In these experiments we, in effect, ask the soil: — " What must 

 you have to enable you to produce a crop," and in proportion as nat- 

 ural inequalities of the soil and accidental causes of variation are 

 avoided the answers are definite and valuable. Our experiments 

 might be regarded as complete without the plots on which barn-yard 

 manure, Ii?i3e and plaster are used, in so far as affording an answer to 

 the above question is concerned : but, for purposes of comparison, 

 these extra plots are introduced. 



The materials used were each applied at the following rates wher- 

 ever employed : — 



Per acre, Pounds. 



Nitrate of soda, 160 



Dissolved bone-black, 320 



Muriate of potash, 160 



Lime, 160 



Land plaster, 160 



Barn-yard manure, 5 cords 



The materials were all sampled and analyzed and the manure used 

 was weighed, so that we are able to calculate the amounts of the 

 essentials — nitrogen, phosphoric acid and potash — applied to the 

 plots receiving this material, and thus to institute interesting com- 

 parisons with the plot receiving the same elements in the form of 

 fertilizers. These comparisons will appear under the several 

 experiments. 



The fertilizers used : — 



Nitrate of Soda. 



