28 MISC. PUBLICATION 194, U. S. DEPT. OF AGRICULTURE 



ment Station shows that July is the most effective time to mow brush 

 such as soft maples, alders, birch, and blackberries. In the Northern 

 States apparently the "critical period" for brush is when the roots 

 contain the smallest amount of starch. Generally, this is at time of 

 bloommg. 



jThe eradication of sprouts and shrubs in the Southern States 

 appears to be much more difficult than in the North. Grubbing them 

 out or killing them with chemicals has so far seemed the only sure 

 way to eradicate them. Both these methods are expensive unless 

 labor is very cheap. 



Figure 8. — Arrangement for feeding cattle on pasture in New York State. Supplemental feed given on 



the pasture conserves fertility. 



EFFECT OF METHODS AND INTENSITY OF GRAZING 



It should be borne in mind that there are striking differences in 

 methods of grazing. Where beef cattle or sheep are grazed, much of 

 the manure is left on the pastures, and the land is enriched if the 

 animals are given additional feed on the pasture during the winter (fig. 

 8). This is usually not the case on dairy farms, where the cattle spend 

 much of the time in yards or stables. It is often remarked that "the 

 pastures are robbed to keep up the fertility of the plowed fields." 



Pastures should not be grazed too early in the spring in the Northern 

 States. At this time the soil is usually soft because the snow and froBt 

 have so recently disappeared, and in many localities rains are frequent 

 at this time. In addition, the plants must have an opportunity to 

 produce leaves and strengthen their root systems, otherwise their sub- 

 sequent growth will be reduced. In the South early grazing is not so 

 harmful. Grazing pastures closely in the late fall, thus preventing 

 any surplus growth of the plants before they enter their dormant 

 period, is harmful also, because they require some food reserves in the 



