574 



THE NATIONAL GEOGRAPHIC MAGAZINE 



of waste, but their ultimate exhaustion 

 is unavoidable. With agricultural and 

 forest land, however, it is otherwise. 

 Eand cannot only be conserved, but 

 constantly improved and its yield in- 

 creased. While in England the iron 

 ores and the coal are becoming con- 

 stantly harder to get and their exhaus- 

 tion is threatened, the agricultural land, 

 after a thousand years of cultivation, is 

 now more productive than ever. The 

 wheat fields of England under intensive 

 cultivation yield 30 bushels to the acre, 

 while the virgin fields of America on an 

 average yield less than 13. 



If a far-sighted national policy in the 

 conservation of natural resources is to 

 make provision for an ever-increasing 

 population, then the greatest possibili- 

 ties lie in the direction of developing the 

 land in all its forms — field, forest, and 

 range — for, notwithstanding all possible 

 economy in the use of the non-renewable 

 resources, they are bound to decrease as 

 time goes on. 



THE USES 01- OUR LAND WILL, CHANGE 

 GREATLY 



One hundred years ago the United 

 States east of the Mississippi River was 

 an almost unbroken forest, comprising 

 something over 1,000,000 square miles, 

 or about 700,000,000 acres. Now, after 

 about a century of settlement, there are 

 not more than 300,000 square miles of 

 merchantable forest land in the eastern 

 United States. About 330,000 square 

 miles have been cleared for farm land. 

 The remainder has been culled of its 

 valuable timber and devastated by fire 

 or else turned into useless brush land. 

 With the growth of population and the 

 greater demand for agricultural land, the 

 ratio between farm and forest land will 

 change still further. The forests will 

 be more and more crowded into the 

 mountains and upon soils too thin or too 

 poor for agricultural purposes. It may 

 be safely assumed that in fifty or one 

 hundred years the proportion of land 

 devoted to the different purposes will 

 change almost as much as it has during 

 the past century. These changes will 



occur especially in the eastern part of 

 the United States, because there the for- 

 est is not confined, as it is in the West, 

 to high altitudes, where agriculture is 

 generally impracticable. In the West 

 the forests, with a few exceptions, as in 

 the low country around Puget Sound, 

 are in the high mountains, which rise in 

 the midst of semi-arid plains, and their 

 original area of 150,000 square miles, 

 half of which lies in the Sierra Nevada 

 and in the Cascades and half in the 

 Rockies, has changed but very little 

 since settlement. In the West the in- 

 crease of agricultural land must be se- 

 cured chiefly through the irrigation of 

 the semi-arid land. 



If we take a long look ahead into the 

 future and try to picture to ourselves 

 what will be the ultimate proportion of 

 farm, forest, range, and desert in this 

 country fifty years from now, in the light 

 of the increasing demand for agricul- 

 tural land and of an approximate knowl- 

 edge of the climatic conditions and the 

 physical properties of the different lands 

 in this country, we shall get something 

 like the condition shown in the diagram 

 on page 575. 



ONE-HALE OE THE UNITED STATES WILL BE 

 CULTIVATED 



The area devoted to agriculture in a 

 half century, instead of being 21 per 

 cent of the total area, as it is now, will 

 be nearer 50 per cent. That this is not 

 an overestimate is indicated by the fact 

 that during the last fifty years the im- 

 proved farm land in this country has 

 advanced from 113,000,000 acres to 

 415,000,000 acres, an increase of nearly 

 370 per cent. 



With more intensive methods of culti- 

 vation larger yields will undoubtedly be 

 obtained from the same area, yet the 

 aiea itself under agricultural crops will 

 have to be increased, especially if we are 

 to remain an exporting country. 



In Belgium the arable land forms 63 

 per cent of the total land area, in Den- 

 mark 68, in France 48, and in Germanv 

 47. These countries are not exporters 

 of cereals, although their methods of 



