IX. A. 1 Cox and Argiielles: Soils of Luzon 25 



PANGASINAN 



No general investigation of the soils of Pangasinan have been 

 made except of the lands within the municipalities of Asingan, 

 San Manuel, Urdaneta, and Villasis included in the proposed 

 Ambalangan-Dalin irrigation system, although a few samples 

 from other districts have been received and analyzed. As 

 shown by the mechanical analysis of soils of the Ambalangan- 

 Dalin district, the soil varies in texture from heavy tenacious 

 clay loam to fine silt and sand or gravel. Mr. G. A. Graham, 

 irrigation soil inspector of the Bureau of Public Works, de- 

 scribes these soils as follows :^^ 



(a) Heavy clay loam. — This type of soil is to be found in the vicinity 

 of Urdaneta and Villasis (see map, fig. 2). The surface and subsoil of 

 this section of land is of the same composition and arrangement; a type 

 of soil which has a maximum water capacity, and is capable of retaining 

 a large percentage of it. These features make the soil especially suitable 

 for rice culture. 



(6) Clay loam and sand. — This type of soil is similar to that described 

 above, but differs essentially in its water-holding capacity, which is due to 

 the varying quantities of sand intermingled with the clay particles. This 

 type of soil, while suitable to the growth of rice, will require more water 

 than the former type. 



(c) Clay loam and gravel. — A class of soil found around San Manuel; 

 the proportion of clay and gravel in this soil is not very uniform. The 

 soil between the Binalonon-San Miguel road and the Aborido ditch contains 

 about 40 per cent clay, the remainder grading from cobble stones to fine 

 sand. North of San Manuel and as far east as the barrio of San Antonio 

 the soil is composed of about 30 per cent clay. 



(d) Fine silt and sand. — By referring to the map it will be seen that 

 a large percentage of the land is composed of fine silt and sand. Most of 

 this soil has been formed by the overflow of the Agno River. This type 

 of soil differs very materially from any that has been described. The 

 surface is mainly of light loamy nature underlaid by a stratum of sand 

 of various grades. On account of the porosity of the soil and the topog- 

 raphy of the land, a large quantity of water will be needed for rice 

 culture. 



These soils were unquestionably all formed in the same way, 

 but natural and artificial means have caused great variations in 

 their physical properties and fertility. With reference to their 

 physical properties as indicated by field observations, Mr. 

 Graham reports with regard to classification and drainage as 

 follows : 



Class I. — This class includes all the lands within the vicinity of Villasis 

 and Urdaneta. The soil is classified as first class for rice, as it has a 

 large water-holding capacity and is of sufficient depth to give ample room 



** An unpublished report made in 1910. 



