492 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



An appropriation should l)e made for the investigation of the 

 relative efficiency of the different forms of fertilizer material. The 

 question as to the relative elliciency of floats, of finely ground phos- 

 phates, of superphosphates, of the diiferent forms of the nitrogenous 

 minerals, of nitrogenous waste products, of which some are esteemed 

 liighly, and others, such as wool waste, are in many States prohihited 

 by law to be used in the manufacture of fertilizers, demands that the 

 Avhole subject of the relative efficiency of different forms of fertilizer 

 material be worked out. 



DIVISION OF SOIL FERTILITY. 



An increase is recommended for the important research investiga- 

 tions that have been carried on by the bureau for some years and 

 which are yielding such important results, particularly in the study 

 of the chemistry of the organic matter and organic compounds present 

 in soils. 



Various organic compounds, resulting from the degradation of the 

 remains of plants and animals, have now been isolated from soils, 

 but the cause bringing about the formation of these compounds, 

 whether they are derived through the agency of fungi, bacteria, 

 protozoa, or enzymes, has not been studied for lack of sufficient 

 funds. An appropriation is needed for soil biology in order that 

 the agencies that act upon the organic matter and form these com- 

 pounds may be studied with the object of eventually being able to 

 control the degradation of the organic matter and to restrict it to 

 normal lines in which it will be beneficial rather than deleterious 

 to plants. 



A small appropriation is needed for the study of the inert organic 

 matter in soils. This material, which is of the nature of charcoal 

 or coallike bodies, forms undoubtedly one of the end products of the 

 'degradation of the organic matter, and to study this so as to trace the 

 line of degradation from the fresh organic matter applied to the 

 soil or left in the soil as the result of growing crops to the final 

 product of the hydrocarbon, requires that the work that has been 

 done by the bureau be extended into those lines of microscopic and 

 microchemical investigation that have to do with the coallike bodies — • 

 lines which have not previously been investigated for lack of sufficient 

 funds. 



An appropriation is requested to enable the bureau, in cooperation 

 with the various experiment stations, to study in a scientific manner 

 the manurial requirements of extensive soil types in order to prove 

 conclusively whether there is any standard difference in the relation 

 of the soil material and the manurial requirements apart from 

 methods of control and of cropping. There is prevalent a general 

 belief that there is a difference in the manurial requirements of dif- 

 ferent soil materials, but there is nothing so far available that will 

 enable us to answer this question in any positive way. 



About one-third of the letters received by the bureau asking advice 

 as to the treatment and use of soils particularly demand information 

 regarding the manurial requirements of the samples sent in by 

 farmers. The investigations of the bureau have now reached a 

 point where methods are available for supplying this informa- 

 tion in a majority of cases, and it is recommended that an appro- 



