aEOLOGICAL CLASSIFICATION OF SOILS 49 



Table VII 



CHEMICAL ANALYSES OF TWO ALLUVL^L SURFACE SOILS AND THE 

 RESPECTIVE SURoFACE SOILS FROM WHICH 



XxlXiX WJcitCJCi JJJiiJtviVJili/, 



Constituents 



1 



Alluvial 



2 



Upland 



3 



Alluvial 



4 

 Upland 



N 



.073 



.076 



1.697 



1.103 



.048 



.041 



1.330 



.200 



.173 

 .118 

 .433 



.417 



.038 



P2O5 



.027 



K2O 



.286 



CaO 



.221 



Delta soils, where they occur in any acreage, are very im- 

 portant. The deltas of the Mississippi, Ganges, Po, Tigris, 

 and Euphrates rivers are striking examples. Egypt, for 

 centuries the granary of Kome, bespeaks the fertility of such 

 land. Flood plain soils are found to a certain extent along 

 every stream, the greatest development in the United States 

 occurring along the Mississippi. This area varies from forty 

 to sixty miles in width and has a length from Cairo to the 

 Gulf of over 600 miles. Such soils are very rich but, if 

 they are first bottoms, they require drainage and protection 

 from overflow. Alluvial fan soils are found over wide areas 

 in arid and semi-arid regions and when irrigated and prop- 

 erly handled have proven very productive. They often occur 

 in large enough areas in humid regions to be of considerable 



* Williams, C. B., et al., Beport on the Piedmont Soils; Bui. IST. 0. 

 Dept. Agr., Vol 36, No. 2, Feb., 1915. 



1. Average of 8 analyses of Piedmont alluvial soils, Congaree 

 series, to a large extent a wash from the Cecil. 



2. Average of 71 analyses of Cecil series soils, the typical upland 

 soil of the North Carolina Piedmont. 



Williams, C. B., et at, Eeport o% the Coastal Flam Soils; Bui. N. C. 

 Dept. Agr., Vol. 39, No. 5, May, 1918. 



3. Average of 8 analyses of coastal plain alluvial soils, Johnston 

 and Kalmia series. 



4. Average of 165 analyses of Norfolk series soils, the typical 

 upland coastal plain soil of North Carolina. 



