45S ANNUAL REPORT OF THE Off. Doc. 



• 



with potassium, but deficient only in the element of nitrogen, and 

 which require only a liberal use of legume crops to be turned under 

 as green manures or returned to the soil as stable manure in order 

 to render them highy productive and profitable soils. Abnormal 

 soils of this class exist in considerable areas in the geologic neigh- 

 borhood of phosphate regions, as in certain sections of Tennessee 

 and Southern Kentucky. Some of these soils contain twenty times 

 as much phosphorus as the average Illinois corn belt soil. 



But, when we consider the ordinar}^, normal upland timber and 

 prairie soils, covering the vast areas of the Central West, the so- 

 called "granary of the world," extending at least from Ohio to Mis- 

 souri — soils of the glacial and loessial formation and of granite or- 

 igin — there are tw^o substances always to be kept in mind and always 

 to be provided in abundance for any and every system of permanent 

 agriculture to be practed on these soils. These two essential sub- 

 stances are phosphorus and decaying organic matter, which will, 

 of course, also supply the nitrogen. 



It is not of so great consequence by what methods or in what 

 forms these materials are supplied. 



Phosphorus may be purchased in grain, or in other concentrated 

 foodstutTs, to be fed with clover hay, it may be, and then ajfplied 

 in the form of farm manure, or phosphorus may be applied in the 

 form of bone meal, which is also a farm product, or it may be ob- 

 tained from the great phosphate mines of our Southern states, as 

 we obtain coal from our extensive mineral deposits in the Northern 

 states. 



The decaying organic matter may be supplied in farm manure, or 

 ill sufficient quantities of legume crops, not harvested and removed 

 from the land, but turned under as green manures, including the 

 use of rotation pasturages, or still better and more easily and usually 

 more profitably, by a combination of these methods. 



r>ut there can be no permanent agriculture for these soils by any 

 system under which the phosphorus is removed and sold in grain 

 and bone in larger amounts than are returned to the soil, nor under 

 any system by which the organic matter of the soil is worn out or 

 destroyed more rapidly than it is replaced. 



On the other hand, sysfems of permanent agriculture for those 

 soils are not only possible, but they are more profitable than any 

 system under which the soil grows less productive. 



The CHAIRMAN: What action shall be taken on this paper? 



On motion, regularly seconded, it was received and placed on file. 



The CHAIRMAN: We will now take up the discussion of the 

 foregoing reports. 



QUESTION: Professor, would you say that raw rock phosphate 

 is profitable the first year? 



PROF. HOPKINS: I could not say that. 



QUESTION: Is it 2 per cent., do you think? 



PROF. HOPKINS: If they use a rather heavy application, they 

 can use it for rotting organic matter. I find the Illinois farmers use 



