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MINNESOTA BOTANICAL STUDIES 



tation of dune regions. Massart's conclusions were supported by 

 very careful observations and soil-analyses, but it seems that a 

 knowledge of the mere chemical composition of the sandy soil fur- 

 nishes little indication of its nutritive content. Several ruderal 

 species in our sandhills develop a luxuriant cover in apparently 

 sterile sand if certain soil-moisture conditions are fulfilled. 



Alway and Bishop (1) have made chemical analyses of the soil 

 from many portions of the state including the sandhills and I repro- 

 duce herewith one of their tables (somewhat abridged), showing 

 especially the nitrogen content of dune sand from this region. 



COMPOSITION OF SOIL SAMPLES FROM SANDHILLS 



These writers state that "3. much higher percentage of nitrogen 

 and humus occurs in the surface soil of the basins and valleys of 

 these sandhills." The comparison of these figures with those 

 secured by the same investigators from prairie uplands in eastern 

 Nebraska brings out rather striking differences. 



COMPOSITION OF SOIL SAMPLES FROM PRAIRIE UPLANDS 

 IN EASTERN NEBRASKA 



In some of the valleys toward the eastern limits of the sandhill 

 region and about the headwaters of the streams and near many of 

 the lakes of the region, there are lowlands where silting-in has been 

 accomplished to a considerable degree and where one may pass in 

 a short distance from the practically "pure" dune sand of the uplands 

 to the fertile dark silt loam of an old marsh. Such silty material is, 

 however, rarely more than a few inches in depth and in many 



