138 REPORT ON PHOSPHATIC AND AMMONIACAL MANURES. 



selling in the market — such as salts of potash, soda, magnesia, 

 and others. We merely affirm that the small quantity of these 

 sold for manuring purposes, and the discordant, and often un- 

 profitable results arising from their use, do not entitle them in 

 the present state of agricultural practice to a locus standi with 

 those in question. 



It is not our intention to descant here upon the theories above 

 referred to, however akin to the subject it may be, further than 

 to remark that much has been said and written regarding each, 

 which is calculated to mislead the practical farmer, and to destroy 

 his confidence in agricultural chemistry. Advancing science 

 has now, however, brought many new facts to light, and the 

 extreme views of the partisans of both theories are very consider- 

 ably modified. One thing is certain, the immense consumpt of 

 bones and other phosphatic manures is proof positive that those 

 containing nitrogen alone are not all-essential ; and, on the 

 other hand, the large quantity of sulphate of ammonia and 

 nitrate of soda applied alone to some of our crops, and used for 

 mixing with manures for others, shows equally plainly that 

 nitrogenous manures are also requisite. 



The fact of farmers having, from time immemorial, sold off 

 the farm the grain, dairy produce, and stock, — all containing a 

 large proportion of " phosphatic and nitrogenous " elements, — 

 without having made an equivalent return, might have been 

 sufficient to have led one to predicate, a priori, that great increase 

 of crops would follow the replacement of these substances, and 

 that fact surely accounts, to some extent at least, for the advan- 

 tageous results which happily follow their application. 



In the following pages we shall attempt to consider — 1st, 

 In what relative proportions phosphatic and nitrogenous elements 

 should prevail in'our manures ; and, 2d, What are their compara- 

 tive effects on our crops. 



In considering fully the first question, many circumstances 

 would fall to be noticed, which not only could not be detailed 

 within the limits of this report, but which would involve specu- 

 lations regarding matters about which but little is known, such 

 as the absorptive properties of soils ; the questions arising 

 from the fact of a phosphatic manure having caused a great 

 increase of crop in a soil comparatively rich in phosphates, and 

 having produced but little effect on a soil containing an almost 

 inappreciable quantity ; the decomposition of the manures ap- 

 plied, and the formation of new compounds which take place in 

 and with the soil ; — these we leave, and merely state a few general 

 results which practice seems to confirm, and which may tend to 

 guide in the making up of " home mixtures " for our field plants. 

 What the relative proportions of phosphatic and nitrogenous 

 elements in a manure should be, depends to a very considerable 



