53 



Soil 

 No. 



Nature of soil. 



Surface 



Subsoil, 



Surface 



Subsoil.. 



Surface . 



Subsoil-. 



Surface . 



Subsoil-. 



Surface . 



Subsoil-. 



Surface . 



Subsoil- 



Surface . 



Subsoil- 



Detritus 

 on 1- 

 mm. 



screen. 



Mechanical analyses of samples (5 grams) of material, district 

 of Ilog-Cabancalan, passing a 1-mm. screen. Samples as 

 prepared for chemical analysis. 



1 mm., mm., 

 gravel, coarse 

 sand. 



> 1.0-0.5 0.5-0.25 '0.25-0. 10 



0.3 

 0.0 

 0.3 

 0.0 

 0.3 

 1.6 

 0.1 

 0.2 

 0.1 

 0.2 

 0.0 

 0.1 

 0.1 

 0.1 



mm., 

 mediumi 

 sand. I 



0.08 ] 



0.00 ! 



0.12 I 



0.02 



0.44 , 



0.94 



0.06 



0.04 



0.08 



0.40 



0.06 



0.02 



0.08 



0.04 



1.28 

 0.26 

 1.14 

 0.80 

 3.36 

 7.70 

 0.42 

 0.20 

 2.62 

 9.00 

 0.98 

 0.38 

 1.44 

 1.74 



mm., 

 fine 

 sand. 



9.96 



7.88 



12.78 



17.16 



14.76 



17.28 



9.90 



7.04 



16.80 



26.54 



12.22 



13.70 



16.44 



27. 12 



0.10-0.06 



0.05-0.005 



mm., : .^„ 

 very fine ™?"- 

 sand. 



32.70 

 31.48 

 45.74 

 35.06 

 10.28 

 9.62 

 39.40 

 32.72 

 34.72 

 21.18 I 

 15.42 ; 

 12.80 I 

 28.44 [ 

 30.32 : 



silt. 



44. 64 



50.48 



33.28 



40.18 



46. 22 



37.60 



38.02 



49.96 



38.34 



32 



52.02 



51.82 



43.38 



33.72 



<0.005 I 

 mm., Total, 

 clay. 



ro ! 



11.42 

 . 9.08 



7.12 

 • 6.60 

 25. 48 

 26.80 

 12. 84 

 10.06 



7.70 



9.92 

 19.24 

 20.40 

 10.14 



7.52 



100.08 

 99.14 



100.18 

 99.82 



100.54 

 99.94 



100.64 



100. 02 



100. 26 

 99. 82 

 99.94 

 99.12 

 99. 92 



100.46 



The average of these surfaces and subsoils is as follows : 

 Chemical composition. 



The practically uniform composition, chemically, of these soils all 

 along the river valley is probably due to their original formation from 

 the same source — sand, silt, and clay brought down from the mountains 

 by the summer floods. In comparison with the districts thus far ex- 

 amined they are much richer in most of the so-called elements of 

 fertility, being exceptionally so in lime, of which substance a very n^uch 



