THE ROTATION OF FARM CROPS 67 



ADDITIONAL READING 



'Decline in Kansas Acre Yields." By L. E. Call. The 



Orange Judd Farmer. Jan. 25, 1913. 

 'Soils and Fertilizers" (a book). By Harry Snyder. 

 'Crop Rotations for Illinois Soils." By Cyril G. Hopkins. 



Circular No. 141 111. Agri. Ex. Sta. 

 'Thirty Years of Crop Rotations." By Cyril G. Hopkins. 



Bulletin No. 125 111. Agri. Ex. Sta. 

 'Married Men Cheaper than Single Help." By Ralph M. 



Ainsworth. Prairie Farmer. March 1, 1913. 

 'The Fertility of the Land." By Isaac Phillips Roberts. 



