508 Philippine Journal of Science 1919 
SOIL 
Hevea brasiliensis does not appear to be exacting in the quality 
or kind of soil necessary for its successful growth. Generally 
speaking, Para rubber may be said to do well on any soil that 
will support a heavy forest growth, provided drainage is good. 
Hevea brasiliensis is rather intolerant of excess of water in the 
soil, and very wet soils should be drained in order to obtain the 
best results. Heavy clay soil is not so suitable for the growth 
of rubber as are loamy or even sandy soils. 
Cox * has shown that, in general, Philippine soils are good and 
contain ample quantities of the inorganic compounds necessary 
for plant growth. There are undoubtedly very large areas in 
the Mindanao region where the soils are suitable for the suc- 
cessful growth of Hevea brasiliensis. Table V gives the results 
of an analysis of five samples of soil taken on the Basilan 
Plantation Company’s property on Basilan. 
TABLE V.—Soils from Basilan plantation. * 
Sample No.— 
1b Qe Be | 44 be 
ittroment UNS) ce oo Gea eee 0, 093 0.119 0. 108 0.127 0.134 
Phosphoric anhydride (P2Os5) -....._____-___.__ 0. 063 0. 078 0. 086 0. 067 0. 075 
Rates (OW) ook on eee ado ek es 0.10 0.27 0.11 0. 22 0,14 
Poteel: CRO se 0.077 0.083 0.064 0. 089 0.119 
PEWINOB oeeeetare cus tens ae 1.18 1.40 1.16 1,29 1.22 
Loss on ignition _____ Scbckoae aceon 13.80 13. 92 14.16 14. 60 13. 72 
Detritus, not passing 1 mm sieve _____________. 40.4 61.1 32 Ba | 89.6 45.8 
Coarse sand, 1.0 to 0.56 mm _..-_.-..._..- 111... 4.8 2.8 2% 4.1 4 
Medium sand, 0.5 to 0.25 mm ________-.-22.2... 4.7 2.9 2.5 3.9 14 
Fine sand, 0.25 to.0.10 mm-_-___.._-.....2.-.-..- 4.0 3.6 4.2 4.4 7.2 
Very fine sand, 0.10 to 0.05 mm________.-._.._. 6.1 6.9 14 8.0 6.7 
Silt, 0.05 to 0.01 mm ____._. ae 4.6 4.6 y 8 Be § 2.4 0.7 
Fine silt, 0. 01 to 0.002 mm ..-.. 2-2 6..02.52 2... 18.9 28.6 24.8 22.5 22.0 
Clay, less than 0. 002 miti.: oc 56.9 50.6 53.5 54.7 60.3 
Total (except detritus) __-_.-_. 22.28, 100.0 100.0 100.0 100.0 | 100.0 
2 Analyzed by A. S. Argiielles, Bureau of Science, Manila, P. I. 
» Rolling land; trees (Hevea) poor. 
© Sandy loam; coconuts. 
4 Gently rolling land; trees (Hevea) good. 
© Swampy land; Hevea. 
* Philip. Journ. Sci. § A 6 (1911) 279-830. 
