1916.] PUBLIC DOCUMENT — No. 31. 19a 



There are three sets of plots on which nitrate of soda at the 

 rates respectively of 300, 450 and 600 pounds per acre is used 

 in connection with manure at the rate of 20,000 pounds per 

 acre. In these trials nitrate of soda at the rate of 450 pounds 

 per acre has given the best yield in so many instances that it is 

 believed to be the maximum which can usually be profitably 

 used, although in a number of instances the yield on plots to 

 which nitrate had been applied at the rate of 600 pounds per 

 acre has been somewhat greater. 



3. At what season does it appear to be best to apply nitrate 

 of soda when used in connection with fertilizers supplying 

 phosphoric acid and potash? 



The methods of application under comparison are as fol- 

 lows : — 



First. — All the nitrate is applied early in the spring when 

 the bed is first harrowed. 



Second. — On other plots all of it is applied at the close of 

 the cutting season and cultivated in. 



Third. — On the other set of plots one-half of the nitrate is 

 applied early in the spring and one-half at the close of the cut- 

 ting season. 



The results do not indicate any clearly defined superiority for 

 either method of application, and in the case of the use of 

 nitrate with manure, where also the three methods of applica- 

 tion above mentioned were compared, the conclusion is the 

 same. 



An effort has been made to determine whether application of 

 the whole or a part of the nitrate early in the spring increases 

 the proportion of the crop during the early part of the season. 

 This does not seem to have been the case where the nitrate is 

 used either with phosphate and potash or with the manure. 



4. Another question on which we have sought to throw light 

 is: in what amount, if any, does acid phosphate when used in 

 connection with a liberal application of nitrate of soda and 

 muriate of potash prove useful? 



In the effort to answer this question acid phosphate has been 

 employed at three different rates per acre: viz., 300, 450 and 

 600 pounds. The increases produced by acid phosphate are, 

 at best, relatively small, and the greatest increase has been 



