9 
west Maui, particularly the land of the Honolua Ranch Co., belong 
to the clay type. 
On the island of Hawaii great diversity of soil types occur, and 
only the most general statements can be made at the present time. 
In the Olaa district, whore the precipitation is very heavy, the soils 
contain a large amount of partially decomposed organic matter and 
are sandy or gravelly in texture. Along the Hamakua coast above 
the sugar belt a comparatively high percentage of clay occurs in 
some places; in others the soil has a high humus content. The soils 
of the Kohala district are clay loams, shading off to the west into 
silty loams. There is a large body of a deep, loose, silty soil, high in 
humus in this district that is now occupied by the Parker Ranch Co. 
In the Kona section the soils vary enormously. In places the virgin 
fern soils contain unusually high percentages of humus and, generally 
speaking, more or less stones and gravel. 
The soils of Kauai, that have been most "thoroughly investigated, 
were from Kapaa and the McBryde homesteads. The Kapaa lands 
contain high percentages of clay and are liberally supplied with 
humus; sometimes they resemble adobe. The McBryde homestead 
section is composed principally of clay loams. An insufficient number 
of samples have been examined from the other sections of the islands 
to justify any generalization. The table of mechanical analyses at 
the end of the bulletin will give some idea of the physical composition 
of representative samples from different districts. 
DRAINAGE CONDITIONS. 
Proper drainage is one of the greatest necessities in Hawaiian soil 
management. The rainfall in some sections is heavy throughout the 
year, and in almost all sections heavy rains sometimes occur. It is 
of the greatest importance that the excessive rains be able to drain 
away without eroding the surface into gullies or flowing over it, for 
in the latter event great injury will result from puddling the clay 
and shutting the air away from the roots of plants. Unless proper 
drainage be provided, suitable conditions of aeration in times of wet 
weather will be impossible. One of the most perplexing questions 
that the pineapple growers have had to contend with is that of drain- 
age, and as yet no thoroughly satisfactory method has been devised. 
Generally the open-ditch system prevails. Drainage is naturally 
most difficult in heavy clay soils such as predominate in the pine- 
apple sections. 
The application of lime for the purpose of ameliorating the heavy 
clays seems to be of doubtful effect. In some instances lime fails to 
cause granulation such as takes place in normal clays. The clay is 
present in a state of such fine division as to be colloidal and has the 
power of imbibing large amounts of water. When wet the iron and 
98554°— Bull. 40—15 2 
