SHELTER-BELT DEMONSTRATIONS OX THE GREAT PLAINS. 17 
adopted of setting out a shelter belt of deciduous species as described 
above and later adding evergreens along the sheltered edge or inside 
of the original planting. Care must be taken to leave a space of some 
20 feet between the two plantings, or the small evergreens may suffer 
from competition with the roots of the older planting for moisture. 
Figure 8 shows Scotch pine planted in 1920 and jack pine planted 
in 1921 in east and west rows on the south side of the hardwood 
shelter belt planted in 1916. This planting is near Isabel, S. Dak. 
The photograph was taken in July. 1921. 
Fig. 11. — Box elder and green ash planted in 1018 in western North Dakota and aban- 
doned to weeds after being cultivated two years. Trees can not compete in this section 
with annual weeds or perennial grass. 
DEMONSTRATION PLANTINGS. 
All of the planting stock used in these shelter-belt demonstrations, 
except the Chinese elm. was grown either from seed or cuttings or 
as transplants in the nursery at the Northern Great Plains Field 
Station. Tables 3 to 6, inclusive, give the number and kind of trees 
sent out for planting in each of the four States in the territory 
covered by this work, during the 5-year period from 1916 to 1920, 
inclusive. 
The shipments of each kind of stock to cooperators in each State 
in 1916 are shown in Table 3. Shipments of planting stock totaled 
701,911. A little over half of this number consisted of willow and 
poplar cuttings which were made up of approximately equal numbers 
of laurel-leaf willow. Russian golden willow, Norway poplar, and 
Carolina poplar. The summer season of 1916 was one of very favor- 
