CHEMICAL MANURES. 53 



with the nature of the plant. The position which I gave each one in 

 certain categories of plants was not an arbitrary act on my part, or 

 the expression of a fancy ; it is the result of an important fact, and 

 one which is absolutely necessary to you, for its application is greatly 

 in favor of the chemical fertilizer. 



If it is true that a mixture of phosphate of lime, potash and lime 

 with azotic matter suffices for all the wants of plants, and for the 

 agriculturist is an equivalent for manure, it is also true that each of 

 these four terms fulfills, in regard to the three others, an alternately 

 subordinate or predominant office, according to the nature of the 

 plant cultivated. The azotic matter is the predominant element for 

 wheat, colza, the beet and tobacco ; for lucerne, peas and beans tlie 

 azotic matter is of secondary importance, and the predominance of 

 which we speak passes to the potash. Phosphate of lime predomi- 

 nates for turnips and rutabagas. 



For each plant, then, there is an element whose influence predomi- 

 nates over the three others, and for this reason we will call it the 

 dominant of this plant. 



As the first application of these ideas, we will suppose the follow- 

 ing rotation : Beets wheat clover oats. 



It is not possible to divide manure ; we may vary the quanthy, but 

 not the composition. We have but two methods of procedure 

 either to put on all the manure the first year, or spread it at different 

 times. In the first case, it is true, we obtain a good yield of beets, 

 but it is to the prejudice of the following cultures. If we divide the 

 manure, the yield of beets is sensibly reduced ; and as this culture 

 is expensive from the multiplicity of dressings it requires, it neces- 

 sarily causes a loss to the producer. 



Things are entirely different with the chemical^ fertilizers. We 

 give each plant the element which has most influence on its harvest ; 

 this has the double advantage of reducing the expense and of raising 

 the return to the highest point. As proof of the advantage in prac- 

 tice of this manner of proceeding, I will cite the example of two 

 parallel cultures of Irish potatoes and wheat one with the complete 

 fertilizer, the other with the same fertilizer divided in the following 

 manner : the first year, the mineral fertilizer alone ; the second year, 

 azotic matter. Now, here are the results of these two cultures : 



First Case. The earth receives enough of the complete fertilizer 

 for two years. 



First Year Return the acre. Price. 



Irish potatoes 22,522 Ibs. $53.70 



Second Year 



Wheat (straw) 4,640 Ibs. 17.64 



(grain) 44 bu. 52.35 



Total of -products ; $123.69 



Second Case. The earth is enriched the first year with the mineral 

 fertilizer, and the second year with six hundred pounds of sulphate 

 of ammonia. 



