212 EXPERIMENT STATION. [Jan. 



its infliience on cranberry vines is not known. In the aerated 

 surface soil, however, it will be transformed into the beneficial 

 highly oxidized compounds, as nitrates and sulfates. 



The present use of water on cranberry bogs is empirical, but 

 a consideration of the conditions under which soil changes occur 

 leads me to believe that water should be withdrawn from the 

 surface at the earliest possible moment in the spring consistent 

 with safety from frost, and held at the lowest possible level at 

 which the vines can secure sufficient moisture for free growth 

 during dry and hot weather. By this arrangement the period 

 of active soil change, and the volume of soil in which it can 

 take place, will be at a maximum, with a consequent increase 

 in the amount of available nutrients for the plants. Flooding 

 the bogs followed by the spring draining undoubtedly causes 

 some loss of soluble fertility, and, on account of the close ap- 

 proach to saturation of the soil during the summer, heavy rains 

 will also result in loss through seepage into the ditches. 



This experiment station has begun an investigation of the 

 problem of cranberry-bog fertility, and Director Brooks has 

 devised a series of 30 miniature bogs described by him in a 

 recent article.^ Each bog is constructed in a 24-inch tile, 48 

 inches deep, and connected with it is a G-inch tile that corre- 

 sponds to the ditch on a large bog, by which the bog can be 

 drained or irrigated. Analyses of the drainage water during 

 the past two summers throw some light on the development of 

 solu1)le material in the peat and its transformation into active 

 nutrients for the vines. The first analyses were made on sam- 

 ples collected July 14, 1910. Other samples were analyzed at 

 intervals until October 19. During most of this period frequent 

 additions of water were required by the bog because the rain- 

 fall was abnormally small. All the water was applied to the 

 snrface of the bogs in order to promote diffusion into the small 

 drainage cylinders. 



There was much variation in the com])<)sition and also in the 

 color of the different samples, which continued until the collec- 

 tion of Se])tember 12. There was, however, a steady progress 

 toward uniformity. A few days previous to Se])tember 12, viz., 

 on the 8th, there was an exceptionally heavy rainfall which 



1 Brooks, Win. P., Proc. Soc. Promotion Agr. Sci., IQH, pp. 23-28. 



