Apr. IS, 191S 



Availability of the Nitrogen in Kelps 



35 



Table V — (Series IV). Ammonification and nitrification of Macrocystis pyrif era, fresh, 

 air-dry, highly heated, and partially dry. Incubated for three weeks 



Material added to 200 gm. 

 of soil. 



Macrocystis pyrif era, 

 fresh 



Do 



Macrocystis pyrif era, 

 air-dry 



Do 



Macrocystis pyrif era, 

 heated to 250° C. . . 



Do 



Macrocystis pyrif era . 



Do 



Do 



Do 



Do 



Do 



^^IT^y Quantity 

 age of "fkelo 



"^"I'T^ added^ 

 m kelp. 



Quantity 

 of nitro- 

 gen 

 added. 



jSy. 00 

 87. GO 



8.68 

 8.68 

 1.44 



Gm. 



7. 00 



14. 00 



.72 



1.44 



■50 



Quantity 

 of soluble 



salts in 

 kelp 



added. 



Mg. 

 19-45 



38.90 



IO-35 



20. 70 



8.43 

 16.86 

 12.32 

 24. 64 



10-73 



21. 46 

 10. 20 

 20. 40 



Gm. 

 O. 27 



•54 

 .27 



- 54 

 -27 

 •54 

 .27 



• 54 

 .27 



• 54 

 •27 



•54 



Quantity 

 of nitro- 

 gen 

 gained 

 in am- 

 monia. 



Quantity 

 of nitro- 

 gen 

 gained 

 in ni- 

 trates. 



14 

 94 



59 



27 

 27 

 27 



56 

 56 

 56 



94 

 94 

 44 

 56 

 56 

 06 

 56 

 06 

 06 

 44 

 44 

 44 

 94 

 94 

 94 

 94 

 94 

 94 

 94 

 94 

 94 

 94 

 94 

 94 

 44 

 94 

 44 



Quantity 

 of nitro- 

 gen 

 gained 

 in am- 

 monia 

 and ni- 

 trates. 



Average 

 percent- 

 age of 

 added 

 nitrogen 

 gained in 

 ammonia 

 and ni- 

 trates. 



Mg. 



5-37 

 4. 17 



2. 54 



9.64 

 II. 78 



II. 22 



- .91 



- .91 

 -1.05 



^•59 

 ^•73 

 1.79 



-^•75 



- .91 

 -1.83 

 -1-47 



55 

 97 

 67 



39 

 67 



8.13 

 7.01 

 6.31 

 1-45 

 1-03 

 1-59 

 5-31 

 7.29 



5^17 

 2. 03 



2-73 

 2.31 



4^51 

 5^31 

 4-65 



20. 67 

 27.97 



None. 

 8. 21 



None. 



None. 

 28.98 

 29. 02 

 15^ 58 

 27-59 

 23.04 

 24. 12 



GENERAL DISCUSSION OF RESULTS 



The preceding studies on the availabiUty of the major kelps of the 

 Pacific coast demonstrate a number of important facts, which are con- 

 sistently shown by all the series of experiments. Nercocystis luetkeana, 

 which is not commercially important, proved to be the most availa- 

 ble. It is not a highly nitrogenous substance, like dried blood or cot- 

 tonseed meal. We should not, therefore, expect it to be so readily decom- 

 posed as these materials. The rate of ammonification and nitrification 

 which it has shown in Series I and III is therefore considered to be 

 very satisfactory. 



