ARTIFICIAL BESEEDING ON WESTERN MOUNTAIN RANGE LANDS 11 



sheep grazing was figured at $0.75 a head for the season, and interest 

 on the cost of seeding at the rate of 6 per cent compounded annually. 

 The interest charged exceeded returns for grazing until the tenth 

 year after the seeding was done. Following that year, however, the 

 value of the grazing was adequate to pay a fair income and, in the 

 eighteenth year after sowing, the investment will be retired and divi- 

 dends thereon will be realized. Kentucky bluegrass is a highly per- 

 sistent and long-lived plant. It is able to spread by rootstocks and, 

 if properly managed, maintains itself indefinitely. 



In another example, where common bromegrass was used, it re- 

 quired eight years for the original cost and the accrued interest to 

 be retired. The total cost of seeding in this instance was $3.28 an 

 acre. The carrying capacity under full production, which began in 

 the third year after reseeding, was 1 acre for a sheep for a 90-day 

 season. Grazing was valued at $0.75 a head for the season, and 

 interest was computed at the rate of 6 per cent on the initial cost of 

 seeding. Common bromegrass is a long-lived plant that spreads by 

 rootstocks and should not require reseeding for many years. 



The third example deals with an area sown to timothy in a region 

 where this species will grow well. The original cost of seeding 

 amounted to $1.34 an acre. Grazing is valued at $0.75 a sheep for 

 the 90-day season. The area was fully producing the third year after 

 seeding, the carrying capacity being 1.2 acres for each sheep. In 

 this instance, because of the relatively low original cost, the return 

 from the increase in forage supply exceeded the interest charge in 

 the third year after sowing, and the original cost was retired in a 

 little more than four years. After about eight years, as frequently 

 happens with timothy, the stand began to thin out, although after 

 16 years many plants were still in evidence. 



SITE CONDITIONS SUITABLE FOR RESEEDING 



'\Aniether introduced plants will grow depends upon the suitability 

 of growing conditions on the range, including moisture, length of 

 growing season, character of the soil, and the extent of the native 

 vegetation with which the seeded plants will have to compete. These 

 points are discussed in detail in the following pages. 



MOISTURE REQUIREMENTS 



Moisture is the most important single factor to consider in arti- 

 ficial reseeding of practically all western mountain range lands. 

 (Fig. 1.) The chief exceptions are in the Cascades of Washington, 

 on the western slope of the Cascades of Oregon, and in the Sierra 

 Nevada and coast ranges of California, where the rainfall is heavy 

 enough to allow sufficient moisture for growth of introduced species, 

 even when much of the precipitation is lost in run-off and evapora- 

 tion. Species differ somewhat in moisture requirements, but none 

 have been found that give satisfactory results where the annual pre- 

 cipitation is less than approximately 17 inches, of which not less 

 than about 6 inches falls during the main growing season. "Wlien 

 special effort is made to prepare the soil for conservation of mois- 

 ture, fairly satisfactory results have been obtained with certain dry- 

 land forage crops in the Southwest with 15 inches of rainfall and 



