The production of herbage from pastures in the humid eastern half 

 of the country can be increased by as much as three times with 

 improved practices. 



Pasture yields are assumed to increase by 50 percent 

 or to 4 AUM's of grazing per acre by 2030. By 2030, 

 pasture yields per acre would be less than 50 percent 

 of cropland pasture yields. Under these yield esti- 

 mates, pasture could provide 454 million AUM's of 

 grazing by 2030. 



Range Sources 



Range grazing trends. — The supply of range graz- 

 ing has historically followed the pattern of changing 

 beef cattle numbers and the price relationships of 

 range grazing to other livestock feed sources. Range 

 grazing increased as the West was settled and peaked 

 during the food crisis of World War I, especially on 

 Federal lands. Thereafter, it stabilized at a somewhat 

 lower level. From the 1940's until the present, most of 

 the increases in livestock feed for the rapidly growing 

 beef cattle numbers were supplied, not by range graz- 

 ing, but by increased use of grain and by roughage 

 sources formerly used for dairy cattle, sheep, and 

 horses. Thus, the production and use of range grazing 

 has been relatively unchanged. In 1976, range pro- 

 duced about 213 million AUM's of livestock grazing, 

 the same produced in 1970. Extending this 1970 to 

 1976 trend to 2030, the supply of range grazing would 

 remain about 213 million AUM's of grazing if the 

 investment in range improvement is not increased 

 above the current level. 



Biological potential. — The Nation's range has the 

 physical capacity to produce more grazing to meet 

 projected demands. The ultimate biological potential 

 production from the range has been estimated at 566 

 million AUM's, more than 2Vi times the 1976 supply 



level of 213 million AUM's. This could be achieved 

 by applying intensive management levels on all of the 

 more than 1 billion acres of range. This production 

 level (566 million AUM's) is not attainable as a prac- 

 tical matter because much of the range is used for 

 other purposes, such as timber production; the 

 increased management for range grazing purposes 

 would adversely affect production of timber and 

 other range outputs. 



A more useful estimate of biological potential is 

 derived by considering only that portion of the range 

 which is currently being grazed (789 million acres) as 

 available for intensive management. Under intensive 

 management, improved grazing systems and range 

 developments are used to maintain and improve the 

 condition of the range ecosystems. Since ranges in 

 less than good condition produce less forage than 

 those in good condition, improvements can be rea- 

 sonably expected to increase production. An illustra- 

 tion of this that does not consider the economic feasi- 

 bility of such improvements follows: 



The largest rangeland ecosystem, plains grasslands, 

 occupies 175.2 million acres and has a natural aver- 

 age potential production of 1,016 pounds per acre 

 (table 2.6). About 25.8 million acres are in good con- 

 dition, 59.9 million acres are in very poor condition 

 (table 5.2). If the 172.4 million acres grazed in this 

 ecosystem were improved to good condition, thereby 

 achieving an average production of 1,016 pounds per 

 acre from all lands in the ecosystem, the expected 

 increase in production would be 21.2 million tons of 

 herbage and browse (table 5.15). This is a third more 

 than the 66.4 million-ton production now obtained 

 from the ecosystem. Similarly, production could be 

 increased from the smaller but more productive 

 prairie ecosystem by 14.3 million tons, from sage- 

 brush by 13.8 million tons, and from desert shrub by 

 1.4 million tons. 



The biological potential for grazing on the Nation's ranges is more 

 than two and a half times current production levels. 



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