not be packed so hard, however, as to be impervious to water, and it 

 is desirable to leave a slight depression around the collar of the plant 

 in order to collect any moisture that may fall. 



CULTIVATION AND CARE. 



The advantage to be gained by continued cultivation of a forest 

 plantation makes rather wide spacing advisable, even though certain 

 species which have a spreading habit may require pruning. Com- 

 pensation for the wide spaces between the rows can be secured in 

 large measure by setting the trees closer in the row. The spacing 

 of many plantations is 4 by 4 feet, but trees set in that way can be 

 cultivated only two or three years. Spacing 3 feet by 8 feet makes 

 it possible to continue the cultivation much longer. Species which 

 need more room can be set 6 feet by 6 feet or 4 feet by 8 feet, and as 

 they grow the space required can be obtained by removing the less 

 promising individuals. Without proper conservation of soil moisture 

 trees will neither grow rapidly nor preserve their vigor. On the 

 semiarid plains wide spacing and frequent cultivation will produce 

 better trees than close spacing and little cultivation. 



Successful forest planting on the plains, w r here the rainfall is light 

 or irregular and the evaporation great, depends largely upon the 

 proper tillage of the soil. It is generally believed that no kind of 

 forest trees can be grown successfully on the high table-lands of the 

 southern portion of this region without irrigation. There is no 

 doubt that irrigation is necessary to grow trees from seed in a forest 

 nursery, but in plantations good tillage will usually suffice. 



The early tree planters often set their trees carelessly, and left them 

 to struggle with the native vegetation and dry weather. Planters 

 now realize that trees as well as agricultural crops respond to good 

 cultivation. The object of cultivation is twofold : First, to conserve 

 the soil moisture; second, to prevent the growth of weeds and grass. 

 The natural supply of moisture on the plains is sufficient for the 

 growth of many species of trees, provided it is fully utilized and not 

 allowed to escape through evaporation or to be appropriated by weeds 

 and grass. 



Cultivation should not be continued too late in the fall, since it 

 unduly prolongs the growth of tender young shoots which are unable 

 to withstand the early frosts. Except on irrigated land or on sites 

 where the ground water is near the surface, the planting of field crops 

 between rows of young trees is unwise, since the trees need all the 

 available moisture. The best implements for the cultivation of the 

 ground are the pulverizing harrow, the disk harrow, the dagger-tooth 

 harrow, and the five-tooth cultivator. The plow should never be used 



[Cir. 99] 



