424 EXPERIMENT STATION RECORD. [VoL 35 



While results with reference to soil productiveness do not in all cases agree, 

 it is considered evident that the injurious action of chlorid solutions on soil 

 productiveness and on crop yield takes place gradually. 



Circulation of manganese in natural waters, V. Vincent (Compt. Rend. 

 Acad. Sci. [Paris'\, 162 {1916), No. 7, pp. 259-261; abs. in Rev. Sci. [Paris], 54 

 {1916), I, No. 5, p. 158). — Experiments with soil water from natural soils and 

 soils treated with mineral fertilizers are reported, the results of which are 

 taken to indicate that manganese is dissolved in the presence of carbon dioxid 

 and that a bicarbonate analogous to calcium bicarbonate is formed which 

 exists only in solution in soil water. The formula for this is given as MnHj- 



( 003)2. 



It was found that natural mineralized soil waters contained more manga- 

 nese than ordinary soil water, which is taken to indicate that the use of 

 mineral fertilizers tends to increase the solubility of manganese in soils. 



A comparative study of the effect of cumarin and vanillin on wheat 

 grown in soil, sand, and water cultures, J. Davidson [Jour. Amer. Soc. 

 Agron., 7 {1915), Nos. 4, pp. 145-158; 5, pp. 221-238). — The results of work 

 by others bearing on the subject are reviewed and analyzed. Pot experiments 

 conducted at Cornell University are reported, the purpose of which was to 

 determine the effect of cumarin and vanillin on wheat in clay loam soil, water, 

 and quartz. 



The soil culture experiments consisted of six series, (1) without additional 

 treatment, (2) with lime, (3) with nitrogen, (4) with phosphoric acid, (5) 

 with potash, and (6) with a complete fertilizer. "The concentrations of 600 

 parts per million of cumarin and of 3,000 parts per million of vanillin, figured 

 on the basis of the total moisture content of the soil, depressed to some extent 

 the yield of wheat grown to maturity in pots. There are indications, how- 

 ever, that the effect was rather on the soil than on the plant. The addition 

 of small quantities of soil to water cultures entirely destroyed the toxic effects 

 of cumarin, while it did not affect the action of vanillin. ... In quartz 

 cultures cumarin proved to be as toxic as in water cultures, while vanillin 

 behaved approximately the same way as in the soil. Vanillin is evidently 

 toxic only in a liquid medium when it is applied in mass, but not when it is 

 distributed as films over quartz grains or soil particles. The ameliorating 

 effect of phosphoric acid on the action of cumarin (E. S. R., 26, p. 224) would 

 not seem to be due to its antagonistic behavior with reference to that toxin, 

 since it did not behave in the same way in a balanced solution. . . . The 

 behavior of toxic substances is so different in the soil than in water cultures, 

 that one is hardly justified in drawing conclusions from results obtained with 

 water cultures as to what might take place under actual field conditions." 



Nitrification, E. R. Allen {Mo. Bui. Ohio St a., 1 {1916), No. 5, pp. 153, 

 154). — Id a brief review of the relations of nitrification in soils to crop pro- 

 duction, it is stated that in studies made on plats of the station there appeared 

 to be a very close relation between crop production and nitrification in sam- 

 ples taken from continuous culture plats. " In those taken from the barn- 

 yard manure series in the three-year rotation consisting of corn, wheat, and 

 clover there was no consistent relation. The results in the one case were 

 just as striking as in the other. This indicates that the factors which limit 

 crop production in the continuous culture plats are not the same as those which 

 exert a controlling influence in the barnyard manure series." 



Recent investigations on the production of plant food in the soil, II, 

 E. J. Russell {./our. Roy. Hort. Soc, 41 {1915), No. 2, pp. 188-199, figs. 5). — 

 This article deals further (E. S. R., 35. p. 322) with the decomposition of plant 

 residues in the soil as influenced by natural changes indicated by the rate of 



