24 



Journal of Agricultural Research 



Vol. IV, No. I 



felt that these will be fairly typical of the materials used in this investi- 

 gation. The figures as quoted are expressed as the percentages of actual 

 radicles occurring in the ash, and the total percentage of ash is the amount 

 found in the plants when calculated to a moisture-free basis. 



Composition of the ash of the harvestable portions of Macrocystis pyrifera, Nereocystis 

 hietkeana, and Pelagophycus porra 



Constituent. 



Ca 



Mg 



Na 



K 



FcOs 



AI2O3 



CI 



SO4 



CO3 



PO4 



Total 



Total percentage of ash in water-free material . 



Macrocystis 

 pyrifera. 



Per cent. 



4.96 



2. 24 



10. 52 



29. 46 



•43 



34-93 

 7.92 



4-44 

 2.30 



97. 20 

 35-^2 



Nereocystis 

 luetkeana. 



Per cent. 



2. 10 



1-55 

 11.05 

 32. 66 



- 17 



40. 89 



4-63 



3. 10 

 I. 91 



98.06 

 50-57 



Pelagophy- 

 cus porra. 



Per cent. 



2. 09 



1.71 



8.63 



34-73 



.26 



40-83 

 4.84 

 1.66 

 2. 18 



96- 93 

 52.66 



There are several very important deductions to be made from these 

 analyses when considering them from the point of view of soil fertility. 

 The very large percentage of total ash present is at once apparent; and 

 from preceding determinations of the soluble salts present in similar 

 samples it is evident that the larger portion of the total ash, about 85 

 per cent, is, in fact, water-soluble. 



Some quantitative separations of the soluble salts were made which 

 showed that small quantities of the calcium and traces of the magnesium 

 only were dissolved, while all the potassium and chlorin and the major 

 portion of the sodium and sulphate ions went into solution. 



The immediate effect, then, of the incorporation of kelp in the soil is 

 a very considerable addition of soluble salts. Three-fourths or more of 

 these will be potassium chlorid or sulphate, while the other fourth will 

 largely consist of sodium chlorid and sulphate. The potash will be 

 fixed in the soil by its well-known precipitative power for this com- 

 pound, while the sodium salts will in any ordinarily well-drained soil be 

 carried off in the drainage water. As the kelp gradually decomposes, 

 the compounds present in the soil will approach those represented in the 

 complete ash analyses above given. They will then tend to make a 

 much more balanced solution, even if all the sodium salts be not removed 

 by that time. 



From C. B. Lipman's work on the toxicity and antagonism of various 

 salts on soil bacteria both in solutions and in soil (7, 8, 9, 10, 12) it 

 would be reasonable to expect that if any disturbance of the biological 

 activities of the soil is caused by the soluble salts from applications 

 of kelp this influence would be very likely to decrease as the soil solution 



