22 ^- Dalkuliara niid T. Iinaseki. 



starch were applied the reaction became evident gradually, reaching the 

 maximum after lo days and then it gradually diminished to a trace after 20 

 days from start. 



(2). In the clayey sub-soil a trace of nitrite was observed in the lower 

 la5''er of all cylinders except that of the control case, and no further increase 

 of nitrite was noticed in the cylinder to which nitrate alone was applied, 

 while in the cylinder with nitrate and starch the reaction increased gradually 

 reaching the maximum after three weeks from the start and afterwards 

 decreasing gradually but showing the reaction until the end of the 

 experiment. 



(3). In the sandy soil with nitrate and starch the nitrate decreased 

 remarkably after 10 days from the start in both upper and lower layers of 

 the soil and after 20 days all the nitrate was reduced, while in the soil with 

 nitrate alone, the nitrate reaction remained intense through the whole period. 

 With nitrite there was no reaction in the control soil and the soil with nitrate 

 alone, while in the soil with nitrate and starch a trace in the upper layer 

 and much of it in the lower layer of soil were observed after 2-3 days from 

 the start, reaching the maximum after 10 days and then decreasing gradual- 

 ly again. 



The above results show that in the soil of the dry land state there is 

 hardly any nitrite formation if the nitrate alone is applied. When, however, 

 some organic matter is applied together with the nitrate some reduction 

 will take place, especially in the sub-soil, where the access of air is 

 insufficient, even all the nitrate here will eventually be reduced. 



(D). Comparison of the effect of some organic manures upon the 

 formation of nitrite and denitrification. 



In order further to compare the effects of different organic matters, 

 such as starch, rape cake, compost and straw, upon the degree of denitri- 

 fication in the dry state of land, the following experiment was carried out : 



Ten glass flasks of ca. I litre capacity with greased stoppers were filled 

 with 700 g of fine humy soil from Nishigahara containing 19,15% of 

 hygroscopic water. 150 cc. of a solution containing 3.5 g of NaNOg, 2 g of 



