EXPERIMENT STATION BULLETINS. 175 



Why add more to abundance? Why not use the material now on hand? 

 There is much in the suggestion. The best warfare is not by hiring 

 mercenaries,, but by "calling out the reserves." It is for this purpose 

 that many of the operations on the farm are carried on. For this we 

 ditch and drain, plow and drag, hoe and cultivate, grind the ground by 

 the roots of plants or the splitting wedge of frost, or open up the soil to 

 air and sun to secure the action of oygen, "the tooth of time" that 

 gnaws at rock and pillar till they are finally reduced to formless dust. 

 It is by accelerating and augmenting the natural but slow changes in the 

 mineral matter in the soil that the reserve materials in the soil are 

 made active and available for plants by making them soluble. The 

 cheapest way to fertilize a soil in ash materials is to make the soil feed 

 itself by making active the reserve compounds of lime, magnesia, potash 

 and phosphoric acid existing in the land. Most of the labor on the 

 farm, aside from sowing and harvesting the crops, while performed for 

 other purposes, contributes indirectly to this end, and is valuable largely 

 for this purpose. The soil is a bank of deposit, and the wise farmer has 

 learned how to draw out the deposits and put them in circulation in 

 growing crops. 



NAMES OF FERTILIZERS. 



In most trades the manufacturers select some distinctive name for 

 their goods, and often some name that shall mark the especial value and 

 uses for the goods. In the same way manufacturers of fertilizers avail 

 themselves of the customs of the trade in naming their products. They 

 must have a name, and if it has a suggestive title that will attract the 

 attention of the farmer and gardener, all the better. But we are not 

 to assume that a "corn fertilizer," "potato fertilizer," or "cabbage fer- 

 tilizer" is only good for this particular crop, and is essential for its 

 growth. Often the name is a catch phrase. 



Discarding the trade names, we may stop to ask, what is a commercial 

 fertilizer? There are 13 elementary substances always found in plants 

 grown under natural conditions; three of these are furnished by the air, 

 nine come entirely from the soil and one (nitrogen) is furnished by air 

 and soil. The 9 mineral elements are found in every soil capable of grow- 

 ing a plant, and most of them in inexhaustible quantities for plant uses. 

 But there are 3 elements that exist in relatively small quantities in the 

 soil, that are taken up in comparatively large amounts by the plant, and 

 consequently are soonest exhausted by cropping, and where their supply 

 in the soil is much reduced, profitable cropping is no longer possible, and 

 the land is said to be exhausted. These three materials are nitrogen, 

 potash and phosphoric acid, and it is only these three fertilizing mate- 

 rials, as a rule, that the farmer and gardener can afford to buy to increase 

 his crops. In one form of combination or another they constitute the 

 bulk of all the commercial fertilizers in the market. When these 

 materials are present in the soil in adequate amount and in a form avail- 

 able to the plant, and the physical conditions of the soil, the supply of 

 water and the right temperature are secured, abundant crops may lie 

 expected. Most soils are so abundantly supplied with the other chemi- 

 cals of growth that with a sufficient supply of these three materials on 

 which plant growth is so dependent — this tripod of agriculture — crop- 

 ping without exhaustion might be carried on to the end of time. In all 



