120 HATCH EXPERIMENT STATION. [Jan. 



For the late crops, including tomatoes, celery, and 

 squashes : — 



Per Cent. 



Nitrate of soda 100.0 



Dried blood, 99.0 



Sulfate of ammonia, ....... 78.4 



Since nitrate of soda furnishes a pound of nitrogen at 

 lower cost than an^^ other of the fairly concentrated fertil- 

 izers, it becomes very evident, in view of our results, that 

 it should be used as the source of this element, as largely as 

 the nature of the conditions permits. It should be remem- 

 bered, as has been stated in previous reports, that the soil 

 of Field C is a moderately retentive loam. Upon a lighter 

 soil the superiority of the nitra^te would probably be less 

 marked. It must again be pointed out that experiments 

 here, as elsewhere, make it very probable that the relative 

 standing of the sulfate of anmionia would be bettered by 

 making a heavy application of lime to the plots where it is 

 used. Since, however, the pound of nitrogen costs more 

 in the sulfate of ammonia than in either the nitrate or the 

 dried blood, it would seem that there can be little probability 

 that the selection of this nitrogen fertiljzer is usually wise. 

 Its physical properties, it is true, are such that it is more 

 readily and conveniently' used in mixtures with other ma- 

 terials than the nitrate, since the latter attracts moisture, 

 while the sulfate of ammonia does not do this to any con- 

 siderable extent. If, however, nitrate of soda which has 

 been recently reground and which has been stored in a dr}^ 

 place be used, and if the mixture can be applied soon after 

 it is made, there is little difficulty in employing nitrate. 



B. — The JRelative Value of Sulfate- and Muriate of Potash 

 for Garden Crojjs. 

 The history of the plots where these two potash salts arc 

 under comparison has been outlined under section A. The 

 crops are the same as those which have been named under 

 that section. Each potash salt is used on three plots, i.e., 

 with each of the three nitro<2;en fertilizers. The results of 

 the past year are shf)\vn in llu^ following table : — 



