100 HATCH EXPERIMENT STATION. [Jan. 



With one exception, it will be seen that the nitrate of soda 

 here, as in the case of the field crops, proves the most effi- 

 cient source of nitrogen. Its superiority is, however, much 

 more marked, as should be expected, because it is immedi- 

 ately available, for the early crops. For the late crops in 

 one instance during the earlier years of the experiment the 

 sulfate of ammonia exceeded the nitrate of soda in efficiency, 

 but during the later years of the experiment it has stood be- 

 hind, even for these crops. It should be stated, further, in 

 comment upon these results, that on one-half the plots in 

 these experiments muriate of potash is used in connection 

 with the various nitrogen manures. The combination of sul- 

 fate of ammonia and muriate of potash, as has been repeat- 

 edly pointed out in former reports, is a bad one, owing to 

 the possible formation and poisonous influence of chloride 

 of ammonia. It should be further pointed out that this field 

 has not received the application of any lime throughout the 

 years during which it has been under experiment. The 

 availability of the sulfate of ammonia would undouljtedly be 

 increased by giving tliis soil a heavy dressing of lime, since 

 the presence of lime promotes those changes wdiich are essen- 

 tial to convert the nitrogen of the sulfate of ammonia into 

 nitrates, which are the most readily available nitrogen com- 

 pounds. 



B. Relative Value of Sulfate and Muriate of Potash for 

 Garden Crops. 

 The period during which the experiments upon which the 

 conclusions now to be stated are based and the crops grown 

 are the same as in the case of the nitrogen fertilizers above 

 discussed, and the relative standing of the two potash salts 

 is shown for the same periods and crops. 



