1912. 



PUBLIC DOCUMENT- Xo. 31, 



209 



h\v the elciueiits contained in the peat. The water used in Hood- 

 ing' and irrigating may be regarded in a similar way, since it 

 is as pnre as the average public water supply and often purer. 



Analyses of the cranberries and cranberry vines reveal an 

 unusually low })roportion of nitrogen and ash constituents, espe- 

 cially in the fruit which, as a rule, is all that is removed from 

 the bog. 



Table 1. — Composition of Cranberries and Vines. 



A crop of lJ)OJ)arrcls--of .cranberries |>er acre, weighing 10,- 

 000 iDounds, will contain only 7 pounds of nitrogen, 3 pounds of 

 phosphoric acid and 8 pounds of potash. One ton of dried vines 

 would contain 15 pounds of nitrogen, G.2 pounds of phosphoric 

 acid and 8 pounds of potash. These figures show clearly that 

 the cranberry crop will never exhaust the potential fertility of 

 the bog ; but it is equally plain that it has become accustomed to 

 a scanty nourishment, and they do not answer the question, 

 " Shall fertilizers be used ? " 



There are on record o-nly three series of fertilizer tests on 

 the cranberry crop. They are somewhat empirical and throw 

 little light on the problem. 



An experiment in New Jersey was reported in 1895.-^ A 

 complete fertilizer gave the best results, with the next best from 

 the nitrogen with phosphorus and nitrogen wath potash. This 

 w^^s indicative of the actual need of nitrogen ; but the soil was 

 described as a black sand somewhat too dry for a good bog. 



In Wisconsin Whitson began a series of fertilizer tests in 

 1004,^ the last detailed report of which was published in 1907.^ 



' Mass. State Exp. Sta. Kept., 1889, p. 274; 1893, pp. 330, 370. 



' N. J. Agr. Exp. Sta. Rept., 1898, pp. 122, 123. 



3 Ann. Rept., N. J. Agr. Exp. Sta., 1895, p. 110. 



i Whitson, A. R., Ann. Rept., Wis. Agr. Exp. Sta., 1905, pp. 291 and 292. 



8 Ann. Rept., Wis. Agr. Exp. Sta., 1907, p. 305. 



