SOILS — FERTILIZERS. 417 



Potash is usually a seconflary need on such soils." All the soils were well 

 supplied with organic matter and only in a few cases was nitrogen necessary. 



The soils of Alabama and their adaptations to crops, J. F. Duggar (In 

 Alabama's New Era. Montgomenj : State Immiyr. Dept. [1911], pp. 39-Jf7, pi. 

 1). — This is a general description of the physiographic divisions of Alabama 

 and their chai'acteristic soils and crop adaptations. 



"Taking the State of Alabama as a whole, it may be said that sandy soils 

 cover a larger area than do either clay loams or clays and that tlie largest areas 

 of clay soils are in the central prairie regions and in the Appalachian A'alley and 

 Piedmont Eegion, in the eastern part of the State. The greater part of the 

 surface of Alabama is slightly rolling, but there are broken or mountainous 

 areas as well as comparatively level land. The largest areas of nearly level land 

 are ( 1 ) in the southern edge of the Coastal Plain, that is, in the quarter of the 

 State nearest to the Gulf; (2) in the Central Prairie Region and adjacent 

 narrow regions on each side of it; and (3) in the Tennessee Valley. By far the 

 greater proportion of the cultivated land of Alabama is free from stones, but 

 the presence of stones, especially in the Piedmont Region, in the region of 

 gravelly hills, and elsewhere, does not decrease productiveness, though the 

 stones interfere with the convenience of cultivation." 



[Analyses of soils of the Burirhat Station Farm] (Ann. Rpt. Agr. 8tas. 

 East Bengal and Assam, IDll, pp. 25-28, pi. 1). — Chemical analyses of samples 

 of soil from fertile and from barren areas on this farm showed very little dif- 

 ference in composition except that the calcium carbonate content in the samples 

 of fertile soil was about twice that in the samples of barren soil. The ratio of 

 magnesia to lime was high in both cases, being generally in the proportion of 

 3 or 4 to 1. Experiments to determine the effect of liming the soil for its 

 improvement are now in progress. 



Weeds in relation to soils, Winifred E. Beenchley {Jour. Bd. Agr. [Lon- 

 don], 19 (1912), No. 1, pp. 20-26). — These studies have been previously noted 

 (E. S. R., 27, p. 29). 



The chemical characterization of soils, E. J. Russell (C'hrm. World, 1 

 (1912), Ko. 1, pp. 5-8, figs. 3). — From a consideration of factors which influence 

 the availability of plant-food constituents of the soil the author concludes "that 

 for a complete account of the fertility relationships of soils a chemical exami- 

 nation alone is not likely to lead to any useful result." It is shown that soils 

 of identical composition as determined by ordinary methods of soil analysis 

 vary widely in productiveness as a result of difference in water conditions, 

 suitability of the organc matter to support active bacterial life, and various 

 other factors. Ordinary analysis must therefore be supplemented by various 

 other inquiries before advice regarding improvement of a soil can safely be 

 given. 



More recent investigations in soil science, Albert (Ztschr. Forst. u. Jagdw., 

 U (1912), No. If, pp. 2JiO-2If9). — The author reviews the development of studies 

 in colloid chemistry, pointing out particularly the application of this subject 

 to the study of the soil. He is of the opinion that the colloid theory is often 

 used to explain hitherto unsolved problems of physics and chemistry without 

 exact knowledge of the scientific basis upon which it rests. There is need of 

 a more careful and extended study of the subject. 



A short bibliography is added. 



Colloid chemistry studies on humus in limed and unlimed soils, W. Thaee 

 (Jour. Landw., 60 (1912), No. 1, pp. 1-18; ahs. in Chem. Abs., 6 (1912), No. 13, 

 p. 1191). — This is an extract from a dissertation which has already been noted 

 (E. S. R., 25, p. 823). Preliminary studies of the chemical composition and 



