SOILS 27 



63. Chemical properties. While it is necessary to have 

 an adequate supply of available plant food, the physical 

 composition of the soil is of much greater importance 

 than the chemical. It is a simple matter to supply ferti- 

 lizers, but practically impossible to make good truck soils 

 out of some types. Manure or green crops may be used 

 with the utmost freedom. Although these greatly im- 

 prove the heavier types, they will not make ideal soils 

 for garden crops. The proper chemical composition of 

 truck soils, however, is important and this matter should 

 receive the most careful consideration. See Chapter 

 VII on the use of fertilizers. 



64. Soil adaptation. Soils differ greatly in their adap- 

 tation to various crops. Late cabbage, for example, suc- 

 ceeds on very heavy soils, while the lighter types produce 

 good early cabbage. Lima beans do best on sandy soils, 

 while field beans prefer the heavier types. These illus- 

 trations simply serve as examples. More definite in- 

 formation' is given in Chapter XXI, which is devoted to 

 the culture of various classes of vegetables. 



