322 GRAZING INDICATORS. 



reasons, chief among them the labor and expense involved and the great 

 difficulty of applying intensive methods to large areas. This is equally true 

 of the appUcation of fertiUzers to increase the growth of grasses, and of the 

 use of irrigation. The application of manure to worn-out pastures was a 

 logical extension of good farm practice, and there is little question that the 

 comjK)sition as well as the yield of native and artificial pastures can be varied 

 more or less at will by the scientific manipulation of different fertiUzers 

 (Skinner and Noll, 1919). However, such methods are limited to pastures 

 in which intensive yields are possible, and are not apphcable as yet to even the 

 smaller pastures of cUmax grassland. Irrigation has a somewhat broader 

 application to western ranges, because the lack of water is the chief limiting 

 factor to production. The cost of irrigation, however, is regularly too great 

 to permit its use, except in restricted areas, where an exceptional production 

 can be obtained. Even in the majority of such cases, the forage is worth 

 more as hay, and is handled in that form. 



Plant introduction on the range. The sowing or planting of desirable native 

 or cultivated species on the range has universally been suggested and often 

 attempted. One of the earliest trials was that of Georgeson (1895: 43), who 

 sowed a mixture of perennial grasses, clover, and bluegrass in the prairie near 

 Manhattan, Kansas. The tame grass made a splendid growth early in the 

 season, but by autumn it had everywhere yielded to the native dominants. 

 Bentley (1901: 16, 30) made extensive tests of native grasses when sown or 

 transplanted in the native cover. Transplanting gave much the best results, 

 practically all the native dominants establishing themselves successfully when 

 due care was taken as to the time and method of transplanting. The most 

 extensive series of experiments in seeding native grassland have been carried 

 on in the Southwest by Griffiths, Thomber, and Wooton between 1900 and 

 1915. As this is the most trying region for the introduction of new plants, it 

 affords the best idea of the difficulties involved. Griffiths has summarized 

 the results of seeding operations on the range reserves near Tucson, as follows : 



" Experimental work carried on thus far in attempting to introduce peren- 

 nial forage plants upon the mesas has given very little encouragement. Pani- 

 cum texanum, an annual, has given the best results of anything thus far intro- 

 duced, and it is believed that more success will be secured with annuals than 

 with perennials. They are not as good feed, but short-lived plants with good 

 seed-habits now furnish the main feed upon the mesas (1904: 61). 



"Many attempts have been made to introduce forage plants in this section, 

 both in the large enclosure and upon the holdings of private individuals. 

 There is but one species, alfilerilla {Er odium cicutarium), that has given any 

 beneficial results. In all, 200 species of forage plants have been tried in this 

 enclosure. Many native species were tried, but the vast majority used were 

 of foreign introduction. At one time the Office of Forage-Plant Investigation 

 of the Bureau of Plant Industry furnished more than 100 varieties for testing. 

 In some cases the seed was covered and in others scattered without any further 

 attention. The plan has been, whenever the quantity of seed permitted, to 

 sow one-half in the fall and one-half in the early summer. In some cases the 

 ground was worked up sufficiently to kill about half of the original vegetation. 

 The net economic result of all this foreign introduction has been practically 

 nil. Most of the species in our experience have never come up, and the few 

 things that did make any growth usually died before seed was produced. 



