BLACK WALNUT: ITS GROWTH AND MANAGEMENT. 43 



ever, should be protected from grazing for a period sufficiently long 

 to allow the trees to become reasonably safe from damage. The 

 period of protection from hogs should be about three years; from 

 cattle and horses, not less than 10 years. The farmer should, how- 

 ever, be cautious ; and, if grazing that has been started in a planta- 

 tion at the end of the tentative period of protection appears to be 

 damaging the trees, the stock should be removed for a year or two 

 longer. Damage from grazing results more from breakage of the 

 trees and from trampling and compacting of the soil than from 

 actual browsing. In one plantation in Indiana, for example, there 

 is a large opening which resulted from the feeding of corn to hogs, 

 a procedure that was continued through many j^ears. The excessive 

 trampling and compacting of the soil, together with the unusually 

 large accumulations of manure at one place, killed out the trees. 

 By wallowing in the depressions about the trees and laying bare 

 the roots, hogs occasionally damage trees planted in low, moist parts 

 of pastures. For this reason trees planted singly in pastures should 

 be set on the slight rises or slopes rather than in the hollows. On 

 account of the better drainage these sites dry off quickly after rains, 

 instead of holding pools of water or mud about the roots of the trees,- 

 and consequently they provide better shade places for cattle. 



ADDITIONAL COPIES 



OF THIS PUBLICATION MAY BE PROCURED FROM 



THE SUPERINTENDENT OF DOCUMENTS 



GOVERNMENT PRINTING OFFICE 



■WASHINGTON, D. C. 



AT 



20 CENTS PER COPY 



V 



