20 MANURING EXPERIMENTS WITH PADDY RICE. 
sulstances and liberates potash from certain silicates, thus supply¬ 
ing the crop to some extent with assimilable nitrogen and 
potash. An action of this kind was certainly displayed in the 
6th series in all those trials in which the lime was applied along 
with green manure. While without lime the little genge 
plants had no effect (compare trials i and 5), the addition of 
this indirect fertilizer caused an increase of nearly 100 kilo of 
hulled grain per tan. As the young plants had, however, not 
yet far developed before the transplantation of the rice, owing 
to too late sowing, they could not yet have assimilated much 
nitrogen from the air, and the question to what extent they 
may display this action to the benefit of the rice crop, if sown 
in the preceding year, remains to be answered by experiments 
in the coming season. 
The preceding researches have shown that under the con¬ 
ditions of our soil the best development of paddy rice is secured 
by the application ofj.5 kilogrms. ( 2.0 kwammej of nitrogen 
and 12.5 kilogrms. (^3.5 kwamme) of phosphoric acid per tan 
( = 10 are), provided that both nutrients are given in a soluble 
form; potash and lime, however, have been found to exist 
in the soil and ordinary manures in quantities sufficient for 
a luxuriant crop. The yield obtained with the above nutrients 
amounted under the very unfavourable meteorological con¬ 
ditions of the season to about 500 kilograms (3.5 koku) of 
hulled grain per tan and may increase in good years up to 650 
kilograms (4.5 koku), whereas the general average of the whole 
empire is, according to the official statistics, only 2 koku. This 
large difference indicates that the manures commonly applied 
by the farmers must be deficient either in nitrogen or phosphoric 
acid or both, and to get clear information on this important 
question, we collected data 7 on the kinds and quantities of 
manures used for rice in various parts of the country, and 
calculated their contents, as follows (per tan in kuwamme) : 
7 For some of them we are indebted to Prof. Fesca. 
