Bureau of Agbioulture. 



159 



standard for a productive soil. Unless organic matter 

 is maintained, soils cannot be kept productive, even with 

 a liberal use of all the ingredients of the so-called com- 

 plete fertilizers, for organic matter has many other im- 

 portant functions necessary to a productive soil besides 

 supplying and liberating plant food. 



The following table shows the average content of 

 potassium and phosphorus in the main soil areas of the 

 State. The figures represent pounds of the elements, in 

 2,000,000 pounds of soil, or an acre to the depth of about 

 seven inches : 



Number of Pounds of Potassium and Phosphorus in 2,000,000 Pounds 

 of Surface Soil (0-7 Inches) in the Main. Soil Areas of Kentucl<y. 



AREA 



Total 

 Potassium 



Easily 

 soluble 

 Potas.» 



Total 

 Phos. 



Easily 

 soluble 

 Phos.* 



Trenton 



Cincinnatian 



Silurian and Devonian 



Waverly 



St. Louis 



Chester 



Western Coal Field 



Eastern Coal Field {Western 



part) 



Eastern Coal Field (Central 



and Eastern part) _ 



Quaternary 



River Alluvium 



26278 

 31960 

 23940 

 19600 

 28220 

 26560 

 29290 



18180 



34213 

 30926 

 34430 



329 

 366 

 224 

 338 

 320 

 218 

 276 



272 



360 

 300 

 390 



9416 

 1924 

 1100 

 650 

 890 

 70:S 

 766 



630 



1260 



980 



1910 



3582 

 69 

 20 

 14 

 18 

 6 

 19 



13 



46 

 26 

 98 



*Soluble in fifth normal nitric acid. (A very weak solution.) 



For the location and extent of the above areas see 

 bulletin entitled "The Soils of Kentucky," by S. D. 

 Averitt. (In press.) 



It wiU be seen that all the soils of the State contain 

 large amounts of potassium, the lowest amounts being 

 found in the Waverly and the western part of the East- 

 em Coal Field. It will also be noted that the amounts 

 of easily soluble potassium contained in the soils of the 

 various areas do not differ greatly. WhUe it is not con- 

 tended that the amount of easily soluble potassium repre- 

 sents the amount available to the crop, yet there is a re- 



