62 NATURAL RESEEDING AND MAINTENANCE 



wiped out. Although it is impossible, in the light of our present 

 imperfect knowledge, to declare definitely what the optimum 

 grazing capacity of a given range unit is, the pasture should be 

 so stocked that at the end of an average year a small amount 

 of forage remains. The most successful cattle and sheep growers 

 of today are grazing their lands on an optimum basis. A large 

 proportion of their unsuccessful neighbors, on the other hand, 

 are cropping the pasture each year to the maximum. The 

 ranches owned by the latter men either are mortgaged or are 

 passing into new hands through foreclosure. The financial loss 

 that the stockman suffers because of failure to recognize and 

 meet the requirements of plant growth is so great that it can not 

 be even approximately estimated. Fitting the grazing plan into 

 the growth requirements of the vegetation greatly benefits the 

 stockman and stabilizes the livestock industry; it is favorable 

 to the irrigation farmer because it regulates the streamflow; 

 and it is an essential element in the preservation of soil fertiUty. 



REQUIREMENTS OF PLANT GROWTH 



The most important objects sought in the revegetation of 

 native pastures are a continuous, vigorous growth and ample 

 seed production. The most important points in this connection 

 are: (i) Extent of forage development when the stock is ad- 

 mitted in the spring; (2) seed production and the time when 

 the seed is scattered and planted; and (3) establishment of the 

 seedhng plants. 



Forage Production in Early Spring. — The \'igor of pasture 

 vegetation may be readily determined by the time growth 

 starts and the amount of forage produced in early spring. Any 

 plant that develops an abundance of leafage early in the season 

 had a large amount of food stored in the roots the previous year 

 and, hence, is in a healthy, vigorous condition. When, however, 

 the plant is repeatedly robbed of its green leafage during the 

 summer, not only is growth in the following spring much de- 

 layed but the amount of herbage produced is small. ^ Vegetation 



' 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, pp. 101-115, 1914. 



