SOILS FERTILIZERS. 317 



Maximum productiveness of soils in pots, K. K. Gedroiz {Trudui »sV7.s7.'. 

 KJkiz, Khhn. Lalt. St. I'etcrh., J/ {1905), pp. 102-112; abs. in Zhiir. Opiiita. Aaron.. 

 [Rk.s.s. Jour. Expt. Landio.], 8 (1907), No. 5, p. 583). — Experiments made in 

 vegetation pots with oats and mustard on 13 soils of different character showed 

 that the maximum productiveness of the soils, i. e., the yield when fully pro- 

 vided with nutritive substances, was not alike under like conditions and varied 

 for oats and mustard. 



Need of fertilizing by Russian soils of various localities according to 

 the vegetation method, K. K. Gedroiz {Trudui Selsk. Klioz. KJtii)). Lab. St. 

 Pcterb., .'i {1905), pp. l-6Jt; abs. hi Zliur. Opuitn. Agron. [Russ. Jour. E-rpt. 

 Landic.'], 8 {1901), No. 5, pp. 582, 583). — Results are given of investigation, by 

 the vegetation method, of the need of 22 soils for fertilizers, with chemical 

 analyses of the soils. From indirect indications obtained in these investigations 

 and from theoretical considerations the author concludes that this method is 

 altogether inapplicable to the determination of the need of soils for nitrogenous 

 fertilizers and that its suitability in the case of other fertlizers is more than 

 doubtful. 



Available phosphoric acid in chernozem soils, A. S. Kudashev {Zhur. 

 Opuitn. Agron. [Russ. Jmir. Expt. Landic], 8 {1901), No. 5, pp. 481-510, fig. 1; 

 abs. in Zentbl. Agr. Chem., 31 {1908), No. 8, pp. 505-501).— The object of this 

 investigation was to find out whether extraction with oxalic acid is suitable for 

 the determination of the phosphoric acid available to plants. The investigations 

 included (1) vegetation experiments with oats, using all fertilizers except phos- 

 phoric acid, and (2) treating the soils with 0.5 per cent solution of oxalic acid 

 and estimating the phosphoric acid in the exti'act. 



Experiments were made with 49 soils from the various governments of the 

 chernozem region of European Russia. Tlie extraction was made by treating 

 200 gm. of soil during 3 hours with SOO cc. of 0.5 per cent solution of oxalic acid, 

 shaking repeatedly, and then allowing to settle for 1 hour after the addition 

 of 4 gm. of potassium chlorid. 



Although the experiments, as the author states, were not carried out under 

 favorable conditions, they seem to strongly indicate (1) that in soils of the 

 same type the yields of oats, wlien phosphoric acid is in the minimum, incx'ease 

 nearly proportionately to the quantity of phosphoric acid extracted by 0.5 per 

 cent solution of oxalic acid, and consequently this phosphoric acid is approxi- 

 mately proportional to the phosphoric acid assimilated by oats, and (2) that in 

 soils of different types, e. g., in the eastern soils (richer in clay and humus) and 

 the western soils (more sandy) of the chernozem region the phosphoric acid 

 extracted by a 0.5 per cent solution of oxalic acid multiplied by the loss on 

 ignition (which is approximately proportional to the amount of clay, humus, and 

 carbon dioxid in a soil) is approximately equal or proportional to the phosphoric 

 acid assimilated from the soil. 



Washing of soils and methods of prevention, J. G. Mosier {Illinois Sta. 

 Circ. 119, pp. 16, fig. 1). — This circular briefly discusses the relation of rain- 

 fall and run-off to surface washing, and explains that the washing produced by 

 the run-off is of two kinds, slieet washing or general surface washing and 

 gullying. Four methods of preventing sheet washing are explained, namely, 

 the growing of cover crops, increasing the organic matter in the soil, tillage, and 

 terracing and hillside ditching. Various methods of preventing and checking 

 gullying are also described. 



The Bremen moor culture station, B. Tacke {Illus. Landtv. Ztg., 28 {1908), 

 No. I'l, pp. 112-115, figs. 1). — This article describes the methods employed and 

 reviews the progress made by the Bremen moor station in reclaiming moor 

 lands. 



