66 MASS. EXPERIMENT STATION BULLETIN 150. 



The amount of this seepage must vary from season to season. The 

 spring seasons of 1912 and 1913 were unusually wet for about three weeks 

 after the surfaces of the bogs were drained, and several rains m.ade it 

 necessary to open repeatedly the stopcocks in the drainage cylinders. The 

 amount of seepage determined by the amount of water which flowed 

 through the outlets amounted to 25.6 quarts per bog in 1912 and 24.5 

 quarts in 1913, or, in round numbers, a little over 90,000 gallons per acre 

 in the first year and over 85,000 gallons in the second, or an average weight 

 of over 700,000 pounds of water per acre, which would contain, discarding 

 fractions, more than 21 pounds nitrogen, 10 pounds of phosphoric acid 

 and 50 pounds of potash. 



There was no evidence that the application of fertilizers in the previous 

 year caused any increase in these substances. 



Fertilizer Scheme for Bogs. 



Bogs numbered 6, 10, 11 and 14 receive no fertilizers. 



Bog numbered 1 received nitrate of soda. 



Bog numbered 2 received acid phosphate. 



Bog numbered 3 received sulfate of potash. 



Bog numbered 4 received nitrate and phosphate. 



Bog numbered 5 received nitrate and potash. 



Bog numbered 7 received phosphate and potash. 



Bogs numbered S, 9, 12, 13 and 15 receive all three substances. 



The period of seepage was succeeded in both seasons by a short space 

 of time during which the water-level fluctuated within narrow limits, and 

 following this interval was a prolonged dry season during which it was 

 necessary to add water repeatedly to the small cylinders to replace the 

 amount of water evaporated from the surface of the bogs. The addition of 

 this water gradually changed the composition of the water in the cylinders 

 until it showed that practically all of the original seepage water had been 

 reabsorbed by the peat. This showed that there was no apparent diffusion 

 from bog to cylinder, and there must be actual movement of water from 

 the bog to cause any loss to the bog of its soluble matter. 



The permanent losses of fertility are limited to the seepage water which 

 actually flows away from the ditches into the main drain or stream passing 

 through a bog. They cannot be avoided; but there is no evidence that 

 the small additions of chemicals in the late spring increase the losses any. 



The amount of water required for irrigation was determined in both 

 years by measuring the quantities added from time to time to the small 

 cylinders. These cylinders were kept covered mth galvanized iron caps, 

 so that evaporation and rainfall would affect only the surface of the bogs. 

 Water was added on seven different dates in the summer of 1912, begin- 

 ning with July 3 and ending on August 16. In 1913 there were eleven 

 different dates, beginning with June 19 and ending on August 28. 



The total amount added in 1912 was 13.75 gallons per bog, equivalent 

 to a depth of 7 inches over the surface, while in the yet drier season of 1913, 

 23.75 gallons were required per bog, or a depth of 12 inches. 



