FERTILIZERS FOR THE GARDEN— VII. 



RURAL NEW-YORKER says: "It is 

 much to be regretted that certain writers 

 are advocating the use of nitrate of soda. 

 Unless the land is well supplied with pot- 

 ash and phosphoric acid and needs nitro- 

 gen alone, nitrogen will not materially increase the 

 crop." This is a self-evident proposition. And the 

 same thing might be said of soda, lime, magnesia, 

 sulphuric acid and iron. All these ingredients of 

 plants are absolutely essential to healthy plant 

 growth. 



There are people who contend that to maintain 

 the productiveness of our land it is necessary to re- 

 turn to the soil the amount of plant food that the 

 crops remove. They overlook the fact that a cer- 

 tain amount of plant food is rendered available each 

 year from the store of plant food lying dormant in 

 the soil. If this is sufficient we need use no manure. 

 If any one element is deficient, we must supply the 

 deficiency or be satisfied with a deficient yield. The 

 weakest link in a chain determines the strength of 

 the whole chain. If we find out the weakest link 

 and strengthen it, then some other link would be the 

 weakest. As a rule, for most garden crops, our soils 

 are deficient, ist, in nitrogen ; and when this is sup- 

 plied, they are deficient, 2nd, in phosphoric acid ; 

 and when this is supplied, they are deficient, 3rd, in 

 potash, and so on through every link in the chain. 



For forty years or more, efforts have been made 

 to find out what ingredients of plant food are most 

 likely to be deficient. It was proposed to analyze 

 the soils. This was found to be practically useless. 

 The idea was then advanced that the amount of 

 plant food in the crops would tell us the amount 

 necessary to apply in manure. Lawes and Gilbert's 

 experiments, over forty years ago, demonstrated the 

 fallacy of this idea, but every now and then it shoots 

 up again and grows as vigorously and perniciously 

 as ever. 



As we said last month, what we need, especially 

 for garden crops, is not "soil tests," but experi- 

 ments that will show what plants require a " sap of 

 the soil" specially rich in nitrogen or in phosphoric 

 acid or potash. In other words, we want to ascer- 

 tain the weakest link in the supply of food for dif- 

 ferent plants ; and there is no way of getting at the 

 facts except by actual experiments. 



When the editor of the Rural says it is much to 

 be regretted that we are advocating the use of ni- 



trate of soda, he overlooks the fact that we advocate 

 the use of superphosphate with equal earnestness, 

 and, in some cases, of potash also. The object of 

 these articles was to show that w hen gardeners use 

 the ordinarj' commercial fertilizers, they spend a 

 great deal of money for plant food that their crops 

 do not need. For instance, if they want to apply 

 100 pounds of nitrogen on an acre of land, and 50 

 pounds of phosphoric acid, and buy a fertilizer guar- 

 anteed to contain 2 per cent, of nitrogen and 12 per 

 cent, of phosphoric acid, they will have to sow 5000 

 pounds to the acre, and this will furnish tivelve times as 

 much phosphoric acid as is required. What we con- 

 tend for is that they should buy the necessary phos- 

 phoric acid in the cheapest and best form and be sure 

 to use enough of it, but not too much. To put on 

 twelve times as much soluble phosphoric acid as is 

 needed, in order to get the necessary nitrogen, is folly. 

 If you want nitrogen as well as phosphoric acid, buy 

 the nitrogen in the cheapest and best form. If we 

 recommend nitrate of soda to those who wish to buy 

 nitrogen, it is because the nitrogen is in the best and 

 most available form, and because, at the present 

 time, it is the cheapest source of nitrogen. 



There are enormous beds of it in South America, 

 and its use in Europe is rapidly increasing, while 

 with us, it is almost unknown. It certainly is well 

 worth our while to see if, especially in our dry and 

 sunny climate, we cannot use it to great advantage. 



The editor of the Rural Ne7v- I'f^'/w further says : 

 "In experiments made at the Rural grounds during 

 two seasons, to ascertain the effects of nitrogen on 

 potatoes, it was found that additional quantities of 

 nitrate of soda or sulphate of ammonia or blood, or 

 all three, bej'ond what was supplied by the ' com- 

 plete ' fertilizer, did not increase the yield in any 

 case. * * * From 1,200 to 2,000 pounds of the 

 fertilizer was used, guaranteed to contain 3 '2 per 

 cent, of nitrogen, 12 per cent, of phosphoric acid 

 and 6 per cent, of potash. It appears, therefore, 

 that the amount of nitrogen supplied by the fertili- 

 zer was amply sufficient for the crop's needs, and 

 that the added nitrogen was so much money thrown 

 away." 



Mr. Carman, the able editor of the Rural Netv- 

 Yorker, made better experiments than his allusion 

 to them above would indicate. Our own personal 

 objection to them is that they were on too small a 

 scale to carry conviction to an old farmer and gar- 



