THE SOILS OF THE HAWAIIAN ISLANDS. 
INTRODUCTION. 
The purpose of this bulletin is to discuss briefly the general prop- 
erties of the soils of the Hawaiian Islands and to point out the prac- 
tical bearings of the investigations 1 that have been made on them. 
For about six years the writers have been investigating these soils. 
One phase of this work has been in the nature of a soil survey. In 
this connection a large number of samples have been collected and 
a number of unusual peculiarities and soil types have been observed. 
Soon after beginning this work it became apparent that the main 
body of Hawaiian soils had not been scientifically investigated. 
Considerable study had been previously devoted to the soils of 
Hawaii, but always with reference to special localities or industries. 
Maxwell's 2 discussion is based on analyses of samples drawn from 
the lands devoted to sugar cane and his use of the terms "uplands" 
and "lowlands" refers to the humid and arid, or upper and lower 
portions, respectively, of the sugar belt. However, only about 
250,000 acres lying along the shore line, out of a total area of over 
4,000,000 acres, are cultivated in this crop. The investigations 
upon which this bulletin is based were made principally on the upland 
soils above the sugar belt. 
Almost the entire surface of Hawaii is characterized by a rolling 
topography. The elevation increases everywhere in passing inland 
from the sea, the grade varying in different localities. Each island 
contains one or more mountains or mountain ranges and usually 
with numerous spurs and sharp ridges projecting toward the sea. 
In almost every section the arable land is broken up by gulches or 
deep ravines, which now form natural watercourses, the beds of 
some of which have been worn to great depths. This has brought 
about the loss of a great amount of tillable land and adds greatly 
to the cost of farm operations. The tillable lands generally occur in 
comparatively narrow strips of irregular size and shape between 
gulches and extend from the sea toward the mountains. 
It is difficult to estimate the area of arable land, only a small 
percentage of which has yet been brought under cultivation. The 
main portion is now being used for pasture in much the same way 
as in the great range sections of the mainland. The rainfall varies 
1 See Hawaii Sta. Buls. 26, 28, 30, 31, 33, 35, 37, and 38. 
* Lavas and Soils of the Hawaiian Islands. Honolulu, 1808. 
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