28 
BULLETIN 1306, U. S. DEPARTMENT OF AGRICULTURE 
thickest planting yielded best in three of the five years in which there 
was a crop, but the average for the entire period was only 1.6 bushels- 
more than from the 24-inch planting, the average yield of the 18-inch 
planting being 63.5 bushels per acre. The yield of the 30-inch 
planting was decidedly less than the yields of the thicker plantings. 
Table 26. — Annual and average yields of potatoes in variety and rate-of-planting 
tests at the Sheridan Field Station for the six years from 1918 to 1923, inclusive 
Variety and spacing 
Yields per acre (bushels) 
1918 
1919 
1920 
1921 
1922 
1923 
Averag©' 
Variety: 
Early Ohio 
74.7 
103.9 
65. 5 







41.7 
41.7 
33.0 
58.3 
33.3 
31.7 
31.7 
11.0 

6.0 
7.5 
9.5 
11.0 
7.5 
113.0 
129.3 
100.0 
114.0 
39.8 
56.7 
Triumph 
64. 8. 
Irish Cobbler 
Pinkeye. - 
Spacing in row: 
18 inches 
85.0 
86.7 
103.9 
82.6 
151.2 
136.2 
127.8 
100.5 
63. h. 
24 inches 
30 inches . 
88. 5 ! 61. 9' 
63. 52. 1 
SHELTER-BELT INVESTIGATIONS 
A strip of ground 80 feet wide and 1,000 feet long on the west 
side of the station grounds and immediately west of the buildings 
was planted to trees for a shelter belt in 1917 in two equal blocks. 
The north block was planted with the trees 4 feet apart each way and 
the south block with the trees 4 feet apart in the rows and the rows 
8 feet apart. The two blocks are known as the 4 by 4 and the 4 by 8 
blocks, respectively. This shelter belt was planted in cooperation 
with the Northern Great Plains Field Station, Mandan, N. Dak. Seed-^ 
ling trees were supplied by that station, and the planting was made 
according to plans lurnished by it. 
The trees in each block were planted in rows in order from east to- 
west as follows: 
South block, 4 by 8 feet. — Golden willow, boxelder, Chinese elm, Chinese elm, 
green ash, boxelder, American elm, poplar, boxelder, golden willow. 
North block, 4 by 4 feet. — Golden willow, green ash, boxelder, green ash, poplar, 
green ash, Chinese elm, poplar, boxelder, poplar, green ash, boxelder, Chinese elm,, 
boxelder, poplar, green ash, boxelder, golden willow, golden willow. 
A drainage course crosses the block near the center. A clean 
cultivated strip about 30 feet wide was left next to the willows on 
the east side, but on the west side native grass came to within 4 feet 
of the outside row. The first (east) row of Chinese elms in the- 
4 by 8 block was taken out in 1918 and replanted to poplar, but the 
poplar failed to survive. This leaves a space 16 feet wide between 
the box elder and the remaining row of Chinese elms. 
Clean cultivation has been practiced since the shelter belt wa& 
planted, but the growth had become too thick in the 4 by 4 planting 
to allow further cultivation after growth started in 1923, except 
where rows had killed out. 
No northwest poplars were included in this planting, Norway pop- 
lar being used. Many of these died each year. Those remaining 
made a rapid growth, but nearly all, except some of those in the- 
drainage course, died in the spring of 1921. Practically all the wrl- 
