320 JOURNAL OF FORESTRY 



1. River sand, used in greenhouse tests. 



2. Clay, modified by screening and the addition of lo to 15 per cent 



(by volume) of river sand, used in the Feather River Nursery. 



3. A light, loose, porous volcanic soil, roughly classified as volcanic 



ash, at Pilgrim Creek Nursery. 



(a) Modified by addition of sheep manure and burnt lime. 



(b) In virgin condition, except for plowing and cultivation. 



In order to determine the effect of character of soil on rapidity and 

 completeness of germination, tests in each of the above soils were made 

 in the greenhouse during the winter of 1916-17. Yellow pine with one 

 test, Jeffre}' pine with two, and incense cedar with one test were used. 

 ]\Iore elaborate comparison was impossible with the small amount of 

 Pilgrim Creek soil which was available, and the expense of shipping it 

 was too great to justify further importations. At any rate, the results, 

 while certainly not the last word on the subject, represent a step in 

 advance toward the ultimate solution of the seed-testing problem and 

 may be accepted at face value pending further work. 



Results are shown in Table i : 



Table i. — Comparative Germination in Different Soils 



Germination— Days 



Species Kind of soil 



20 40 60 80 



Yellow pine Ash, unfertilized 28.0 58.0 64.0 



Ash. fertilized 0.5 19.5 61.5 64.0 



River sand 0.0 16,0 55.0 60.0 



Clay 0.0 4.0 48.0 54.0 



Jeffrey pine Ash, unfertilized 0.0 23.0 55.5 63.0 



Ash, fertilized 0.0 28.0 66.0 69.0 



River sand 0.5 11. 5 62.0 69.5 



Clay 0.0 7.0 42.0 48.0 



Incense cedar Ash, unfertilized 0.0 2.5 10. 12.0 



Ash, fertilized 0.0 11,5 18.0 19.0 



River sand 0.0 5.5 22.5 24.0 



Clay 0.0 2.0 13.0 18.0 



Germination is possibly a trifle more rapid and complete in the fer- 

 tilized Pilgrim Creek soil than in the unfertilized, which points to the 

 desirability of the past practice at that nursery. For the pines the tests 

 in sand (the greenhouse medium) are practically identical in rapidity 

 and completeness with the fertilized ash, while for cedar sand gives 

 the best results. Results of greenhouse tests can apparentl}^ be applied 

 directly to the Pilgrim Creek conditions. Tests in clay are lower than 

 any other and also slower for the pines, and check the conclusion pre- 

 viously reached that seed sown in the Feather River Nursery does not 

 hold up to greenhouse values. The incense cedar in clay is lower than 

 for sand, but exceeds the average of the tests in the ash soil. 



