Experiment station bulletin^. 



409 



nating Carolina poplar with conifers. The conifers shonld be so set 

 that they stagger in the succeeding rows in order to furnish greater ob- 

 struction to the wind. Toward the last of the planting a few men may 

 be taken from squad B to distribute and spread the dead cover. 



Except on very severe blows the dead cover need not be spread uni- 

 formly over the whole area, but applied in strips at right angles to tlie 

 direction of the prevailing wind. These strips may be from ten to 

 twenty feet wide with interA^als between of twice this A^ddth. Usually 

 about one-third of the area should be covered. Where both fine and 



Fig. 17. A paper birch alone and unprotected on the face of a dune. This tree stands on 

 a mound of sand eight feet high and twenty feet across. The roots held the mound while the 

 sand around the mound was swept away. A valuable tree to encourage because of the sand 

 holding power of its root system. 



coarse materials are available, the coatings alternate with coarse, fine, 

 coarse, fine, etc. Grass, marsh hay, straw and other light materials 

 that are liable to be moved by the wind may be held in place by brush. 

 Where well rotted sawdust is available it may be used alternately with 

 strips of grass or straw and brush. Sawdust cannot be used alone as it 

 dries out and blows readily. In some cases, when the season is damp 

 and there is plenty of moisture at the surface, a broad-cast sowing of 

 rye or oats may serve to help bind the dead cover and protect the planted 

 grass. The success of this expedient will depend entirely upon frequent 

 rains to insure the germination of the rye, however. 



