FERTILIZERS FOR VEGETABLES 



237 



as immediate availability is concerned, being used in fertili- 

 zer. The manufacturers of fertilizers now have found a 

 simple v^ay of putting them into the fertilizer honestly. 

 When the rock phosphate is treated v^ith sulphuric acid, they 

 put into that mixture the hair or the leather, and during the 

 action the sulphuric acid wholly changes such things as 

 leather and hair into forms of nitrogen that are about as 

 available as good tankage. So it is possible under commer- 

 cial conditions to change those worthless things into fairly 

 good form. You may have seen in the paper the expression 

 'Vet process" of mixing fertilizer. It means just this pro- 

 cess. 



Question: Could muck be put in that way and be made 

 very available? 



Professor Van Slyke: Yes, only there is not very much 

 nitrogen in muck. It would hardly be worth while. 



How Long Are Fertilizers Available? 



Question: How long will a complete fertilizer in the 

 ground, if not used, be available to the plant? 



Professor Van Slyke: Nitrate of soda would not stay 

 there during the season. Sulphate of ammonia would stay 

 till it is changed into the nitrate and washed out. The acid 

 phosphate is fixed in the soil, so that very little of that is 

 lost. The potash compounds are also fixed in the same way. 

 Organic nitrogen would stay longer. 



Mr. Russell : How long would nitrate stay in a clay soil 

 that would not leach very fast? 



Professor Van Slyke: I should say it ought to stay 

 through one summer season and over into another. 



Question: Would any evaporate? 



Professor Van Slyke: No, the nitrate is just like com- 

 mon salt or sugar, and it will not volatilize. 



Lime. 



A Member : I live near the Caledonia lime deposit where 

 they get the agricultural lime. Our people are using con- 

 siderable of that agricultural lime. Can you tell me how 



