28 Maine Agricultural Experiment Station. 1919. 



years. The "base" which was used in these goods was made by 

 the wet process, whereby nitrogen from rather low grade goods 

 is made as available as from high grade goods. The available 

 phosphoric acid was furnished in the form of acid phosphate 

 and the potash in the form of sulphate of potassium. The fer- 

 tilizer was free from chlorides so as to preclude the possibility 

 of the formation of poisonous ammonium chloride. The base 

 carried approximately one-third of the nitrogen that went into 

 the formula. The remainder of the nitrogen was furnished in 

 the form of nitrate of soda and sulphate of ammonia, as indi- 

 cated in the following plan : 



Plot i. Basal mixture and 2-3 of the nitrogen in form of 

 nitrate of soda. 



Plot 2. Basal mixture and 2-3 of the nitrogen in form of 

 sulphate of ammonia. 



Plot 3. Basal mixture and 1-3 of the nitrogen in form of 

 nitrate of soda and 1-3 in form of sulphate of ammonia. 



Plot 4. Basal mixture and 1-3 of the nitrogen in form of 

 high grade organic and 1-3 in form of nitrate of soda. 



Plot 5. Basal mixture and 1-3 of the nitrogen in form of 

 high grade organic and 1-3 in form of sulphate of ammonia. 



In each case the finished fertilizer analyzed 5 per cent am- 

 monia, 8 per cent available phosphoric acid and 7 per cent pot- 

 ash. In each year the fertilizer has been applied in the planter 

 at the rate of 1500 pounds per acre. Other than the fertilizer 

 used the plots were planted, cultivated, sprayed and cared for in 

 all particulars alike. In each year duplicate plots each about 

 one-half acre in area have been grown with each mixture. 



The results for 1914 and 191 5 are reported in detail in 

 Bulletin 246, those for 1916 in Bulletin 260 and those for 1917 

 in Bulletin 269. The detailed results for the experiment in 

 19 18 are given in the table that follows. 



