FERTILIZERS. 547 



as a model, has nowhere been formulated for discussion. It 

 may be said, without fear of successful contradiction, that it is 

 high time that the problem before these institutions was stated 

 in plain, intelligible form ; and the data comprising the various 

 inductions, upon which the several general propositions rest, 

 can then be more speedily, more easily, and more satisfactorily 

 developed and arranged. 



In general terms, the problem may be stated thus : What are 

 correct rotation and methods of culture, for the given locality, 

 having in view the full utilization of fallows, animal manures, 

 and commercial fertilizers ? It being settled what a correct 

 rotation is, investigation will naturally fall into right channels ; 

 experiments will be directed to the best selection and manage- 

 ment of a fallow crop, and its proper place in the rotation ; the 

 best animals to feed and how to feed them, no less than how 

 best to save and apply the manure ; at what point in the rota- 

 tion the commercial manures should be applied, and the best 

 method of application ; as, of course, also the best forms of such 

 manures to use. 



The following great questions need solution ; viz. : Can the 

 full use of fallows and animal manures enable us to wisely dis- 

 pense with ammoniated superphosphates ? And can we wisely 

 replace dissolved phosphates by the use of raw ground phos- 

 phates, in the rotation used ? Should such raw phosphate be 

 applied directly to the staple money crop, or to the fallow, 

 or other crop, which precede the money crop in the rotation ? 

 Does not some other crop in the rotation, and especially the 

 fallow, assimilate raw phosphate (or dissolved phosphate) more 

 readily and completely than the money crop ? 



It is the opinion of the writer that we can and ought to devise 

 a complete system of fertilization, in which we may dispense 

 with the enormous cost of the sulphuric acid, drier, and manipu- 

 lation of dissolved phosphates and ammoniated superphosphates. 

 If our dealings in mineral manures can be as nearly as possible 

 limited to natural products, less cost of manipulation, it will be 

 an immense gain in economy of production of the great staples 

 which mainly support the commerce of the world. This does 

 not imply that we may dispense with dealers in commercial 

 manures. Certainly mineral phosphates and raw bones must be 



