TENURE AND USE OF ARID GRAZING LANDS. 9 
Since nearly all of the forest and woodland is operated as arid 
grazing land, it follows that over half of the area of the 1 1 Western 
States is used as arid grazing land and must continue to be so used. 
Practically all the Government land remaining unreserved is arid 
grazing land and lies scattered in smaller or larger parcels among 
lands of other tenure in all of these States. Hence the conclusion 
is reached that the land policy under which the disposal of these 
lands is made is of great importance to one of the principal in- 
dustries, occupying about half the area in the western half of the 
country, and employing many people. 
SOME FACTORS CONTROLLING STOCK RAISING ON ARID GRAZING 
LANDS. 
In the business of raising stock on the arid grazing lands, prac- 
tices which may be adopted are automatically limited by (1) physical 
or natural factors, like climate, soil, topography, etc., (2) the resultant 
forage crop, and (3) social and economic conditions, such as the 
laws and customs which determine the method of using the land, 
the marketing conditions, the methods of financing the business. 
THE NATURAL CONDITIONS. 
The natural conditions governing the stock-raising industry are 
those which determine the quantity and kind of feed that maybe 
produced and the time at which it may or must be used. 
The quantity of feed produced per acre in any part of the arid 
grazing region is usually small, much smaller than that grown on 
an equal area of cultivated land. Hence the area of land necessary 
to produce sufficient feed for an animal for one year is always large 
as compared with the area required to produce feed for an animal 
of the same kind on a farm. Rarely less than 7 to 10 acres and often 
more than 50 acres are required to support a mature cow, or equiv- 
alent live stock, for a year. For the southwestern states (not in- 
cluding the desert area) the average is approximately 30 acres per 
cow. 
This region receives relatively little precipitation, there are a 
large number of clear days during the year, and ordinarily a very 
dry atmosphere. The plants are subjected to strong light, high 
daily temperatures, sudden and large changes in temperature,- and 
a wide annual range of temperature, as well as a limited supply 
of moisture. The different adjustments of these factors of moisture, 
heat, and light, modified to a greater or less degree by the soil and 
topography, determine the area over which each kind of plant may 
grow. The combination of plants growing over an area forms the 
plant association for that area, and the plant association determines 
in a broad way the grazing capacity for live stock. 
60835°— 22— Bull. 1001 2 
