MANURING EXPERIMENTS WITH PADDY RICE (SECOND YEAR). 
15 
trial from the total residuary nutrient, and calculate how much 
in 100 parts of the amount thus found was consumed by the 
crop, we obtain the following figures : 
No. 3. No. 4. No. 5. No. 6. 
9-3% 9-i% 9-o% 
The close coincidence between these results justifies our 
assumption that about 6.5 kilogramms of phosphoric acid per 
tan had become entirely unfit for the nutrition of rice. 
III. Series. 
HOW MUCH NITROGEN CAN BE SUPPLIED TO 
RICE BY THE PRECEDING CULTIVATION OF 
A LEGUMINOUS PLANT (ASTRAGALUS 
LOTOIDES, LAM.) AS GREEN 
MANURE ? 
Astragalus lotoides Lam., in Japan, commonly known as 
genge, is cultivated in several districts as green manure for 
rice. It is usually sown between the rice plants in September 
or October, when irrigation is discontinued, and in the suc¬ 
ceeding year about the beginning of May attains the flowering 
stage, when it is dug into the field on which it was raised. 
As leguminous plants unlike others, have the peculiar faculty 
of assimilating free nitrogen from the air, this practice has for 
its object an accumulation of nitrogen in the field, and con¬ 
sequently a reduction of the amount of nitrogenous manure 
otherwise required. As it was not known how much nitrogen 
is gained by a successful culture of this plant, or whether, 
besides the green manure, other nitrogenenous fertilizers are 
needed for the rice, experiments had been commenced as early 
as 1889, but the time for sowing (April) was then past, and 
when the time came for transplanting the rice, the genge was 
still very small, and had not yet accumulated much nitrogen. 
