THE NATIONAL GEOGRAPHIC MAGAZINE 



WHEAT YIELD INCREASED I33 PER CENT BY PHOSPHATE 



Wheat-growing experiments at Urbana (Illinois) Agricultural Station, on land where 

 cow peas had been plowed under. Land shown in upper picture was given an application of 

 lime, and yielded only 9.2 bushels of wheat per acre. In lower picture lime and phosphorus 

 were used together, and yield was increased to 21.5 bushels per acre. 



