430 SOIL SCIENCE [Bot. Absts. 



INFLUENCE OF BIOLOGICAL AGENTS 



2930. Ames, J. W., and G. E. Boltz. Effect of sulfofication and nitrification on potas- 

 sium and other soil constituents. Soil Sci. 7: 183-195. 1919. — The nitrification of dried 

 blood and oxidation of sulfur in the soil increased the water soluble potash, calcium, alumi- 

 num and manganese. Magnesium was less easily attacked than calcium. Ammonium sul- 

 fate had a solvent effect on calcium and potash. — William J. Robbins. 



2931. Anonymous. [Rev. of: Gainey, P. L. Effect of paraffin on the accumulation of 

 ammonia and nitrates in the soil. Jour. Agric. Res. 10:355-364. 1918.] Jour. Ecol., 7:97. 

 1919. 



2932. Anonymous. [Rev. of: Hills, T. L. Influence of nitrates on nitrogen-assimilat- 

 ing bacteria. Jour. Agric. Res. 12:183-230. 1918.] Jour. Ecol. 7:96. 1919. 



2933. Anonymous. [Rev. of: Millar, C. E. Relation between biological activities in 

 the presence of various salts and the concentration of the soil solution in different classes of 

 soil. Jour. Agric. Res. 13:213-223. 1918.] Jour. Ecol. 7:94. 1919.— The author reports 

 the data obtained from experiments conducted to show the effect of various salts upon the 

 bacterial flora of soils. They tend to prove that the effect of the salts was much modified 

 by the nature of the soils to which they were added. It seemed improbable that the osmotic 

 pressure of the soil solution was the governing factor in determining the nature or abundance 

 of the soil flora. — Geo. D. Fuller. 



2934. Fellers, C. R. Longevity of B. radicicola on legume seeds. Soil Sci. 7:217-232. 

 1919. — Dry sterile soy bean and alfalfa seeds were inoculated with B. radicicola in nodule 

 infusions, in soil or commercial cultures. After varying periods of storage in dry condition 

 the number of B. radicicola per seed was determined by plating methods and nodule formation 

 was determined in soil cultures in the green house. Soy bean or alfalfa seed inoculated with 

 a nodule infusion retain viable organisms on the seed coats for 6-9 months. Infected soil or 

 commercial cultures gave as good results as the nodule infusion. Five minutes contact with 

 the inoculant gave as good results as longer periods of contact. It is not recommended that 

 inoculated seeds be stored for long periods before planting but a delay of several days or 

 even a month should do no great harm. — William J. Robbins. 



2935. Gainey, P. L. Parallel formation of carbon-dioxide, ammonia and nitrate in soil. 

 Soil Sci. 7:293-311. 1919.— The carbon-dioxide, ammonia and nitrates were determined in 

 soils in cylinders through which a current of air was drawn. The carbon-dioxide and ammo- 

 nia production under conditions favorable for bacterial activity when cottonseed meal was 

 added to the soil reached a maximum in the second 24 hours. In the case of dried blood the 

 maximum is reached between the 6th and 8th days. Insufficient moisture retards both car- 

 bon-dioxide and ammonia production, the latter more markedly. Insufficient aeration re- 

 tards the carbon-dioxide and ammonia production. Accumulation of nitrate was directly 

 proportional to moisture content. Insufficient aeration retarded the initial accumulation of 

 nitrate but after nitrification became active the accumulation was inversely proportional to 

 aeration. — William J. Robbins. 



2936. Haas, A. R. C., and E. B. Fred. Effect of soybean germination upon the growth of 

 its nodule-forming bacteria. Soil Sci. 7: 237-245. 1 pi. , 2 fig. 1919.— When mercuric chlo- 

 ride is used to sterilize soybeans sufficient mercuric chloride is retained by the seed to retard 

 the development of its nodule bacteria in agar plates in the vicinity of the seed. Germina- 

 tion of bacteria-free soybeans secured directly from the pods excrete no substance toxic to 

 the growth of the nodule bacteria but favor this growth. Nineteen varieties of soybeans 

 tested showed no difference in susceptibility to inoculation. — William J. Robbins. 



