SOILS FERTILIZERS. 1019 



The nitrog'en cycle and soil org-anisms, S. F. Ashby (West Indinn BuL, S 

 (1907). y<>. 1. 1)1). 94-1(12; Hmniii. I'ltnitcrs' 31o., 26 (1901), No. 12, pi). .'/7S- 

 4S6). — This is a sumniary of present linowledj^e on nitrogen fixation, breaking 

 down of nitrosrenoiis matter, nitrification, and denitrification. 



Experiments with Nitragin, C. Macias (Com. Par. Agr. [Mexico], Circ. 67, 

 1)1). .'i, [jIs. 5). — This is a brief report of successful experiments on alfalfa with 

 a pure culture prepared and distributed by the Commission of Agricultural 

 Parasitology of Mexico. 



The power of sodium nitrate and calcium carbonate to decrease toxicity in 

 conjunction with plants growing in solution cultures, O. Schreinek and H. 

 S. Keed (Joid: A)nn\ Chcin. Soc, 30 (1908), Xo. 1, pp. 85-97, pi. i).— This 

 paper reports the results of a study of the action of living plants upon solutions 

 of toxic organic compounds (vanillin, cumarin, arbutin, etc.) with and without 

 the addition of sodium nitrate, calcium carbonate, and other substances. (See 

 also E. S. R., 1!), p. S22.) 



The authors conclude from the results obtained in water cultures with wheat 

 plantlets that "the activities of the plant roots are able to decrease the toxicity 

 of organic compounds to a certain extent, provided the original concentration 

 of the solution is below that able to cause death of the plants. It is probable 

 that the oxidizing power of the root plays a greater or less part in the process 

 of amelioration. The first set of plants may have absorbed directly some of 

 the toxic material from the solutions, but the greatly diminished toxicity of the 

 solutions as well as the formation of dyestuffs indicated that other changes had 

 taken place. 



" The addition of certain inorganic salts to solutions of toxic organic com- 

 pounds was distinctly beneficial to plant growth. That the inorganic salts and 

 the physiological activities of the plant working together had accomplished the 

 destruction of toxic substances was shown by both plant growth and chemical 

 tests." 



Experiments with fertilizers, J. H. Stewart and H. Atwood (West Tu- 

 ginia Sta. Bill. 112, pp. 55-86, pis. 9). — This bulletin summarizes experiments on 

 the station farm during the past 8 years. The results of the first 6 years' 

 experioieats have also been summarized in a previous bulletin (E. S. It., IS, 

 p. 20). 



The results show in general that the soil upon which the experiments are 

 being made " is very deficient in available phosphoric acid, and that as soon 

 as this deficiency is supplied then there is a lack of nitrogen and to a less ex- 

 tent of potash also." 



" If leguminous crops are raised and either plowed under or fed on the farm 

 and the resulting manure carefully saved and applied to the soil it is very 

 probable that in practice it will be nec-essary to i)urchase only phosphoric acid 

 in order to increase the productiveness of soils of this type and to uiaintain 

 them in a condition of high fertility. 



" Stable manure has demonstrated again its great value as a restorer of fer- 

 tility to a poor worn out soil." 



Demonstration experiments with fertilizers during the year 1906 in the 

 Province of Goritz-Gradiska, A. Devakua (Ztschr. Luiidw. Yersuchsic. Ostcn:, 

 10 (1907), Xo. 10, pp. 725-7.',9; ahs. in Chem. Zcntl)1., 1907, II, No. 23, p. 1865).— 

 The experiments of which these were a continuation were begun in 1000. From 

 the 204 cooperators who uncU'rtook the experiments only SS complete reports 

 were obtained. "> for experiments on grass lands and 13 fen* experiments on 

 clover soils. The principal constituents of the fertilizers used were 40 per cent 



