I
<q See al See ee || ae Pay sacle aoe sao) 0 0 Ee me LCG 0 0'T PT 86 rT 0% Cama. apeagnens ae Tire acleL
S spoysng | sjaysng | s7aysng | sjaysng | spunod | spunog | spunog | spunod | spunodg | spunog | sjaysng | sjaysng | sjaysng | sjaysng | sjaysng | sjaysng
ie) = SSS 808000606090 EES Ear, | EEE ———__ ——
5 Cyt one sa) IOAO[O sseid oY poe a eee Boy Boum
SBMaE a) ey peal eau (PIO [exop ital \eqeroge | 8 ou sel SsIemy |; 810g |e exe [ee [Kouba | 5980 al corr | amv itg 180 X
E guiidg CAN Pe TAL w109 : ;

or) B§-SI6] ‘suvah OG ay? Lof wo1;M}8 aLoMpsP ay) 1D ppaif Wor1;D7,01-do.19 ay} Ut sjo)d 77D WoOLf spzath asap yonUUD obDLaay—Z% ATAV J,

INVESTIGATIONS AT ARDMORE, S. DAK. 4

The average yield of spring wheat was 3.4 bushels per acre higher
than that of winter wheat. In only 2 years out of 20 did the yield
of winter wheat exceed that of spring wheat. In the fall preceding
each of these years the September precipitation was exceptionally
high. This indicates that if winter wheat is to be grown, it is
likely to be superior to spring wheat only in years following heavy
fall precipitation.

Loss of stand of winter wheat is much more frequently due to soil
blowing in the early spring than to winter-killing. Wheat does not
make enough growth in the fall to form a cover for the soil. Freez-
ing and thawing during the winter put plowed and cultivated soil in

a friable condition that is almost certain to blow enough in the

spring to injure winter wheat in its then weakened state. Winter
wheat offers the greatest chance of success when planted in standing

- cornstalks or in clean grain stubble.

The yields of spring wheat and oats in pounds of grain per acre
do not differ materially. Wheat averaged 984 pounds per acre and
oats 1,018 pounds. As wheat usually is more valuable, pound for
pound, than oats, it is a better crop to grow for sale.

The average acre yield of barley was 1,032 pounds. This is a
little higher than that of oats, but does not represent the true differ-
ence in yield between the two crops. A greater proportion of the
barley plots than of the other principal grain crops were grown under
poor methods of cultivation, and other varieties of barley have been
found to yield more than the ones used in the rotations from 1913
to 1921. A comparison of crops by cultural methods, which appears
in later pages, shows the relative yields of the two crops under
comparable conditions.

The importance of the choice of varieties is shown by a compari-
son of barley and oats. The same variety of oats was used through-
out the 20 years. During the period 1913-21 six-rowed barleys of
the Manchuria type were grown. During this period the average
yields per acre were 1,142 pounds of oats and 965 pounds of barley.
White Smyrna barley was used from 1922 to 1932. During this
period oats produced an average yleld of 915 pounds per acre and
barley 1,090 pounds. The relative producing power of barley as
compared to oats was increased approximately 350 pounds per acre
through the use of a better adapted variety.

Flax produced an average yield of only 3.9 bushels per acre. As
a speculative crop on new breaking, flax sometimes may be very
profitable. It does not seem to be adapted to a regular place in a
permanent farming system in this section.

As only one plot of winter rye was harvested, it must be com-
pared with other grains on the basis of plots grown under the same
type of soil treatment. The 5-year average yield of rye was 8.3
bushels per acre. Winter wheat grown under the same preparation
during the same period of years averaged 7.3 bushels per acre. The
yield of winter rye did not exceed that of winter wheat enough to

make up for the usual difference in price.

The delayed-seeding wheat was produced on a group of plots
handled in exactly the same way as a group of plots on which seed-
ing was done at the normal date, except that seeding was delayed
1 month and the plots were cultivated to destroy weeds before seed-

8 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

ing. The average 5-year yield of the delayed-seeding wheat was 2.8
bushels per acre. The corresponding group of plots seeded at the
normal time produced 7.0 bushels per acre. The destruction of a
crop of weeds did not compensate for the lower yield resulting
from later seeding.

Corn produced an average yield of 14.8 bushels of grain per acre.
This is lower than the yields of small grains. However, in most
years corn produced a fair yield of stover, which gives it a value
beyond its grain production. Corn fits into rotation practice well,
and yields of grain following corn are generally above the average.

Sorgo produced an average yield of 4,159 pounds per acre. This
is far above the yield of any other forage crop. Sorgo has proved
to be a valuable feed for beef cattle and an excellent feed for horses
and other livestock. It apparently deserves a place of much higher
importance in the agriculture of the section than it now occupies.
The factors that seem to limit the acreage in this section are the
necessity for careful cultivation of land to eliminate weeds before
planting and the danger of livestock being poisoned by pasturing
on the stubble in the fall. In spite of these drawbacks, the acreage
of sorgo, the most productive feed crop, could be increased mate-
rially to the advantage of the country.

Experiments described on other pages show that the yields of
grain following sorgo are nearly as high as those following corn.
The value of sorgo as a crop not relished by grasshoppers was demon-
strated in some sections of western South Dakota in 1931.

The average yield of second-year and third-year alfalfa was 1,517
pounds per acre. The yield of third-year alfalfa was higher than
that of second-year. The average second-year and third-year yield
of bromegrass was 1,372 pounds per acre. The yield of third-year
bromegrass was sharply lower than that of second-year bromegrass.
Neither alfalfa nor bromegrass proved adapted to short rotations, but
alfalfa appears to be much better fitted for use in permanent fields.

Growth of medium red clover was discontinued in 1922, after it
had clearly demonstrated its lack of adaptation to the section.

Second-year sweetclover averaged 1,638 pounds of hay per acre
during the period 1920-82. During the same period alfalfa aver-

aged 1,187 pounds per acre. Sweetclover is not adapted to growth —

in permanent fields as a hay crop, because it is a biennial. It fits
into rotation practice much better than alfalfa. Its chief value in
this section, particularly on lighter soils, is as a pasture crop in the
same field with native grasses. At certain stages of growth the
sweetclover is readily eaten by livestock, but sweetclover alone does
not make a desirable pasture for dairy cows.

Potatoes produced an average yield of 83.1 bushels per acre. The
average percentage of marketable tubers did not exceed 70. In
heavy soil, like that at the Ardmore station, the growth of potatoes
beyond the quantity needed for home use is not justified. On lighter
soils potatoes have been much more productive.

Great Northern beans were grown only 3 years. In one of these
years a fair yield was obtained. The other 2 years beans were a
failure, but yields of other crops were also low. Further trials are
necessary to determine if bean production offers a possibility of
success.

INVESTIGATIONS AT ARDMORE, S. DAK. 9
COMPARISON OF FOUR TILLAGE METHODS FOR CROPS GROWN CONTINUOUSLY

Spring wheat, winter wheat, oats, barley, corn, sorgo, and flax
were grown continuously under different methods of cultivation
from 1913 to 1932. The four methods used were spring plowing, fall
plowing, subsoiling, and listing. All plots of a crop were seeded
on the same date with seed of the same variety. The average yields
of each of the crops grown by the different cultivation methods are
shown in table 3.

TABLE 3.—Average acre yields of 7 crops grown continuously under 4 different
_ methods of cultivation at the Ardmore station for the 20 years, 1913-32

Spring plowed Fall plowed Subsoiled Listed
Crop ped ae EB hs OTE ED
Grain Stover | Grain | Stover } Grain Stover | Grain Stover
Bushels | Pounds | Bushels | Pounds | Bushels | Pounds | Bushels | Pounds
Spring wheat__-.......------ Als Bie aes ds AO ME Sess = 2s 10335 |Past see 1H alt) eee See
Winter wihCatewsss-2- esse WS [ee me 27 O Wem eee 2 i UB ras oO te ee nae it ee
CONG Be tg ES eRe eee a BS Q556n eee DARD pas eee: 2UNSh | eee 2 Pee 2000). ies hea
Barley wise 2s lee pa ut 1628) |e eee IQS Op ese Lea ee ee Ae: D0: Sie (esas eee
Wax ee AF EAS ee! WG Jel [apt cS, 326) || poe 4:3: aeeneee® 356h| eee eee!
Gorn sien tek Seek! 15. 2 1, 624 1595 1, 630 14, 2 1, 694 14.0 1, 378
SOLE Qe re ee eae he ee | ee oe BL EBY) |e SOG | ee ee AA Ay) roe ee 4, 478

1 Late-fall plowed.
’ Karly-fall plowed.

The most notable feature of these yields is the comparatively small
differences that resulted from major differences in cultivation meth-
ods. Differences in individual years were sometimes high, but on
the average these differences balanced each other so that, with a few
exceptions, variations in yield in most cases represent no more than
the experimental error.

Since average yields were not materially influenced by the cultiva-
tion method used, it follows that the selection of method may be based
largely-on factors other than yield. The amount of labor involved,
the distribution of labor, and the timeliness of operations should be
the bases for determining the cultivation to be given land.

For example, spring plowing and fall plowing are about equally
productive. There is, however, a limit to the amount of spring plow-
ing that can be done without unduly delaying seeding, and delayed
seeding almost invariably results in reduced yields. To determine
between spring and fall plowing one should decide whether the lesser
amount of power usually required for spring plowing compensates
for the possible loss of yield through later seeding. The fact that the
two methods produce nearly equal average yields permits a wide
latitude in choice. Fall plowing can be done in years when moisture
conditions are such that plowing is not too difficult. If a dry, hard
soil in the fall makes plowing difficult, plowing can be postponed
until spring, with the assurance that no loss in yield will be ex-
perienced, if unfavorable weather does not too long delay seeding.

The fact that subsoiling increases costs without increasing yields
eliminates this method of cultivation.

103768°—37——2

10 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Listing or “busting out” with a lister in the fall for small grains
lessens the expense of fall work but increases the amount of work
necessary to prepare a seedbed in the spring. Listing for corn or
sorgo, where no fall work is done and when the crop is planted with
a lister planter, is much less expensive than plowing. Observations
on corn show a smaller growth of stalks and a lower yield of grain
from listing in good years. The difference in size of stalk is reflected
in the yield of stover. In dry years listed corn generally remains
green longer than surface-planted corn. Listing is not to be recom-
mended on very heavy soils, as the surface is very likely to crust
badly and prevent emergence.

Prior to 1926 the listed sorgo plot was blank-listed in the fall,
and the sorgo was planted in the partly filled furrows the following
spring. From 1926 on listing and planting were done as a single
operation. Observations on listed sorgo since 1926 show less tillering
and a slower growth than for surface planting. Listing for sorgo is
not recommended as far north as Ardmore. 7

It appears certain that sequence plays a more important part in
the production of most crops at Ardmore than does the cultural treat-
ment under which they are grown. When only slight differences in
yield follow such major differences in cultural methods as those
under trial, it seems certain that small differences in cultivation such
as disking after harvest and other similar cultural refinements can-
not materially affect the yields of grain crops.

Continuous cropping to grain for so longa period has been possible
only because certain noxious weeds, such as wild oats, have never
become established in the plots. The continuously cropped fiax plots
were discontinued in 1928 because redroot amaranth (Amaranthus
retroflecus Li.), which does not come up until after the flax has
emerged, had become so prevalent that flax yields on these plots were
near failures. Continuously cropped winter wheat suffered a reduc-
tion in yield in the later years from the prevalence of cornbind
(Polygonum convolwulus L.).

During the first few years, grain grown under a continuous-crop-
ping system produced yields approximately equal to those of grain
following grain in rotations containing a cultivated crop, but later
the yields from continuous cropping were distinctly lower. How-
ever, in the year 1927, when soil moisture was ample throughout
the season, the yields of most grain crops grown continuously were
higher than the average yields of all plots, indicating that the ability
of the soil to produce good yields of these crops had not been
permanently impaired.

COMPARISON OF DIFFERENT METHODS OF PREPARING CORN GROUND FOR SMALL GRAINS

Wheat was grown during the 20-year period on disked corn ground,
fall-plowed corn ground, and spring-plowed corn ground. The aver-
age difference in yield between these methods was less than half a
bushel per acre. ‘This is less than the experimental error. Disking
is the cheapest method of preparing corn ground for a crop, and
there appears to be no reason for plowing corn ground as a prepara-
tion for wheat.

INVESTIGATIONS AT ARDMORE, S. DAK. 11

No oats were grown on fall-plowed corn ground. The average
difference between oats grown on spring-plowed corn ground and
oats on disked corn ground was less than a bushel per acre. As with
wheat, the preceding crop and not the cultural treatment seemed to
determine the yield.

No barley or winter wheat was grown on plowed corn ground.

The average yield of flax was less than a bushel higher on spring-
plowed corn ground than on disked corn ground. This is not enough
to pay the cost of plowing.

It appears that for all grain crops tested, where corn has been
kept clean, disking for grain is preferable to plowing.

COMPARISON OF DISKING AND PLOWING GRAIN STUBBLE FOR SMALL GRAINS

The expense of plowing the heavy soil at Ardmore makes it unde-
‘sirable to plow more frequently than is necessary. The practice of
disking in wheat on wheat stubble is common in the section. Three
rotations were started in 1927 to determine the effect of disking
stubble. Wheat was grown on all plots each year. The essential
difference between the rotations was that in one, plowing was done
every second year; in another, plowing was performed every third
year; and on one plot plowing was eliminated entirely, the wheat
being grown continuously on disked land. For 5 years the average
yield of wheat on continuously disked land was 7.1 bushels per acre.
Where plowing was done every second year, the yield was 8.3 bushels
per acre following plowing and 8.7 bushels on disked land. Where
plowing was done every third year, the yield was 8 bushels per acre
following plowing, 8.5 bushels on first-year disking, and 8.1 bushels
on second-year disking.

The results show that where noxious weeds do not constitute a
problem, disking for at least 2 years may be practiced without mate-
rial loss of yield. On land continuously disked the yields were lower |
in the fourth and fifth years than those on plowed land. The series
of years during which these rotations were conducted was much
below the average in precipitation and crop yields.

A rotation in which corn took the place of the plowed plot in the
3-year rotation was started in 1928 to determine whether one culti-
vated crop in 3 years is sufficient to control weeds. This rotation
was not used long enough for results to be conclusive, but it appears
likely that the method will control weeds fairly well and that the
aggregate yield of the three crops will be higher than in a 3-year
rotation of small grains only.

COMPARISON OF CROPS GROWN UNDER ALTERNATE FALLOW AND CROP SYSTEMS WITH
SAME CROP GROWN CONTINUOUSLY

Yields on fallowed land were obtained during the 20-year period.
With each crop two plots were used, one of which was fallowed
through the season and the other planted to crop. The yields of
grains grown continuously and the yields of the cropped plots in the
alternate fallow and crop series are given in table 4.

12 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

TAPLE 4.—Average acre yields of crops grown continuously and under an
alternate fallow and crop system at the Ardmore station for the 20-year
period, 1913-32

- Continuously Continuously
Aver- cropped Aver- cropped
ae es ase |——_—_—___ pave
Crop yield _ | yield on Crop yield yield on
on fallow on eT | fallow
fallow !| Plots age fallow!} Plots age
yiel yield
Num- Num-
Bushels ber |Bushels| Percent: Bushels ber |Bushels| Percent
Spring wheat__- 172 4 iGo GYAalh (Oforsaise 522s Moe 20. 2 5 14.6 38
Winter wheat___ 17.4 4 8.6 102
Oats eee ee 38. 3 4 23. 2 65 Pounds Pounds
Barleyss. = so. oe Slee 4 18.5 LP AS OL LOS See ee 4, 502 4} 4,082 10
Dlaxed= Se Ee Dao 4 3.7 43

11 plot in each case.
2 Yields of flax are for the years 1916-27.
3 Yields of sorgo are for the years 1916-32.

The yields of spring wheat, oats, and barley averaged from 55 to
71 percent higher when grown on summer-fallowed land than when
continuously cropped. Winter wheat showed a much higher per-
centage increase, but the actual yield on fallowed land was approxi-
mately the same as that of spring wheat. Under continuous -crop-
ping the yields of winter wheat were much lower than those of
spring wheat. The yields of flax were so low that the percentage
increase in yield has little significance. The actual increase was
less than 2 bushels per acre. Cultivated crops showed materially
lower response to fallow than grain crops.

The response of small grains to fallow is as great at Ardmore as
in many sections where summer fallowing is a common practice.
The possibilities of fallow in the agriculture of the section have
been discussed in detail in an earlier publication.?

COMPARISON OF YIELDS OF SMALL GRAINS IN DIFFERENT SEQUENCES

It has been shown that with a few exceptions only minor differ
ences in average yields were obtained through differences in cultiva-
tion, where the crop sequence was the same. The effect of crop
sequence in determining yields is shown in table 5. To reduce the
experimental error due to soil differences, as many plots as possible
were used in determining the averages. The yield of a grain crop
on fallow represents the average yield of all plots of that crop
erown on fallowed land, regardless of whether the fallow appeared
in 2-, 8-, or 4-year rotations. In like manner, the yields on corn
ground include all plots planted on corn ground, regardless of the
length of the rotation or the method of cultivation used. Yields
after small grains include all plots grown after oats, spring wheat;
winter wheat, barley, and flax.

2MaTHEWS, O. R., and CLARK, V. I. SUMMER FALLOW AT.wARDMORE, S. DAK. U. S.
Dept. Agr. Cire. 213, 15 p. 1932. For sale by the Superintendent of Documents, Wash-
ington, Di,©.> Price oO cents.

13

‘CC6L PUB FIGI UI [Ivey Aq poAoIsop sdolg

INVESTIGATIONS AT ARDMORE, S. DAK.

L1¢ | 8% | FOL | 6:92 | 9:09 | 069 | 299 | ¢-ze | o-ue | 92% | e999 | coe | eoze | est | zse] 22 |eir|os9|oorl| rt ioc rai e MOTICA

692 | 9°82 | F'9 | +68 | 62 | 862] 9°99 | C22 | o-zp | e9r | ose | 9:02 | tz} 2 19°09) 9°¢ | Fez] oer) o | 1 Irrcrcroo- doo powani| ‘wpe > ae = Mole
G61 | 81 |o% | Tet | 9'2r | 6216 Lb er ot | 22188 | oor] sir|s9¢| ez |e9¢)0¢ |e) emg) o | 2 \rrcrcrcro suled3 [[vurg

clr |Z} 19 | 962 | OF | 9°92 | 9°62 | zee] 2 -9F | 0 | 6:89 | 0-09 | €99 | z-9e | Bz | Fst | Zor | O-eR | Tien | 90 [rtotrecneee MOTIC

eve | est | te | toe | 222] 1°0F| 919 | e-2z | 6g | cer | 869 | o zr | $19 | 6'€c | 6°99 | 9'FL | Foe | PIS] Fl er. \-croooo do1o poyeary[ng ft -7-----7------= “480
p22 | 6°SL | 2:2 | tet | o'er | 9'ee | 2:29 | 66r | 1 0c | 901 | 6's¢ | 8'6z | 9-29 | Sot | 290 | Tr | 698 | bez | on | et [voce suredd [[BUTS

78l |02 |8e | 991 | 9%) 048 | Ser} az | Fz | Zor | 9c | F ze} ore | oze|zi2|so1|91e|ouelog |@ [non -- AMOTTR AT

Geral tO 12° Oe | 9% | 8% | over | 21 | oz] oo | For | ser lesz | 6st | 8:9 | org |e | F9¢ |. 0. ke ~w lac--y > loro peveammoy|-----=— JVOU[AL 10,0 AA
ge |F2 [st iez itr |2irl|zerio¢o |p. |at |aerles |etz|ou leorlap:|ene| pec) o | ¢ |---ntre- SUIvAS [[BUIg

T6l |Z 2t|%% | 611 | 92 | 8'9¢ | Fee | Gor | 2-81 | set | 2:92 | 8-ze | e-oz | 2 tte | 26 1s et | 9091 a2 bor: I s--o to MOTTC AT

cor | sat) +e | 921 | 91t | ¢-2z| see] e9 | p21] 68 | e'ez | ter | 908 | Zor | zs¢| 96 | 9:82 | 9371 2° | st. \---n--- dow poywantng ¢|--~-----yvoym Suyadg
Oz |ss jez }|o9 }9o9 | eet] pecl|ts |szt}19 | trl 26 |¢o-z|29 |6o2| ez | 6-90) zor] 9:0 | 8 |-------------surel3 [jug

‘ng | ‘ng | ‘ng | ng | ng | ng | ng | ng | ng | ng | ng | neg | ng | ng | cng | cng | ng | ong | ong | con

a3B

- 2)

Moog | ce6L | Teer | oger | ezer | seer | zeer | ozer | szor | reer | ezor | tzer | ozer | eter | ster | zt6r | oter | eter | exer | stora Mean orenntaene doig

128-GI6I ‘savah og ay, sof uornjs LOU pyr a4} 1D Mops pun ‘dowd paywaryjnoa ‘suros6 JJoWs Buimojof sdouo snosa fo spjaih au0p—G @Iav

14 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

The average yield of spring wheat after a cultivated crop was 38
percent higher than following a small-grain crop. This illustrates
the value of a cultivated crop in a rotation, above its value as a crop.
The yield of spring wheat averaged 59 percent higher on fallow than
it did following small:grains. The total production of a farm all
planted to small grain would be higher than that of the same farm if
half of it were planted to grain on fallow and half of it kept fallow.
The value of the fallow lies in the fact that the yield is better dis-
tributed between years, and that the distribution of labor would en-
able one man to handle a larger acreage of land with the same
equipment.

The effectiveness of fallowing in overcoming drought is shown in
the yields by individual years. Not counting the 2 years when hail
totally destroyed crops, spring wheat on fallow produced 10 bushels
or more of grain per acre in all except 3 of the 18 years. During the
same period spring wheat after small grains produced less than 10
aaiae per acre in 10 of the years.

The average yield of winter wheat was 47 percent greater on corn
ground and 109 percent greater on summer fallow than it was fol-
lowing small grain. The apparently greater response of winter wheat
than spring wheat to corn ground and fallow was not due to larger
yields following those preparations but to lower yields following
small grain.

The yield of oats following a cultivated crop exceeded that of oats
after small grains by 18 percent, and the yield on fallow exceeded
that following small grains by 51 percent. The response of oats to a
cultivated crop in the rotation was lower than that of spring wheat.
The response to fallow was nearly the same. The yield of barley
was 84 percent higher after a cultivated crop and 64 percent higher
after fallow than it was after small grains.

The influence of the type of season on crop production is shown by
the production in different crop sequences during different periods
of years. For the purpose of study, the records were divided into
two 10-year periods. During the first period the increase for grain
on fallowed land above that of grain after grain was 45 percent for
spring wheat, 80 percent for winter wheat, 37 percent for oats, and
28 percent for barley. The increase during the second 10-year period
was 76 percent for spring wheat, 158 percent for winter wheat, 66
percent for oats, and 95 percent for barley. The percentage increase
due to fallow during the second 10-year period was double the in-
crease during the first 10-year period. This illustrates the value of
long-time determinations of results. Had the experiments been
~ conducted during only the first 10 years, the results would have been
relatively unfavorable to fallow. Records kept during only the sec-
ond 10 years would have given fallow an importance above its aver-
age deserts. Some of the increase dae the last period may have
been due to better management of the fallow, but the major part
must be attributed to seasonal conditions.

A comparison of crops in terms of pounds per acre instead of by
bushels is made in table 6.

INVESTIGATIONS AT ARDMORE, S. DAK. 15

TABLE 6.—Average annual acre yields (pounds) of crops under 3 different
sequences at the Ardmore station for the 20-year period, 1913-32

Average acre yields

ae Aft ll} After culti

ersma er culti-
grains j|vated crops After fallow

| Pounds Pounds Pounds
| Sphingew Men tears eee. It is Seen een ee a os 7 1, 146
ee ee EAR TIEN olvcto i
ESE E ee Sees Boe ee ps ee ee eee oe tee a eee Es sees ;

I ARC er ae see te ne Ce oS ee ea ee Se eeu a soo ca ae 926 1, 243 1, 522

_ With all crops and for all sequences winter wheat made the
_ lowest yields per acre, spring wheat the second lowest, oats next, and

‘barley the highest. The yield of spring wheat was much higher than
_ that of winter wheat on soil preparations other than fallow. This
indicates that if winter wheat is to be grown at all it should be
grown under the best possible conditions. When grown under ordi-
nary methods, spring wheat is much more productive than winter
wheat.

The relatively low yield of winter wheat on corn stubble is due
partly to soil blowing. Recognition of this fact led to the addition
of a rotation in which winter wheat was planted in standing corn-
stalks. Five years’ results are available from this rotation. During
this period the yield of winter wheat in this rotation was materially
higher than that of winter wheat following harvested corn, and
slightly higher than that of spring wheat on corn ground.

For the period for which records are available, seeding winter
wheat in standing cornstalks offered the greatest possibility of suc-
cess with that crop of any method under trial. All the years in
which this rotation was used were years of drought injury, in which
the snow held by the cornstalks was of material benefit. Without
exception, the stands of wheat in this rotation were better than those
on corn ground from which the corn was harvested with a binder,
the difference in stand being due to lack of injury by soil blowing
in the plot protected by stalks. — :

Oats were more productive than spring wheat in all three se-
quences, the smallest difference being shown on corn ground. ‘The
differences in yield on other methods of cultivation are not great
enough to make up for the difference in price, if grown for sale. The
results clearly indicate that if oats and wheat are both grown, the
corn ground should be planted to wheat.

Barley was more productive than oats in all three sequences. The
difference was much greater after corn and fallow than after small
grain, which indicates that barley should be given the preference in
the better crop sequences. For the 11-year period in which White
Smyrna was used, barley on fallowed land and on corn ground
produced over 500 pounds per acre more than oats on corresponding
methods of cultivation.

Barley is the most productive small-grain crop. The growth of
an adapted variety a barley and the selection of a livestock-pro-

16 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

duction program that will permit the best use of barley as a feed
are steps forward in establishing a well-balanced farm program.

COMPARISON OF SMALL GRAINS GROWN CONTINUOUSLY WiTH SMALL GRAINS FOLLOW-
ING SMALL GRAIN IN 8-YEAR ROTATIONS CONTAINING A CULTIVATED CROP

The 20-year average yields of grains following grains in 3-year
rotations containing a cultivated crop were more than 20 percent
higher than those of grains produced under continuous cropping.
This difference did not appear during the early years of the experi-
ments, but was in evidence from 1916 to 1932. The extent of the
difference varied with the character of the season. In the produc-
tive year of 1927, the yields of grains grown continuously on the same
land were materially higher than those of grains after grain in the
3-year rotations. The same relation appeared for some crops in
1915 and 1918, but the differences were smaller. In general, the
yield of grain after grain in the 3-year rotations showed the greatest
increase over continuous cropping in years in which drought injury
was above the average but not severe enough to cause a nearly com-
plete failure. In productive years the difference was generally
small,

The fact that the same condition was true for all crops makes it
appear positive that the benefit derived from growing a cultivated
crop extends to the second crop following. The carry-over is suffi-
cient to increase yields materially in years of drought injury.

COMPARISON OF YIELDS OF CORN AND SORGO IN DIFFERENT CROP SEQUENCES

The effect of sequence on the yields of corn and sorgo is shown
in table 7. As with small grains, the effect of plot variation is re-
duced by the inclusion of as many plots as possible. For example.
the yield of corn after small grain represents the average yield ob-
tained from all plots where corn followed small grain, regardless
of the length of the rotation, the grain crop, or the method of cultiva-
tion under which the corn was grown. Corn was grown after corn
only under a continuous cropping system, and only one plot was
crown on fallowed land. Sorgo was grown after sorgo only under a
continuous cropping system. Only one plot of sorgo was grown on
fallowed land.

17

‘spunod Fg¢‘¢E ‘OSvs0AG IBOA-G ¢
‘spunod ¢g0‘z ‘esB10A8 IBOA-G |

SS

INVESTIGATIONS AT ARDMORE, S. DAK.

ZOG *Fe|0L8 [006 ‘% |00F ‘b 1000 ‘F |OSL ‘b /0S0 ‘OT|O9T “F J0S0 *F jOSt ‘2 joOF ‘9 l00E ‘F jOcE ‘F |09‘E |000 ‘o |00z ‘9 [OOF Z j009 {9 |---7T) TTT STITT Mone

2380 ‘Frles9 Ieee ‘T jooe ‘Ee loch ‘% \¢22 ‘% |Gz1 ‘6 jOF8‘e \e16‘E |000‘Z |¢ze ‘2 l008 ‘F \ezz ‘F |8ET ‘& |GOL‘E |Sz8‘9 |G2z ‘8 |OST ‘9 J7~7 TTT ina poeges0 3106) Sree OSIO9

COTE CHM ()Q eC Sea Tia OU GeC aA Ce Cal GS ese ce sac, [ase alice tae gee ent age Shee apa ec ee ge [ae wear I Ng ig RE it Ce | an SUIBIZ [[VUIS

€16‘T OST |099 |0€%‘T JO9T ‘Z |OF6 ‘I jOSS ‘T |089 ‘T Jogh ‘% jogs *% OS 002 ‘T \00z ‘% |0S8 ‘I |006 ‘% [000 '% [OOF ‘I \009 ‘% |000 'F jOET IT JOA ‘T [Lf AOTC

8L9°T [OPT 08S |26T 'T Z99 ‘I |P10 ‘I |006‘T |OLb ‘I |8h9‘T OLE ‘T [OE ‘% JOZE“T JOST ‘% j009 ‘T jose ‘T Or6 ‘T |OTS ‘I |086‘% jogo ‘e |r ‘T |988 |¢ beter. UIOD |" ~~ (4904S) TOD

616 ‘T lcte {166 |060‘T |869 ‘2 |890‘z |S69‘e |F80‘% 1690 ‘% \EFO ‘Ss |6F9‘Z \SIh‘T ere ‘T |929‘T |20G ‘T |ZeT ‘2 |For ‘T |ZFO‘S |999‘E [Gh6 2488 |8@ | -~ SuIeId [[BUIS

TEN GEN CTE SIE NTE Ne OPV OG EN SCG NG CI ES C09 eM tT EO) NN I CIE IMT EN STG No C01 los he ee) 9 IEG

Z 06 <i9°8l 69 \0°eS IP BE IL9s |2°6 |2iZ1 1229s |O1t IZ°1E.. |0s: |@ er i226 |S er |9'6c~ |S 9 16°08 ser 0 910 I Sy bs ee AONTBI) (5 Lif

QUE EIQat ela OM Scrl lsiGne cIZCST. \Gusem (Zhe 1ONCTo ILcte siPale Cue “(Sint noun leQke. IPacous | teQtee Omg. |ORGC=uI0 0 g Dee La OO) l= oe a (OTG19) n100 |

CaF CoOL ls Omen |9steeni6 6, «0 0c TSS. |6°1le |S8Cl |Giceen (Cue aI SePe Pa Sie |Z cSlee | uGm Ge GCM Lue lee || pas LGmesl Gece 10 0 Ser Meine as sureis [[eurg

NT NT NT ‘N”T NT ‘NT NT ‘NT NWT NY NT NT NE NY “Ne NT NE” Ng” NT ‘NYT NT “ONT os
1

Osu pogjeur esey[r} be

-19Ay | 861 | TE6T | O€6T | G26T | 8ZET | AZT | QE6T | GZET | FEET | EZOT | V2ET | TEGT | OZGL | GIT | STI | ATT | OTT | IGT | FIGT SI6l |S10ld | pus ‘Aue JI do1p t=

: dojo snolAolg Ss

re

GS-SI6T ‘savah O@ ay? sof
UOUDIS BLOUPLY ay} 70 nopof uo puD ‘paddouo fysnonunuos ‘suvvsb yous buimopjof obsos pun usoo fo spjath a490 yonuun aboiaay—y W1AV J,

18 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Results from the 20-year test show that the average yield of ear
-corn where corn followed a small grain crop was only a little lower
than where corn followed corn, and the yield of stover was materially
higher. The fact that corn stover has some value as a feed makes
it apparent that corn following small grain is at least as valuable
as corn after corn.

Corn on fallowed land produced 42 percent more grain than corn
following small grains. The yield of stover was not increased
through fallowing. It is apparent that fallowing has no place in the
production of corn.

The average yield of sorgo on fallowed land for 17 years was only
a little higher than that of sorgo grown continuously. Sorgo was
grown following small grains for only 5 years. During this period
the average yield exceeded that of sorgo after sorgo. Sorgo should
be grown on land where small grains have been grown, and sorgo
ground should be planted to small grains rather than to grow each
continuously. |

The value of long-time records in determining the response to
cultural methods is again demonstrated in table 7. During the last
5 years of the experiment both corn and sorgo showed a response to
fallow much higher than for the entire period. Experiments con-
ducted during only the last 5 years would be very misleading.

EFFECT OF SOD CROPS ON YIELDS OF SUCCEEDING CROPS

Only two grain crops, oats and flax, were grown on sod land in |
the rotations. For the 20-year period oats following alfalfa produced —
a yield of 20.3 bushels, oats after bromegrass 23 bushels, and oats
after clover or sweetclover 27.1 bushels per acre. The average yield
of oats following any sod crop was less than the yield of oats follow-
ing small grain, the reduction in yield being especially sharp following
alfalfa and bromegrass. These two crops leave the soil so extremely |
dry that the succeeding crop is likely to suffer from drought. Sweet- |
clover, a biennial, usually makes little or no growth following cutting
in its second year, and consequently does not dry the soil so com- —
pletely. Yields of oats after sweetclover were substantially the same —
as after small grains.

A depressing effect on crops following sod sometimes extends into ©
the second and even the third year. In the sod rotations the oats
were followed by corn. Volunteer alfalfa and bromegrass sometimes
persisted in the corn crop and increased the cultivation necessary to
keep the corn clean. In some cases the volunteer growth was suffi- |
cient to reduce the yield of corn. In all rotations containing sod |
crops the yield of corn was lower than the average yield in rotations
not containing sod crops. |

Flax after sod was nearly as productive as in other sequences, but |
flax as a sod crop in a regular rotation was not a success. Good yields —
were occasionally obtained, but many years of failure or nearly com- |
plete failure were recorded. Flax on sod was a complete failure in
the 4 years, 1929-32. |

Low yields of crops following sod crops, and the fact that a year.
is lost in securing a productive stand of the sod crop, make it ap-_
parent that these crops have no place in short rotations,

INVESTIGATIONS AT ARDMORE, S. DAK. 19
; COMPARISON OF YIELDS ON MANURED AND UNMANURED FALLOW

One of the major fields of rotation studies is the cumulative effect
of continuing cultural practices over a long period of years. In-
volved in this is the possibility that rotations in which no fertiliz-
ing material is added to the soil will eventually decrease in yield.
For this reason rotations receiving barnyard manure and rotations
including winter rye, peas, and sweetclover to be plowed under for
green manure were grown in comparison with rotations in which
no such material was added. Im the rotations where manure was
used, it was applied at the beginning of the fallow period to the plot
to be fallowed. This was for the purpose of permitting the manure
to rot and become thoroughly incorporated with the soil before a
crop was grown.

The 20-year average yield of wheat grown on manured fallow was
1.3 bushels per acre more than that on fallow not manured. The
number of plots entering into the comparison was small, and origi-
nal differences in soil may account for much of the difference in
yield. The principal value in manure should be in maintaining or
increasing the fertility of the soil. A study was made of the yields
during the whole period to determine whether the difference in
favor of the manured rotations was greater during the last few
years than it was earlier in the course of the experiments. Results
showed no cumulative effect in favor of the manured rotations.
There were differences from year to year, but as a whole there was
no measurable increase in the differences between the manured and
the unmanured wheat plots during the 20-year period. Results
from individual years indicated that the greatest returns from
manure were obtained in years of good production. In the 11 years
when the yields of wheat were above 20 bushels per acre, the wheat
on manured fallow produced 2.5 bushels more per acre than wheat |
on unmanured fallow. In the years when yields were below 20
bushels per acre, the yields on manured fallow were 0.2 bushel lower
than on unmanured fallow. It appears that the increase in vegetative
_ growth brought about through the use of manure may be detrimental
in years of low precipitation.

Oats on manured fallow yielded 2.3 bushels per acre more than
on unmanured fallow. No increase in the difference appeared dur-
_ing the 20 years. In fact, there appeared to be a tendency for the
_ difference to become less rather than greater. It is safe to say that
no cumulative benefit from manure appeared during the 20 years of
_ the experiment.

In years when oats produced more than 40 bushels per acre the
_ yield was 5 bushels higher on manured than on unmanured fallow.
_In years when production was less than 40 bushels per acre, oats
on manured fallow yielded 0.4 bushel per acre less than on un-
'manured fallow. These differences are almost exactly the same in
pounds per acre as those for wheat. ‘They show that the benefit
from manure is obtained largely in years of good production, and
_ that manure may lower the yields in dry years.

This conclusion is borne out by observations of other fields where
applications of manure were much heavier than in the rotations.
In these fields there was a stimuiation of growth that resulted in

*

20 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

high yields in favorable years. In years when the moisture supply
was insufficient to maintain this growth, these fields suffered more
severely from drought than fields in which no manure was used.

COMPARISON OF YIELDS ON FALLOW WITH YIELDS FOLLOWING A GREEN-MANURE CROP

Yields of wheat obtained from plowing under rye, peas, and sweet-
clover for green manure may be compared to those obtained on sum-
mer-fallowed land in comparable rotations during the 20-year period.
The yields following both rye and peas plowed under approached
but did not quite equal those on fallowed land. The yield after sweet-
clover plowed under was materially lower than that on fallowed land.
It is apparent that any increase in fertility brought about through
plowing under a green-manure crop was counterbalanced by the loss
of moisture used in producing the green manure.

The lower yield after sweetclover was undoubtedly due to a defi-
ciency in moisture. Sweetclover is plowed under later than other
green-manure crops, and when opportunities for moisture storage
are low after the sweetclover has been plowed under, yields the fol-
lowing year are likely to be lowered, particularly in dry years.
Yields following sweetclover were fully as high as following other
green-manure crops in years when the lower moisture storage was
not a limiting factor. ;

The results of the 20 years indicate that no appreciable benefit
had been derived from plowing under green-manure crops. Fer-
tility in the plots not receiving manure was still high enough to
produce good yields under favorable conditions. Moisture rather
than fertility was the limiting factor in crop production, and the
limits set by the relatively low precipitation were such that other fac-
tors had little chance to show their effect.

The difference in favor of bare fallow over green-manure crops
was more pronounced with oats than with wheat. As with wheat
the number of plots that could be compared was small, and experi-
mental error caused by original differences in productivity of the
plots may account for much of the difference. A study of the 20-
years’ record makes it appear certain that no measurable increases in
yields on green-manured land over those on fallowed land took place
during the progress of the experiment.

Summing up the results of the 20-years’ experiment, it may be
stated that cumulative benefits from adding humus to the soil were
not a factor during the course of these experiments. Any beneficial
effect was upon the crop immediately following. Factors other than
fertility played a more important part in determining the yield.

Reduction in yield from practices that tend to deplete the fertility
of the soil were not noticeable where weeds and similar factors not
associated with fertility were kept under control. It may be said
that the effect of any particular crop or method of production did
not make itself evident for a period of more than 3 years, and that
in most cases little effect was noted beyond the first year.

APPLICATION OF RESULTS FROM ROTATIONS

Average results from rotation experiments indicate what may be
expected from the use of certain crop combinations in field practice.
Average yields may not represent the utmost that may be obtained

INVESTIGATIONS AT ARDMORE, S. DAK. 7)
but are sufficient to establish what may reasonably be expected from
different cropping practices.

The choice of crops that a farmer makes depends upon the live-
stock that he raises. The farmer or rancher with a large number of
stock to be wintered should have a considerable acreage of corn or
sorgo, and he may find that a 2-year rotation of a cultivated crop
followed by small grain will about meet his requirements. In such a

_ rotation the grower could reasonably expect an average yield of ap-
_ proximately 14 bushels of ear corn and 1,900 pounds of stover or 2

tons of sorgo fodder on land that had produced grain the year before.

On the land that had been in corn or sorgo the year before, the

average production should be about 16 bushels of wheat, 32 of oats,
or 26 of barley.
A grower with less need for cultivated crops might plant only one-

third of his acreage to them and two-thirds to small grains. In this
ease the expected yield per acre of cultivated crops would be the
same as where half the cropped acreage is in cultivated crops. Half
of the small grain could be expected to yield at the rate following cul-

tivated crops, the other half at the rate following small grains, or

12 bushels for wheat, 27 for oats, and 19 for barley. This is actually
the minimum expectation, as some effect of the cultivated crop would

extend into the second year.

The choice of small grains would depend on the use to which they

are to be put. Wheat normally commands the best price on the mar-
_ ket, and should be the choice when a crop is grown for sale. Barley

is the most productive grain crop and can be depended on to produce
the most feed, and should be grown to the extent that it can be uti-
lized. Oats can be grown to the extent of their use for specialized
classes of livestock.

Modification of the system can be made as required. Sharp reduc-
tion of the livestock may make it desirable to replace part of the ©
acreage of cultivated crops with fallow. Regardless of the combina-
tion, probable average crop yields, as shown in the sequence studies,
should be easily determined.

Wheat, as the cash crop, should be planted where it will have the

least chance of becoming mixed with other crops. Mechanical mix-
ture with other grains is less important with feed crops than with

eash crops.

Alfalfa and similar hay crops are not adapted to growth in rota-
tions, but nearly every farm has favorably situated land on which
they may be grown in comparatively permanent fields.

The first consideration in a farming system should be the produc-
tion of feed suited to the needs of the livestock to be grown. Second-
ary consideration should be given to the production of grain for sale.
During years of good prices, returns from grain farming may be
attractive, but very few farmers not producing livestock have been

able to continue through successive years of drought or low prices.

FIELD TRIALS

_ AVERAGE YTELDS FROM FIELD TRIALS COMPARED WITH AVERAGH YIELDS FROM

ROTATIONS

Crops were grown on a field scale from 1917 to 1932. Production

of crops was for the purpose of furnishing feed for the livestock

D2, CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

on the farm. <A few fields were divided into the required units,
and crops were grown on them in definite rotation. These fields give
continuous records of different crops and can be studied as rotations.
By far the most fields were used as units, and the crops grown
were changed from year to year according to the needs of the live- ~
stock. Corn was grown largely for silage, but in many years some
of the corn was husked. Sorgo was grown both for fodder and
silage. In nearly every year, however, some corn was husked for
grain and some sorgo was grown for fodder.

In most years all the staple crops were grown on some field
or other. While the individual fields do not furnish much in the
line of comparable information, the average yields from all fields
are valuable.

The yields from fields were averaged in order to obtain repre-
sentative figures for the different crops. For example, the yield
for ear corn given in any particular year is the average production
from all fields where the corn was husked. The average yield of
sorgo fodder for any given year is the average of all fields on which
sorgo was harvested for fodder, except field 13, which was located
on soil much less productive than that of any other field and where
difficulty was experienced in obtaining a good stand of sorgo. In
some years only one or two fields were planted to a certain crop.
In another year it may have been grown on 8 or 10 fields. Exactly
the same fields may not appear in the average in any 2 years. Asa
whole, the averages give very good indications of the yields that
may be expected over a number of years by farmers using good
production methods.

Since the purpose was the production of feed for livestock, it
follows that the fields were devoted to five principal crops—corn,
sorgo, oats, barley, and alfalfa. All the yields of these field tests
are shown 'in comparison with the averages of all plots in table 8.

23

INVESTIGATIONS AT ARDMORE, S. DAK.

cept |G2 | 0g 00% ose ‘tT | OOF ‘T | Szo‘e | 002 0S 00g OSG) Cs | O0GeE GE O06: Ge 1ESCl Go. |gen oes OST: Fi) COG ST 5 tire meee ieeserieel emma Ole
Ooh T | OCE‘T | ST BLL 1g8 agg 690‘F | SIZ 628 0cZ | PES | H9F‘E | OCBT | OGLE [-----~ GOUT) CL8r 2 irae aan aeeee «lion PEE
0L6'€ | 0&2 089 ‘T | OOF ‘€ | 099'% | OF@‘E | OSE‘6 | 006° | OF6‘E | 060% |--~-~ > 00g‘ | 062‘h | OFO’® | F968 | O0L‘9 |7-777 7” Oot ‘e | OF ‘9 |-77-""" "401d
L8 ‘6 | ITZ PPL T | €98°€ | 498% | OEE | 0289 | B8L'E | OLS | HEE T | 867 6 | 619‘ | 9e0'9 | 9e0’9 | e0L "9 | 0Z‘L | 919°9 |--"-""" Pel
SPUNO | SPUNOT | SPUNOT | SPUNOT | SPUNOT | SPUND | SPUNOT | SPUNDT | SPUNOT | SPUNDT | SPUNOT | SPUNOT | SPUNDT | SPUNO | SPUNOT | SPUND | SPUNO | SpUNOT | spunvoT 703109
Z “Ge 0'8I | 09 Tee" | 19% | 10h | 8:99 | 8 | O'ee | eer | Ti6s 0 Gt 1899 | Fe | 199 |S: | 868 | ek | 40d
GSE 9° | 0°9 8'8I |972 |60F |929 |97% | 968 | Ser | c:99 0 LOE Gy [10 TH ole S pAb (50509 /OrGL, 2018Y ce | OTL. Ginane cg as
0 °S% fr | 99 LEGG VB LNs = S| LEZ | 8.09 Sel OStet Bree sagt NNGUEy We | nema melt es ot nie © Titel bokeh. bases SR SR MAC ak [ge tele |e amd,
908 r02 «=| 9°9 €'6Gret | SAUTE: OST [eer 20 | UOT he 0E | OCD aleTeOG . eeu all eee [mat al et yaaa, Lice | pan peri ae lee ie eee PPA
:AOLIVE
0°91 OS | ree 9€ Ol GS} Pn0Cme 50 G8: KCaT Tee |ROKEL anal pac GGG! Sal i8) Vio egos co) GiCG, all apace We 1.20, @\ NG) SEs. | pegeugendOld
ers) ag 0 0 Lv OrCT = (50106 | TOle unord 0 87 |CI | 69 (OR AG SNS CA ARG Sipe 0% 21906 | s PIO
S]AYSNET | SPAYSN | SpaysSN | spaysng | sjaysng | sjaysng | sjaysng_ | spaysng | spaysng | saysng | spaysng | spaysng_ | sjaysng | spaysng | spaysng | sjaysng | spaysng | speysng | spaysng *100
OsvIOAV) ZE6I | TE6I | Of6 | G626T | S26I | Z26I | 926 | G26E | FOOL | EEL | S26 | T26E | O@6I | GIGT | BGI | 2T6L | 916E | SI6T do19
68 —GI6T

‘sipah 9] ay} of Uo1jn}s aLowpspy ay) 1D 807d 7) fo spjarh asp ponNUUD abd..aaD YUN paLodwod s7}sa) pray 70 fo spjath asap JoNUUD abv.iaay—3 ATAV J,

QA CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

The average yield of all plots as given here is not exactly the same
as given in table 2, as all years are not included in the average. For
example, barley represents an average of the last 9 years only, be-
cause barley was not grown on a field scale prior to 1923. With corn
the year 1917 is omitted, because no field was harvested as ear corn
in that year. In other words, average yields of plots appear for only
those years in which comparable fields were harvested.

The most striking feature of the results is the fact that crops
grown on a field scale produced yields nearly as high as and in some
eases higher than those obtained on the plots. This result was
hardly expected as the rotations were on land slightly above the
average of the whole farm in general productiveness.

The greatest difference in favor of the plot yields was with corn.
Part of the difference was real, but part of it was due to the fact that
corn was grown largely for silage, and the most productive fields
were generally put in the silo. Corn harvested for grain, except for
one or two fields, was the portion of the crop not needed for silage.

The average yields of sorgo on plots and on fields were nearly
equal although much variation between plots and fields was shown
in individual years. In 1917 and 1928 all fields of sorgo were har-
vested as silage, and no yields of air-dry fodder were obtained.

The yield of oats on plots exceeded that of oats in fields, but the
difference was not great.

Barley in fields produced a higher yield than barley in plots. This
is accounted for by the fact that a proportionately high number of
barley plots was grown under poor conditions. In the fields barley
was generally grown after a cultivated crop or on fallowed land.

The average yields of alfalfa from fields and plots were practically
equal, although there were material differences in individual years.
The yields of alfalfa on plots were the yields obtained the second
and third years after planting. The yields from fields generally rep-
resent those of established fields that were kept in alfalfa for longer
periods of time. Yields from plots are sometimes much higher, but
this is balanced by the fact that failure to obtain a good stand some-
times reduced the yields of plots.

Alfalfa in fields was usually stacked in the field and weighed when
hauled. There was always a certain amount of loss from weathering.
If the weights had been obtained when the alfalfa was stacked, the
field yields would have exceeded the plot yields, which averaged |
nearly three-fourths of a ton per acre.

The comparative figures as a whole indicate that farmers should
be able to obtain average yields at least as high as the averages of
all plots. :

Figures on crops harvested for silage are not given in table 8,
because none of the rotation plots were harvested for silage, but it
can be stated that there never was a total failure of corn or sorgo
for silage in the 20 years that the station operated. In such years
as 1917, 1930, and 1931 the silo utilized a crop of corn that would
have been worthless for husking.

Results of fields also show the possibility of successive years of
low yields and the desirability of carrying over grain reserves from
years of good production.

INVESTIGATIONS AT ARDMORE, S. DAK. 25
COMPARISON OF CORN AND SORGO AS PREPARATIONS FOR WHEAT AND OATS

The value of a cultivated crop in rotations is determined to a
considerable extent by the yields of grains following it. Results show
that sorgo as a crop is well adapted to the section. The question
arises whether yields of grain crops following sorgo are likely to
be lower than following corn. For the purpose of determining the
fact, four 2-year rotations were established in small fields in 1916.
In all of these rotations the grain was grown on disked corn or
sorgo stubble and the cultivated crop on fall-plowed grain land.
The rotations were as follows: Corn and wheat, sorgo and wheat,
corn and oats, and sorgo and oats.

The yields of grain in these rotations are given in table 9. The
. year 1916 is not included, because the preceding crop and preparation
were uniform.

TABLE 9.—Annual and average acre yields of wheat and oats following corn and
sorgo at the Ardmore station for the 16 years, 1917-32

Crop : 1917]1918]1919} 1920) 1921) 19221) 1923) 1924] 1925] 1926} 1927/1928/1929)1930|1931|1932 ne

Bu.| Bu.| Bu.| Bu.| Bu.| Bu. | Bu.| Bu.| Bu.| Bu.| Bu.) Bu.| Bu.| Bu.|Bu.|Bu.| Bu.

Wheat following corn___| 6. 8/35. 2|15. 9/18. 5|17. 7 0)23. 9} 7. 1/20. 0}10. 2/23. 6/17. 511. 9}11. 9] 4.5) 7.2) 14.5
Wheat following sorgo__}| 4. 8/24. 6/14. 5/28. 6/13. 1 0} 22. 4/10. 0}15. 7/13. 0)19. 8}17. 9)12. 6}11. 4) 2.6)10. 7} 13.9
Oats following corn____- 24. 3)57. 2)19. 3}43. 9/41. 1 0/63. 8)12. 8]32. 4122. 7/39. 9137. 9)17. 5/30. 8/10. 7/22. 5| 29.8
Oats following sorgo__-__|26. 0/61. 1/20. 4/58. 7/24. 4 0/60. 2)16. 0/37. 7/22. 5)55. 6/39. 2)18. 0/27. 8} 2.8/24.8) 31.0

1 Crops destroyed by hail.

The averages indicate that the yields of grain following sorgo may
be expected to equal or nearly equal those obtained on corn ground.
The reiative acreages of corn and sorgo should be determined from
the value of the crops themselves, without reference to the yield of
grain that may be grown following them.

FEED-CROP ROTATIONS

A rotation to determine whether a more certain production of feed
could be assured through a definite rotation was started in 1916.
This rotation contained sorgo, corn, oats, and fallow, the fallow being
heavily manured. The heavy application of manure was designed
not only to show the effect of manure on crop production, but to
determine whether it would correct a bad physical condition of the
soul.

The soil at the time the experiment was started contained many
aikalied or slick spots that crusted badly on drying and prevented
emergence of crops. The quantity of manure added to this field was
sufficient to correct this condition, and when the work ended in 1932
the soil appeared to be as mellow and to cultivate as readily as that
of some of the more favorably situated fields. The manure induced
a heavier vegetative growth of grains than was noted on fields not
recelving manure. In good years this resulted in increased yields,
but in some adverse years it reduced them. In 1927, when moisture
for small-grain production was ample, the yield of oats from this

26 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

rotation was very high. In 1930, overstimulation of the oats in its
early stages of growth resulted in a complete failure to produce grain
when severe drought checked the growth of the crop before grain
had started to form. ~
The yields of oats, corn, and sorgo in this field for 16 years are
given in table 10. The sorgo was harvested for fodder in 1930 and
1931. Green weights for those years were computed from the dry
weight.

TABLE 10.—Acre yields of crops in a 4-year field rotation at the Ardmore station
for the 16 years, 1917-32

|

Crop | 1917 | 1918 | 1919 | 1920 | 1921 | 1922 | 1923 | 1924 | 1995
}

|
| Pounds| Pounds Pounds) Pola Pinta Pounds| Pounds) Pounds| Pounds

Cornih. 28s. <1 eee 5,087 | 15,741 | 4,441 | 7,567 | 4,390) 3,915 | 11,689 koe: = 4, 460
SYP SUT Ve es ee pe ee 10, 799 | 17,693 | 10,661 | 11,841 7,695 ' 10,451 | 17, 213 | 8, 27 13, 003
| Bushels Bushels| Bushels Pubes) Bushels euiels Bushels —- Bushels

15. 2 59. 6

See Oe eee 16.7| 70.2) 25) 352 | 47-2) 20) 65.1

1928 | 1929 | 1930 | 1931 | jae) Sve

| Pou sata pacers | peta Prasat Pounds| Pounds) Pounds) Pound:

Gorn 85: Bice 3 he das fee Be | 9,418 | 10,175 | 8, 766 4, 433 | 3,902 | 2,000 | 6, 445
STs pe ee eS ee 17, 075 | 25, 497 14,115 | 9,555 | 14,375 | 8,060} 1,762} 12,379
| Bushels| Bushels| Bushels| Bushels Bushels Bushels| Bushels| Bushels

'
i '
U

Oats te ’snla ts og no. 5 cpl sats 8 34.0} 85.7] aad at 30 aN aie 36.3
2)

1 Total green weight. _
2 Crop destroyed by hail.
3 No grain produced because of drought.

Corn and sorgo were harvested for silage. The sorgo was grown
on manured fallow in this rotation. However, the yield of sorgo
in this rotation was not materially higher than the yields in other
fields. The air-dry weight of sorgo mature enough for silage is
approximately one- “third of the green weight. On this basis, the
average yield of air-dry stover was approximately 2 toms per acre.

The results indicate’ that dependable yields of feed crops can
be obtained throughout a period of years. Oats failed to produce
grain in 2 years. ‘In one of these, 1922, hail destroyed the crop. In
1930 no grain was produced because of drought following a period
of heavy early growth. In that year the oats were cut for hay
after it appeared certain that no grain would be produced, and a
hay yield of more than 1.5 tons per acre was obtained. In some of
the years when ‘the yields of grain were low, good farming practice
would have dictated cutting the crop for hay. Yields of grain are
so varied that a carry-over from years of good production is
necessary.

Sorgo and corn never were complete failures during the 16-year
period. In 1922, when small-grain crops were a total loss, sorgo
recovered sufficiently to produce a yield of over 5 tons, green weight,
per acre. The value of a crop like sorgo in such years cannot
be overestimated. In only one year after ‘this rotation was started
was the yield of sorgo for silage less than 7,500 pounds per acre.
Calculated as dry fodder, the average yield of sorgo was nearly 2

é

_

INVESTIGATIONS AT ARDMORE, S. DAK. 27

tons per acre, and only once was the yield less than 1 ton. In feeding
tests with steers conducted at the station, sorgo closely approached
alfalfa in feeding value. The dependable production of nearly 2
tons of feed per acre is of great value in a livestock-production
program.

No total failure of the corn crop occurred during the period of
the experiments, but there were several years when little or no ear
corn was produced. The silage production of corn was only about
half as high as that of sorgo, and the difference in favor of sorgo
was greater in poor than in good years. Sorgo is the more produc-
_ tive feed crop, but corn is more valuable in years when a good crop
of ear corn is produced. The greater ease of handling a corn crop
and the need for ear corn for feed make corn the preferred cultivated
crop. It is believed, however, that part of the corn acreage could
be advantageously planted to sorgo.

In the field rotation just described, the sorgo was grown on fal-
lowed land and the corn or sorgo land. Since its yields are in-
creased by the use of fallow, sorgo had the preferred place in the
rotation. In 1924 a new field rotation was started in which the corn
followed manured fallow and the sorgo was grown on corn ground.
In this rotation the sorgo was planted with a lister from 1927 to
1932. The yield of corn was proportionately greater than on the
rotation previously described, and the yield of sorgo was smaller.
The production of sorgo, however, remained higher than that of
corn, in spite of the fact that sorgo does not do its best in this
locality when planted with a liter.

Both of these rotations show that a fairly dependable production
of feed may be obtained from corn and sorgo, and that good grain
yields can be produced in most years. Neither of the rotations is the
best that could be selected for general farm use. One cannot afford
to grow corn after sorgo or sorgo after corn. Yields of small-grain
crops are higher after a cultivated crop than after small grain. On
the other hand corn and sorgo yield no more after cultivated crops
than they do following small grain. Results obtained from rotations
indicate that both corn and sorgo should be followed by small grain,
the kind to be grown depending on the disposal to be wriaete of
the crop.

The ef for barley for feed led to the establishment of a field of
alternate barley and manured fallow in 1926. In this rotation the
fields were 10 acres in size. The yield was below 25 bushels per
acre in only 1 of the 6 years, 1927-32, and averaged 387.7 bushels.
During the same years the average yield of barley from all plots
was 24 bushels per acre. The average yield of all plots was below 25
bushels in 3 of the 6 years. Yields indicate that the same surety of
production may be expected from fields as from plots. They also
show that in years of exceedingly severe drought, such as 1931, even
grain on fallowed land may fail to produce a crop worth harvesting.

VARIETAL TESTS

Varietal tests with grasses and forage crops were started in 1914.
Forage-crop tests were carried on consistently, except for 3 years

28 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

when no variety tests were conducted. Grain variety tests were
continuous from 1923 to 1932. The number of varieties was in-
creased in 1926. From 1929 to 1932 the 10 varieties of wheat in-
cluded in the uniform variety test conducted by the Division of
Cereal Crops and Diseases were grown in cooperation with that Di-
vision. Wheat varieties in other years, and other crops in all years,
were grown under informal cooperation with divisions of the Bureau
of Plant Industry.

The extreme importance of selection of varieties of grain to be
grown in this section is shown by the tables for wheat, oats, and
barley. Differences in yield between varieties of the same crop
grown under identical conditions frequently exceed differences ob-
tained under different crop sequences. For example, the difference
in yield between White Smyrna and Coast barley, a variety of the
type most widely grown, is greater than the difference between
barley grown on corn ground and that grown on summer fallow.
Poorly adapted varieties, like Hannchen, may yield only about half
as much as better adapted varieties. No variety of oats is so out-
standing as White Smyrna is among the barleys, but the loss in
- yield that could be experienced through the selection of a midseason
variety like Swedish Select is clearly apparent. :

With both barley and oats, earliness is an important factor. No
late variety of either oats or barley produced yields comparable with
those of earlier varieties. The early varieties are comparatively
more productive in dry years than later varieties. Selection of the
variety to be grown plays an important part in distributing pro-
duction between years.

The wheat varieties tested were more uniform in yield than other
grains, but even with wheat the selection of a good or a poorly
adapted variety may change the yield 20 percent or more.

Variety tests of small grains were generally conducted on corn
ground under uniform conditions. Comparison of the best varieties
can be made to determine the relative productive capacity of the
different crops. Kubanka wheat, Brunker oats; and White Smyrna
barley were the most productive varieties during the period
1926-32. In pounds per acre the comparative yields of crops as
represented by these varieties were 852 pounds for wheat, 986 pounds
for oats, and 1,243 pounds for barley. These results are in harmony
with those obtained in rotation studies.

WHEAT VARIETIES

Table 11 gives the annual and average yields of wheat varieties
from 1923 to 1932. With each variety, the yield for each year is the
average of three plots.

INVESTIGATIONS AT ARDMORE, S. DAK. 29

TABLE 11.—Annual and average acre yields of wheat varieties at the Ardmore
station for the 10 years, 1923-32

Average
In per-
CI centage
Class and variety oul 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | 1930 | 1931 | 1932 of Mar-
; 1923-|1926—| quis
32 | 32 | during
com-
parable
years
' Hard red spring: Bu. | Bu. | Bu. | Bu. | Bu. | Bu. | Bu. | Bu. | Bu.| Bu.| Bu. | Bu.
Rewards) 22s 2s SIS) ees Le Se eee bey Be GreK ORL Tb 248 |Pe5AS Sse 2 ees 173
Double Cross II-
21-47 (Minn.
PAN) oe eee 1 OOO | Secee es | eres | eres eee ad eee (Slax | ee G4 | eee ee 161
> Marquillo____.___- GSSF aes ee | ee ee Bee | ee eee OL. G83 Bits] ee 0 fee eee 135
ope 2s 2s eh S178 | Soe Ee res |e eee EEE eA ORS aa .6 STi es | 125
InGIR Ca 731 0|seae |e |e We OlBSS8Glez255|) 982 1053/— ali, 12 9/sa 12.9 119
Ceres a8 i ee 6900 | 22 ee | eres Ace Gao Oo s2 EOL GSOle tls 4 eZ Soo| pee 12.7 117
Mar quisse2= es 3641| 27.8] 1.7] 22.7)- 8.5] 32.2! 20.0) 5.8] 7.5 .6| 1.4} 12.8] 10.9 100
Supremes sense es SOZ6 |e ee es ae SI es 2es WETS. Ole Selle Oxi AS | oe eee an | ee 99
= Olas se sesso e es 5878) 20.7} 4.5] 13.0} 7.5) 24.5] 18.9} 8.3) 8.6 28)P 455) 1121) 10:4 87
urum:
INOodaks as Taree G519 ie serps S. Sa eA 7a Olea Selle S23 |e oe ang | eee es ee 124
Kerbanka sts. ees 1440) 24.4) 4.7) 18.3} 11.2} 40.0) 21.1] 10.3] 8.6) 2.2! 5.7) 14.7) 14.2 114
INGE a ee 5284192599 | 4a) dee Tilda Si 4a5Oe Oral. TAS eagle 2 eee pe ates hs 111
IRelisseeet see lee 1584} 27.0) 3.4] 18.3) 5.2} 40.3] 16.9} 10.3] 10.1) 1.4] 3.5] 13.6) 12.5 106
IM OTC PPO a 2 OG | emer te | eee | em eters |e n eMac 14.8) 6.9) 9.4 TO ANG eee = | poe 103

Marquis wheat was grown continuously in these trials and affords
a standard by which to measure other varieties. It is the variety of
wheat most commonly grown in the section, and a new variety must
be superior to Marquis to warrant a place in the crop program.

KXota proved to be less productive than Marquis over the 10-year
period. There were no years of heavy stem rust infection, so rust
resistance was not an important factor in determining yields. It is
noteworthy that Kota produced higher yields than Marquis in dry
years when there was little or no rust infection, and produced lower
yields in years more favorable to stem rust. For the period as a
whole, Marquis was distinctly superior to Kota.

Ceres and Reliance were practically equal in yield, and both were
more productive than Marquis during the 7 years that they were
under trial. As stated before, there were no years when yields
were noticeably lowered by stem rust, so the difference was not due to
rust resistance. In 6 of the 7 years both of these varieties equaled or
exceeded Marquis in yield.

The varieties grown only since 1929 had no opportunity to show
their production in favorable seasons. Yields of all varieties were
so low that large percentage gains mean little, and none of these
varieties can be recommended without being tried in years of good
production. Reward appears to be the most promising. During 1931
and 1932 its earliness was the principal factor in producing yields
above the average. Hope lacks heat resistance and produced lower
yields and a poorer quality of grain during the time 1t was grown
than Ceres, Reliance, Marquillo, or Reward. All the hard red spring
varieties grown from 1930 to 1932, except Hope and Supreme, are
worthy of further trial in the section,

30 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Kubanka wheat was one of the best yielding durum wheats. Its
quality for the manufacture of semolina and macaroni and its wide
distribution make it the best variety. Kubanka exceeded all durum
varieties except Nodak in yield. Its much better qualities make it
more valuable than Nodak.

During the period 1926-82 Reliance, the best yielding variety of
hard red spring wheat, produced an average yield of 12.9 bushels per
acre. During the same period Kubanka, the highest yielding durum
wheat, produced an average yield of 14.2 bushels per acre. The dif-
ference in yield in favor of Kubanka was not proportionately so high
as the price difference in favor of hard red spring wheat. When
any great margin in price exists, it more than makes up for the
higher yield of durum wheat. ;

OAT VARIETIES

Comparative yields of oats are shown in table 12. Sixty-Day was
used as a standard for measuring other varieties.

TABLE 12.—Annual and average acre yields of oat varieties at the Ardmore:
station for the 10 years, 1923-32

Average
Tn per-
Gui centage .
Group and variety * ~* | 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | 1930 | 1931 | 1932 of Six-
ek 1923-|1926-| ty-Day
32 | 32 | during
com-
parable
years
Early white: Bu.| Bu.| Bu.| Bu.| Bu.| Bu.| Bu. | Bu.| Bu.| Bu.| Bu.| Bu.
Copher === 2027) sa eer | peer 18.1) 85.9) 35.4) 9.9) 23.7) 1.1] 25. 3]-.-.- 28.5 107
VOW at ee RAT eet | re ee | eres 18.1) 88. 5} 31.8)" 7.8) 15.1) V2 0) 21. 1)-- 22 26. 2 98
Nebraska No. 21_-_]| 841] 52.0/_____ 40%6) On 174903183) 7a 2/16! 9) Ree | ee Seek eee 92
Early yellow:
Richland! 22-3 TSG ek S| ees Ee eee LE eee ee 256) 92166 eee |e 106
SixtiveD ayers = == 165) 52.9} 4.2] 36.9) 21.6} 75.0] 34.9} 16.7) 15.4 5| 22.4] 28.1) 26.6 100
Burt X Sixty-Day- COPA (eae [sa a Min 21.3) 67.7) 29.2) 10.4) 24.5} 1.0 Olt eraer 25.8 97
Marly reds brunker2es)|| (2054) 22222 |a2 Ssh 21, 3) 80. 2| 33.8} 19.3} 27. 1) 2:6) 31. 1)__-2- 30.8 115
Midseason white:
Swedish Select. --- 134) 41.3} 1.5] 20.0] 0 64.0] 25.5) 4.2) 5.2) 2.1) 12.5} 17.6] 16.2 63
Midseason yellow:
Miarktonee- 2 ea 21) 53 | | eee | ee 26n3| “OM roona | eon ce LOLs) Osa 20NG | nee 25. 4 95
Golden Rain-_--_-_- 493] 45.2] 3.1] 35.0} 0 6630 | 22686 |h 5:2], 0256) eer ee eee eee ee 71
Hull-less:1 Fowlds__--| 1996/_-_-- AS24050) 9X41) GOS9|S26RG]|, (Se ao 5:| |e | eee ee 78

1 Calculated at 32 pounds to the bushel.

Brunker was the outstanding variety of oats. During the 6-year
period this variety produced an average yield 4.2 bushels per acre
higher than Sixty-Day, and in dry years the grain was generally
of better quality. In the very dry years, 1931 and 1932, Brunker
was the only variety of oats that produced grain weighing more
than 32 pounds per bushel. |

Gopher oats were less productive than Brunker but were consider-
ably better than other varieties. During the 6-year period they pro-
duced an average yield of 28.5 bushels per acre. Three other varieties
of oats, Iowar, Burt X Sixty-Day, and Markton, produced yields
closely approaching each other but all lower than Gopher. Very ht-

INVESTIGATIONS AT ARDMORE, S. DAK. 31

tle oat smut appeared during the variety test, and the smut resistance
of Markton was not a factor in influencing yield.

Midseason varieties were uniformly unproductive. Swedish Select,
the only midseason variety grown continuously, produced 17.6 bushels
per acre during the 10-year period as compared with 28.1 bushels for
Sixty-Day over the same period.

Brunker appears to be the variety best suited to this section, and
its Increase is recommended.

BARLEY VARIETIES

The yields of barley varieties during the period 1923-32 are shown

in table 18.

TABLE 13.—Annual and average acre yields of barley varieties at the Ardmore
station for the 10 years, 1923-32

Average
|
In per-
centage
Variety Cod 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | 1930 | 1931 | 1932 oe
1923-/1926-

32 [agee ae
during
compa-
rable

ch years

Bu.! Bu.| Bu.| Bu.| Bu.| Bu.| Bu.| Bu.| Bu.| Bu.| Bu.| Bu. | Percent

JC pe Eee ea Sere TUS 5 | ee re | aie | ee ZARG ud eZON cee Os | elon || eee 104
White Smyrna_-____--_ 658} 38.0) 2.8] 44.2) 27.7) 67.0] 25.3] 18.4} 24.1] 0 18.9] 26.6] 25.9 100
War ehine 2223s ey 3G 7| ee | aa CI |e ee IL, Gyr PRS BY eis; Antes Ae ee 90
reise eset ae ek 936} 52.6} 3.3} 31.3] 10.6) 68.1] 19.4! 12.8] 16.3) 2.8] 9.0) 22.6) 19.9 85
HMormt252 2.3 en aes! O26) St | Serene. aes MOL O25 5 A W255 ONT AQ Aiey Ss Sie = 21.7 84
Odessanektar ules oe 182} 47.4) 1.8) 23.3) 11.5) 73.3] 20.5) 4.2) 16.9) 2.8) 65.7} 20.7) 19.3 78
Coast. Oe RA Ae 690 tse | See 16. 5} 50.0) 21.2) 17.0} 17.0] 0 259 se 2 19. 2 74
White Gatami_______- SPAN SE) ab SS] DRL RY CLAY ZO aIZACON TEE aie ee || te Se ee ee 65
Glabron_\ 42 3-3 LAG V TN acl [ace cee Rol | BA I Ed | LL HOS St PA ba si7d eh 61
orsfordass228 es 0 7i| Petes eles PD, BY) AEA Ea TG. BY GC) Tai ae et 58
Hannchen= 52s z= Bad 2473 le 2. SIZ Ol Oe Ne6459| i7ze7) S51 3.1) 0 0 14. 4] 12.7 54
Wielivetti 2 Ss ee 4252|Ss0e— | mien ae | CE ES Ee Se BF Ce Le ae 1FS|' S150) 45] ee eee 31

White Smyrna (C. I. 658) was outstandingly more productive than
other varieties. During the period 1926-32, its average yield was 4.2
bushels per acre higher than that of any other variety. Ace, a variety
grown from 1928 to 1932, equalled White Smyrna in yield. This
variety is a selection of White Smyrna and was grown under the
impression that it was taller, but it proved to be shorter than White
Smyrna. As one of the principal objections to White Smyrna is its
short straw, Ace appears to be no improvement.

Vaughn barley, a short, stiff-strawed, six-rowed variety, produced
yields approaching those of White Smyrna during the 4 years it was
grown. It may be valuable for replacing White Smyrna on soils
where that variety lodges. Without production data during good
years, it is impossible to tell to what extent Vaughn will respond to
more favorable conditions.

In nearly all years a good quality of grain was obtained from
White Smyrna, even in years when many other varieties produced
shriveled grain. The dependable production and good quality of

a2 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

grain apeabea! by White Smyrna make it the variety best nigend
to this section of those under trial. In spite of this fact, the acreage
of White Smyrna has not increased rapidly. Its ragged appearance
in the field ae a prejudice against it.

FLAX VARIETIES

Flax varieties were grown in 1930 and 1931. The crop was a com-
plete failure in 1931. In 1930 yields were too low to be significant.

CORN VARIETIES GROWN FOR GRAIN

Corn varieties were grown for grain production during the years
1923-82. There was little to choose from in yield between several of
the early varieties of dent corn and some of the flint corns. North-
western Dent, Payne White Dent, Falconer, Alta, Gehu Flint, Mercer
Flint, and White Flour corn may be depended on to mature every
year. Later varieties do not mature on heavy soil like that at
Ardmore but do mature on lghter soils within the section.

Corn varieties do not have the fixed characteristics of small-grain
varieties. The date of ripening, height of ear, and many other char-
acteristics may be greatly changed by selection. Two strains of the
same variety ror different localities may exhibit markedly different
characteristics. The source of the seed used in a variety test is often
a stronger factor than the variety in determining yield, and the
results of variety tests may be misleading.

For this reason no table of corn yields is included. Adapted strains
that have been produced locally for a number of years are likely to
be more productive than corn brought in from a distance. Since
maturity is an important factor, if corn seed is introduced an effort
~hould be made to procure it from a source where the season is as
short as or shorter than the season where the crop is to be grown.

CORN VARIETIES GROWN FOR SILAGE

Varietal tests of corn for silage were conducted from 1923 to 1981.
Results are given in table 14. In most years sunflowers and Dakota
Amber sorgo were grown for comparison. Sunflowers were discon-
tinued after 1929. They were less productive than some varieties
of corn and contained much less dry matter. In some years they
were too immature to make silage of good quality.

33

Na
-
Q
nN
on
cc
a 26 8 826 ‘OL | _88L°% 096 ‘F 802 ‘ POSES OG Oe SS ae 002 °2 OO Cll | seit ca |e Bios so eee Joqury B1OABC :0810g
= 96 8 OLO nO iS ge ee |e ee 802 ‘9 920 ‘IL Ch9 ‘GZ 068 ‘IL 009 ‘9 028 ‘8 096 ‘2 OSORCe eine: a En sioMopung
Q 1g. 9 G2g ‘¢ LLL 009 ‘% 199 9 006 ‘2 08s ‘OL G29 ‘Fb ee lames ee tad Oslin ee a lng|| in ea a ee ee ILA NyeH
a 619 Or cer 9 SBI '€ 062 ‘b G18 ‘9 ge8'4 | 06901 | Ser 'g G28 °9 002 14 Ogg tL OU Y Ee Milian Sana. oser que OFT M CuABT
<q OL OL $89 ‘9 881 ‘8 G29 ‘b 80 ‘S 880‘2 ° | 092 ‘CI GLE ‘L G16 ‘9 GLI ‘9 OSPF ‘IT O00 fGen eS ee otoee quod U19}SeMq4I0N
PL Pp BRUGES glia Betnee: Figs 2 ORE gees Fae ek ee Eo ead ee 000 ‘2 0g9 ‘¢ OSF ‘2 OS OS Sal Rees apa as ge Og M UI YL
= 92 P 916 '9 Se gn (ae, ele Sete [ees 28. (2 Riek tence GZ¢ ‘9 00¢ ‘¢ oss ‘6 06026 Me alt eo ee ea ers E81 MOTIDEIES “§ "A
92 Se 692 ‘8 i < Gor iL 092 ‘2 068 ‘8 O18 ‘TT 008 ‘8 008 ‘OL 0S9 ‘2 OZ RNCRE Ho |e gece es | en ee eu M DOLLY
NM OL 6 COL “L 888 ‘Z 629 ‘PF $80 ‘¢ 889 ‘8 GIL SI GLI ‘2 003 ‘2 OSP ‘8 OOC AUIS cate TSca ce ee ear JUI[] 10010 7A[
7, i 4 BS 8 Nia Gh alk ee | ee ee le tie OZT ‘ST Gol ‘9 au d OO ake |Rie aemeise OC ORF a pecchecaetcace se cata MOTIOA Torrie
TonO se et ome thee. 1 (ne. seem Zag * GIZ ‘GT 092 ‘6 ocz “ GLE“ Sit |S eae ce gee ea peels sees yued Moje x W04
= u: ol 699 ‘2 8eL ‘Z 092 ‘g CGP ‘9 8El ‘8 OF9 ‘ST 0g8 ‘8 096 ‘6 002 ‘2 OOT ‘OT OL ee ais ee i a EI SLOSOUUL/L
P CASH des ae wR et Se a el eee 096 ‘8T GLI ‘6 OORg ial ia Same 3 eagcel © cee oa cc eo ee are ued Od1[eO
<q 0or Or C69 ‘6 Z09 ‘E 0¢2 ‘8 191 ‘9 829 ‘6 GIL ‘8% OSL ‘ZI G10 ‘9 00S ‘OT G19 ‘6 OSC SE |e ees JUILT MOquiery
S LOQUUN AT SpUuUNn0T SpunogT Spunv0g Spunod SpUN0d SpuUNn0T spunod SpUN0T SpuUnv0g SpUunodT SPUN0T sU109
a eet accel ic See ne lS Tous aite cca tie areailiemed ans mune | ootere nang lias SP a bul We eee
ap)
sl sieok
erqevied
A -uu100
sulimp ise
4a A UMOIS persed
és Sv OJ 1861 O&86T 6261 8261 1261 9261 C261 P61 £261 261 AyoliwA pus do1p
MOqUIBY | siv9az
Jo o3u OsBVIOA YW
-ju9010d
Ul proré
OBVIOA VW

: IS-G@6T ‘sivah OT

34 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Rainbow Flint produced by far the highest yield of any variety
of corn tested. This variety does not mature grain regularly at Ard-
more, but acclimated strains mature sufficiently to make a good qual-
ity of silage. Of the varieties of corn that mature, Northwestern
Dent, Mercer Flint, and Payne White Dent were about equally pro-
ductive. These earlier maturing varieties contained a slightly Tiohes
proportion of dry matter than Rainbow Flint, and probably con-
tained a higher percentage of grain. The much higher yield of Rain-
bow Flint more than compensates for this difference.

Minnesota 13 produced yields of silage somewhat higher than those
of the early varieties, but it always was immature when harvested.

The air-dry matter present in the corn when harvested for silage
was determined during the 6 years, 1926-31. While the green weight
of Rainbow Flint was 44 percent higher than that of Northwestern
Dent the air-dry matter was 39 percent higher.

MILLET VARIETIES

Millet varietal tests were conducted from 1915 to 1931 with the ex-
ception of 8 years. Sorgo and Sudan grass in 7-inch drills, the plant-
ing method used for the millet varieties, were grown in comparison
with the millets. During the period 1915-20 these tests were con-
ducted by the Office of Alkali and Drought Resistant Plant Breeding
Investigations. Results are shown in table 15.

30

INVESTIGATIONS AT ARDMORE, S. DAK.

SOT 868‘e | 009 ‘T | S28‘F | 299‘% | O09 ‘F | 29T‘8 | 006‘ | OOF | O OOF Se 1088 9 =|, O88. Ta 12029-8: 3] 0868. [S008 a aan nneeete es sees Sseig ng
TST 819g | O92 ‘T | 000'S | eee‘9 | see‘o | eeg‘sT | 0269 | OVT‘T | 0 OO Qe O86;Sa| OL8¥a R0LIay |sO88-2) OL¥ 2 |eccrs cipeent se aeen Ua Joqury B10x8q +asI0g
G8 89T‘s | 00g G16‘% | 002‘% | €80‘¢ | eso‘ | oso‘e | oso’e | 0 O86 Fa |KOLTEy V0G8iGr IROLEnS wIEOLGme | OG8)0) | sasanneenan cemcinaens Sees uvireson xy
06 eee aan | RS oie Re lige eeel| 5 ee 1c eas Se ces | GP ea eee 026‘8 | ogs‘s | O22‘h | 00c‘e | 089 “1a aetatatnin er niciiskilete scales ce TOuIuLOG)
£6 1992 Gen OL Tales | 1 ae aoe oso‘@ | osz‘e | 291‘6 | ozo‘e | Ocr‘'2 | 0 OLOSVae | ROST AY a Ocl Ga InOGceG = |COGL uC 1806.9) | gan pes meine rae eee ee UCULIOf‘)
COM ites ene eee co pees eke | as ee |: ee Se lee ee ll eee OLGeSerinOLy Se | OL Ger. /OSGL Ge NOLS UY a | ian mame gees minirn an eee nee ¢ ‘ON ¥sIny
96 LLG '€ | O80'T | Sco‘ | Log‘% | OG4‘9 | 299% | OzE‘e | 008% | 0 OCO) Iie OL OnGes I OW, Ces ROBE 6 =| OO: Ge 100 G9) P- Iiacg on penis au nein surTAL PIOD
16 e6c‘e | o¢e‘T | Sort | 296‘T | 000‘9 | esc‘b | osz‘z | oze‘e | 0 O26 sham 1 OSTs?, =| 069 GaninOL lap. |NOLGrG, |"080-0) ln aan: paaicanrs cite eene manent UWeLIEqIg
OoT 024‘€ | O80‘T | s99‘e | 498‘% | 0¢z‘9 | Ocz‘e | OOF‘ | O68‘e | 0 QOL LOLESe | OLS Seal OGhar. -|OpGae> 1,090 cl = aaecnnes ceases —-ysIny 8joyxed

SPUNOT | SPUNOT SPUNOd | SPUNOT SpunodT SpuUNOT SPUNOT | SPUnROT SpuUunod Spunod spunod SPpuUnOdT Spunod SpuRnod spunogd SPOTL
siv0h
e[qvied
-u100
SUDA laa
eae -ioay | [e6r O86T 6261 8261 LZ61 9261 GZ6I VC6I £261 0261 6I6T SI6T 9161 SI6I Ajoyiva pues dog
jo
e3e10e0
-Jod Uy

IS6T 1

GI6I wmouf saveh urjse0 Burunp uoynis asouply ay} yo ssviG unpngy pup ‘obuos ‘sayariva jazpw fo spay auov abvi2ap pup Jonuupy— | @IAaV,

36 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Both sorgo and Sudan grass were more productive than the
millets, but the difference in yield between Sudan grass and the
more productive varieties of millet was small. Dakota Kursk was
the highest yielding millet. This variety has fine leaves and a rela-
tively fine stem. As it excels the other varieties not only in yield
but in quality, it can be recommended as a catch crop.

Sudan grass produced slightly higher yields than millets, and its
feeding value is at least as high.

Neither millet nor Sudan grass approached sorgo in yield, but
sorgo produced in drilled plots is difficult to handle. It dries
very slowly and is subject to damage by rain while curing. Sorgo
is a recommended forage crop, but for convenience in handling it
should be grown in cultivated rows.

SORGO VARIETIES AND SUDAN GRASS

Sudan grass and three varieties of sorgo were grown continuously
in 42-inch rows from 1923 to 1932 and one additional variety from
1925 to 1982. The yields are given in table 16. Some variety
testing was done prior to 1923, but the records were not continuous
and are not given. During the period 1923-32 Red Amber sorgo
produced the highest yield and Black Amber only slightly less.
All.the sorgos exceeded Sudan grass in yield. Of the sorgos Dakota
Amber produced the lowest yield but the highest quality of feed.
It matured fully every year, and there always was a considerable
amount of ripe seed in the forage, which increased its feeding value.
Sorgos appear to increase both in feeding value and in palatability
as they approach maturity, and Dakota Amber is recommended be-
cause it matures. Red Amber and Black Amber matured in some
years, but in other years they were far from mature when harvested.
Black Amber appears to be a little earlier than Red Amber and
produced a greater percentage of matured grain. It is a more
valuable crop to grow than Red Amber. Leoti Red produced good
yields during the peree it was grown, but it is the latest of the ©
varieties under trial and never approached maturity when harvested. —

TABLE 16.—Annual and average acre yields of sorgo varieties and Sudan grass
at the Ardmore station for the 10 years, 1923-32 |

Variety 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | 1930 | 1931 | 1932 ae pee

———_ | ——— ———_ | | | | | | | | | |

Lb. | Db. | Eb: | Db. | Lb.) |) Lb.) Bb.) Gb.) Eb. 3) be
eoti/Red 2s 22242 = 22s ee eee 3, 050) 6, 280/11, 035) 4,510) 3, 250) 5, 460) 1,150) 2,556) 4,661) 106
Red Aim berses2s sae 6,600 521} 3, 040} 3, 730/11, 310} 5, 168) 3,042) 5,060} 840} 2,926] 4,224) 100
BlackoAmbers=2 2222 =- = 6, 520) 1,061} 4,210) 4,010) 8, 440) 5,177) 3, 208) 5,360) 1,177) 2,399) 4, 156 98
4,910} 6, 988} 4,193} 2,917] 3,065} 1, 268) 1,397} 3, 243 77
2, 450} 3,917/ 2,070) 1,675) 3,415) 872) 935) 2,305 55

INVESTIGATIONS AT ARDMORE, S. DAK. od

Sorgo and Sudan grass were grown in 42-inch rows in the sorgo
variety test and in 7-inch drills in the millet variety test during
certain years from 1915 to 1931. Comparison of the yields from the
two methods of production is made in table 17. Both sorgo and
Sudan grass produced higher yields in drilled plots than in rows.

TABLE 17.—Acre yields of sorgo and Sudan grass grown in 7%-inch drills and
_ in 42-inch rows at the Ardmore station, during certain years from 1915 to
1931

Crop 1915 | 1916 | 1918 | 1919 | 1920 | 1923 | 1924 | 1925 | 1926 | 1927 | 1928 | 1929 | 1930 | 1931 ee
Sorgo: ! Lb. | Lb. | Db. | Lb. | Lb. | Lb. | Lb. | Lb. | Lb. | Lb. | Lb. | Lb. | Lb. | Lb. | Lo.
Dried. 5s 7, 470|7, 830/4, 170/4, 870|8, 880/5, 100} —_0/1, 160/5, 920|14, 833/5, 333 6, 333/5, 000|1, 750) 5, 618
ROWS ie atte 8, 300/6, 860]5, 850|3, 930/3, 650/4, 320] 9386/2, 433/4, 910] 6, 988|4, 193|2, 91713, 065|1, 268] 4, 259
- Sudan grass:
~ Drilled_-------|--___ 3, 980/3, 670|1, 80/5, 830/3, 400, —_ 0/4, 400)2, 900) 8, 167|4, 500|2, 667|4, 875|1, 500| 3, 675
IO WSLELE 2222s Panis 3, 660)4, 180) 2, 4302, 820)5, 090 628 2, 000) 2, 450) 3, 917/2, 070/1, 675|3, 415} 872) 2,708

1 Dakota Amber.

Sudan grass cures readily when cut and is easily handled as hay.
It should be planted with a drill and handled like any other hay crop.
Sorgo dries very slowly and is subject to injury by wet weather dur-
ing the curing process. Sorgo in rows produces a much higher per-
centage of seed than that planted in drills, and is easily handled as
a fodder crop. In spite of the lower yield, its production in culti-
vated rows is recommended. The better quality of feed and the
greater ease of handling more than make up for the difference in

tonnage.
ALFALFA, BROMEGRASS, AND CRESTED WHEATGRASS

Tests of alfalfa, bromegrass, and crested wheatgrass were con-
ducted by the Office of Alkali and Drought Resistant Plant Breeding
Investigations during the period 1917-22. No tests were conducted
during the period 1923-25. Seedings of bromegrass, crested wheat-
grass, and four varieties of alfalfa were made in 1926, from which
yield data are available from 1927 to 1980.

Results given in table 18 show that crested wheatgrass and alfalfa
approached each other very closely in yield during the entire period.
In the early seeding crested wheatgrass was more productive, and
during the later period alfalfa was more productive. Bromegrass
was decidedly lower in yield than crested wheatgrass during both
periods. Reduction in yield through becoming sod-bound was re-
sponsible for much of the lowered yield of bromegrass. -In neither
of the seedings that were made did crested wheatgrass become sod-

bound.

TABLH 18.—Annual and average acre yields of alfalfa, bromegrass, and crested
wheatgrass hay at the Ardmore station, during certain years from 1917 to
1930 \

Aver- | Aver-
Crop and variety 1917 | 1918 | 1919 | 1920 | 1921 | 1922 | 1927 | 1928 | 1929 | 1930 age, age,
1927-30) 1917-30

Alfalfa: Tobe ba ebse eb. Wb eb. | Gb. | Dib. Eb. 1) Gb...) Gb. Db. Db.
Grimiin'= = 22eo 2 Sa 1,800] 5,570) 1,170) 550) 1,600) 2,000) 4, 567) 1,150) 1,160) 350) 1,807) 1,992
meeDak: INiopl2ss2 s)he fh 53) | ees alps a gee ee eS 5,017} 1,517) 1,360} 850) 2,186)_-____-
TORT EN ite ae SSS Bae ae| Sees ere 4,667) 1, 117| 1,360) 635) 1,920)_-_____
Coss eka sere eae Ae Sree ee 2 EEE | 2 |S 2 2S 4,400} 1,350} 1,327) 485) 1,891)_-_----

SLOMEPTASS o> - -S-- 3, 400} 2,300} 240} 160) 800) 800) 2,267/ 1,100) 833) 550) 1,188) 1,245

Crested wheatgrass - -_-- 5, 400| 4,800] 1,100) 250) 1,400) 1,500) 2,227) 1,533) 733) 1,135) 1,407) 2,008

38 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Native common, or South Dakota No. 12, alfalfa was more produc-
tive than any other variety under trial during the period 1927-30.
This difference was consistent from year to year. For hay pro-
duction there is no variety superior to the acclimated native alfalfa.
For seed production, varieties whose seed commands a higher price
are recommended.

SHELTERBELT INVESTIGATIONS

The need for trees to provide protection from wind and snow led
to the planting of the first shelterbelt at the field station. Later
Ardmore was selected by the United States Northern Great Plains
Field Station, Mandan, N. Dak., as one of four stations where a
definite set of uniform experimental plantings was made. These
experimental plantings were made to study the species of trees
adapted to shelterbelt use; the spacing of trees in the shelterbelt;
the advantages and disadvantages of pruning; and the relative merits
of mulching, clean cultivation, and lack of cultivation during the
early years of a shelterbelt.

During the life of the experiments nearly all the trees used were
shipped to the station from Mandan, N. Dak., and annual inspections
of the shelterbelt were made by officials from that station.

The heavy soil and dry subsoil at Ardmore produce conditions of
exceptional severity, under which only the hardiest species of trees
were able to survive. The drought of 1931 was instrumental in com-
pleting the destruction of less hardy trees. :

The first shelterbelt was planted along the west side of the build-
ings and grounds in 1917. This belt was divided into two blocks
each 450 feet long, one block being spaced 4 by 4 feet and the other
4 by 8 feet. Siberian pea-tree in both blocks were spaced 2 feet
apart in the row. Nine rows of trees were planted in each block in
the following order from west to east:

(1) Laurel willow (Salix pentandra L.); (2) boxelder (Acer
negundo L.); (8) green ash (fraxinus pennsylvanica lanceolata
(Borkh.) Sarg.) ; (4) boxelder; (5) and (6) Northwest poplar
(Populus sp.); (7) American elm (Ulmus americana Ll.) ; (8) box-
elder; and (9) Siberian pea-tree (Caragana arborescens Lam.).

All trees, except Siberian pea-tree, in the block spaced 4 by 8 feet
were pruned. Ordinarily the low-growing, hedgelike type, in this
case Siberian pea-tree, should be planted on the windward side, in
this locality the west side, of the shelterbelt to trap snow in the belt
itself, but in this planting it was placed on the east side. A good
stand was obtained from all species planted.

The trees in the section spaced 4 by 4 feet did well until their
spread prevented cultivation with available equipment. They
reached that stage without shading the ground sufficiently to check
weed growth, and the block became a breeding plot for weeds. Weed
seeds produced in it were scattered to other parts of the farm. The
poplars made good growth, and a loss of not over 20 percent was in-
curred prior to the winter of 1921. They had used up nearly all
available moisture by autumn that year and went into the winter
dry. The next spring about 80 percent of them were dead, and the
remainder were weakened. By 1925 the only trees of this species
remaining were those in favored locations at the end of the row.

INVESTIGATIONS AT ARDMORE, S. DAK. a9

Laurel willow and boxelder in the 4 by 4 foot planting suffered only
partial winter killing until about 1929. From then on many trees
died each year, and in the winter following the dry year 1931 these
species were entirely eliminated. The American elm and ash sur-
vived fairly well, though they made little growth owing to their
crowded and weedy condition. Ash proved to be more hardy than
elm. In the spring of 1932 practically all the ash and about 60
percent of the elms in the original planting were still alive.

In the section spaced 4 by 8 feet cultivation was carried on for a
longer period, and the trees grew more rapidly. The poplars and
willows, however, commenced to die following the winter of 1921,
and within the next few years were entirely eliminated. The box-
elders survived fairly well until 1929, when they had exhausted
.the moisture in the wider area provided by the 8-foot planting.
During the winter of 1929 portions of many of them died, but very
few trees were entirely killed. During the winters of 1930 and 1981,
practically all the boxelders were killed outright, and by the spring
of 1932 the only trees left in this planting were the ash and the
American elm. These two species were injured but not killed dur-
ing the winter of 1931, and with favorable weather in the spring
of 1932 seemed to be again in fair growing condition. The elms
and ash in this planting averaged somewhat greater height and
diameter growth than those in the planting spaced 4 by 4 feet. The
elm and ash in both tests were injured by borers in 1932.

The single row of Siberian pea-tree survived during the entire
period and in 1932 was one of the finest examples of a snow trap to
be found. The trees make a practically solid row approximately 10
feet in height, and each winter collect a large drift of snow that
not only holds much snow away from the buildings, but gives this

row of trees and trees situated to the east of them a surplus supply.
of moisture, The species is perfectly hardy.

Differences in spacing distance had little effect on survival in this
_ test. Qualities inherent in the species, rather than the closeness of
_ planting, determined their ability to survive adverse conditions.
_ Either rate of planting was thick enough to exhaust the available

soil water.

Plantings of conifers were made from year to year in a strip of
land east of the row of Siberian pea-tree. Conifers are much more
_ difficult to transplant than deciduous trees, and only a small per-
centage of survival was obtained each year, but the trees seemed to
__be hardy after becoming established. Continued plantings in spaces
where trees failed to survive were carried on until 1922. By that
time there was a fair stand of conifers and the roots of the trees
had become so well established that newly planted trees had little
chance of surviving. For the first few years the growth of these
conifers was slow, but during the'later years they grew rapidly and
in 1932 were the most showy part of the shelterbelt.

_ The species of conifers used in the test were jack pine (Pinus
_ banksiana Lamb.), Scotch pine (P. sylvestris L.), and ponderosa,
_ or western yellow pine (P. ponderosa Dougl.). Until the winter of
1930, the conifers, owing to a thinner stand and to water provided
by trapped snow, did not experience a distinct water shortage. In
_ the summer of 19381, the jack pine showed some evidence of drought

40 CIRCULAR 421, U. 8S. DEPARTMENT OF AGRICULTURE

damage, and a few of them died. The ponderosa pine and the
Scotch pine were still in good condition in 1932. They have ex-
tended their branches enough to cover most of the space between
them and have become very valuable, both for wind protection and
as snow traps.

In the spring of 1917, three rows of Chinese elm were planted on
the north side of the garden, and a row of Siberian pea-tree was
planted between the north row of Chinese elm and a strip cf sod
bordering the cultivated land. The Chinese elm made a remarkable
growth, and by 1925 they were the tallest trees on the station. Nearly
all of these trees were still alive in 1932, though there was some killing
of branches following the winters of 1930-31 and 1931-32. The row
of trees next to the garden is several feet taller than the row next
to it, and this row in turn is taller than the row bordering the Si-
berian pea-tree. This difference is accounted for by the fact that
the trees on the side next to the garden are able to draw upon the
cultivated soil in the garden for moisture. No doubt the second row
also obtains some moisture from the garden. This has been a great
benefit to the trees but not to the garden crops. Occupation of the
soil by tree roots has made unproductive for garden crops a space
approximately 40 feet wide bordering the Chinese elm. :

The row of Siberian pea-tree between the Chinese elm and the sod
is an example of survival under adverse conditions. This row is so
overshadowed by the Chinese elm, and has such a small area of cul-
tivated ground from which to draw moisture, that it has had a severe
struggle for existence. In spite of the adverse conditions, practically
all the trees have lived and there has been no killing of branches.
Naturally these trees have grown very slowly, but their survival
shows that they are able to withstand the most severe conditions.

PRUNING AND SPACING EXPERIMENT

In 1918 three blocks of trees were planted for a pruning demonstra-
tion. One of the blocks was to be pruned high, one medium, and
one left unpruned. Each block was planted to 10 rows of trees
arranged in the following order: (1) Buffaloberry : (Lepargyrea
argentea (Pursh) Greene); (2) willow (Salta sp.); (8) boxelder;
(4) green ash; (5 boxelder; (6) Northwest poplar; (7) green ash;
(8) boxelder; (9) laurel willow; and (10) Tatarian maple (Acer
tataricum L.). The trees were spaced 4 by 4 feet in half of each
block and 4 by 8 feet in the other half. a

The evil effects of pruning were apparent as soon as the trees had —
reached a height of 7 or 8 feet. The pruned blocks of trees were en-
tirely unsatisfactory for catching snow or providing protection from
the wind. The ground in the pruned block was almost invariably
blown free from snow, while driftstof snow collected in the unpruned
block. Trees in the unpruned block were more vigorous than those
in the pruned blocks, and the survival was better. A shelterbelt in
this section should be left unpruned, in order that it may catch the
snow that would otherwise drift around the farm buildings. The
water from the melting snow furnishes a much needed supply for the
trees. |

The willows were the first to die, except for end trees which
were able to send their roots into the cultivated area outside of the

INVESTIGATIONS AT ARDMORE, S. DAK. 41

belt. The poplar became eliminated next, and these were followed
by boxelder which have practically all died in recent years. The
few surviving boxelder trees have suffered heavy killing back.
Green ash were in the best condition of any species in 1932, though
they showed some damage from borers. Buffaloberry had suffered
very little loss, but the trees presented a very ragged appearance,
chiefly as a result of top and side crowding by sharpleaf willow in
the adjacent row. Tatarian maple seems to be semihardy. This
tree appears to be especially palatable to rabbits, and until the

_ shelterbelt was surrounded by rabbitproof fence in the fall of 1927,

trees were killed nearly to the ground each year by rabbits. After
1927 these maples made fair growth, though portions of the trees

| . were killed following the dry year 1931.

COMPARISON OF CULTIVATION, MULCHING, AND LACK OF CULTIVATION

Comparison was made of clean cultivation, lack of cultivation, and
mulching in the care of a shelterbelt. The same species of trees and
spacings were used as in the pruning test. The neglected or un-
cultivated block was a continual source of weed seed that blew over
the adjoining fields. Losses of species were much the same as in
the previous experiment. The willow, poplar, and boxelder, how-
ever, died out at an earlier age, and the more hardy species, green
ash, buffaloberry, and Tatarian maple, made a slower growth in
the noncultivated block than in the blocks of other cultural treat-
ments.

The mulched block of trees was covered with straw to a depth of
about 6 inches, and straw was added each year for several years
to maintain this mulch. This block of trees did not grow so well as
the clean cultivated block, and the less hardy species, willow, poplar.
and boxelder, died out at an earlier age. In 1932 all except the
hardiest species, ash, buffaloberry and Tatarian maple, were dead
in both blocks. As in other tests the green ash proved hardiest.

SPECIES BLOCKS

Blocks of trees, each set in pure stands, were planted in 1918.
The species used in this test were Northwest poplar, laurel willow,
boxelder, and green ash. Each block was divided, one-half being
spaced 4 by 4 feet and the other half 4 by 8 feet. Nearly all the
poplar trees died following the winter of 1924-25. The willow trees
did not entirely die, but killed back to the ground each winter, and
new growth took place from the roots the next spring. These two
blocks of trees were pulled in 1930. The boxelder trees grew with
but little injury until about 1927. During the years 1930-82 nearly
all the boxelders died either in whole or part, and the boxelder block
then presented a very ragged appearance.

The block of ash trees has shown very little killing, although
many of the trees appeared to be weakened in the spring of 1982.
This was followed by a good recovery, and the trees were in good
condition in the autumn except for borer injury. The trees have
not made much growth the past few years, the block spaced 4 by 4
feet having an average height of 10 feet and a diameter of 1.5 to 3
inches, as compared with an average height of 9 feet and a diameter

42 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

of 2.5 to 3 inches in the block spaced 4 by 8 feet. As in previous
tests. this species has proved to be the most hardy of those tested.

HOG-HOUSE SHELTERBELT

The hog house at the field station was located to the north and west
of the other buildings in a comparatively exposed position. To pro-
tect this house a shelterbelt consisting of three rows of Chinese elm,
three rows of Russian-olive (Hlaeagnus angustifolia L.), and one of
honeylocust (Gleditsia triacanthos L.) was planted in 1925. <A severe
freeze in September 1926, before the trees had ceased growth for
the season, caused partial killing of the young elm and Russian-olive
trees. Conditions were favorable the next spring, and these trees
made a rapid growth, but the character of the growth was bushy
because of the killing of the top branches.

The killing back causing a bushy growth resulted in this becom-
ing the best snow catcher of any belt on the farm, entirely eliminat-
ing snowdrifts from the hog house and farrowing pens. The large
amount of snow held by the belt gave the trees additional moisture,
which has been very clearly reflected in the resultant remarkable
growth.

The Russian-olives, since 1926, have shown little winter injury, ex-
cept for certain trees whose smaller branches have been killed. Chi-
nese elms showed little winter injury from 1926 to 1931. In the
spring of 1932 a few elms were found to be entirely dead, and many
others had dead branches.

Honeylocusts have survived fairly well, but have been very poor
trees for shelterbelt purposes. They have few branches near the
ground, and as a result are valueless as snow catchers. This species
should be planted in interior or leeward rows where it will serve
for wind-protection purposes, rather than toward the windward side
where the chief function would be to hold drifting snow. The use of
the thornless variety is recommended for shelterbelts.

CONCLUSIONS FROM SHELTERBELT INVESTIGATIONS

The accumulated results to date indicate that shelterbelt plantings
should be restricted to a few species of hardy trees. Low-growing
bushy species to check snow should form the border rows on the
north and west. Siberian pea-tree and Russian-olive are adapted to
this purpose. Ash and American elm have proved to be the best
adapted of the taller-growing species, with ash the most hardy of the
two but having a slower growth rate. Chinese elm has also given good
promise, and its rapid growth rate makes it a valuable species for
use In a windbreak where quick protection is desired. They should
be planted with full understanding that they may not be fully hardy,
and that in time they may be eliminated. By the time the Chinese
elm has killed out, the ash and American elm should have reached
a height sufficient to check the wind in the immediate vicinity.
Northwest poplar also has a rapid growth rate and can be used as
a temporary tree on the more favorable sites. Where rapid growth
and a good survival is desired over a period of years, the Chinese
elm should be used in preference to Northwest poplar on all sites
except those which are very favorably situated in relation to moisture.

INVESTIGATIONS AT ARDMORE, S. DAK. 43

In general it may be stated that many species of trees are hardy so
long as available moisture is present in the soil. Going into the
winter dry is the most severe test for a tree. Trees that can survive
this condition are in a position to form part of a permanent shelter-
belt. Moisture is so much of a factor in hardiness, that a shelter-
belt holding snow has a great advantage over one not catching snow.
The amount of moisture above the average precipitation obtained
through retaining snow is a vital factor in the growth of shelterbelts.

The losses of less hardy species sustained in the shelterbelts at
Ardmore might lead one to believe that shelterbelts are not a success.
This is not true. The trees remaining in the shelterbelts at Ardmore
serve their purpose in holding snow away from the buildings. The
_shelterbelt as a whole greatly improves the appearance of the farm
and makes it a more pleasant place to live. For the sole purpose
of catching snow, a shelterbelt pays for its upkeep. In adding to the
appearance of a farm and as an aid in making a farm a real home,
the shelterbelt has a value that cannot be measured. Results from
experiments with shelterbelt plantings should enable farmers to avoid
costly mistakes in establishing them.

FARM ORCHARD INVESTIGATIONS

Plantings of fruit trees were made at different times following
the establishment of the shelterbelt. Severe rabbit injury caused the
loss of many trees, and in the spring of 1927 not over a 15-percent
stand of trees remained in the orchard. Replacements of all dead
trees were made in the spring of 1927, and the orchard and shelter-
belt were surrounded with a rabbit-proof fence. There was no fur-
ther rabbit injury, as the few rabbits that made their way into the
enclosure were easily removed. Some of the less hardy varieties of
trees died each year, and replacements with hardier varieties were
made each year until 1931. By 1931 the roots of the older trees occu-
pied the soil so completely that newly planted trees had little chance
of surviving.

The trees have not reached a condition where moisture shortage
plays a part in determining hardiness. The wide spacing and clean
cultivation practiced in the orchard should indefinitely postpone the
reaching of such a condition. Fruit trees need moisture for the pro-
duction of fruit, and ample room, combined with freedom from weed
competition, appears to be essential to successful fruit growing.

The greater proportion of the fruit trees in the station orchard
was procured from the United States Northern Great Plains Field
Station, Mandan, N. Dak. Selection of varieties for Ardmore was
based largely on results at Mandan. Detailed reports on the hardi-
ness and quality of different species of fruit trees for the section are
contained in Farmers’ Bulletin 1522. This bulletin also gives in-
formation on selection of site, care of trees, planting, spacing, and
pruning.

No extensive variety test of fruit trees was made at Ardmore, but
the varieties that are still growing well in the orchard appear to
have the hardiness necessary in this section. The less adapted varie-

3 BarrD, W. P. THE HOME FRUIT GARDEN ON THE NORTHERN GREAT PLAINS. Wats:
Dept. Agr., Farmers’ Bull. 1522, 49 pp., illus. 1927

44 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

ties have died. The behavior of the different varieties of apples and
plums in the station orchard will be briefly discussed.

APPLE VARIETIES

No standard variety of apples has yet borne much fruit, though
some varieties have begun to bear. The Anoka produced fruit the
earliest after setting out. It appears to be fully hardy and has
ample foliage to protect the tree. The Hibernal is very hardy,
but the foliage is too scant for sun protection, and the trees had not
commenced to bear in 1932. Wealthy and Oldenburg (Duchess)
appear to be hardy with adequate foliage and are beginning to bear.

The trees of all standard varieties of apples are still small, and
it will be many years before they produce much fruit.

Crab apples made much more rapid growth than standard varie-
ties, and many trees are now producing good crops of fruit. Dolgo
is a consistent producer and the trees are thrifty. The fruit is small
but of fairly good quality. Florence produces the heaviest crop of
fruit, though the production from year to year is not so consistent
as it is with Dolgo. The trees of this variety are strong growing
and the foliage is ample. The fruit is above average size. Sylvia
bears some fruit each year and the fruit is of better than average
quality. The foliage is slightly sparse and does not fully protect
the fruit. Transcendent and Siberian are hardy and the trees are
vigorous in growth. Production of fruit is fair, but the quality is not
equal to some of the other varieties, although the quality of Trans-
cendent generally is considered good. Virginia is hardy and the fruit
is of good quality, but the foliage is scanty and the fruit crops have
been small. Whitney is hardy, and the fruit is of superior quality,
but the tree is slower in reaching bearing age than some of the
other crabs.

PLUM VARIETIES

Opata, Sapa, Compass, and Zumbra were the first varieties of
plum-sand cherry hybrids to produce fruit. Sapa and Zumbra were
very short lived, and portions of the trees began to die within a few
years. Opata and Compass were longer-lived. They produced fair
crops of fruit earlier than standard varieties. All trees of these
two varieties are now dead or in very poor condition, but their loss
is due more to location than to lack of hardiness. Both of these
varieties were in the row bordering the shelterbelt and were unable
to stand the competition of the larger trees in the shelterbelt. Opata
and Compass are short-lived as compared with standard varieties,
and the quality of fruit is not so good for eating out of hand,
though they are acceptable for culinary uses. They are valuable in ©
the early development of an orchard, because they produce fruit
when better varieties have not commenced to bear.

Standard varieties of plums that have proved hardy and produc-
tive are Red Wing, Teton, Radisson, Mammoth, Emerald, and Cree.
Teton, Mammoth, and Cree are not considered very good quality
plums, but they are hardy and productive. The trees of Mandan
Selection No. 73 grew more rapidly than those of any other variety
and are fully hardy. The fruit is of medium size and average qual-

INVESTIGATIONS AT ARDMORE, S. DAK. 45

ity. The trees suffered more wind damage than those of any other

variety, apparently because the wood is more brittle. This plum

| has not been so productive as the other varieties mentioned, but part

of the lower production may be ascribed to the destruction of fruit

| buds by birds,

FRUIT PRODUCTION

Production of fruit in this section should be limited to production

|-for home needs. There are some favored locations where commer-

cial orcharding is feasible, and some locations in which unusually
able fruit growers have made a success of commercial orcharding

| under ordinary conditions. For the average grower on the uplands,

the production of more fruit than is needed for home use is an
economic loss.

The orchard should be small enough so that its cultivation is not
an undue burden. Such an orchard can be well taken care of with-
out hindrance to field work. Larger plantings require more time
for cultivation and other care, and are likely to be neglected when
field work presses for time. Unless an orchard is well cared for it
might better not be planted.

No detailed study of small fruits was made at the station, but
several varieties of currants and gooseberries were found to be hardy
and productive. These small fruits should be spaced wide enough

| to prevent crowding. Bushes 6 feet apart in the row and rows &
| feet apart is a suggested spacing.

Suggestions for a selection of trees for a home orchard are as fol-
lows: Some early bearing plums should be included, such as Opata

| or the Compass, that make up in earliness of bearing for what they
| lack in quality. Opata is considered good quality for cooking on

account of thin skin, small pit, and flavor. These varieties appear to

| be short lived and can be removed when they become unthrifty.
| Selection of standard plums can be made from the varieties men-
| tioned as hardy. These trees should be producing well by the time
| the Opata and Compass become unthrifty. Apples should be selected
| largely from the crab-apple group, because of earlier and more pro-
| lific bearing. Anoka and Wealthy appear to be the most desirable
| standard apples, though the Anoka may be short lived. Care should
| be taken not to attempt to grow too many varieties or too many trees
| of a variety. A small orchard, well kept, should produce fruit sufii-
| cient for the needs of a family. If the orchard is small enough so
| that its care is not a burden, it will be a source of satisfaction to
_ the grower, and the fruit will provide a much desired addition to the
| regular diet throughout the year, either as fresh or canned fruit,
| or in jellies, pastries, and preserves.

SUMMARY

The Ardmore Field Station completed 20 years of experimental

_ work in 1932. Crop rotations and cultural-method experiments were
' continuous during that period. Other lines of investigation were con-

_ ducted for shorter periods.

The average precipitation at Ardmore was 15.90 inches for the

21-year period 1912-82. Normal expectation is for drought injury
_ at some period of the crop year,

46 CIRCULAR 421, U. S. DEPARTMENT OF AGRICULTURE

Crop-production work was conducted along three principal lines:
(1) Crop rotations, (2) fields, and (38) variety tests.

Average yields of all crops grown in the rotations during the 20-
vear period give a fair index of the yields that may be expected under
dry-land conditions in the section.

Methods of cultivation played a relatively unimportant role in de-
termining crop yields. The preceding crop rather than the method
of land preparation seemed to determine the yield, so long as the
method of cultivation did not encourage weed growth or delay
seeding.

Difference in crop sequence resulted in major differences in yield.
Small grains grown after a cultivated crop produced yields approxi-
mately one-third higher than after small grain, and after fallow they
produced yields approximately two-thirds higher than after small
grain. Somewhat different responses were shown by the different
erain crops. |

The yields of cultivated crops were not appreciably higher when
grown after cultivated crops than after small grains. Cultivated
crops showed less response to fallow than small grain crops.

The effect of a cultivated crop in a rotation was evident the second
year following. Yields of grain after grain in 3-year rotations con-
taining a cultivated crop were approximately 20 percent higher than
where grain was grown continuously.

Yields of grains following manured fallow were somewhat higher
than following unmanured fallow. This difference was greatest in
the most productive years. When yields were low, the yields fol-
lowing manured fallow were as low as or lower than yields follow-
ing unmanured fallow. No cumulative benefit from the use of
manure was evident during the life of the experiments.

Small-grain crops on green-manured land produced lower yields
than on land that was bare fallowed. No cumulative benefit from
plowing under green-manure crops was shown.

Crops were grown on fields for the purpose of producing feeds.
Average yields from fields compared favorably with average yields
from plots. Results from one field demonstrated that corn land
and sorgo land are practically equal as preparations for small grains.
Feed-crop rotations showed that dependable production of feed
crops can be obtained over a series of years.

Variety tests with wheat demonstrated that both Ceres and Reli-
ance were more productive than Marquis during the 7-year period ©
1926-82. Some varieties grown only after 1929 showed promise and
should be tried further. Brunker oats were the most productive
variety tested. Gopher oats were better than Sixty-Day but not so
productive as Brunker. White Smyrna barley and Ace, a selection
of White Smyrna, were outstandingly more productive than other
varieties tested. Early varieties of both oats and barley were more
productive than midseason or late varieties. Variations in yield
between varieties were extreme, and sometimes accounted for greater
differences in yield than resulted from major differences in crop
sequence.

Rainbow Flint corn produced higher silage yields than any other
corn variety grown. Yields of Dakota Amber sorgo were as high
as those of Rainbow Flint in terms of dry matter per acre. Little

INVESTIGATIONS AT ARDMORE, S. DAK. A7

difference was shown between several varieties of corn in grain pro-
duction. Growth of acclimated strains that will mature is
recommended.

Dakota Kursk millet produced the highest yield and the best qual-
ity of hay of any variety under trial. Red Amber and Black Amber
sorgos produced the highest yields. Dakota Amber sorgo produced
the lowest yield but the best quality of feed of any of the sorgo
varieties. It was the only variety to mature regularly.

Both sorgo and Sudan grass were more productive in 7-inch drills.
than in 42-inch rows, but greater ease in curing and a higher pro-

duction of grain make it advisable to grow sorgo in cultivated rows
in spite of the lower yield.
Shelterbelt investigations demonstrated that shelterbelts can be
‘grown successfully under the severe conditions at Ardmore. Selec-
tion of hardy species and arrangement so that snow is trapped and
held in the shelterbelt are requisite to the successful growth of a
_ shelterbelt. A good shelterbelt improves the appearance of a farm
and is of great value in keeping snow away from the buildings and
in checking winds.

Adapted varieties of apples, plums, and small fruits can be suc-
cessfully grown. A home orchard is a farm asset.

ORGANIZATION OF THE UNITED STATES DEPARTMENT OF AGRICULTURE
WHEN THIS PUBLICATION WAS LAST PRINTED

ECreLanriynOol VAQTIUCUILLNe= sae ee ee Henry A. WALLACE.

Under Secretary ooo ees ee eee ee. RexForD G. TUGWELL.

Assistant sect elanyce. fo 3 See eee ae M. L. Wiuson.

Director of Extenston Work. 2252-22 2 C. W. WARBURTON.

Director of Finance... 702) fee WAS ome:

Director of Information....---.-------.--. M. S. EIsENHOWER.

Director Of senSOnnels sa. a eee W. W. STocKBERGER.

DPTeCtorsOy PC SCOLCI ee ae ee JaMES T. JARDINE.

Solver = 202 e Sle ee eee ees eee Mastin G. WHITE:

Agricultural Adjustment Administration.... H.R. Touurny, Administrator.

Bureau of Agricultural Economics_...------ A. G. Buack, Chief.

Bureau of Agricultural Engineering..------ S. H. McCrory, Chief.

Bureau of Animal Indusirys sooo) 22 ee tee JoHN R. MoutEr, Chief.

Bureau of Biological Survey__.__.__.-------- Ira N. GABRIELSON, Chief.

Bureau of Chemistry and Soils__.-....----- Henry G. Knieut, Chief.

Commodity Exchange Administration__----- J. W. T. Duve., Chief.

Bureau of Dairy Indusiyeecn ee see ee O. E. Rexp, Chief.

Bureau of Entomology and Plant Quarantine. Ler A. Strone, Chief.

Office of Experiment stavions22 2202 eee JAMES T. JARDINE, Chief.

Food and Drug Administration. .....------ WaLtTER G. CAMPBELL, Chief.

Forest: Service. 2220-22 22 eee ee ER DINAND! AG SILCOxes Chives

Bureau of Home Economics_..------------ Louise STANLEY, Chief.

YD LTR RY ER pen SA A A case) SN Ae ee Oe Ts CLARIBEL R. BARNETT, Librarian. |
Bureau of Plant Indusiry.._-....--------- FREDERICK D. Ricuey, Chief. |
BuUreaofePuvliceodds == = ean earn las a . THomas H. MacDonatp, Chief.

owl ‘Conservaivon Service. 2 2) a) = kun eee H. H. BENNETT, Chief.

Weather Bureau es 8 fe) Ae Pees 8 Witus R. Greaa, Chief. |

This circular is a contribution from

Burea of Plant Industry ee FREDERICK D. RicHeEy, Chief.
Division of Dry Land Agriculture__-__ C. E. LeieHty, Principal Agronomist,
in Charge.
48

U.S. GOVERNMENT PRINTING OFFICE: 1937

ores

cs

pr eer a

rnp me ere