40 ANXUAL REPORTS OF DEPARTMENT OF AORTCULTURE. 



wliicli is not only a valuable fertilizer inf^redient, but an essential 

 element in the manufacture of munitions. Of all the nations in- 

 volved in the war, Germany alone had a sufficient nitrate supply 

 within her borders, but En<2;land, France, and Italy are now rapidly 

 perfecting plans to make themselves equally secure in this respect. 

 Increased interest lias been manifested in this country, also, in the 

 study of methods for fixin<;^ atmospheric nitroo;en, and the Depart- 

 ment of Agriculture, through the Bureau of Soils, has actively co- 

 operated with the War Department in this important field. The 

 production of ammonium sulphate from by-product coke ovens and 

 gas plants has greatly increased, but not sufficiently to meet the de- 

 mand for fixed nitrogen. 



The nitrogen fixation plant at Muscle Shoals, Ala., completed 

 shortly before the armistice, offers a hope for an independent 

 source of nitrogen for fertilizer use in time of peace. This plant is 

 prepared to make calcium cyanide, or, by some additions, to manu- 

 facture ammonium sulphate. With modifications, also, it may be 

 equipped for the preparation of highly concentrated fertilizer ma- 

 terials which wnll be free from filler, and therefore result in a con- 

 siderable saving to the consumer in freight charges. The plant is 

 still idle, awaiting the necessary authority from the Congress for its 

 operation. It is hoped that the matter will receive consideration at 

 the next session of the Congress, and that the requisite authorization 

 will be granted without further delay, in order that the Nation may 

 escape, once for all, from dependence upon foreign nitrate fields, 

 and that an adequate supply of nitrogen may be developed, both as 

 a protection in times of national stress and to meet the growing de- 

 mand for this valuable product for fertilizer purposes. 



POTASH FROM KELP AND OTHER SOURCES. 



The experimental kelp plant at Summerland, Calif., the purpose 

 of which is to demonstrate the practicability of extracting potash 

 and useful bj^^-products from the giant kelps, is in active operation 

 and valuable results are being secured. Unquestionably, it will be 

 possible, when the best methods have been worked out, to develop 

 a potash industry on the Pacific coast capable of supplying a consid- 

 erable part of the Nation's needs. 



Two processes for the recovery of potash from certain rocks have 

 recently been developed by the Bureau of Soils, and both are 

 being utilized in commercial practice. The 87,000 tons of 

 potash annually lost from flues and stacks of cement plants 

 are still, in the main, going to waste. Only about 1 per cent 

 was recovered in 1919. A similar situation exists witli refer- 

 ence to the collection of potash from blast furnaces. The department 

 is now making a survey of this situation, and preliminary results 



