Smithsonian Report, 1949.—Kellogg 
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A, profile of a dark-colored soil developed under tall grasses in lowa (Webster clay loam—a Wiesenboden). 
During its development drainage was poor, which has intensified the effects of the grasses in producing 
abundant supplies of humus and kept leaching at alow point. When drained this is one of the most pro- 
ductive soils in the world for the crop plants of temperate regions. (Photograph by Dr. R. W. Simonson.) 
B, profile of a light-colored, leached soil developed under forest in the humid Atlantic Coast Plain (Ruston 
sandy loam—a Red. Podzolic soil). In this environment little humus accumulates in the soil and 
leaching is active. ‘The thick black layer so prominent in the Webster soil is essentially absent. Col- 
loidal material has left the surface horizon, and part of it has been moved to the layer beneath. The 
peculiar mottling of the soil in the lower part is characteristic of those developing in warm humid climates. 
Although not naturally productive for crop plants, this soil can be made so through proper fertilization to 
supplement the plant nutrients already in the soil, crop rotations that emphasize the deeply rooted leg- 
umes, and by water-control systems that prevent accelerated run-off and erosion when cropped. (Photo- 
graph by Dr. R. W. Simonson.) 
