ANNUAL REPORT, 1934 29 



PRODUCTION OF DRY MATTER, POUNDS PER ACRE. 



Plots 5, 8, 10 Plots 6, 7, 9 



With Residual Nitrogen* Without Residual Nitrogen 



Western Eastern Western Eastern 



Half Half Half Half 



Legume sections 4,051 3,988 4,267 3,937 



Non-legume sections 3,395 4,729 3,343 4,349 



NITROGEN IN SURFACE SOIL, PERCENT. 



Legume sections .139 .156 .137 .162 



Non-legume sections .149 .176 .145 .172 



*N'itrogen at the rate of 4.5 pounds per acre was applied in 1933, and in the preceding years 

 1924, 1926, 1928, 1930, and 1932. 



The plots with residual nitrogen were definitely ahead of those without it on 

 the non-legume sections, but on the legume sections the residual nitrogen was 

 without effect. 



Hungarian millet was previously grown in 1932 as the non-legume. In that 

 season the average production on the non-leguminous sections without nitrogen 

 was 3464 pounds of dry matter per acre, and on the similar sections with applied 

 nitrogen it was 5385 pounds of dry matter per acre. This year the average produc- 

 tion on the eastern and western sections taken together was 3846 pounds of dry 

 matter per acre without nitrogen, and 4062 pounds per acre with the residual 

 nitrogen from previous applications. These two crops contained respectively 

 32.76 pounds and 36.59 pounds of nitrogen as determined by analysis of their 

 samples. Application of 45 pounds per acre of nitrogen in 1933 and plowing under 

 the crop grown upon it gave but 216 pounds more dry matter and 3.83 pounds 

 increase in recovered nitrogen over the plots that have been without nitrogen 

 or legumes since 1923. 



Soil samples were secured from all the plot sections on August 23 and 24, 

 representing the surface soil to the depth of 8 inches. Total nitrogen was de- 

 termined in each sample. The results are tabulated in the same manner as dry 

 matter in the crops. 



The figures for the non-legume sections are positively higher than for the 

 legume sections, showing no tendency toward exhaustion of soil nitrogen in the 

 continued absence of legumes. 



Chemical Study of Cranberries. (F. W. Morse.) A method for the determina- 

 tion of quinic acid in cranberries has been developed and applied to numerous 

 samples of leading varieties. 



Citric, malic, benzoic and quinic acids are found in the cranberry. A water 

 solution of cranberry pulp or of cranberry juice is exactly neutralized with barium 

 hydroxide. To the neutralized solution is added three times its volume of 95 

 percent alcohol. After thoroughly mixing the alcohol with the cranberry solution, 

 the barium citrate and barium malate are precipitated, while barium benzoate 

 and barium quinate remain in solution. Enough more alcohol is added to make a 

 definite volume, as 250 cc. or any other convenient volume. The precipitate is 

 removed by filtration and a measured volume of solution is used for quinic acid 

 measurement by precipitating the barium with potassium sulfate. From the 

 amount of barium, its equivalent quinic acid is calculated. Barium benzoate 

 cannot be separated from the barium quinate. Benzoic acid may be determined 

 by a special method in another portion of cranberry and deducted from the 



