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Vol. XV DECKIVIBER 2, 1918 No. 9 



JOURNAL OP 



AGRICULTURAL 

 RESEARCH 



CONTENXS 



Page 



Experiments on the Value of Greensand as a Source of 



Potassium for Plant Culture _ _ - _ _ 433 



RODNEY H. TRUE and FRED W. GEISE 



( Contribution irom Bureau of Plant Industry ) 



Effect of Farm Manure in Stimulating the Yields of Irri- 

 gated Field Crops - - - - - - - 493 



C. S. SCOFEELD 

 ( Contribution from Bureau ol Plant Industry ) 



Relation of Inorganic Soil Colloids to Plowsole in Citrus 505 

 Groves in Southern California - - 



CHARLES A JENSEN 

 (Contribution from Bureau of Plant Industry) 



PUBUSHED BY AUTHORITY OF THE SECRETARY OF AGRICULTURE, 



WITH THE COOPERATION OF THE ASS0CL4TI0N OF AMERICAN 



AGRICULTURAL COLLEGES AND EXPERIMENT STATIONS 



WASMINOTON, r). C. 



I51 



WASHINOTON : oqvernMent PKi^rriMa office i nt» 



