FERTILIZERS AND MANURES FOR THE ORCHARD 189 



crops, it would seem to be adapted to orchard use. Unfor- 

 tunately, sufficient data are not as yet available to warrant 

 a definite statement of its value, but in demonstration tests 

 the results have fully equaled those of nitrate of soda. Rei- 

 mer ^ used sulfate of ammonia in an experiment with Winter 

 Nelis pears in the Rogue River Valley, Oregon, and finds 

 that "The plot which received 5 pounds of sulfate of am- 

 monia produced a notable increase in yield, almost equaling 

 the yield produced by 10 pounds of nitrate of soda. The 

 5 pounds of sulfate of anmionia contains as much nitro- 

 gen as 63^2 pounds of nitrate of soda." Other experimental 

 work in Oregon with both the peach and apple demonstrate 

 that this material is of increasing importance in orchard 

 work. With certain of the field crops, however, it has been 

 found that this source of nitrogen is not quite equal to the 

 same units of nitrogen in nitrate of soda. Also the chemi- 

 cal changes which take place will ultimately exhaust the 

 bases of the soil unless the land is well supplied with cal- 

 cium or else lime is applied to offset the loss. 



161. Time of application. — So far as is now known, the 

 quickly available forms of fertilizers should be applied not 

 later than blossom time to secure the best results, and it 

 is convenient to add all materials at the same time whether 

 they are readily soluble in water or not. They may be 

 broadcast on top of the grass or mulch or sown with a fer- 

 tilizer drill in the case of a tilled orchard. 



There seems to be some definite evidence to show that an 

 application of nitrate of soda about two weeks before the 

 blossoms open will greatly stimulate the "set" of fruits of 

 the apple, this being particularly noticeable on weak trees. 

 This seems to have been reported first by Ballon - from work 

 in southern Ohio. An orchard of twenty-year-old Rome 



» Ore. Agr. Exp. Sta. Bull. 166. 1920. 

 - Ohio Agr. Exp. Sta. Bull. 301. 1916. 



