52 



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

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

 natural inequalities of the soil and accidental causes of variation are 

 avoided, Ihe answers are definite and valuable. Our experiments 

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

 manure, lime and plaster are used, in so far as affording an answer 

 to tiie above question is concerned ; but, for purposes of comparison 

 these, extra plots are introduced. 



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

 ever employed : 



Per Acre. Pounds. 



Nilrate of soda., 160 



Dissolved hone-blacky 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 was 

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

 tials — nitrogen, potash and phosphoric acid — applied to the plots 

 receiving this material, and thus to institute interesting comparisons 

 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. 



Moisture at 100° C, 



Nitrogen, 



Sodium oxide. 



Dissolved bone-black. 



Moisture at 100° C, 



Organic and volatile matter. 



Total phosphoric acid, 



Soluble " 



Reverted, " " 



Insoluble " " 



Insoluble matter. 



Muriate of Potash. 



Moisture at lOO'' C, 



Potassium oxide, 



Chlorine, 



