SOILS FERTILIZERS. 21 



Report on the work of the soils section of the Institute for Agricultural 

 Plant Production of the University of Breslau, 1902-1909, P. Ehkenberg 

 (Mitt. Laudit: Inst. Breslau, 6 {1910), No. 1, pp. 1-32).— This is a review of the 

 chemical, physical, and bacteriological investigations on soils which have been 

 carried on at this institution, including particularly the investigations of Pfeiffer, 

 Ehrenberg, et al., on fertilizers, green manures, rotations and fallows, nitrogen 

 economy of soils, soil inoculation, physical (especially colloid) properties of 

 soils, irrigation, and effect of zinc in pot cultures. Lists of the principal papers 

 reporting these investigations are given. 



Characteristics of the newer methods of geological-agronomical soil map- 

 ping, H. Geuneb {Dcut. Landw. Presse, 37 (1910), Nos. 12, pp. 779-781; 73, p. 

 79/,; 74, pp. SOJf, 805, fig. i).— This article discusses the development and signifi- 

 cance of geological-agronomical soil mapping, as well as the views of various 

 investigators, particularly Reiss and Koehne, as to what such maps should 

 include. 



Bibliography of North American geology for 1908, with subject index, 

 J. M. NicKLES (U. 8. Geol. Surveij Bui. J,09, pp. 1J,8). — This contains a list of 

 serials examined, a bibliography arranged alphabetically by authors, a subject 

 index, and lists of chemical analyses, minerals, rocks, and geologic formations 

 referred to. 



Barium in soils, G. H. Failyee {TJ. 8. Dept. Agr., Bur. Soils Bui. 72, pp. 23, 

 pi. 1 ) .—This bulletin reviews the literature relating to the occurrence of barium 

 in soils and reports the results of determinations of barium in a number of sam- 

 ples of soils, especially of the Great Plains, and of other parts of the United 

 States. These results indicate " that barium is a widely disseminated element 

 and is present in most soils throughout the United States, and in larger quanti- 

 ties, as would be expected, in soils derived from masses carrying barite deposits 

 and in the soils derived from the rocks of the Rocky Mountains. 



" The soil moisture may be expected to carry small amounts of barium. In all 

 cases the feldspars of the igneous rocks from which the soil material has been 

 derived seem to be an original source of the barium of soiLs." 



The adaptation of the plant to the soil, A. D. Hall (Jour. Roy. Hort. Hoc. 

 {London}, 36 {1910), No. 1, pp. 1-21, figs. 11).— The variation of plant growth 

 with the character of the soil is illustrated by the changes which the natural 

 herbage has undergone in the course of 48 years on plats of Rothamsted soil 

 treated in different ways. 



A study of these soils indicates the difficulty of correlating the plant with the 

 composition of the soil upon which it grows. The author therefore presents a 

 study of the distribution of a few crops over a small range of country, namely, 

 the distribution of fruit, hops, barley, and potatoes in the counties of Kent, 

 Surrey, and Sussex. Mechanical analysis of the soils shows a great similarity 

 of type, regardless of geological origin, of the soils on which these crops are 

 grown in different localities. 



The conclusion is reached that the structure of the soil as revealed by 

 mechanical analysis is the chief of the causes determining the association of 

 given plants with a given soil because on the size of particle and structure 

 depend the water supply, temperature, and humidity. 



Of the secondary factors which determine the association of plants and soils 

 the reaction of the soil is probably the most important, since the microflora 

 which plays so large a part in the nutrition of the higher plants are determined 

 almost entirely by the acidity or alkalinity of the soil. It is this fact that 

 explains in large part the effect of the lime content of soils upon the character 

 of vegetation. 



