DIRECT SOWING. 49 



(2.) A temperature not lower than 45, but better 



from 5575 Fahr. 

 (3.) Admission of air, whence the oxygen is derived. 



The presence or absence of light are of no importance. 



These conditions can easily be provided in the case of 

 small experiments, but in operations conducted on a 

 large scale they are only to a certain extent rendered 

 practicable by a suitable condition of the germinating 

 bed, by the manner of covering the seed, and by 

 sowing at the most suitable time of year. 



a. The Germinating Bed. 



A suitable condition of the germinating bed is of prime 

 importance; it, is secured by working or loosening the 

 soil, in some instances by draining or irrigating, and in 

 exceptional cases by manuring. 



Loosening the soil secures the following advantages : 



(1.) It enables the roots to spread more readily, and to 

 penetrate deeper into the ground, thus rendering the 

 young plant more independent of variations of moisture 

 in the surface soil. 



(2.) It effects a mixture of the different layers of 

 the soil, thus rendering the nourishing substances more 

 readily available and causing greater activity in chemical 

 changes. 



(3.) It freely admits air and heat. 



(4.) It exercises a favourable effect upon the degree 

 of moisture in the soil. Bain-water penetrates more 

 readily and to a greater depth, while subsequently, 

 during dry weather, it rises again by capillary attrac- 

 tion. 



VOL. II. E 



JL 



