SOILS FERTILIZERS. 313 



tlecline of both linnms couiiiountls and mineral constituents, the reverse being 

 true where the conditions favor accumulation of the soluble constituents. The 

 lime and magnesia of the plant residues, as well as of the soil, play the leading 

 rr.le in these changes. The degradation of the chernozem soil as well as the 

 •' regradatiou " of the gray forest soil into chernozem can be brought about 

 artificially. 



[Org'anic matter as a means of preventing' loss of soluble plant food by 

 leaching'], A. W. Blaik (Florida *S7«. A'/j^ 1908, pp. XXXIX-XLI). — In experi- 

 ments in which a rather coarse sandy ^oil without admixture and with varying 

 amounts (-1 to 10 per cent) of muck was subjected to leaching, it was found 

 that the addition of the organic matter reduced the loss of plant food through 

 leaching and imjiroved the capillary power of the soil. 



The relations between permeability of soils and their adaptability to irri- 

 gation,. A. MiJNTz and L. Faure (Compt. Rend. Acad. Sci. [Paris], IJ/S {1909), 

 Xo.22,pp.lJ,35-lJ,J,0; ahs. in Rev. Sci. [Paris],. ',7 (1909), I, No. 2.',, p.763).— It is 

 shown that the permeability of the soil is an essential factor in connection with 

 the use of irrigation water. The permeability may iu certain cases be so great 

 as to render irrigation unprofitable or greatly reduce the benefits that may be 

 derived from it. 



It is recommended that the determination of the permeability of the soils 

 should precede the establishment of every irrigation project and that in case of 

 a limited supply of water its application be limited to the soils of medium per- 

 meability. The distributing syst?m could iu this case be more economically 

 installed and the efficiency of irrigation would be increased. 



Moisture determinations, A. W. Blair (Florida St a. Rpt. 1908, pp. XLI- 

 XLIV). — Determinations of moisture during April and May in samples of vari- 

 ous soils taken in 1 ft. sections to a depth of 4 ft. are reported. 



Contribution to methods of bacteriological soil investigation, "\'ogel and 

 Zeller (Milt. Kaiser WiUicIins Inst. Landic. Brombcrg, 1 (1008), Xo. 2, pp. 

 167: abs. in Centbl. Balct. [etc.], 2. Abt., 22 (1909), Xo. 1J,-17, pp. J,18- 

 420). — The authors' experience with various chemical-biological methods of 

 soli examination with reference especially to the increase of the nitrogen sup- 

 ply of soils by bacterial activity is given. 



Investigations on Azotobacter chroococcum, S. Krzemieniewski (Centbl. 

 Balct. [etc.], 2. Abt., 23 (1909), Xo. 6-9, pp. i6J-i7J).— Studies' are reported 

 which show that mixed cultures of Azotobacter chroococcum are more active in 

 fixing nitrogen than pure cultures. Both Azotobacter and Granulobacter fix free 

 nitrogen, but iu a medium free from humus the latter is much more active than 

 the former. In neither case does Radiobacter alone fix nitrogen, although it aids 

 fixation by other organisms. In the decomposition products of carbohydrates 

 (humate) in cultures of Azotobacter the author, contrai'y to the observation 

 of Stoklasa, found neither alcohol nor organic acid in determinable amounts. 



Experiments on the inoculation of legumes with nodule bacteria, Geklach 

 and VoGEL (Mitt. Kaiser Wilhelins Inst. Landiv. Broniberg, 1 (1908), Xo. 2, pp. 

 123; abs. in Centbl. Bald, [etc.], 2. Abt., 22 (1909), Xo. l.',-17, pp. J,16- 

 J/IS). — The results of pot experiments with soils from different parts of the 

 provinces of Poseu and West Prussia to determine the extent of distribution 

 of active root tubercle organisms show that in many cases inoculation is 

 needed, particularly on new or peaty soils and where new leguminous crops are 

 introduced. If inoculating material were cheaper general use of it would be 

 advisable. 



A new theory of soil fertility, A. Einecke (ilitt. Dent. Lundio. GcselL, 2.'f 

 (1900), Xo. 21, pp. 3.'i0, S'll). — This is a review of the theory advanced by the 



