BETTER ADAPTATION OF PLANTS 357 
Sampson goes on to say: “A knowledge of agronomy and animal 
husbandry, however, is highly useful to the range manager, though 
these subjects apply less directly to the understanding and solu- 
tion of range problems than such subjects as plant physiology, 
ecology, and taxonomic botany.” Evaluating the range in terms 
of its climax status presupposes that the climax vegetation is the 
most productive or most economical (64). It is encouraging to see 
different ideas expressed by some workers in America (40, 45, 48), 
New Zealand (49), and Uruguay (57). 
How Can We Develop a Program of Revegetation? 
This question may have been directed to the broad program 
after basic research information is available. It will be discussed 
in two parts: research and development. 
Avenues of Research 
There are several aspects to revegetation, any one of which 1s 
more applicable to some land than to others. On some ranches a 
combination may be used with great benefit to the whole opera- 
tion. These aspects are fertilization, use of competitive plants, 
seeding of long-lived species, and special problems. 
1. Fertilization of Otherwise Unimproved Range. Research in 
California has shown two ways that fertilization can be used to 
improve forage yields: first, the use of phosphorus or sulfur to 
increase the yield of resident legumes (2, 9, 10, 38); second, the 
use of nitrogenous fertilizers alone or in combinarian with phos- 
phorus and sulfur to increase total production and also to provide 
feed earlier in the season (25, 33, 38, 46). In extensive tests Martin 
and Berry found that yields of meat could be increased two- to 
fivefold, the better soils providing the lower increases and the 
poorer soils, the higher increases. Conrad (10) has developed an 
“exploratory” test method for this purpose (Figure 1). 
2. Fertilization of Improved Seeded Range. his will be dis- 
cussed in the following paragraphs. 
Use of competitive plants. The fact that on many soils annual 
legumes respond to phosphorus or sulfur fertilization makes possi- 
ble an important development in range improvement. A dense 
