74 NATURAL RESEEDING AND MAINTENANCE 



numerous nutritious grasses, especially species that produce 

 large seeds. On the other hand, annual plants, with their strong 

 seed habits, and especially those with small, round, heavy seeds 

 reproduce exceedingly well. Thus yearlong protection favors 

 the recuperation of only the vegetation already in existence. 

 As this plan fails to accomplish the planting of the seed, it likewise 

 fails to accomplish the reproduction of a large proportion of the 

 most important pasture plants. 



In summing up the results of the practice in question, the 

 writer states:^ " Yearlong protection is not an efficient one, be- 

 cause the most valuable perennial species fail to reproduce by 

 seed. While the carrying capacity of the land is increased, 

 this increase is slow and does not compensate for the waste of the 

 forage crop during the long period necessary for revegetation.'' 



Deferred Grazing. — The two grazing systems discussed fail 

 to accomplish revegetation because they are not based upon the 

 growth requirements of the vegetation. What is known as the 

 deferred-grazing system takes into account the requirements of 

 plant growth from the time of the germination of the seed until 

 the seedHng plants are thoroughly established. After that it aims 

 to maintain the forage cover at all times in a high state of vigor. 



The essential principles of the deferred-grazing system are: 

 (i) An overgrazed area, sufficiently large to supply the forage 

 from the time of seed maturity until the end of the grazing 

 season, is protected from stock until the seed crop has matured. ^ 

 (2) Upon maturity of the seed crop the forage is grazed closely 

 during the first season, but not to the extent of injuring the seed 

 plants. (3) The same area is protected to about the same date 

 in the second season and longer if necessary, or until the new 

 plants have been thoroughly established. (4) When the area 

 has been satisfactorily reseeded, it is grazed early in the season, 



' Sampson, Arthur W., "Natural Revegetation of Range Lands Based upon 

 Growth Requirements and Life History of the Vegetation." U. S. Dept. of Agr., 

 Jour, of Agr. Research, Vol. 3, No. 2, p. 125, 1914. 



^ Sod-forming grasses withstand cropping better than do bunchgrasses, yet when 

 sod-forming plants are overgrazed their decline in yield is marked and conspicuous. 

 It is a good practice, therefore, to defer the grazing occasionally on weakened sod- 

 forming lands, as elsewhere, until the spring growth is reasonably well advanced. 



