1919] SOILS — FERTILIZERS. 25 



fertilized. This leads to the conclusion that there will be required 1.7:10,000 

 tons of superphosphate and basic slap and 470,000 tons of sulphate of ammonia 

 or its equivalent. No estimate of the amount of potash required is given. 



The nitrogen problem in relation to the war, A. A. Notes (■lour. Wash. 

 Acad. Sci., 8 (1918), No. 12, pp. 881-394; abs. in Nature [London], 102 (1918), 

 No. 2550, pp. 26, 27). — This article, by the chairman of the Committee on Ni- 

 trate Investigations of the National Research Council, gives a^roneral view of 

 the nitrogen situation with brief descriptions of sources of supply and methods 

 of meeting the demands for nitrogen compounds. 



It is pointed out that the Chilean nitrate supply is at best precarious, and 

 that the utmost possible supply from by-product coke ovens is wholly inade- 

 quate. It is, therefore, necessary to develop methods of manufacture. The 

 most promising of these so far developed are the cyanamid, cyanid, arc (nitric 

 acid), and synthetic (ammonia) processes. 



It is stated that the nitrate division of the Ordnance Department has greatly 

 simplified the process of absorption of nitric vapors and that the Bureau of 

 Mines has brought the oxidation process to a high state of perfection. 



Storage of sulphate of ammonia on farms (Jour. Bd. Agr. [London], 25 

 (1918), No. 6, pp. 703-705). — Directions are given for storage either in bags or 

 loose in a heap. It is essential that the sulphate should be kept dry. 



Utilization of phosphate deposits of Australia, J. W. Paterson (Aust. Ad- 

 visory Council Sci. and Indus. Bui. 7 (1918), pp. 96-107, fig. 1).— This article 

 reviews the results of various investigations on the amount and availability of 

 phosphoric acid in soils and the relative availability of different kinds of phos- 

 phates, and notes briefly the results of examinations of 24 soils from different 

 parts of Australia which show them to be low in total phosphoric acid but 

 specially so in available phosphoric acid as determined by Dyer's method. The 

 total phosphoric acid varied from 50 to 68 parts per 100,000 of soil, of which 

 only from 5.3 to 15 per cent was available. 



In pot tests with wheat, comparing calcium rock phosphate, aluminum phos- 

 phate, and iron phosphate, it was found that the calcium phosphate was de- 

 cidedly superior to aluminum and iron phosphates when no lime was used, but 

 that when lime was used iron phosphate was nearly as effective and aluminum 

 phosphate apparently fully as effective as calcium phosphate. It is stated that 

 the native phosphate deposits are of two kinds, calcium phosphates of low grade 

 and iron and aluminum phosphates of various kinds. Various methods of utiliz- 

 ing these phosphates are suggested, and a plan for studying them by means of 

 chemical investigations, pot tests, and field experiments is outlined. 



Condition of fertilizer potash residues in Hagerstown silty loam soil, W. 

 Frear and E. S. Erb (Jour. Agr. Research [U. &.], 15 (1918), No. 2, pp. 59-81).— 

 This is a report in detail of studies made at (he Pennsylvania Experiment Sta- 

 tion of the solubility of the potash of Hagerstown silty loam soil in hot, strong 

 (1.115 sp. gr.) hydrochloric acid, fifth-normal hydrochloric acid, distilled water, 

 carbonated water, and approximately third-normal ammonium-chlorid solution. 



A comparative study was made of the solubility of the potash in a soil which 

 has in the past 36 years received in 18 equal biennial applications 1,800 lbs. of 

 fertilizer potash and that in a neighboring portion of the same soil which has 

 been unfertilized but has been tilled and cropped in the same manner. Hot, 

 strong acid dissolved somewhat larger amounts of potash from the fertilized 

 soil. The remaining solvents dissolved in a short time at moderate tempera- 

 tures twice as much potash from the fertilized soil as from the unfertilized. 

 Of the weak solvents used fifth-normal hydrochloric acid dissolved the largest 

 amount of potash. The clays separated by sedimentation in water contained 

 less potash than the nonclays. 



