218 



SOILS. 



most commonly the plowing was done " up-hill and down," so that the 

 " dead-furrow " afforded a ready opportunity for the formation of washes 



cutting into the subsoil, during the 



torrential rains sometimes falling 

 during the summers. Even when 

 filled with soil by plowing, these 

 washes would frequently re-open 

 during rains, shedding the soil in a 

 muddy flood upon the lower lands. 

 The washing-away of the surface 

 soil, thus brought about, of course 

 diminished the production of the 

 higher lands, which were then com- 

 monly " turned out " and left with- 

 out cultivation or care of any kind. 

 The crusted surface shed the rain 

 water into the old furrows, and the 

 FIG. 40. Erosion in Mississippi Table Lands, latter were quickly deepened and 



causing destruction of agricultural value both of . . , . . ... , 1,1 



Uplands and Valleys. (McGee, th Ann. Kept. Widened into gullies "red Washes 



u. s., 1890-91.) whose presence rendered any 



resumption of cultivation difficult. In the course of a few years the 

 soil-stratum of brown loam was penetrated into the loose or loosely 

 cemented sand which underlies it almost everywhere, and is very readily 



FIG. 403. Erosion in Mississippi Table Lands, causing destruction of agricultural value both of 

 Uplands and Valleys. (McGee, izth Ann. Kept. U. S. G. S., 1890-91.) 



washed away. Soon the water, gaining yearly in volume, undercut the 

 loam stratum so_as to cause it to "cave" into gullies in huge masses, 



