24 STATE HORTICULTrRAT. SOCIETY. 



I have been able to double the growth on two year old trees in culti- 

 vation by the use of a handful of nitrate of soda per tree. I have in 

 mind two orchards in sod which have been brought up from a state of 

 low production to one of high production by the use of manure rather 

 than nitrate of soda, although it took a much longer time. These in- 

 stances lead me to believe that the increase in vigor and production is 

 due to available nitrogen rather than counteraction of toxicit5^ 



Gourley while in New Hampshire showed that under sod nitrofication 

 proceeded very slowly, but that under a system of good tillage nitrates 

 were usually present in excess of the needs of the trees. I believe that 

 this, therefore, is the heart of the explanation. In other words, there is 

 greater need in practically all cases for the application of a nitrogenous 

 material to a sod orchard than to one in cultivation, but that it is possible 

 for cultivated soils to become sufficiently deficient in their power of 

 supplying nitrates to warrant the application of a nitrogen carrier. 



I believe with you that there is still much to clear up concerning the 

 fundamental problems in connection with orchard fertilization and I 

 trust that the various experiment stations will continue their good work 

 imtil these problems are answered. 



Very truly yours, 



R. B. C. 

 Professor. 



MEMORANDUM. 



The New York Agricultural Experiment Station, at Geneva, has 

 positivel}^ proven that nitrate of soda on their soils at the Station does 

 not benefit apple trees that are in clean cultivation for a part of each 

 season, and they have confirmed these results in a number of other 

 orchards also under clean cultivation. 



The Ohio Agricultural Experiment Station has proven conclusively 

 that a number of orchards in Ohio in sod are very emphaticallj' bene- 

 fited by nitrate of soda, and the Michigan Agricultural College is piling 

 up evidence in confirmation of the Ohio work. 



The Woburn Experiment Station in England, in a series of very unique 

 experiments, has proven that the roots of grasses give off a substance 

 that is poisonous to apple trees, at least to the extent that it makes the 

 foliage yellow and retards growth. But this toxic material is oxidized 

 if it comes in contact with the air and is then no longer detrimental to 

 apple trees. 



Chemists know that nitrate of soda is a very powerful oxidizing agent 

 and without doubt would destroy any organic material in June grass sod 

 that the oxygen of the air would destroy. 



The above four facts do not contradict each other. On the other 

 hand, they make clear what would otherwise appear to be a contra- 

 diction. In England they oxidize the toxic material from June grass 

 by letting the water leaching from the sod rain through air before com- 

 ing in contact with the apple roots, and thereby oxidize the detrimental 

 material. In Ohio and Michigan they oxidize it with nitrate of soda, 

 converting it into nitrate of soda, which does not detract from its ferti- 

 lizing value. This nitrate produces a heavy growth of grasses that add 

 to the organic matter in the soil, which is an undoul)te(l advantage on 

 poor soils. 



