59 
Moisture on samples E and F determined at San Ramon; on all others at the 
laboratory, Manila. 
Fine earth determined on original samples. 
Loss on N, P,O;, K,0 determined and percentages calculated to original sample 
on soil dried at 100°—105°. 
Soils marked “A” were taken at a distance of 60 feet from the sea, A, being 
the surface, A, 18 inches, and A, 3 feet below. 
The B soils were taken from 2,800 feet inland, 40 feet above sea level, where 
trees were not bearing so well, and at the same depths as the A soils of correspond- 
ing numbers. 
The C soils were from the same place as those marked “A,” but were taken at 
a greater depth so as to reach the locality.of the deepest roots, C, being from 
4 feet and C, from 8 feet below the surface. 
The D soils were taken from the same place and depths as the C soils. 
Soil E was taken at a depth of 3 to 4 feet, 6 feet distant from a very healthy 
5-year-old tree near the sea. 
Soil F was taken at a depth of about 3 feet and about 1,800 feet from the sea, 
where trees do not bear so well. 
Davao soils. 
; ; Fine | Mois- — Losson : Fo 
| Sample. | earth. | ture, ignition, P29: K,0. | N. Cao. 
| | 
ae acl i ie | st 
| 40 mesh, | 
95 7.60 5.42 0.16 0. 26 0.05 2. 85 
| Ul | 91.9 1.30 1.42 11] 18 03 2.06 
Ss ees) eee noes : Se) Ses i ee 
Soil marked “I” was taken at a distance of 50 yards from the Davao River 
about 1 mile inland from the sea, where trees were growing well. 
Soil marked “II” was taken at the mouth of the Davao River about 50 feet 
from the sea. In this location a few young trees were doing fairly well. 
Both samples were taken at a depth of about 1 foot. 
Chemically, the results of these analyses show very little difference 
between the soils near the shore and those farther inland. The latter, 
contrary to what would be supposed, were found to be somewhat superior 
to the former, although neither could be called extremely fertile. Chlo- 
rine was determined in the first six of these samples, with the idea that 
this element might play some part in the better growth of trees near the 
sea, but the amounts found were so small as to be almost negligible. 
From these results it is evident that the inferior quality of the inland 
trees can not be explained by the analytical difference in the soils; 
neither does the salt from the sea appear to an appreciable extent, even 
around those trees which are actually growing on the beach. 
However, the superior growth of trees near the sea might well be 
accounted for theoretically by the physical characteristics of the soil 
alone. For example, the soil marked “E” in the foregoing table is prac- 
tically nothing but a very porous sand which, at a depth of 3 feet, is 
completely saturated with moisture; while F is a very stiff clay, such as 
the Spaniards formerly used for making bricks. While it is true that 
the latter contains more total moisture and plant nutriment than the 
