22 PHILIPPINE AGRICULTURE 



soil. Gravel is made of still larger particles, but it is 

 hardly fit for plants to grow in. 



Loam and Clay. A soil of which between 20 per 

 cent and 40 per cent is made of particles as large as 

 0.025 mm in diameter is called loam. Alluvial soil and 

 mold are usually loam. 



FIG. 23. A sandy beach on the coast of Luzon near Atimonan, Tayabas 



Most soils of which less than 20 per cent is made of 

 particles as coarse as 0.025 mm in diameter are clay. 



Take half a kilogram of each of these soils, air-dry. Let each stand 

 overnight in water. Carefully pour off what water will run off, and then 

 weigh the soils. How much water will each now hold ? In the pre- 

 vious experiment with sand and clay, which held more water when 

 air-dry ? 



Soil and Water. You have already learned that the 

 finest soils will hold the most water. The water which 

 sand can hold is less than 25 per cent of the weight of 

 the sand. Loam can hold 25 per cent to 80 per cent 



