150 FOOD FOR PLANTS 



2. Applications of Nitrate of Soda alone (five 

 pounds per tree) increased the average yield in some 

 instances as much as 450 per cent, and in three ex- 

 periments averaged a cash gain per acre of $125.75 

 per year for five years. 



Ohio experiments have also shown more profitable 

 yields from a fertilizer mixture containing 5.6 per 

 cent available nitrogen than one of only sy^ per cent 

 available nitrogen. 



Studies over a period of six years at the Pennsyl- 

 vania Agricultural Experiment Station * brought 

 out the following conclusions: 



1. Applications of nitrogen and phosphates and of 

 manure were very beneficial. Potash was of little 

 service. 



2. Nitrate of Soda alone gave a large increase in 

 yield over the check plots, with a still greater increase 

 when acid phosphate was applied with the Nitrate. 

 The increase in one case was as much as 1,100 bushels 

 per acre. 



3. The beneficial effects of nitrogenous fertiliza- 

 tion were evident by the middle of the second season. 



4. The gains from fertilizations have not been 

 transitory. In some experiments they were greater 

 in the sixth and last year of the experiment than at 

 any other time. 



5. Nitrogenous fertilizers when applied too late 

 in the season retarded somewhat the maturity of the 

 fruit. 



6. For this reason, the apples on the too-late 

 Nitrate-treated tree did not have so good a color as 



* Pa. Agr. Exp. Sta. Bui. 121. Also Fertilization of the Apple Or- 

 chard by John P. Stewart, — Pub. by Chilean Nitrate Committee. 



