On the Behavior of Nitrate in Paddy Soil. 



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(a). Test for nitrite.^^ 



(b). Test for ammonia. 



The above result shows that by the presence of a certain amount of 

 organic matter the reduction of nitrate in the paddy soil is much accelerated 

 and all the nitrate added (0,2%) reduced entirely after 9-12 days even at 

 room temperature in spring and after 2 days when kept at 30-3 2°C. 



LABORATORY EXPERIMENT. III. 



Former experiments carried out by various investigators show that 

 fresh stable manure favors denitrification more than a well rotten one, but 

 in regard to fresh and rotten oil cakes no special observations seem to have 

 been made, therefore we have made the following experiment : 



(a). On Aug. 14, 1905, 100 g of soil from our Station at Nishigahara 

 2 g of rape cake (i) and 5 cc. of glycerine (2) and 150 cc. of the nitrate 



i). The amount of nitrite was also here approximately determined colorimetrically by Griess 

 test. A standard solution of pure KNO^ served for the comparison. 



