ESTABLISHING FORESTS BY PLANTING 



391 



emphasize the desirability of fertile soil next to the roots of newly 

 set plants. Although the trees remain alive when sterile soil is 

 used, the foliage assumes a lighter color and little or no new 

 growth takes place. In European practice fertile soil is usually 

 brought to exceptionally poor sites for use as a filling soil. Fer- 

 tilizers mixed with the native soil are also used for the same 

 purpose. 



34. The Advantages of Planting in Deep Notches 

 on Steep Slopes x 



The loosening of the soil incident to mountain planting is usu- 

 ally the cause of more or less erosion, particularly on exposed open 

 sites. When the plants are set flush with the surface soil, as is 

 the common practice on level land, they are likely to be badly 



A '''UliUlltliv B 



FIG. 107. 



A. Plant set in a step-like niche on a steep slope. 



B. Plant protected by stones on a steep slope. 



injured or destroyed through erosion. The author has witnessed 

 great injury from this cause in the mountains of New Mexico and 

 elsewhere in western United States. This danger can be avoided 

 by placing the planting hole in a deep, step-like niche. The size 

 of the niche should be determined by the size of the planting stock, 

 steepness of the slope, and the soil and climate. 



On shallow, rocky soils that do not permit . of making step- 

 like niches for the reception of the plants, stones, clods of soil, 

 or bits of wood should be placed on the slope just above the plant, 

 to protect it from erosion and assist in retaining moisture in the 

 surface soil (Fig. 107). 



