ANNUAL REPORT, 1931 229 



Dry Matter and Nitrogen Removed from Non-Legume and Legume Areas 



in 1931 and in 8 years 



(Pounds per Acre) 



WITHOUT NITROGEN WITH NITROGEN 



Dry Matter Nitrogen Dry Matter Nitrogen 



Non-Legume, 1931 2,105 26.9 2,194 28.0 



Legume, 1931 2,600 45.8 2,659 49.5 



Non-Legume, 8 years 23,886 254.9 33,395 354.5 



Legume, 8 years 28,058 534.4 29,867 563.3 



areas they were clover hay, corn fodder, soy bean fodder, corn fodder, clover hay, 

 clover hay, Japanese millet, pea and oat hay. On the non-legume areas the plots 

 which had received 180 pounds nitrogen in 8 years produced 9500 pounds more 

 dry matter per acre which contained 100 pounds more nitrogen than was ob- 

 tained from the plots that had been without nitrogenous fertilizer for 50 years. 

 The use of leguminous crops made the nitrogenous fertilizers comparatively in- 

 effective. The gain of 1800 pounds of dry matter and 29 pounds of nitrogen was 

 due mainly to the non -leguminous crops used in the rotation. 



The soil from each individual section of the plots was sampled and analyzed 

 in 1924, 1927, and 1931. To check results, a few samples of 1924 and 1927 were 

 again analyzed simultaneously with the samples of 1931. The repetitions varied 

 only a trifle from the originals, proving that reagents had been carefully pre- 

 pared in each season. The individual analyses are averaged and summarized in 

 the table. 



Percentages of Nitrogen in Surface Soil 

 (Depth 8 inches) 



WITHOUT NITROGEN WITH NITROGEN 



Year 



Non-Legume Legume Non-Legume Legume 



1924 130 .135 .158 .133 



1927 190 .160 .195 .180 



1931 165 .170 .170 .168 



The figures clearly show no deterioration in soil nitrogen in the absence of 

 nitrogenous fertilizers, and no accumulation of nitrogen in the soil where they 

 were used. Since 254 pounds of nitrogen were removed from the soil where no 

 legumes had been grown for 8 years, it appears that this nitrogen was supplied 

 by soil organisms which took it from the air. Growing leguminous crops in 

 rotation doubled the amount of air nitrogen thus secured. 



Chemical Study of Cranberries. (F. W. Morse). At the request of Dr. 

 H. J. Franklin of the Cranberry Station, analyses were made of Early Black 

 and Howes cranberries which had been produced in a comparison of dry bogs 

 versus watered bogs during the season of 1930. Dry matter, total acids calcu- 

 lated as citric acid, and total sugar were determined, with the results shown in 

 the following table. 



Composition of Cranberries from Dry and Watered Bogs 



EARLY BLACK HOWES 



Dry matter, per cent.. 



Total acid, per cent 



Total sugar, per cent.. 



