150 THE PRINCIPLES OF AGRICULTURE 



capillarity, the air is driven out, and the soil 

 swells and tends to become puddled (81). 



252. Many seeds will not germinate if planted 

 out of season, or when the soil is cool, no matter 

 how well the seed-bed is prepared. Then, if it 

 is desired to plant early, make the land fine and 

 loose, for in so doing the temperature of the 

 soil is raised. The soil of a fine, porous seed- 

 bed, resting on a well -drained subsurface and 

 subsoil, is much warmer than one resting on a 

 compact, undrained foundation. However, it is 

 not wise to plant seeds out of season or when 

 the weather is unsuitable. 



253. If small seeds are covered with but little 

 earth, they may fail to germinate for lack of 

 moisture. If covered with enough fine earth to 

 insure a constant supply of moisture, the young 

 plants have a hard struggle to reach the surface. 

 Only a few of the small seeds, as clover and 

 many of those planted in the kitchen -garden or 

 flower-garden, ever produce plants. Sometimes 

 the seeds are imperfect, but more often the fail- 

 ure to secure vigorous germination is due to a 

 poor seed-bed or to careless planting. To ob- 

 tain better results, not only prepare a fine seed- 

 bed and sow at the proper time, but compact 

 the soil immediately over the row of seeds. 

 This will enable capillary attraction to bring 

 moisture to the surface, or near it (103). The 



