CHAPTER IV 
THE WORLD’S CEREAL AND FOOD-CROPS AND ITS 
MINERAL NEEDS 
In order to get something like an accurate idea of the 
possible extent available of the world’s surface, for 
the growth of the cereals and food-crops required to 
meet its inhabitants’ needs, we note that if the land- 
areas of the whole world, of Japan, and of the United 
States be compared, we get the following significant 
facts, viz.:—For the whole earth 31-2 per cent. is 
actually productive in some way; for the United 
States, 27-8 per cent., which may ultimately be raised 
to as much as 42-0 per cent.; and for Japan, 78-3 per 
cent. The land classed as arable, however, is only 
9-98 per cent. for the whole world; 18-39 per cent. 
for Japan; and as existing in the United States at 
present 15-17 per cent., which however might possibly 
be increased to say about 24 per cent. as an ultimate 
limit. The actual areas utilised for the growth of 
cereals and food-crops are, however, less than this. For 
different countries they are, as one would expect, very 
different proportions of the whole, ranging from less 
than one in a thousand to over 43 per cent. Thus 
in many cases the proportion actually cultivated 
for cereals and food-crops is much greater than the 
world-average of the land classed as arable. The 
following table will give a more definite idea of the 
great range in the proportions devoted solely to the 
cultivation of cereals and food-crops:—