334 ANNUAL REPORT SMITHSONIAN INSTITUTION, 195 7 



means, reminiscent of the introduction of clover into English farming, 

 there are almost limitless possibilities for increasing the fertility of 

 Australian soils. 



Superphosphate, subterranean clover, and a few trace elements have 

 the power to make at least much of southern Australia fertility- 

 producing. But the existence of the means is not enough to effect 

 the revolution. The high price of wool that resulted from the Korean 

 war gave a great fillip to soil improvement, but will not last forever. 

 The Australian people, however, are already three-quarters urban and 

 are developing secondary industries which should produce a surplus 

 of wealth with which to fertilize the soil. Australians occupy a huge 

 continent and are concentrated mainly in five large cities. It remains 

 to be seen how far the fertilizing influence of these five widely sep- 

 arated cities will spread into the outback, most of which is still in 

 the shifting-cultivation stage. 



TROPICAL LANDS 



In the mostly thinly populated areas within tropical latitudes, Man 

 has seldom succeeded in ousting the plant world from its dominant 

 position in the soil's economy. The Indian subcontinent is the best 

 existing example of permanent tropical agriculture that has continued 

 for centuries. It is also one of the most densely populated of tropical 

 countries. As elsewhere in the Tropics, the basis of this permanent 

 agriculture has been paddy cultivation in which flooding suffices to 

 maintain plant nutrients in the soil at a level adequate for at least sub- 

 sistence production of rice. The example of other countries, like 

 Japan and Australia, shows that rice yields could be greatly increased 

 in India by fertilizers, mechanization, use of high-yielding varieties, 

 etc., and there should be no difficulty in providing all the people of 

 India with adequate food from her soil, if the wealth to fertilize the 

 soil were there — which, of course, it is not. There is far too high a 

 proportion of the people on the land for its efficient utilization, and 

 they are too poor to fertilize it. The rapid increase in India's rural 

 population within the last century seems to have accelerated soil ex- 

 haustion, at least as far as soil erosion is symptomatic of it. There 

 has been no increase in average crop yields during this century. This 

 may indicate the normal exhaustion phase of soil evolution under Man, 

 to be followed by a conservation phase when the country has been 

 urbanized and enriched by industry, or it may represent a later phase 

 in which society is too old to adapt itself to the creation of soil fertility. 

 The Indian Government is exerting every effort toward industrializa- 

 tion, wherein undoubtedly lies the main hope for the future fertility 

 of Indian soil. 



