PKBPARING SEED BEFOEE SOWIJSTG. 



2or 



come, as it has been retarded in its development, it 

 will frequently perish. And j^et, when too near the 

 surface it will be exposed to the variations of the 

 weather. Hence, the importance of some approximate 

 idea of just what the most desirable depth for planting 

 should be. No definite rule can be given, as it varies 

 with the climate and soil, and in many cases should be 

 determined by practical experience. Groven's experi- 

 ments give some idea of the variations in the number 

 of plantlets appearing above ground after a period of 

 days and at various depths. 



He, therefore, concluded that about one-half to 

 one inch was the best depth. On the other hand, 

 Walkhofif took up the subject and concluded that if we 

 admit that the soil has a temperature of 15 degrees C. 

 (59 degrees F.), the number of days for seeds to appear 

 above ground at various depths was as follows: 



For seed at a depth of 6 m. m. (0.24 inch) 13 days. 



" " " " 13 m. m. (0.61 inch) .9 " 



" " " " 19 m. m. (0.74 inch) 9 " 



" ■' " " 26 m. m. (1.02 inches) 9 " 



When the surface of the soil is caked for one rea- 

 son or another, the seeds are unable to penetrate it, 

 even when one-tenth inch in thickness. Hence, the 

 importance of keeping the soil in a thoroughly open 

 condition. If the seed is not sufficiently covered it 

 will rot; if too much covered, it does not show itself. 

 Consequently, it is a question of texture of soils; if very 

 light, the sowing should be at a certain depth; if heavy, 

 near the surface. 



