1917] SOILS — FERTILIZEES. 519 



stance of this bulletin has been previously noted from another source (E. S. R., 

 36, p. 423). 



The significance of nitrification as a factor in soil fertility, P. L. Gainey 

 {Soil Sci., 3 (1917), No. 5, pp. 399-Jfl6) .—The author reviews the work of others 

 bearing on the subject and work by himself at the Kansas Experiment Station 

 in an effort to show that productivity in nonproductive soils, in so far as 

 nitrogen is the limiting factor, is not limited by the processes of nitrification. 



Soil constituents which inhibit the action of plant toxins, E. TiiuoG and 

 J. Sykoha {Soil SH., 3 {1917), No. 4, pp. 333-351, pis. 5).— Studies conducted at 

 the Wisconsin Experiment Station on the constituents of soils which inhibit 

 the action of plant toxins are reported. The soils used were acid Plainfield 

 sand and acid Wabash silt loam. 



" The experiments indicate that chemical reactions are probably very im- 

 portant factors in lessening the harmful effects of plant toxins in soils. Calcium 

 carbonate, a very common soil constituent, inhibited to a remarkable degree 

 the toxicity, to wheat seedlings, of copper sulphate and copper nitrate. . , . 

 The toxi ^ effects of the strong base guanidin were markedly inhibited by the 

 presence of either kaolin or an acid clay soil. . . . The results of pot experi- 

 ments with natural soils indicate . . . that vanillin can, at most, be but a 

 very slight factor in soil fertility if the soil has an adequate supply of the 

 fertility elements and is not acid in reaction. Here, again, calcium carbonate 

 seems to inhibit or prevent the harmful effects of the toxic agent. ... It is 

 believed that the data presented show that, in the amelioration of toxicity in 

 soils, chemical reactions probably play fully as important a role as physical 

 phenomena such as adsorption, and possibly the former have the greater effect." 



The extraction and saturation of soils with volatile antiseptics, J. P. du 

 BuissoN {Soil Sci., 3 {1917), No. 4, pp. 353-391, pis. 2).— Experiments con- 

 ducted at Cornell University with Dunkirk clay loam and Volusia silt loam 

 soils to determine the influence of treatment with the volatile antiseptics 

 alcohol, benzene, ether, conuuercial gasoline, and toluene are reported. The 

 treatment in general consisted in extracting and saturating each type of soil 

 with the individual solvents. 



It was found that " the application of volatile antiseptics to the soils used 

 in this investigation gave beneficial results on the crops subsequently grown 

 thereon." A beneficial, residual effect was observed for the second crop after 

 the application of the antiseptics, but this was in all cases less marked than 

 with the first cropping. Both types of soils responded to treatment, but some- 

 what differently. 



The volatile antiseptics had a definite effect upon the ammonification and 

 nitrification of the soil, enhancing the former and inhibiting the latter. There 

 was a tendency to increase the water-soluble salts of the soil. The effect of 

 the anti.septics upon the ammonifying and nitrifying processes of the soils after 

 two crops were grown seemed to disappear. No marked differences were 

 observed as to plant growth and biological activity between the saturation and 

 extraction methods of applying the antiseptics to the soil. In these experiments 

 the physical condition of the soil as indicated by its ammonification and nitri- 

 fication did not seem to be the cause of the influences noted upon plant growth 

 and bacterial action. By the extraction of soil with alcohol, a substance was 

 removed which was toxic in water cultures but not at all toxic when in the 

 soil itself. The development of acids in the soil as a result of some action 

 or change of the alcohol was found to be too slight to account for the marked 

 effects of volatile antiseptics upon plant growth and bacterial action. 



It is finally concluded that " the beneficial influences obtained by treating 

 the soil with volatile antiseptics can not be ascribed to a change in physical 



