20 Elementary Principles of Agriculture 



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Fig. 16. Seed-testing devices 



surface, but also dryer. If planted too deep, it will 

 take a longer time to begin germination, because the 

 deeper ground is colder, particularly so in early spring. 

 The table below shows the effect on the time in 

 coming up, of planting wheat at different depths, and 

 the number of seedlings that grew. 



Proportion of seed 

 Depth Time in coming up that grew 



^ inch 11 days J 



1 inch 12 days all 



2 inches 18 days . 



3 inches 20 days . 



4 inches 21 days . 



5 inches 22 days . 



6 inches 23 days . 



The seedling will be more exhausted before it reaches 



the surface if planted too deep. 

 The seedling stage is a delicate 

 one. Success, therefore, in 

 getting a good stand will often 

 depend on how well the soil 

 has been prepared for the 

 seeds. The soil intended for 

 the seeds should be warm, 

 moist and mellow. The par- 

 ticles should be so fine that 

 the seed will be in contact with 

 grains of soil on all sides. Small 

 seeds, like tobacco, are merely 



Fig. 17. i, Pea planted just deep pressed into the surface with a 



enough to be in well moistened v i TTT-J.I i n j 



soil; 2, too deep seedlings delay- board. With SUCh Small Seeds, 

 ed in reaching surface 3 too i 111 



deep.unabie to reach the surface, special arrangements should 



