422 EXPERIMENT STATION EECOED. 



ing on the newly settled regions of the world for materials with which to feed 

 their crops. Now that we have reached the period where we need to do the 

 same thing, there are no great areas of virgin soil from which we can draw 

 such supplies. Indeed, it seems that the countries of Europe will not always 

 be able to draw on supplies of this character from other parts of the world, 

 because they will soon be needed in the regions where they are produced. The 

 American farmer can therefore not hope, at least in the near future, to import 

 feeding stuffs with a view to enriching his land, but he will be making a long 

 step forward when he quits exporting these materials and returns them to his 

 own soil." 



Agricultural geology, E. Cord {Geologic Agricolc. Paris, 1909, pp. .'i50, figs. 

 316; rev. in .lour. Soc. Cent. Agr. Belg., 57 (1909), No. 2, pp. 43, .'/.'/).— This is 

 one of the volumes of the Encyclopedie Agricole. It is divided into three parts, 

 dealing respectively with land and water, the geological history of the earth, 

 and the stratigraphy of the earth. One chapter deals particularly with the 

 soil and surface geology. 



Agrogeology, K. O. Bjorlt'KKe (Norges Landbi: Hoiskolcs Skr., 1909, No. 11, 

 pp. 56. fig. 1). — A report of the first International Agrogeological Conference 

 at Budapest, April 14-23, 1909. The papers relating to agrogeology have been 

 previously noted from another source (E. S. R., 23. pp. 314. 315, 316). 



The bacterial life in the soil, B. Hansteen (Norsk Lnndmandsblad, 29 

 (1910), Nos. 8, pp. 101-103; 9. pp. 113-115). — A lecture delivered at the farmers' 

 course at the Agricultural College of Norway. January, 1910. 



Bacterial activity as a corrosive influence in the soil, R. H. Gaines (Jour. 

 Indus, and Engin. Chen., 2 (1910), No. 4. pp. 128-130; ahs. in Gliem. Ztg., Sit 

 (1910), No. 32, p. 282). — Previously noted from another source (E. S. R.. 22, 

 p. 715). 



On the '' sick " soils of Porto Rico, O. Loew (Porto Rico Sta. Circ. 12, pp. 

 2J^), — Studies of the chemical compositiou, bacteriological condition, and fer- 

 tilizer re(iuirements of certain "' sicb: " coffee, cane, tobacco, and pinapple soils 

 are reported. 



It was found that as a rule these sick soils did not respond to ordinary fer- 

 tilizing, indicating that their condition was not due to lack of fertilizing con- 

 stituents. The soils showed, however, an abundance of micro-organisms which 

 produce butyric acid. In some cases organisms which change sulphates into 

 sulphids were also observed. Disinfection of the soil with bisulphid of carbon 

 was an effective corrective, but is expensive. A deficiency of aeration and the 

 presence of fermentable substances in the soil were found to present favorable 

 conditions for the growth of facultative or strictly anaerobic micro-organisms 

 which often produce injurious fermentations. 



The action of manure on a certain Iowa soil, E. B. Watson (Proc. Iowa 

 Acad. Sci., 16 (1909), pp. 103-130, pis. 6. fig. 1; Wallaces' Farmer, 35 (1910). 

 Nos. 7. p. 37//. fig. 1; 10, p. ^35, fig. 1: 11. p. -i8J,, fig. 1; 13, p. 570; l',. p. 610. fig. 

 1; 15, p. 651). — Pot experiments comparing manure and fertilizer on clover on 

 a loess soil from southern Iowa are reported. See also a previous note (E. S. R., 

 20, p. 742). 



The experiments showed that manure was much more effective in increasing 

 the yield of clover than were mineral fertilizers. This beneficial effect is 

 attributed to the antitoxic efliect of the manure. "There was a toxin in the 

 soil which was neutralized by the manure. The soil pots treated with mineral 

 fertilizers had the toxin corrected by the combined action of the clover roots 

 and the chemicals, but this was a slower process than the action of the manure." 

 Cockleburs which grew abundantly on the field from which the soil was 

 obtained are considered the source of the soil toxin. 



