MANURING EXPERIMENTS WITH PADDY RICE (SECOND YEAR). 
31 
powder, in spite of its very fine division. Good results may 
be expected with this phosphate only on peat or moor land 
rich in sour humus which has the capacity for dissolving 
considerable quantities of phosphoric acid from this mineral 
fertilizer. As soils of this kind are, however, rare in Japan, 
it will be advisable to discontinue the separation of so-called 
“ floats ” i.e. the finest dust obtained while grinding the 
raw phosphorite in superphosphate factories and to convert 
these “ floats,” along with the other particles, into superphos¬ 
phate. 
Our experiments will be continued in the coming season in 
order to determine the effect of the unrecovered phosphoric 
acid. 
V. Series. 
COMPARATIVE EXPERIMENTS ON THE 
EFFECT OF VARIOUS NITROGENOUS 
MANURES ON RICE. 
This series occupied a section of the paddy field of the 
college farm adjoining that on which the phosphatic manures 
were tested, and comprised 105 plots, of which 6 were not 
supplied with nitrogen, while the other 99 received various 
nitrogenous fertilizers, each of which was applied in two doses 
containing a 3.45 grms. per plot = 4.i4 kilogrms. per tan and 
b 7.90 grms. per plot = 8.28 kilogrms. per tan; the doses b 
being, therefore the double of a. To all plots alike a general 
manure was applied consisting per tan of 22 kilogrms. of 
phosphoric acid as sodium phosphate and 11 kilogrms. of 
potash as carbonate. 
The following nitrogenous fertilizers were tested in this way : 
1) Ammonium sulphate, which was applied in the form of a 
solution. About 3 kilogrms. of the wet soil of the 
