PHILIPPINE A GRICUL TURE 



be used on other plots, if these fertilizers are available. 



The effects of the fertilizers on these little plots will 



show what one it will be 

 best to use on the whole 

 field. Sometimes a mix- 

 ture of fertilizers will give 

 good results at the least 

 cost. 



The Caingin System. 

 Since plants use up the 

 food in soils, it becomes 



FlG. 26. Maize in rich soi 



FJG. 27. Mai/.e in sand or gravel 



impossible after a time to raise good' crops, without ferti- 

 lizers, on ground which was once fertile. The caingin 



