;J60 ANNUAL REPORT OP" THE Off. Doc. 



as va}M)i- or gas wliile burning. The solid matter found in the ashes, 

 is pi'esenr in all soils, in practically unlimited quantities, except 

 phosphoric acid, potash and sometimes, lime; and the farmer has 

 no need to concern himself about any others, except nitrogen, 

 which it not found in ashes, but is very necessary to plant growth. 

 It too, is taken from the soil, and is the one element most easily de- 

 pleted, and is at all times the most expensive. 



Then we reduce plant growth to the elements. Potassium salts, 

 pliosphorus and nitrogen, all combined, forming a very small part 

 of the plant. Yet if any one of them be absent the plant cannot 

 exist. These elements in their crude state are not soluble, and not 

 a\-;iilable to the growing crop. They become available only by the 

 slow process of deca^', or by breaking down, which makes them 

 soluble. All soil is a combination of broken-down mineral matter, 

 pulveri;'-ed rock and vegetable matter; but if the cropping has been 

 severe or continuous, nature cannot supply the soluble material 

 necessary to make plants fast enough, they suffer for food, are 

 liLingrv and cannot thrive. But the use of commercial fertilizers 

 here alTords a way out. In these we can secure the nitrogen, phos- 

 phoric acid and potash, in exactly the form nature would have sup- 

 plied it, if lime enough were allow^ed, and under favorable soil con- 

 dition we can secure perfectly developed plants. 



Then, too, these fertilizing elements can be applied wherever and 

 whenever plants are hungry. The conditions of soil may be per- 

 fect as to moisture, heat, fineness, etc., but if any one of these three 

 elements are not present in sufficient quantities the plant suffers. 

 As a chain is not stronger than its weakest link, so a plant is vig- 

 orous or otherwise only in proportion to the needed element that is 

 present in most limited quantity and availability. A particular 

 soil might contain enough phosphoric acid and potash to make a 

 crop of wheat, but if nitrogen was lacking, there could be no growth. 

 Again there might be present enough nitrogen and phosphoric acid 

 to produce 200 bushels of potatoes; but if potash was not available, 

 there could be no tubers, and so on through the whole range of 

 plants, from the tin}' grasses to the giant tree. It is scarcely neces- 

 sary for me to argue further that by the continuous use of only one 

 or two of these elements, plarit growth must suffer. At first there 

 was enough of the third or other one, but stimulated growth more 

 quickly exhausted it, and growth and profitable cultivation halted. 

 T'here are soils that seem to contain an abundance of potash, and 

 others lime, for all practical purposes, and upon these to add more 

 would be wasteful. On a feldspar soil, ground bone containing 

 only nitrogen and phosphoric acid gives excellent results, but if that 

 soil was broken-down mica schist it would beg for potash. Often 

 we hear the remark that commercial fertilizers now fail to ])i'oduee 



