III. 



IV. 



Oil llie Belia.viui- of Nitrate i» Pafldy Sail. 2^- 



K2HPO4 and 0,3 MgSOi were added to the flasks No. I-V, and the same 

 amount of a solution containing only 2 g K2HPO4 and 0.3 g MgSO^ without 

 nitrate to the flasks No. VI-X, after mixing the soil thoroughly with the 

 organic matters^^ mentioned : 



I- NaNOs ... 3.5 g. 



jj fNaNOa 3-5 ., 



\Starch 5.0 „ 



fNaNOa 3 5 » 



(Compost, well rotten ••. 21.0 „ 



rNaN03 3.5 „ 



(^ Rape cake 5.0 „ 



^ iNaNOg 3-5 - 



ISiraw ••• lo.o „ 



VI. Starch (Control (a)) 5.0,, 



VII. Compost well rotten (Control (b)) ■21.0,, 



VIII. Rape cake (Control (c)) 5.0 ., 



IX. Straw (Control (d)) lo.o „ 



X (Control (e)) — 



The experiment was begun Sept. 5, 1905, and every 10 days a certain 

 portion was withdrawn from each vessel, the same amount of water added 

 and tested for nitrite in the filtrate. After 10 days much nitrite was 

 observed in the flasks II and IV, the amount of which as potassium salt 

 approximately determined 0.35% resp. 0.088% KNO.j. In flask III only a 

 little nitrite and in all other flasks (except II and IV) only a trace or none of 

 it was observed. After one month in all the flasks only traces of nitrite 

 could be found. 



The result shows that in top-soil of " dry " land only certain organic 

 matters, such as starch or rape cake, favor nitrite formation to some extent, 

 but well rotten compost and straw do not.-^ 



Increase of moisture will lead to an increase of nitrite and loss of 

 nitrogen ; water was added after 33 days from the start at the ratio of 10 cc. 



i). The contents of N in the nitrate and organic manures are the same as in Lab. Expt. V. 



2). Stoklasa (Z. Landw, Vers. Wes. in Oesterreich, 1906, p. 844.) observed in Austrian soils 

 serving for culture of sugar beets also denitrification did not take place to such an extent that it 

 could be proved analytically. 



