THE PLAINS SHELTERBELT PROJECT 



and summer. Altogether, however, the deciduous or hardwood trees 

 appear better adapted to the plains conditions than evergreens, with 

 the exception of red cedar and ponderosa pine. Thus the mass effect 

 of tall and sheltering trees and shrubs with a combination of ever- 

 greens and deciduous trees will create an effective and dense barrier 

 against the winds. Openings in the shelterbelts will be left for roads, 

 cattle lanes, and other local purposes. 



Before planting, the ground is plowed and fallowed for at least one 

 summer to accumulate moisture. Deep penetration of the moisture 



FIG. 135. Black locust plantation five years old, spaced 4x6 feet, near Medicine 



Lodge, Nebraska. 



is desirable if deep-rooted trees are to be used. This will be obtained 

 by impounding by means of pits, side ditches, contour listing, and 

 other measures in connection with ground preparation and cultivation 

 as a means of sure survival and to encourage maximum height growth. 

 Thus, moisture conservation is one of the major factors considered 

 in planting and especially with shelterbelts. Weed growth will be dis- 

 couraged by cultivation for several years after planting or until the 

 trees shade the ground sufficiently to suppress such growth. Later the 

 mulch provided by the leaf litter will serve the purpose of moisture 

 conservation in the soil. 



