SOILS AND FERTILIZERS 351 



The structure of the soil as determining the compactness and 

 affecting root penetration and aeration, as well as drainage condi- 

 tions, has much to do with crop adaptation. The crawfish lands of 

 Tennessee are extreme types of soils which run together when wet 

 into an almost impenetrable mass. 



Economic conditions are changing constantly, and these may 

 make of great value soil areas that heretofore have scarcely been 

 considered worth cultivation. The introduction of bright yellow 

 tobacco in North Carolina, for instance, increased the price of the 

 sandy lands tenfold. Some of the sandy types, which thirty or 

 forty years ago would have been classed as of low rank, have by 

 special adaptation to truck growing been changed during the last 

 generation to a position of the highest rank. Similarly, by reason 

 of special adaptation, some of the stony loams and clays have passed 

 from the lower to the higher ranks. 



The peculiar adaptation of soils to special crops has long been 

 recognized. The hot-house lettuce of Boston has been esteemed 

 the finest product of the kind received in the New York markets. 

 The soil used for the production of this lettuce is peculiar to the 

 locality. It is probable that some of the soils which are regarded 

 as unproductive and unsuited to the production of staple crops, 

 may be found peculiarly adapted to new crops for food, drugs, or 

 fibre, or plants might be adapted to them by introduction and 

 breeding. Thus the light sands of the Coastal Plains, which a few 

 years ago were considered quite worthless for agricultural crops, 

 have become profitable by the introduction of truck crops. Also 

 the utilization of the valueless coast prairie lands of Louisiana and 

 Texas for rice culture, by the introduction of a variety of rice from. 

 Japan. There are large areas of soils in the United States not now 

 profitably cultivated to crops because they are unsuited to any of the 

 staple crops. 



Much is being accomplished through the development of irri- 

 gation systems, as well as through the reclamation of swamps and 

 overflowed lands adapted after reclamation to special crops of high 

 value, for example, truck crops, peppermint, celery, onions, and the 

 like. We have, however, an apparently even more difficult prob- 

 lem in the utilization of some of the extremely sandy soils or bar- 

 rens, where the sand is so loose and incoherent, so deep and dry, 

 that none of our present crops are adapted to them. We also have 

 large areas of gravel soils and stony soils that are of little use, al- 

 though with the same amount of gravel and stones in other soils 

 we can adapt them to very profitable purposes. We also have the 

 extreme types of plastic clays, like the Susquehanna clay, covering 

 large areas, very poorly adapted to any of the common crops, poorly 

 adapted to fruit or forest growth, and which are so costly to im- 

 prove that they are at present practically useless for profitable agri- 

 culture. It would seem that some kind of crop or some industry 

 could be devised for the profitable utilization of these at present 

 useless lands if the problem were conscientiously studied. We have 

 the utilization of vast areas of cut-over pine lands, and the people 



