220 
have more influence upon the reduction of nitrate than the same 
materials well rotted, which agrees with former observations on 
stable manure.” 
Wdiile ammonium sulphate has usually been found to be very 
effective as a source of nitrogen in submerged rice culture, in 
acid soils it exerts a detrimental influence. The same has been 
found true of organic forms of nitrogen, especially those of a 
vegetable origin, as rape seed and soy bean cakes : those of animal 
origin, as dried blood, tankage, flsh guanos, etc., much less so. 
When, however, such soils (which form fully 90% of Japan's 
paddy fields), are neutralized by liming, these fertilizers again 
exert their maximum power. 
At the time of the visit to the Kyushu Station a series of pot 
and plot fertilization experiments were under way, which strik- 
ingly demonstrated these points. The soil under consideration 
was an acid granite soil, which, untreated, gave a poor yield. 
\Mien treated with just enough lime to bring about a neutral 
condition, a fair crop was produced. When a complete manure 
was added in addition to the lime, whose constituents were all 
acid, i. e., a formula consisting of 5% nitrogen as sulphate of am- 
monia, 5% phosphoric acid as acid phosphate, and 5% potash as 
sulphate of potash, the yields were materially increased. But 
when the same fertilizer was applied to the unlimed soil a detri- 
mental efifect was noticeable. The same held true of sulphate 
of ammonia or organic materials of a vegetable origin used 
alone. Wdien a complete fertilizer was made up of non-acid 
constituents, beneficial results were obtained, even when the soil 
had not previously been neutralized by liming. 
From these and many other experiments, it has been con- 
cluded: 1. That many soils of reasonable fertility fail simply 
because of excessive acidity, and that this condition may be cor- 
rected by moderate liming. 2. Acid soils, instead of being 
benefited by fertilizers that are acid, are made worse. Fertili- 
zers, rich in organic materials of animal origin, may prove bene- 
ficial on acid soils without liming, but liming greatly enhances 
their value. 3. Organic fertilizers of a vegetable origin are 
less suited to acid soils than are organic materials of animal 
origin. 
It is interesting to note that the liming of paddy soils has been 
placed under government supervision in Kyushu because it was 
found that the indiscriminate use of lime tended to destroy the 
soil humus, and in other ways proved detrimental. 
As much of the research in the chemical division is of a highly 
technical character, reference is made to the published data 
given in the bibliography. 
(To be continued.) 
