PROPERTIES AND CONDITIONS OF SOIL 287 



the one that has holes in the bottom ? What is your con- 

 clusion as to the effect of drainage on temperature of soil ? 

 Other conditions being the same, which will give you the 

 warmer soil in the spring, a field that has under drainage 

 or one which has not? 



Thus far we have seen that the soil contains water and 

 certain chemical compounds that are used by the plants, 

 also that different kinds of soil differ in regard to their 

 physical properties. We are now ready to find out some- 

 thing about the relations of plants to the soil and water. 



Farmers' Bulletins: Exercise in Elementary Agriculture: 

 Office of Experiment Station, Bulletin 186; Management of 

 Soils to Conserve Moisture, No. 266; Soil Moisture, etc.; 

 No. 87; Some Soil Problems for Practical Farmer, No. 306; 

 Farm Drainage, No. 40. 



