1917] SOILS FERTILIZERS. 217 



ysis the more available the nitrogen of the compounds formed, since, as has 

 been shown, the final products of hydrolysis are utilize<l by the plants as such 

 and are at the same time more readily changed into ammonia by soil organisms 

 than are the intermediate compounds produced by partial hydrolysis." 



Sources of nitrogen compounds in the United States, C. G. Gilbert (U. S. 

 Scimte. 64. Ccmg., 1. Sess., Doc. Ifll (1916), pp. 11; ahs. in Nature [Londoni, 

 9S (1917). No. 2466, pp. 431. JfS2). — This is an article on the natural occurrence 

 of nitrogen and its adaptability to use, especially as a fertilizer. In sum- 

 marizing the situation it is stated that " the evolution of a practicable process 

 for the oxidation of by-product ammonia to render present resources available, 

 with the development of an atmospheric nitrogen fixation output by the cyana- 

 mid process carefully timed to meet growing demands following a reduction 

 in the retail price of nitrogenous fertilizer, would appear to be the desirable 

 governmental procedure as t)eing the one least liable to disastrous conse- 

 quenc-es." 



The nitrate industry. E. Cuevas (.Veto York: W. S. Myers, 1916, pp. 61, pis. 

 3. figs. 4)- — This is a paper presented at the second Pan American Congress at 

 Washington, D. C. It gives a brief history of the Chilean nitrate fields and 

 describes in detail the character and composition of the nitrate deposits as well 

 as the methods of mining and preparing the material for industrial purposes. 



The author is of the opinion that the deposits are capable of supplying the 

 needs of the world for at least 300 years. It is suggested that as a matter of 

 national preparedness, from both the military and the purely agrictiltural stand- 

 point, the United States should proceed at once to buy and store large quantities 

 of the nitrate. 



In an introductory note by the publisher, attention is called to the fact that 

 " the Central Empires of Europe imported from Chile in the five years ended 

 December 31, 1914, an unheard of tonnage of nitrate of soda, amounting to 

 about 5.000.000 tons. The area of the Central Empires is hardly greater than 

 the combined areas of California and Texas. These empires imported more 

 than all the rest of Europe for the period named. It is not improbable that a 

 very great amount of this 5,000,000 tons is still held in reserve in Gtermany, and 

 It is privately reported that no Chilean nitrate is to be permitted to be used in 

 agriculture for some time to come." 



When are summer crops to be fertilized with lime nitrogen? P. Wagnee 

 (Deut. Landir. Presse, 43 {1916), Nos. 18, pp. 149, 150; 19, pp. 158, 159).— Data 

 relating to the time of fertilizing summer crops with lime nitrogen, obtained 

 from numerous experiments carried on at different stations, are reported. 



It is concluded that it is not necessary to apply lime nitrogen to loam and 

 clay soils previous to seeding time. On heavy soil the ground should be worked 

 with a harrow as early as pos.sible and lime nitrogen applied and thoroughly 

 mixed with the soil just prior to seeding. Better results were obtained by 

 applying all the lime nitrogen just prior to seeding than by applying a part as 

 a top-dressing. 



Fertilizer experiments {Minnesota Sta. Rpt. 1916, pp. 58, 59). — The results 

 of several years' fertilizer experiments at the different Minnesota experiment 

 farms are taken to indicate " that the experiment station is not justified in 

 recommending the use of phosphates in general farming operations in this 

 State." 



Phosphate rock. R. W. Stone {U. S. Geol. Survey Bui. 666-^J [1917]. pp. 4).— 

 This is a brief review of the phosphate rock resources of the United States and 

 Includes data on production. It is stated that the total output for 1916 was 

 1,980,000 toas, valued at §5,897,000. 



