RICE SOILS OF HAWAII: THEIR FERTILIZATION 
AND MANAGEMENT. 
INTRODUCTION. 
The extensive soil investigations that have been made up to the 
present time have dealt principally with dry lands, in which the 
moisture and other conditions differ greatly from those prevailing in 
rice soils. In America in particular very little study has been devoted 
to submerged lands, and little, indeed, is really known about them. 
Consequently recommendations for the treatment and management 
of rice soils are generally based on knowledge gained from experience 
with dry lands. It is evident, however, that conclusions applicable 
to dry soils do not necessarily apply to submerged soils such as are 
used in rice culture, and, in fact, it is well known in oriental countries 
that rice lands demand different treatment from those devoted to 
dry-land cultures. 
The one condition that is most obviously different in rice soils and 
dry lands is that of aeration. The fact that aeration is essential to 
the successful growth" of most crops, and the belief that fertility is in 
some way dependent upon its maintenance, has caused agriculturists 
to recommend for rice soils practices designed to secure aeration in 
the belief that this is as essential for successful rice culture as for 
culture of other crops. Experiments are not wanting, however, 
which show this to be untrue. 
One of the most important matters affecting the culture of rice is 
the form in which nitrogen is taken up by the crop. It is well known 
that the degree of aeration in soils determines very largely the form 
assumed by available nitrogen. This phase of the subject has been 
reported upon previous!} 7 by the writer, 1 but will be further empha- 
sized in this bulletin on account of the principle involved and the 
practical importance attached to it. 
In connection with the general soil investigations, which have been 
under way in the laboratory of the Hawaii station for several years, 
the rice lands of the Hawaiian Islands have received considerable 
attention. For a Dumber of years also ii<'l<l experiments with different 
i Hawaii Sta. Bui. 24. 
(3) 
