SOILS FERTILIZEES. 125 



kept iu the Incubator at 27° C. for a definite period. Subsequent] j^ the different 

 soil portions were transferred to copper flasks, about 200 cc. of water and 

 magnesia were added, and the ammonia was distilled oft and titrated against 

 standard hydrochloric acid." 



The influence of varying the amount of material used and the time of treat- 

 ment was also tested, and the results of the ammonification tests were compared 

 with results of pot experiments with the various materials. As a further check 

 upon the results of the ammonification tests studies were made of the rates of 

 nitrification. The results of the nitrification experiments agreed with those of 

 the ammonification tests in indicating a sharp distinction between available 

 and unavailable nitrogen, and " may be made to serve a useful purpose in the 

 study of availabilities of nitrogenous fertilizers." 



In further experiments it was found that the addition of inert substances, 

 like peat, to the more available nitrogenous fertilizers, like dried blood, de- 

 creased the rate of ammonification to a certain extent, and it appeared that the 

 dried blood was of but little help in stimulating the ammonification of the peat. 

 It was found in general that mixing of nitrogenous materials depressed am- 

 monification. 



Applying the method to mixed fertilizers, it was found that " everything con- 

 sidered, the ammonification and vegetation tests show sufficient agreement to 

 indicate that the former will be found useful in determining the availability of 

 organic nitrogen compounds in mixed fertilizers." 



Experiments with lime nitrogen, ammonium sulphate, and sodium nitrate 

 in 1910, Weh-Nert {Laadv. Wchnhl. Schles. Hoist., 61 (1911), Nos. 3S, -pP- 

 743-7-^8; 39, pp. 768, 769; 40, pp. 786-789). — ^A continuation of previous coopera- 

 tive experiments comparing these fertilizing materials under a variety of con- 

 ditions of crop and soil is reported, the results in general showing a high efii- 

 ciency for the lime nitrogen as compared with the other materials. Attention 

 is, however, called to the difficulty in applying the very finely pulverized lime 

 nitrogen. 



Active phosphoric acid and pot experiments, G. S. Fraps (Trans. Texas 

 Acad. Sci., 11 (1908-9), pp. Ii5-'i9). — This is a short article based upon experi- 

 ments which have been more fully reported elsewhere (E. S. R., 23, p. 423). 



Phosphates, R. W. Richards, G. R. Mansfield, H. S. Gale, and E. Black- 

 welder (U. S. Geol. Survey Bui. Jt70-H, pp. 115, pis. 9, figs. 12; rev. in Amer. 

 Pert., 35 (1911), No. 12, pp. 21-30, figs. 4). — This publication contains pre- 

 liminary reports on a portion of the Idaho phosphate reserve, rock phosphate 

 near Melrose, Mont., and a reconnaissance of the phosphate deposits in western 

 Wyoming, and is based upon examinations during 1910 in continuation of those 

 of previous years reported in Bulletin 430-H (E. S. R., 24, p. 25). 



The first report gives a description of the geogi-aphy, origin and nature, 

 and geology of the Idaho phosphate field, based upon the results of a detailed 

 study of lands in Bear Lake and Bannock counties in southeastern Idaho, in- 

 cluded in "the phosphate reserve created by the withdrawals of December, 

 190S, and December, 1909, by the Secretary of the Interior, which were ratified, 

 confirmed, and continued by tlie President under the act of June 25, 1910, and 

 also a reconnaissance examination of lands possibly phosphate-bearing out- 

 side of the reserve," It is estimated that the 9 townships examined in this 

 area in 1910 are capable of yielding 1,158,970,000 long tons of high-grade (70 

 per cent) phosphate. The area previously examined was estimated to be 

 capable of yielding 266,9.'i0,000 tons. Extending the same ratio of yield to the 

 area which has been examined only in part by reconnaissance the total supply 

 is estimated to be 2,500,000,000 tons of 70 per cent phosphate. 



