274 AGRICULTURAL APPROPRL\TION BILL, 1924. 



being carried on to discover methods of utilizing the various waste, nitrogenoup 

 products which may take the j)lacp of some of the more expensive nitrogen product? 

 now going into feed stuffs. 



Phosphoric rtriV/— Investigations on the utilization of run-of-mine and low-grade 

 phosphate material have led to the discovery that these materials may be used in a 

 process for the volatilization and recovery of phosphoric acid. As already pointed 

 out, the manufacture of concentrated fertilizer material is dependent upon the volati- 

 lization proce.x.x of making i^hosphoric acid cheaply, and by the utilization of this run- 

 of-mine material a cheaper source of the manufacture of this phosphoric acid is assured. 

 Material heretofore of little value has been utilized for direct smelting in the fuel-fed 

 furnace. This material carries a low percentage of phosphoric acid and too much 

 aluminum, iron, and lime to make it available for use in the ordinary manufacture of 

 superphosphate, but these characteristics which are undesiralde in manufacturing 

 superphosphates impart a good slagging quality to the charge used in smelting. These 

 experiments carried out with a small oil-fired furnace have been highly satisfactory 

 and a larger and improved furnace has been installed at Arlington and is now ready 

 for experimental runs. The earlier work of the bureau on the volatilization of phos- 

 j)horic acid was done in an electric furnace. This method was so successfully 

 demonstrated that the process has been taken up by an industrial concern and furnaces 

 installed at Anniston. Ala. This company is now manufacturing phosphoric acid la- 

 this process, although all the product at present is going into high-grade chemicals 

 and medicinal or food products. 



Potash. — The Bureau of Soils is continuing to investigate the available sources of 

 American potash, although at the present large amounts of German and Alsatian 

 potash are coming into this country. The former work of the bureau has shown a 

 numbeii of different sources from which potash may be obtained, and these present a 

 potential supply of such capacity that the emergency needs of this country could be 

 met under conditions similar to tho.se prevailing during the war. when the supply 

 of (ierman potash was cut off. Our demonstration of available American sources of 

 potash renders the position of this country secure in the event that exorbitant prices 

 shoulcl be charged for the foreign material. F'urther research may develop more 

 eliicient methods, so that American potash may compete normally with that from a 

 foreign source. 



A difficulty experienced in the use of American potash a few years ago was the 

 pres(!nce of deleterious amounts of borax in .the material produced from the Searles 

 Lake brines. This bureau quickly discovered the source of this undesirable material 

 and developed methods for detecting and determining the quantities of borax present 

 in the potash. After our order designating the amount of borax permissible in potash 

 the companies immediately changed their methods, so that all danger from this source 

 has been eliminated. 



Chemical investigations. — The work of the Chemical Division is closely interrelated 

 with that of the Soil Survey and at the same time this division is depended upon for 

 the investigation of fundamental chemical changes taking place in the soil. I think 

 farmers and all those engaged in supplying the farmer with practical information con- 

 cerning soil management will agree with me that fundamental soil chemical investi- 

 gations are recpiired before we can give certain aspects of farm practice the scientific 

 certainty nt^eded to make farming a less venturesome business. 1 refer particularly to 

 the adaptation of crop to soil and the u,se of lime and fertilizers. 



A large number of complete chemical analyses of soils must be made each year if the 

 work of soil cliussilical ion by the Soil Survey is to be conducted properly. The com- 

 plete cliemicai analysis of a .soil is an exacting and time-consuming o])eration. and 

 although \\i' have developed rajtid petrographic methods for the examination of certain 

 Boil constituents, soil analysis forms a large ])art of the work of this division. From 

 time to time also a consideralde amount of chemical soil work on special ]>roblems 

 inuHl be done for other liurc^aus in the (leparUnent and forother departnu-nts of the 

 (jo\ernini'iit. 



The investigation of fumlamcnlal soil i)roce.s.ses for the past year has been directeil 

 chielly to th«' colloidal mutter in soils. Nlethods for determiniiig the total ((uantity of 

 colloidH in soils an- i>eing develo])ed. and we have fouiul that soils tontain from 'i to 'h) 

 percent of colloidal material instead of I to ?. ])er cent, as some of the earlier .soil scien- 

 tittls sujiposeil. 



Ina-imucli us one kind of colloid may affect one properly of the .soil and another 

 colloid alferi uiiotlirT property, it is obviously important to develop methods for deter- 

 mining llie dilfereni kinds of colloids in the' soil, ("erlain colloids niav inlluence the 

 retention of plant f(M)d. which may bt> with or without much effect (in the i)hvsical 

 prr>i)(«rtieH of a soil, or conversely. 



'I his is a <omi)arativeiy unworked field of soil investigation which gives promiso of 

 being moHt pnxhK-tiv*' of both scientili*- and practical results. 



