204 MASSACHUSETTS HORTICULTURAL SOCIETY. 



this one instance merely to show what can be done with coraraer- 

 ciiil manures when intelligently used, — to show that they do con- 

 tain all the food required by crops, — and that, with their assistance 

 only, a farm can be brought up from a low condition to a higher 

 one, and held there for a series of years ; and no one can show 

 that what is true of farm crops sliould not be true of garden and 

 fruit crops as well, — if not to the same extent, yetto a large extent. 

 They feed on the same kinds of soil, and in the same manner, and 

 require the same nutrients in general ; and the same particular 

 nutrients that are speciall}- important for farm crops are, so far as 

 we know, speciallj' important for garden and fruit crops ; the pro- 

 portions required may be different, but perhaps not more so than 

 they are even for different farm crops : the same mixture of nitro- 

 gen compounds, phosphate, and potash salts will not answer 

 equalh' well for wheat and for potatoes, nor even for wheat and for 

 corn, which are more nearl}' alike than wheat and potatoes. 



What are the obstacles in the way of the more extensive use of 

 commercial fertilizers in the garden and fruit orchard, and of less 

 dependence on the products of the cit}' and village stables? In 

 answering this question we naturally ask, first, what does stable 

 manure contain that is not supplied in commercial fertilizers? 



The valuation of a commercial fertilizer in the trade is based, as 

 3'ou know, on the quantities of nitrogen, phosphoric acid, and potash 

 that it contains, — some fertilizers containing only one of these 

 nutrients, others two, and others all three of them. There is no 

 question that in respect to just these nutrients we can meet the wants 

 of any crop better by supplying commercial fertilizers than we can 

 b}' stable manure, if there is an}' difference between the two as to 

 effleienc}'. But, besides these, the crop must find in the soil, sup- 

 plied from some source, lime, magnesia, sulphuric acid in the form 

 of sulphates, of which plaster is one, a very little iron, possibl}' 

 chlorides, of which common salt is one, and, perhaps, silica. 

 Every superphosphate contains an al)undance of lime and of sul- 

 phuric acid. The muriate of potash, brought from German}-, is a 

 chloride, and contains chlorine. Of iron every soil has an abun- 

 dance, many thousand times more than an}' crop needs ; and the 

 same is true of silica ; of magnesia there is enough to be had in 

 the German kainite. But as to all of these nutrients last men- 

 tioned — sulphate, chloride, silica, iron, and magnesia — there is 

 no proof that the average soil is not abundantly rich in them for 

 the production of good crops. Hence it is that we are justified in 



