100 CIVIC BIOLOGY 



PRODUCE IN ELEVEN YEARS, PKU ACRE 



Learn the results of local experiments in fertilizing land 

 and collect all available records and data on local soil analyses 

 and surveys. The possible value of such work is well demon- 

 strated iii the following from the Oswego Experiments with 

 strawberries : 



RICH BOTTOM LAND, SEASON FAIRLY DRY (1807) 



Plat 1 : 350 11). dissolved rock per acre ; yield, 13,597 <jt. 

 Plat II : 700 11>. dissolved rock per acre; yield, 20,0(>(> <|t. 

 (An expense of $7.00 made a gain of $353.55 over Plat 1.) 



Value of land. Some land may be dear as a gift. Agricul- 

 tural nitrogen is worth $0.15 a pound, potassium $0.06, ground 

 limestone $0.005, and phosphorus 1.0.03. At these prices let us 

 compare the values of two samples of land. 



POUNDS IN 2,000,000 POUNDS OF SOIL 



Of course, beyond a certain limit additional amounts of any 

 plant food may not be of immediate value, but the above fig- 

 ures indicate a fundamental reason for the rush of agricultural 

 emigration to the northwest. Still, with all the experience of 



