SCIENCE IN MAN’S STRUGGLE ON ARID LANDS 43 
difficult phases of the problem are economic. Let us suppose that 
a farmer starts a cereal grain farm on a holding of some 600 acres 
on soil unsuitable for crop use on a sustained basis. A great many 
have done just that. In a few years when it is clearly established 
that the soil cannot be maintained in production except under 
grass, how is he to manage to enlarge his unit? A unit economical 
for grazing would be much larger. During the transition period of 
reseeding and low-carrying capacity, how is the farmer to live 
and pay expenses? Large numbers of cultivators on the edge of 
the desert in the Near East, for example, were born into such a 
situation. 
Despite advances in natural science, clear answers to the tough 
problems of adjustment are lacking. More nearly appropriate 
institutional techniques are needed. 
Irrigation Farming 
The improved methods for irrigation farming have already 
been explained. It has been estimated that we have many more 
millions of acres of arid soil in the world that could be developed 
(3). Yet irrigation can be overdone. Where arable soil exists only 
in small areas, intermingled with land suitable only for grazing, 
the cutting out of these small irregular areas for industrial crops, 
such as cotton and sugar beets, harms the use of the region as a 
whole. It is by conserving such soil areas for hay and feed crops, 
rather than using them for other crops, that efficient use can be 
made of the range land. 
Even at best irrigation is an expensive undertaking. If it is to 
be done, it should be well done so that water is properly controlled 
and so that other limiting factors, such as low fertility, salinity, 
hazards of soil blowing, and waterlogging are avoided. 
We have the scientific techniques to make these determinations. 
We have fairly good methods for the economic analyses of the 
results over short-run periods; but good methods for appraising 
the long-run economic benefits and costs of irrigation are lacking. 
Thus, given accurate soil surveys, current research results for 
guiding the physical management of arid lands are more nearly 
adequate to our present problems than those for guiding their 
social management. 
