62 SUCCESSFUL FARMING 



locality may place it in the other group in a distant locality. The high 

 price of a crop is in some cases determined by location. For example, 

 the early strawberries and early potatoes of the South that reach northern 

 markets very early are often worth five to ten times as much per unit as 

 are the late strawberries and late potatoes grown in the North and at some 

 distance from markets. 



Character of Fertilizer Related to Soil. In general, fertilizers that 

 stimulate the production of seeds and fruit should be used on rich lands. 

 On poor land the elements that force vegetative growth combined with 

 those that mature fruit may be used. High-grade phosphates in a readily 

 available form hasten maturity and increase the proportion of fruit. 

 This is well illustrated in the fertilizer plats at the Ohio and Pennsylvania 

 Experiment Stations. As the oats and wheat approach maturity on 

 these plats the visitor is at once impressed with the earlier period of 

 ripening of those grown on plats treated with acid phosphate. Nitrogen 

 tends to a prolonged growth of the crop and retards maturity. The 

 grain on the plats treated with liberal applications of nitrogen matures 

 a week or ten days later than on the phosphate-treated plats. 



In the use of fertilizers one should distinguish between a large in- 

 crease of crop and a profitable increase, and this will be determined chiefly 

 by the value of the crop grown. In general there will be an increase in 

 yield accompanying an increase in the amount of fertilizer used, but it 

 is a fact that the first unit of application, that is, the first two hundred 

 or four hundred pounds per acre, will give a relatively larger return than 

 the second or third unit, and there will always be a place where an added 

 unit will give a return, the value of which will be no greater than the 

 cost of the unit of fertilizer. It is most profitable to stop before one 

 reaches this point in the application of fertilizers. 



Finally, the purchaser of fertilizers should bear in mind that the 

 composition of the fertilizer and availability of its constituents, its 

 mechanical condition, the economy of its purchase and application are 

 all factors that bear directly upon the economy of its use. This calls for 

 a knowledge of the requirements of the soil and the crops grown. 



What the Farmer Should Know. Commercial fertilizers are valuable 

 mainly because they furnish nitrogen, phosphoric acid and potash. In 

 some cases they may act as stimulants, but their chief function is to 

 supply available plant food. The returns will be approximately in pro- 

 portion to their content of such constituents, when the selection is so 

 made that it meets the needs of the soil and crops to which applied. The 

 agricultural value of these constituents depends largely upon their chem- 

 ical form, and these forms must be contained in products of well-defined 

 character and composition. They may be purchased as such from both 

 dealers and manufacturers. The farmer may put them together in pro- 

 portions to meet his own needs, if he is competent to do so. 



The farmer should know the deficiency of the soil on his farm. He 



