No. 6. DEPARTMENT OF AGRICULTURE. 439 



TABLE III. EFFECT OF FERTILIZERS ON YIELD. (Johnston Orchard). 

 (Average returns from certain treatments during past 3 years.) 



These tables are from cue ui' our ••combination" experiments, in- 

 volving both fertilization and cultural methods, and started in 1908. 

 The fertilizers have, therefore, had a chance to atfect the crop only 

 during the past 3 years, and it is for that period that the totals and 

 annual yields per acre are computed. 



E-en a glance at these tables can leave no doubt as to the posi- 

 tive and iirofound efl'ect of proper fertilization on the yield of apples. 

 It will be noted that the checks run fairly uniform, averaging a 

 little over 190 bushels per acre annually. Lime applications (at 

 the annual rate of 1,000 lb. per acre) have given almost exactly the 

 same returns as the average check. The phosphate and potash com- 

 binaticm has atiected yield in this case rather decidedly, having 

 raised it by 123 bushels per acre. This may be partly due to a slight 

 superiority in location, as indicated by the fact that its adjacent 

 check is the highest in yield and is within 88 bushels of the phos- 

 phato-potash treatment, ^^'hile this increase in yield is fairly satis- 

 factory, there is nothing in the growth or appearance of the trees 

 of Plot 5 that would leave one to believe that their treatment is 

 appreciably superior to that of the checks. In other words, the trees 

 of Plot 5 still look starved and indicate that there is something else 

 lacking, although it will be noted that this is the fertilization ordi- 

 narily recommended for orchards. 



This lack is very decidedly met by the manure treatment of Plot 

 8. In this plot, the trees are making a luxuriant growth, both in 

 wood and foliage, and the yields have been increased by 390 bushels 

 per acre annually, — a very satisfactory exchange for 12 tons of stable 

 manure. Even this increase in yield, however, is considerably less 

 than tliose obtained on the plots receiving a nitrogen-carrying fer- 

 tilizer. Under the latter treatment on three plots, the average annual 

 yield has been increased from 191 bushels on the checks to 649 bushels 

 on the fertilized plots, or an annual increase of 457 bushels of apples 

 per acre. This resulted from fertilizer apj)lications that actually 

 cost less than $17, and the essentials of which can be bought at 

 retail for about |10 per acre. During the past year, the fourth 

 year of the experiment, as shown in Table II, the yield on Plots 2 

 and 3, compared with that of their adjacent checks, was at the rate 

 of 17 to 1, the yield on the checks being at the rate of 54 bushels 

 per acre, while that on the intervening nitrogen plots was 922 bus- 



