152 TwENTY-FlBST BlENNIAL EePOBT 



The teachings of this bulletin No. 191 show that a 

 great amount of this million and a half dollars annually 

 could be saved by the farmers by the use of acid phos- 

 phate, raw rock phosphate, or basic slag and limestone 

 followed by leguminous crops. Of such importance, in 

 our opinion, is this bulletin to a thorough knowledge of 

 the basis of soil building that we have asked the privi- 

 lege from the Experiment Station to here reproduce it, 

 and we hereby give credit to Dr. Joseph H. Kastle, Di- 

 rector of the Station, and to Prof. George J. Roberts, 

 to whom all credit is due for this publication. 



BULLETIN No. 191. 



The Teachings of the Kentucky Ageictiltxjeaij Exper- 

 iment Station Relative to Soil Fertility. 



Introduction by Joseph H. Kastle, Director. 



There was a time in the earlier years of the work of 

 the Kentucky Agricultural Experiment Station when 

 considerable attention was paid to the study of the effect 

 of commercial fertilizers on the growth of certain crops, 

 such as hemp, potatoes, corn and tobacco, the results of 

 which seemed to indicate that considerable financial re- 

 turns followed the application of such materials to the 

 soil ; and upon a piece of poorly drained, wet, crawfishy 

 soil on the Experiment Station farm, the studies of Drs. 

 Scovell and Peter indicated considerably increased yields 

 of com, hemp and potatoes following the application of 

 potash salts. In the year 1909, however, in a bulletin 

 entitled "Fertilizers," by Professor Roberts, it was 

 pointed out first, that the farmer was paying for phos- 

 phoric acid, nitrogen and potash in mixed fertilizers a 

 great deal more than these materials were worth and a 

 great deal more for each of these as constitunts of com- 

 plete fertilizers than the prices at which they could be 

 bought separately, and that the lower the grade of com- 

 mercial fertilizers, the higher the price charged per 

 pound for these several elements of plant food. This 

 bulletin alst) contained a section on the general subject 



