New York Agricultural Experiment Station. 89 



Sulphate of ammonia, nitrate of soda, sulphate, nitrate and muriate 

 of potash are j^enerally held to be entirely exhausted by the crops 

 grown the season of their application. 



Preferences Shown by Plants for Different Forms of Food. — 

 It is a fact of great interest and importance that one form of a fertil- 

 izing constituent is preferred by some plants to the same constituent 

 in another form. This preference is indicated by greater yield or 

 better quality of product or by both. Thus, wheat seems to give 

 better results when nitrogen is applied in the form of nitrate of 

 soda than in any other form. Spinach has been found to do better 

 with sulphate of ammonia than nitrate of soda, while the reverse is 

 true of asparagus. The quality of tobacco is injured by potash in 

 the foi*m of muriate and, hence, only sulphate should be used for 

 fertilizing purposes. The quality of sugar beets and of potatoes 

 appears to be better when sulphate of potash is used, while peach 

 trees are said to prefer the muriate. 



Much investigation in this interesting field remains yet to be 

 made. The facts now known are meagre, but so far as known they 

 should be utilized. Whenever a plant shows any marked prefer- 

 ence for any special form of food, we should supply that particular 

 form if practicable. 



Economy in Purchasing Different Forms of Plant-food. — 

 Other things being eqnal, we can effect considerable saving in pur 

 chasing fertilizing materials by a careful selection based upon a 

 study of market values. 



The most expensive form in which nitrogen is usually purchased 

 is that of sulphate of ammonia. AV^hen high-grade sulphate of 

 ammonia sells for $70 a ton, each pound of nitrogen in it costs 

 about 17 cents. When high-grade nitrate of soda sells for $45 a 

 ton, each pound of nitrogen in this form costs about 141 cents. As 

 between these two forms, the nitrogen of one is nearly 3 cents a 

 pound cheaper than the nitrogen of the other, and it will, therefore, 

 be found more economical to use nitrate of soda rather than sulphate 

 of ammonia, when special circumstances do not require the use of 

 the latter. Dried blood, containing 13 per cent, of nitrogen, at $40 

 a ton furnishes nitrogen at an approximate cost of 14|- cents a 

 pound. The nitrogen in fish-scrap may cost somewhat less. In 

 such forms as wool-waste, ground leather and hair, nitrogen may be 

 purchased at much less, but these forms are not economical when 

 anything like quick returns are desired. 



