MANURING EXPERIMENTS WITH PADDY RICE. 
2 3 
as yet entirely unfamiliar to him. The condition for success is, 
of course, a reasonable price which should not exceed 24 Sen 
per Kilogram (go Sen per Kuwamme) of assimilable phosphoric 
acid, and at the same time the manure should be high-graded 
to diminish the expense of transportation. Among the con¬ 
centrated phosphatic fertilizers manufactured in foreign countries 
the “double superphosphates" or “ biphosphates" with more 
than 40% of assimilable phosphoric acid, and Thomas phosphate 
powder containing 17-20% of total phosphoric acid, and 80% of 
fine powder passing through the standard sieve, deserve to be 
taken into consideration for the purpose of importation. The 
former kind, like all superphosphates, is suitable for all 
soils that are not of a mere sandy or gravelly character, and 
even on the latter it may be applied if large doses of lime have 
been incorporated with the soil in preceding years. The 
Thomas phosphate powder is suitable for all paddy soils, but 
it must be kept in mind that only about half its phosphoric acid 
will be available in the first season. 
The cost of 2.5 kuwamme of assimilable phosphoric acid 
which have been found to be deficient per tan in the ordinary 
manures, is, at present rates 2.25 Yen in the double super¬ 
phosphate and 3 Yen in the Thomas phosphate. Adding to 
this the cost of the increase of nitrogen, which will be about 
50 Sen, we get as total increase of the manuring expenditure 
2.75 resp. 3.50 Yen per tan, by means of which a crop of about 
3.5—4 koku of hulled grain can be secured in mean seasons. 
As 2 koku is the average yield in our neighbourhood and 1 koku 
is worth at least 4.5 Yen, the profit to be realized by the pro¬ 
posed system of manuring is considerable. 
It is furthermore important to remember that the rice crop 
consumes in the first season only about 20-25% °f the assimil¬ 
able phosphoric applied and that the remainder is left in the 
soil in an active condition and not liable to be extracted by 
irrigation or rain. The expense of the auxiliary phosphatic 
manure is accordingly greatly diminished in the subsequent 
seasons. 
