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LAKE STATES FOREST SiG STATION, * 
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“Growth Response of 
The establishment and growth of shelter- 
belt trees are seriously hindered by the com- 
petitive growth of grasses and other weeds 
throughout much of the Northern Great 
Plains. In the semi-arid parts of the region 
where droughts are frequent, trees often can- 
not compete successfully against the better 
adapted grasses for sparse soil moisture. The 
results are poor survival and stunted growth. 
For the best survival and growth, authorities 
recommend cultivation of shelterbelts, if pos- 
sible, until tree crown closure shades out the 
undergrowth.! Unfortunately, this practice 
has not been followed in many tree plant- 
ings. A 1954 survey showed a large percent- 
age of windbreaks, especially in the Dakotas, 
were sod- and weedbound. Less than 1 per- 
cent of all sample windbreaks were still being 
cultivated.” 
1 George, E. J. Cultural practices for growing 
shelterbelt trees on the Northern Great Plains, 
U. S. Dept. Agr. Tech. Bul. 1138, 33 pp. 1956. 
2 Read, Ralph A. The Great Plains shelterbelt in 
1954. Great Plains Agr. Council Pub. 16, Bul. 
411, 125 pp. 1958. 
ST. PAUL 4¢ MINNESOTA, 
MAINTAINED AT 
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oe : . ‘ S Sora ” S* Cranes 
GAVMRENT. SEBRRL RECORDS 
“RESEARCH NOs = 
U.S. DEPARTMENT OF AGRICULTURE 
S| 
Some Shelterbelt Species — 
Following Sod Removal | ++ Preliminary Results”, 
The question arises: Can the various 
species of a sod-bound planting be stimulated 
to increased growth by renewed cultivation, 
and if so, what degree of sod removal is ac- 
tually necessary to obtain a satisfactory re- 
sponse? 
In an attempt to answer this question, two 
shelterbelts were selected in 1960 for renew- 
ed cultivation in north central North Dakota, 
one near the town of Souris and the other near 
Westhope. The one near Souris is a 1949 
farmstead planting of two rows of caragana, 
one of boxelder, and one of green ash. It had 
been cultivated for about the first 5 years, 
after which brome grass and other weeds in- 
vaded the site and created a dense ground 
cover (fig. 1). The one near Westhope is a 
field shelterbelt that was planted in 1946. It 
consists of one row each of caragana, Rocky 
Mountain juniper, American elm, boxelder, 
and a mixed row of. caragana and chokecher- 
ry. It had reportedly been cultivated no more 
than 2 or 3 years after planting and was 
densely sod-bound, primarily with brome 
grass. Both sites have a medium to heavy- 
F-500501 
FicgurE 1. — Sod-bound 
shelterbelt partially 
renovated by sod re- 
moval (moderate 
treatment ) using a 4- 
foot-wide _ rototiller. 
Grass is Bromus iner- 
mis, height 3 to 4 
feet. Souris, No. Dak. 
IN COOPERATION WITH THE UNIVERSITY OF MINNESOTA 
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