498 



EXPERIMENT STATION RECORD. 



Drainage water and nilric nitrogen from a soil stirred <(t the anr/acc and from an undis- 

 turbed soil. 



Date at which drainage water was 

 iiillected. 



March 8 



July 27 



October 9 



October 24 



November 26 



Entire period 



Stirred soil. 



Amount 

 of'drain- 

 iigo water 

 obtained. 



Litem. 

 5. 700 

 7. 9M 

 5. 000 

 3.180 

 6.000 



21.830 



Nitric 

 nitrogen 

 per liter. 



Nitric 

 nitrogcu 



Unstirred soil. 



Amount 



a°/e^vater' "ifogen , nitrogen 

 age \\ ai< r ,.„„ ,;»„„ ,•. . 



Nilric 



Nitric 



*»""d- Xtaine:i.ll'«^'-l'ter. found. 



Grama. 

 0. 022 

 .118-1 

 .104 

 .041 

 .030 



Grams. 

 0. 125 

 .164 

 .820 

 .130 

 .180 



.065 



1.419 



Liters. 

 6.000 

 2. .500 

 5. 150 

 3.000 

 7.200 



23. 850 



Grains. 

 0.020 

 .067 

 . 073 

 .030 

 .028 



.040 



Grams. 

 0. 120 

 •.167 

 .376 

 .090 

 .201 



.954 



The effect of cultivation was appreciable ouly on October 9. During- 

 the first part of the period the results obtained on the two soils are 

 very similar. A number of other soils were used in this comparison 

 and the sums of the nitrogen found on March 8 and November 20, cal- 

 culated to 50 kg. of soil, are given in the table below. 



Nitric nitrogen fonnd in enUirafed and nncullivaied soils. 



All of the results point in the same direction, despite the fact that 

 the season was so unfavorable that nitrification was almost completely 

 checked. 



The soils of Auvergne in the region of Palbost and Marmilhat were 

 also experimented with. They are easily affected by drought and 

 when they are not cultivated nitrification goes on very slowly in them. 

 The results obtained on these soils were as follows: 



Nitric nitro'jen fonnd in cultivated and nvcnltirated soils. 



It is evident, .therefore, from the above results that cultivation and 

 aeration of the soil favor to a marked degree the activity of nitric fer- 

 ments. But before drawing any conclusions let us examine the results 

 obtained by experiments in this line on vegetation boxes. 



