208 P:XFI:UIMEXT station. fJun. 



THE NATURAL FERTILITY OF CRANBERRY 



BOGS. 



BY F. W. MORSE, M.SC. 



Years of experience by practical men have shown that cran- 

 berries are best grown on a peat bog the surface of which has 

 been covered with a thin layer of sand. Furthermore, the best 

 results with this soil are obtained only when there is an abun- 

 dance of water by which at times the land may be flooded and 

 at other times irrigated ; and at the same time there must be 

 opportunities for thoroughly draining the land at some stages 

 of growth. This combination of peat subsoil, sandy surface and 

 varying amounts of water is unusual in any other line of crop 

 production, and most of the present methods pursued iu cran- 

 berry culture are wholly empirical in their character. 



One important problem now puzzling the cranberry grower is 

 that of fertilization ; is it necessary or unnecessary ? The poten- 

 tial fertility of a true peat soil, that is, the amount of the ele- 

 ments of plant nutrition contained in its dry matter, is known 

 to be high. Hopkins ^ states that a peat soil contains in the 

 upper layer (6% inches thick) of 1 acre, 35,000 pounds of nitro- 

 gen, 2,000 pounds of phosphorus and 2,900 pounds of potas- 

 sium, while a layer 40 inches deep over 1 acre contains 197,000 

 pounds of nitrogen, 8,600 pounds of phosphorus and 21,400 

 pounds of potassium. He further states - that but little of this 

 enormous store of material is in an actively available form, and 

 estimates that a corn crop can get at not more than 7 pounds of 

 potassium ])er acre, while in an ex]ieriment on a poorly drained 

 field, corn was benefited by the addition of nitrogen.'"^ The sand 

 on the surface of the peat may be disregarded as a source of 

 plant nutrients, but it is an important agent in making availa- 



■ Hopkins, O. G., Soil Fertility, Ginn & Co., 1910, pp. 83-87. 

 * Ihid., p. 471. 

 " Ibid., p. 172. 



