462 Philippine Journal of Science 1920 
Aso and Bahadur *° found that a combination of ammonium 
sulphate and disodium phosphate produced better results with 
paddy rice in the field than did combinations of any other salts 
in their tests. 
Krauss " also reported results from pot and field experiments 
with rice, indicating that (of the different nitrogenous fertilizers 
that he tested) ammonium sulphate ranked above calcium ni- 
trate and sodium nitrate by the criterion of yield of grain. 
The superior fertilizer value of ammonium sulphate, as com- 
pared with the values of sodium nitrate, calcium nitrate, mag- 
nesium nitrate, and ammonium nitrate, was also noted for the 
rice plant by Kelly.2» He employed lowland rice in both field 
and pot cultures, adding nitrogenous fertilizers before planting 
and, in other cases, at intervals during the culture period. The 
cultures supplied with ammonium sulphate showed good growth 
and gave good yields of both straw and grain, while those in 
which nitrogen was supplied to the soil only as sodium nitrate 
gave but low yields. Apparently this nitrate was ineffective as 
a fertilizer. He also found that the ammonium salt applied 
before planting proved more beneficial than did the same salt 
applied at intervals during the culture period. In pot cultures 
the addition of nitrate to the soil proved beneficial in the latter 
part of the growth period, from near the flowering stage to 
maturity. This last observation agrees with that recorded for 
maize by Lehmann (1875). Kelly suggested that this difference 
in the response of the rice plant to soil fertilization with sodium 
nitrate and with ammonium sulphate, might be due to the fact 
that the lowland rice plant “has in a large measure lost the 
power of reducing nitrates,” which, in turn, might be due to 
the fact that this plant has been “grown for centuries under con- 
ditions that largely exclude the formation of nitrates.” While 
these considerations may be of interest in connection with 
genetics and phylogeny, still the physiological reasons for the ob- 
served state of affairs (which must be sought in the plant it- 
self) remain untouched. From the standpoint of genetics it 
may be asked whether the paddy rice plant ever had the power 
of reducing nitrates. Kelley appreciated the unsatisfactory sta- 
* Aso, K., and Bahadur, R., On the influence of the reaction of the ma 
nure upon the yield, Bull. Coll. Agr. Imp. Univ. Tokyo 7 (1906) 39-46 
" Krauss, F. G., Ann, Rept. Hawaii Agr. Exp. Sta. 1907 (1907) 67-90. 
Ibid. 1908 (1908) 65-84, 
“ Kelley, W. P., The assimilation of nitrogen by rice, Hawaii Agr. — 
Sta. Bull. 24 U. S. Dept. Agr., Washington, D. C., 1911. 
