32 EXPERIMENTS IN BLUEBERRY CULTURE. 



fungi, and other organisms by which ordinary decomposition pro- 

 gresses can not live under this condition and decay is suspended. 

 The acids developed by this vegetable matter in the early stages of 

 its decomposition are also destructive to some of the organisms of 

 deca}^, especially bacteria. These acids act therefore as preserva- 

 tives and greatly assist in preventing decomposition. So effective 

 are these conditions of acidity and lack of oxygen, assisted in north- 

 ern latitudes by low temperature, which is also inimical to the organ- 

 isms of decay, that bogs sometimes preserve for thousands of years 

 the most delicate structures of ferns and mosses. 



Tests have been made of the acidity of typical peat bogs in New 

 England where swamp blueberries are growing. These peats were 

 always found to be acid and the degree of acidity was within the 

 range found satisfactory for blueberr}^ plants in pot cultures. 



The reason why peat is a particularly satisfactory type of acid soil 

 for blueberries is, apjjarentW , because the acidity of peat is of a mild 

 type, yet continually maintained. 



Not all peats are acid. About the larger alkaline (but not destruc- 

 tiveh^ alkaline) springs of our southwestern desert region are 

 deep deposits of rather well-decayed vegetable matter that must 

 be classed as peat. The characteristic vegetation growing on these 

 peats is tule {Scirpns occidentalis and S. olneyi). The water of 

 one of the great tule swamps of the West (Lower Klamath Lake in 

 southern Oregon), which contains thick beds of peat formed chiefly 

 from Scirpus occidentalis, has been examined recently by Mr. J. F. 

 Breazeale, at the request of Mr. C. S. Scofield. It was found to con- 

 tain sodium carbonate, and the peat gave a distinctly alkaline reaction. 



The peat formed about marl ponds in the eastern United States 

 is also, in all probability, alkaline unless formed at a sufficient dis- 

 tance from the lime-laden water to be beyond the reach of its acid- 

 neutralizing influence. 



Such alkaline peat-s, while not actually tried, are believed from 

 other experiments to be quite useless for groAving blueberries. Cer- 

 tain it is that neither blueberries nor any of their immediate relatives 

 are found on these soils in a wild state. In the eastern United 

 States, however, such alkaline peats are comparatively rare, and the 

 use of the word " peat " conveys ordinarily the idea of acidity. All 

 the soils used by gardeners under the name of peat are acid. 



(8) Peat suitable for thf swamp blueberry may be found either in bocs or 

 ON the surface of the ground in sandy oak or pine woods. 



In the vicinity of Washington deposits of bog peat are few and of 

 limited extent, and the peat is thin. As a matter of fact no bog peat 

 of local origin is used by the gardeners and florists of AA^ashington. 

 For growing orchids, ferns, azaleas, and other peat-loving plants, 

 either peat shipped from New Jersey is used or a local product some- 



193 



