SHELTER-BELT DEMONSTEATTONS ON THE GREAT PLAINS. 



21 



Table 7 shows the number of shelter belts planted by codperators 

 with trees furnished by the Northern Great Plains Field Station 

 during the 5-year period from 1916 to 1920, inclusive. It also 

 shows the number of the plantings made each year that were listed 

 as successful on January 1, 1921, the number listed on that date 

 as having failed, and the percentage of failures. In the five years 

 1,234 plantings were made and at the end of the period 716, or 58 

 per cent, of these were listed as successful and 518, or 42 per cent, 

 as having failed. Almost exactly 50 per cent of the plantings made 

 in each of the years 1916, 1917, and 1918 were listed as successful 

 at the end of the 1920 growing season. 



Fig. 12.^0utline map of the Northern Great Plains region. Each township in which one 

 or more plantings of slielter belts had been made in 1917 or in which application had 

 been made for planting in 1918 is indicated by a dot. 



Failures may be and w^ere due to any one or more of several causes. 

 The more frequent causes have been improper planting, lack of care 

 and cultivation, prolonged drought, and the owner leaving the farm. 

 The years from 1917 to 1920, inclusive, were all years of severe 

 drought over the greater part of the territory covered by the shelter- 

 belt work. Such a. succession of drought years is unprecedented in 

 the time for which records are available. The work has consequently 

 been in progress during the most unfavorable years it is likely to 

 experience. Continued drought leads to economic stress which is re- 

 flected on such projects as this either by abandonment of the farm 

 or inability to properly care for and protect the plantings. Consid- 

 ering the unusual stress of climatic and economic conditions, it is 



