THE APPLICATION OF NITROGEN-CARRYING FERTILIZERS 213 



elements, in increasing yields. Perhaps it should be noted that the trees 

 in both of these orchards were in a rather weak vegetative condition 

 before fertilizers were applied. 



Table 71.:^Influence of Quickly Available Nitrogenous Fertilizers on 

 Yield of Apples in the Hood River Valley 

 {After Lewis and Allen^-^) 

 Treatment Average Yield per Tree 



(in Loose Boxes) 

 0.90 



Check (no fertilizer) . 

 Nitrate of soda 



10.01 



In contrast to such striking results from the use of fertilizers it 

 should be mentioned that nitrogen, alone and in combination with other 

 nutrients, has been applied to many orchards without resulting in materi- 

 ally increased yields. Thus Hedrick and Anthony^*^ summarize the 

 results of a 20-years' experiment in a New York orchard as follows: 

 "Adding acid phosphate at the rate of 340 pounds per acre per year has 

 not given a noticeable increase in yield. The addition of 196 pounds of 



Table 72i'^^VERAGE Annual Results from Orchard Fertilizers in Ohio 

 (After Bnllou") 



Treatment 



^vFitrate of soda 5 pounds 



Nitrate of soda 5 pounds, acid phos- 

 phate 5 pounds, muriate of potash 

 2}4 pounds 



Tankage 5 pounds, bone 5 pounds, 

 muriate of potash 5 pounds 



Nitrate of soda 5 pounds, acid phos- 

 phate 5 pounds 



Muriate of potash 5 pounds 



Stable manure 2.50 pounds 



CGhecks (no fertilizer) 



muriate of potash to the 340 pounds of acid phosphate seems to have 

 resulted in an increased yield. The annual application of 50 pounds of 

 readily available nitrogen in addition to the phosphoric acid and potash 

 has caused no increase in yield." Gourley,^^ likewise, working in New 

 Hampshire with a soil of entirely different character, obtained but slightly 

 increased yields from the use of nitrogen alone or in combination over 

 those attending a clean cultivation-cover crop method of soil management 

 without fertilization. The first of these two investigators states, how- 

 ever: "An analysis of the soil before the experiment was begun shows that 

 at that time there was, in the upper foot of soil, enough nitrogen (total) 



