CYRIL GEORGE HOPKINS 



Increasing Fertility. Pub. by International Harvester Co. in Farm Sci- 

 ence. Also pub. in For Better Crops, by the Service Bureau of the 

 International Harvester Co. of America. 



1907 Soil Improvement for the Worn Hill Lands of Illinois. (With J. E. 



Readhimer) ///. Agr. Exp. Sta. Bui. 115. 



Illinois Soils in Relation to Systems of Permanent Agriculture. ///. 

 Agr. Exp. Sta. Circ. 10S. Also Rpt. 111. Farmers' Inst., vol. 12, 

 p. 248. 



Improvement of Upland Timber Soils of Illinois. (With J. E. Read- 

 himer) ///. Agr. Exp. Sta, Circ. 109. 



Ground Limestone for Acid Soils. ///. Agr. Exp. Sta. Circ. 110. 



Culture Experiments for Determining Fertilizer Needs. Cyclopedia of 



American Agriculture, vol. 1, p. 472. 

 The Breeding of Maize. Cyclopedia of American Agriculture, vol. 2, 



p. 421. 

 Unification of Terms Used in Reporting Analvtical Results. Journ. 



Amer. Chem. Soc, vol. 29, p. 1312. 

 Land Ruin Compared with Soil Improvement. Penn. Agr. Dept. Bui. 



154, p. 118. 



1908 The Fertility in Illinois Soils. (With James H. Pettit) ///. Agr. Exp. 



Sta. Bui. 123. 

 Thirty Years of Crop Rotations on the Common Prairie Soils of Illinois. 



(With J. E. Readhimer and Wm. G. Eckhardt) ///. Agr. Exp. Sta. 



Bui. 125. 

 Phosphorus and Humus in Relation to Illinois Soils. ///. Agr. Exp. 



Sta. Circ. 116. Also Rpt. III. Farmers' Inst., vol. 13, p. 177. 

 Seven Years' Soil Investigation in Southern Illinois. (With J. H. 



Pettit and J. E. Readhimer) ///. Agr. Exp. Sta. Circ. 122. 

 Chemical Principles of Soil Fertility. ///. Agr. Exp. Sta. Circ. 124. 

 Soils and Crops. Rpt. III. Farmers' Inst., vol. 13, p. 266. 

 Alfalfa. Rpt. III. Farmers' Inst., vol. 13, p. 311. 

 Chemical Principles of Soil Classification. Science, n.s., vol. 28, p. 857. 



1909 Shall We Use Natural Rock Phosphate or Manufactured Acid Phos- 



phate for the Permanent Improvement of Illinois Soils? ///. Agr. 



Exp. Sta. Circ. 127. 

 The Use of Commercial Fertilizers. ///. Agr. Exp. Sta. Circ. 129. 



Also Rpt. III. Farmers' Inst., vol. 14, />. 201. 

 A Phosphate Problem for Illinois Landowners. ///. Agr. Exp. Sta. 



Circ. 130. 

 Lincoln's View of Agriculture (with Some Projections by Hopkins — 



1909). Pub. by the University of Illinois. 

 Illinois Corn Belt Soil. The Illinois Agriculturist, vol. 13, No. 4. 

 How Can the Farmer Maintain the Fertility of the Soil? Quart. Rpt. 



Kans. Bd. Agr., 28, No. 109, />. 35. 



1910 Crop Rotation for Illinois Soils. ///. Agr. Exp. Sta. Circ. 141. Also 



Rpt. 111. Farmers' Inst., vol. 15, p. 156. 



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