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FERTILIZERS FOR VEGETABLES 



Professor Van Slyke: If I had grown celery on the 

 land before, I should be governed primarily by that. If I 

 did not know anything about it, I should use from six hun- 

 dred to a thousand pounds. 



Question : As to the effect of the keeping quality of the 

 celery with nitrate of soda, will it stand up in cold storage? 



Professor Van Slyke: If you do not put on too much. 

 You can make, Ave will say, two applications of seventy-five 

 pounds or three applications of fifty pounds. Possibly in 

 connection with the keeping quality of celer^^ the question 

 of disease comes up — the matter of rotting ; and it is generally 

 recognized that over-feeding with nitrogen tends to make a 

 plant more sensitive to the attack of plant diseases. That is, 

 the tissues are more tender, more easily broken, and there- 

 fore more susceptible to attack of disease. 



Effect of Fertilizer on Acidity. 



]\Ir. Russell: What danger is there of making a soil 

 sour by the use of acid phosphate? 



Professor Van Slyke: If you use large amounts of acid 

 phosphate without applying lime carbonate or any other form 

 of lime or without using nitrate of soda, there is sooner or 

 later danger of making your soil acid, and particularly if you 

 use along with it sulphate of ammonia and either muriate 

 or sulphate of potash. It is not the acid phosphate that makes 

 the soil acid. That may sound like a contradiction. While 

 the soluble calcium phosphate, which is the compound that 

 does the Avork in the acid phosphate, is an acid compound, it 

 is not that that makes the acid in the soil, because that is 

 taken up and used by the plant. The trouble comes from the 

 land plaster (calcium sulphate), which is in the acid phos- 

 phate. 



Question: Does it not make a difference what it is treat- 

 ed Avith, AA'hether it is sulphuric acid or the refuse from the oil 

 manufactory? 



Professor Van Slyke: No, I do not think it makes any 

 difference. The statement has been made, but AAuthout 



