516 EXPERIMENT STATION EECORD. 



Special reference is made to llie work of tlie Bureau of Soils of this Depart- 

 U'ent on the subject. 



The eJRPect of soluble humates on nitrogen fixation and plant growth, 

 W. B. BoTTOMLEY (.Ri>t. Biit. Assoc. Adv. Sci., 1913, pp. 777, 77S).— A continu- 

 ation of previous experiments is reported (E. S. E., 30, p. 323). Data obtained 

 from pot and field experiments with the so-called " bacterized " peat prepared 

 by the author's method are presented to show that this material not only pro- 

 motes nitrogen fixation in the soil but has a direct effect in increasing the 

 growth of plants, and it is stated that " this is probably due in part to the pres- 

 ence of ammonium humate, which, in addition to being a direct source of 

 nitrogen for plants, stimulates their root development in a remarkable manner." 



Nitrification in pasture soils, C. T. Gimingham (Rpt. Brit. Assoc. Adv. Sci., 



1913, p. 777; abs. in Nature [London], 92 (1914), No. 2305, p. 516).— A study of 

 nitrification was made in a soil intermediate in character between the true 

 moor and the true fen soil. This soil contained a large amount (30 to 40 per 

 cent) of organic matter and only traces of carbonate, but the soil water was 

 neutral in reaction. The soil was found to be capable of bringing about imme- 

 diate and rapid nitrification of peptone. Ammonium sulphate was also quickly 

 nitrified, but the soil in this case became slightly acid in reaction. 



A note on the use of nitron in the determination of nitrates in the soil is 

 appended. 



Investigations on the protozoa of soil, T. Goodey (Rpt. Brit. Assoc. Adv. 

 Sci., 1913, p. 775; obs. in Jour. Soc. Chcm. Indus., 32 {1913), No. 18, p. 919; 

 Nature [London], 92 {1914), ^o. 2305, p. 516).— A rapid method for obtaining 

 j)rotozoa from a hay-infusion culture of soil was devised. The organisms first 

 obtained by this method were ciliated protozoa, chiefly Colpoda. The indica- 

 tions were that these protozoa were present in soil only .in an encysted con- 

 dition and, therefore, could not inhibit bacterial activity. 



Partial sterilization by means of volatile antiseptics had no effect on the 

 rate of development of bacteria in a soil which had been kept in bottles since 

 1846 and contained no protozoa, but a soil kept since 1870 which contained a 

 few protozoa (amoeba and flagellates) was improved in bacterial activity by 

 partial sterilization. 



Improvement of swamp land in Finland by addition of sand, A. Rindell 

 {Finska MosskuUurfor. Arsbok, 16 {1912), No. 2, pp. 181-188; abs. in Jour. Soc. 

 Chem. Indus., 33 (1914), No. 8, p. 432). — "Experiments with oats extending 

 over two years showed that loam is much superior to sand as an addition to 

 unmanui'ed marshy land. The addition of sand did not produce any improve- 

 ment unless more than 400 cubic meters per hectare (about 5,700 cu. ft. per 

 acre) was added. If the land was otherwise provided with phosphates and 

 potash, the difference in efi'ect between sand and loam was not appreciable." 



Greater profits from land, A. L. Dbysdale (Edinburgh, London, and Lcipsic, 



1914, pp. Till +187, pis. 7). — This is primarily a summary of results of agri- 

 cultural investigations carried on at the Dalmeny Experiment Station in 

 Scotland during eight years beginning in 1895, with an introductory chapter 

 discussing some fe:itures of recent progress in agricultural science and tables 

 showing how the unexhausted value of applications of manure and fertilizers 

 may be estimated. 



New views on fertilization (Mitt. Dent. Landio. Oesell., 29 (1914), Nos. 10, 

 pp. 145-147; 11, pp. 154-156; 12, pp. 171-173; 13, pp. 181-183; I4, pp. 196, 197; 

 15, pp. 207, 208; 16, pp. 216-218; 17, pp. 230, 231; 19, pp. 259, 260; 21, pp. 292, 

 293; 23, p. 337). — This is a symposium on this subject contributed by a number 

 of the more prominent investigators in the field of soil fertility and fertilization. 



