BUREAU OF SOILS. 379 



promise that the cost of extracting potash from these raw materials 

 will be greatly reduced. This work is being carried out with a full 

 understanding and utilization of the results obtained in the extensive 

 war-time investigations of these raw materials. Potash from the 

 western fields must be refined to a high state of purity in order that 

 freight charges to market may be reduced to the minimum, and 

 by-products must be yielded simultaneously to reduce proportionately 

 the cost of producing the potash. These fundamental economic 

 considerations are the basis of present investigations. To solve 

 the problem of extracting potash commercially from the greensands 

 of New Jersey — a problem which thus far has resisted solution — 

 would render available for American agriculture a very large and 

 close-at-hand supply of potash. 



Additional articles descriptive of the results obtained in the 

 department's experimental kelp-potash plant at Summerland, Calif., 

 have appeared, and others are ready for publication. 



By modifying the process ordinarily used in the preparation of 

 ammonium phosphate so as to include the use of commercial potas- 

 sium chloride as well as phosphoric acid and ammonium, it has been 

 found that a product of corresponding concentration may easily 

 be obtained which contains all three of the essential constituents of 

 fertilizers. The chemical and physical properties of this material 

 make it admirably suited as a medium for transporting the fertilizing 

 elements and for increasing the concentration of other fertilizer mix- 

 tures. Outside interests have taken such an interest in this process 

 as to express a willingness to test out the method on a commercial 

 scale. The bureau has for many years advocated the use of more 

 concentrated fertilizers and the elimination of many of the fertilizer 

 brands, and a striking confirmation of the value of our work has been 

 shown during the last year in a number of conferences held in Chicago, 

 Boston, Baltimore, and other sections of the country, in which definite 

 formulas for fertilizer mixtures were adopted. These formulas were 

 fewer in number and were of higher concentration in the fertilizer 

 ingredients, the average result showing about a 50 per cent increase 

 in the content of essential plant-food constituents carried by the 

 adopted brands over those of about 10 years ago. 



A study has been undertaken of conditions suitable for the home 

 mixing of materials and the changes taking place in the mixed ma- 

 terials while in storage. 



As a result of the work on nitrogen fixation during the past year 

 an improved method has been evolved for the recovery of ammonia in 

 liquid form from the mixed gases in the synthetic process. This 

 method promises a more efficient recovery, produces the ammonia 

 in a more convenient form than from the older methods, and marks 

 a distinct advance in the technical operation of the Haber process 

 for nitrogen fixation. A report on the results of this investigation, 

 which was carried on in cooperation with the Fixed Nitrogen Research 

 Laboratory, is now being prepared for publication. 



In the routine laboratory work a great many samples have been 

 examined with reference to the possibility of utilizing the materials 

 as sources of fertilizer. 



