PHYSICAL PROPERTIES OF HAWAII SOILS \) 
difficulty in this locality chiefly on account of the poor drainage 
conditions, which are being somewhat improved by ditching. 
Soil No. 15 is a sandy clay loam from field W, section G, in the 
Mountainview section of Olaa plantation. It is residual in origin, 
having been formed from pahoehoe lava rock which is found about 
12 to 18 inches below the surface and causes the soil to be very shal- 
low. This gray (black when wet) acid soil is of high moisture- 
holding capacity and is very rocky and full of clinkers. Like soil 
No. 12, this soil, due to excessive rainfall and poor drainage, is 
water-logged. The sugarcane grown on it is stunted. 
Soil No. 17 is a sandy loam from the fern forest along the main 
road to Volcano about 1 mile from Volcano House. This is a 
residual soil originating partly from the decomposition of volcanic 
ash and partly from lava immediately underlying the surface soil. 
The soil is only 12 to 18 inches deep and is black and high in organic 
matter from the decomposition of dense overgrowth. The hygro- 
scopicity and moisture-holding capacity of the soil is low. 
Soil No. 21 is a clay from field 3-1, Honaunau, Kona, Hawaii 
(coffee plantation). It is considered to be a typical coffee-district 
soil, and was recently cultivated for the first time. The soils of this 
district are the decomposition products of the various lava flows 
and ash deposits of Mauna Loa and are partly residual and partly 
alluvial. Soil No. 21 is a brown, well-aerated, productive type of 
good physical condition, containing a large amount of organic mat- 
ter in a well-decomposed state. 
Soil No. 23 is a clay from field 10-IV, Honaunau, Kona, Hawaii 
(coffee plantation). This typical coffee-district soil has been under 
cultivation for about 30 years. In origin and physical character- 
istics it is similar to soil No. 21, except that it is more granular 
in structure than the latter and contains clinkers. This soil is of 
medium productivity. 
Soil No. 31 is a clay from pineapple fields located on the Kohala 
Mountain slopes at a medium elevation of about 750 feet. The soils 
of this district are brown uniform clays or clay loams of more or 
less neutral character and contain considerable humus. They are of 
good tilth and fertility. The annual rainfall in this district is low. 
Soil No. 33 is a brown clay loam from an experimental edible- 
canna field of the station at Waimea, 4 miles east of Kamuela. This 
soil is typical of a large part of the Waimea plains — a rather cool, 
humid, and wind-swept region at an elevation of about 2,700 feet. 
The soil is of high organic content, fine uniform physical structure, 
and good productivity. 
Soil No. 37 is a clay from the upper end of field 2, Honokaa plan- 
tation, about 100 feet from the main road. This light-brown acid 
soil is typical of the mauka (upper) fields of the upper Hamakua 
district. The high organic content of the soil here often causes an 
acid condition, which is being remedied by the application of lime. 
The soil is of a good capillarity and good moisture-holding capacity. 
Soil No. 42 is a clay from field 8 of the Honohina section of Haka- 
lau plantation, Hawaii. This is a light yellowish-brown surface 
soil of considerable plasticity from the low elevations of the Hilo 
coast where the annual precipitation is upward of 200 inches. 
Soil No. 48 is a clay from the Haleakala substation, Makawao, 
Maui, on the slopes of Haleakala, at an elevation of 2,160 feet. 
52031—31 2 
