I20 



Journal of Agricultural Research 



Vol. XVI. No. 4 



Tabi.R X. — Percentage of nitric nitrogen formed in lOO gm. of soil containing 2 gm of 

 dried blood and varying amounts and kinds of chlorids 



[The untreated soil is taken as 100 per cent] 



All of the chlorids tested increase the accumulation of nitric nitrogen 

 in the soil, and it would appear from the results that the extent of stimu- 

 lation is governed largely by the cation while the toxicity of the com- 

 pound is determined by the anion. Measured in terms of the effect upon 

 nitrification, calcium chlorid is the most effective stimulant of the chlor- 

 ids tested, followed in the order: Sodium chlorid, ferric chlorid, mag- 

 nesium chlorid, manganous chlorid, and potassium chlorid. 



These results undoubtedly account for the varying results noted when 

 sodium chlorid is used as a fertilizer. Some experimenters obtain a good 

 yield from its use; others obtain just as good a yield without it. 



Storp (10), in an article on sodium chlorid as a manure, attributes the 

 benefit derived from its use as being due to the decomposing of insoluble 

 plant food by the sodium chlorid. If this be the correct theory, we can 

 account for yields such as those obtained by Voelcker {11). As an average 

 of five experiments, on land which had been manured with sodium 

 chlorid, the yield of mangels was 36,060 pounds. On the adjoining un- 

 manured ground there were but 26,035 pounds, a difference of a little 

 over 10,000 pounds due to the use of sodium chlorid. Now, if the land 

 was rich in insoluble plant food and the chlorid was able to liberate it, 

 we could expect a large yield. On the other hand, if the land had been 

 poor in unavailable plant food, no good result would have followed its 

 use. Wheeler (12) seems to have established the fact that sodium 

 chlorid can not to any great extent take the place of potassium salts. 

 However, he does think that sodium chlorid can liberate phosphorus from 

 insoluble forms, as the following statement will show : 



It may, however, be stated here that sodium salts seem to liberate phosphorus and 

 potassium so that under certain circumstances they may act as an indirect manure. 



