Apr. 15. iQis 5*017 Acidity as Influenced by Green Manures 



185 



Table X. — Nitric nitrogen in air-dried green-manured soils 

 [Results expressed as pounds of nitric nitrogen per 2,000,000 pounds of soil] 



Material. 



Control soil 



Legume mixtures: 



Soybean 



Sweet clover. .. . 



Alfalfa 



Red clover , 



Hairy vetch . . . . 



Subaverage . . . 



Nonlegume mixtures 



Rape 



Com 



Rye 



Redtop 



Sorrel 



Subaverage. .. 



Grand average 



Table XI. — Changes in nitric nitrogen of air-dried green manures 

 [Results expressed as pounds of nitric nitrogen per 2,000,000 pounds of soil] 



Materials. 



End of 

 third to 

 end of sev- 

 enth 

 month. 



During 



eighth 



and ninth 



months. 



Control soil 



Legume mixtures: 



Soy bean 



Sweet clover 



Alfalfa 



Red clover 



Hairy vetch 



Subaverage 



Nonlegume mixtures: 



Rape 



Com 



Rye 



Redtop 



Sorrel 



Subaverage .... 



Grand average . 



16.66 



30.68 

 53.36 

 30. 18 



34.44 

 48.30 



5.20 



32.20 

 16. 64 

 40.38 



23.34 

 21. 62 



Since the same materials throughout vi'ere not used in Series I and II, 

 the figures from the analyses of the mixtures of those materials used in 



