Consequences of Using Arid Lands 
Beyond Their Capabilities 
CYRIL LUKER 
Soil Conservation Service, United States 
Department of Agriculture, Washington, D. C. 
“Using land within its capability” is a phrase that has come to 
have special significance in the soil and water conservation work 
of the United States Department of Agriculture. It means recog- 
nizing the physical limitations affecting each acre of land and being 
guided by those factors into the kind or kinds of use for which the 
land is best suited, and under which it can produce most efficiently 
on a sustained basis. 
The consequences of using any land beyond its capability are 
generally adverse. This is especially true of the arid lands. In arid 
climates the balance between land, water, and people 1s more 
critical than in any other agricultural province. When the balance 
is upset the consequences are generally more severe than in humid 
areas because recovery from the effects of overuse usually takes 
longer in arid zones. 
In the technical assistance program of the Soil Conservation 
Service in the United States, soils are grouped into eight capability 
classes for purposes of dealing with land-use problems. This pro- 
vides an especially effective approach in arid and semi-arid areas 
where land condition and production are so sensitive to land use. 
These eight classes range from Class I, which is the best kind of 
farm land to Class VIII, which is land with such severe limitations 
that it cannot be used for forestry, grazing, or cultivated crop 
production. 
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