i86 



Journal of Agricultural Research vci. xiii, no. 3 



Series I, that were also used in Series 11, and representing likewise the 

 same periods as are covered by the figures of Series II, have been grouped 

 in the following tabulations (Tables XII and XIII) : 



Tasle XII. — Average limestom reqiiireynent and nitric nitrogen in manured mixtures 

 [Result', expressed iu poundi per s.ooo.oco pounds of soil] 



"The averages in the last column of this table represent only the data for the third, fifth, and sixth 

 periods. 



Table XIII. — Average changes in limestom requirement and nitric nitrogen 



[Results expressed in pounds per 2,000,000 pounds of soil] 



Materials. 



Limestone requirement. 



First 2 

 weeks. 



End of 

 second 

 week to 

 end of 

 third 

 month. 



End of 

 third to 



end of 

 seventh 

 month. 



Eighth 



and 



ninth 



months. 



Nitric nitrogen. 



End of 

 third to 



end of 

 seventh 

 month. 



Eighth 



and 



ninth 



months. 



Control soil 



Fresh green manures: 



Legume 



Nonlegume 



Air-dry green manures: 



Legume 



Nonlegume 



Stable manure 



-2,589 

 -2,575 



(?) 



-773 

 •'37 



868 

 766 



-53 

 80s 



2.243 

 1,813 



1,966 

 1, 169 

 1.752 



—941 

 —691 



-851 

 - I , o? I 

 -974 



101.90 



52-54 



39-59 

 41.85 

 30.92 



-4-87 

 8-55 



26. 24 

 19.01 

 22.58 



It is evident from Table XII that the fresh green manures affected the 

 limestone requirement in greater degree and for a longer period than the 

 corresponding air-dried green manures; that the changes in lime require- 

 ment after the first period of fermentation were not so great in case of the 

 air-dried as in that of the fresh material; and that, with a single excep- 

 tion, this requirement did not reach so high a point with the air-dried 

 materials as with the fresh, the exception noted being for the nonlegume 

 materials in the last months of the experiment. The limestone require- 

 ment of the air-dried mixtures, as contrasted with that of the soil un- 

 treated, was in general about on a level with the latter until the end of 

 the third month, after which it became considerably higher. 



