251 MORE ABOUT 



FERTILIZERS 



first applied. But sulphate of ammonia, although 

 it will dissolve, must be changed into a nitrate, in 

 the soil, before the plants can use it, and this 

 probably takes several days, hence, it is not 

 quite so quick acting. 



The organic forms of nitrogen vary much in 

 their usefulness. The nitrogen of dried blood 

 or tankage is the most easily absorbed. These 

 substances are sometimes sown at seeding- 

 time, and become useful later in the season 

 when the soil becomes warm. Other forms, 

 however, as muck, leather parings, etc., are used 

 considerably in making some low-grade fertil- 

 izers. Notwithstanding the tradition that you 

 must bury an old shoe at the foot of the vine, 

 the nitrogen in these may never be of very 

 much value. 



The phosphorus is found in fertiUzers both in 

 forms that will dissolve and in forms that won't. 

 Acid phosphate and dissolved bone contain a 

 large portion of phosphorus in the form of a 

 soluble phosphate of lime ; this is often marked 

 on the bag as being equal to 12, 14, or 16 per 

 cent, of phosphoric acid. Ground phosphatic 

 rock, also called "floats," and raw bone-meal 

 contain phosphorus combined with lime in the 

 form of an insoluble phosphate. 



Basic slag is still another form of phosphate 



