30 



EXPERIMENTS IN BLUEBERRY CULTURE. 



blneberr}^, was distinctly alkaline. A chemical analysis of this mold 

 showed that it contained 2.86 per cent of calcium oxid. 



The good blueberry soils in all the experiments were acid, the acidity 

 at times of active growth varying from 0.025 normal down to 0.005 

 normal. 



It is of interest and suggestive of utility in indicating the acid or 

 nonacicl character of soils to record that in the case of the alkaline 

 leaf mold described on page 24 the surface of the soil in all the pots 

 became covered in a few months with a growth of a small moss iden- 



tified through the courtesy of Mrs. N. L. 



Britton as Physcomitrium 

 iminersum. On the sur- 

 face of acid kalmia-peat 

 soils the characteristic 

 green growth consisted of 

 microscopic alga^, accom- 

 l^anied often by fern pro- 

 thallia and other mosses, 

 but never Physcomi- 

 trium. 



The natural distribu- 

 tion of blueberries and 

 their relatives indicates 

 their close adherence to 

 acid soils. They occur in 

 abundance throughout the 

 sandy Coastal Plain of the 

 Atlantic seaboard. They 

 occur generally through 

 the cool humid hill lands 

 of New England. They 

 occur in sandy pine bar- 

 rens and peat bogs 

 throughout the eastern 

 United States. They are absent, on the contrary, from limestone 

 soils, rich bottom lands, and rich woods, where the soils are neutral 

 or alkaline. In the lower elevations of the whole subarid West, where 

 acid soils are almost unknown, these plants do not occur. Within 

 reach of the fogs and heavv rainfall of the Pacific coast or on the 

 higher mountains of the interior, where conditions favor the devel- 

 opment of acid soils, blueberries occur again m characteristic abun- 

 dance. 



From an examination of the reports of those who have attempted 

 at the agricultural experiment stations to domesticate and improve 

 the blueberry, it is evident in the light of the present experiments 

 that the primary reason for these failures was that they did not recog- 



193 



Fig. 9. — Blueberry seedlins fed with alkaline nutrient 

 solution. (Natural size. ) 



