EXPERIMENT STATION BULLETINS. 463 



The phosphorus content of representative soils occurring in twenty 

 counties has been determined. The results show that pine and scrub 

 oak lands usually contain less than 750 pounds. Prairie soils are the 

 highest in this element, while others occupy an intermediate position. 



Not only should the cost of the fertilizer be considered in estimating 

 the profit obtained from its use, but also the market price of the cropy 

 growTi. 



The increase in yield of crops by the use of phosphorus reduces both 

 the man and horse labor hours, required to produce a given amount of 

 material. 



Many of Michigan's sand, loam, clay and muck soils respond profitably 

 to applications of phosphorus. The readily available, or acid phosphate, 

 is the most extensively employed. 



By means of cooperative experiments with county agricultural agents 

 many farmers, and managers of county farms we have been able to obtain 

 information with respect to the phosphorus needs of several of ^Mich- 

 igan's soils. In view of the favorable results obtained we are forced to 

 conclude that every farmer who has not ascertained to his satisfaction, 

 by means of thorough field trials whether the judicious use of lihosphorus 

 on his soil is a profitable investment, should do so. 



