1919J SOILS — FERTILIZERS. 623 



resistance to alkali salts, the usual order of resistance being barley, oats, wheat, 

 alfalfa, sugar beets, corn, and Canada field peas. Results from solution cul- 

 tures and from soil tests did not agree in all cases. The period of germination 

 of seeds was considerably lengthened by the presence of soluble salts In the soil. 



The acid and not the basic radical apparently determines the toxicity of 

 alkali salts in the soil, chlorid being the most toxic of the acid, and sodium 

 the most toxic of the basic radicals. The injurious action of alkali salts was 

 not always proportional to the osmotic pressure of the salts. The antagonistic 

 effect of combined salts was not so great in soils as in solution cultures. Tox- 

 icity of alkali salts was influenced by the percentage of soil moisture. Salts 

 added to the soil in solution had a greater effect than those added in the dry 

 state. 



On nitrification: II, Intensive nitrite formation in solution, A. Bonazzi 

 {Jour. Bad., 4 (1919), No. 1, pp. 43-60, pi. 1, figs. 2).— This is the second of a 

 series of articles on nitrification in soils contributed from the Ohio Experiment 

 Station (E. S. R., 33, p. 421). 



It was found that the ordinary Omelianski solution for the growth of the 

 nitrite former will support a very abundant growth of this organism as meas- 

 ured by the production of nitrous acid. The conditions under which this 

 luxuriant growth was produced were (1) shallow layers of the solution in- 

 clined at an angle of 5°, (2) slow rotary movement of the culture, and (3) a 

 temperature of 25 to 30° C. The growths reported are considerably in excess of 

 any yet reported for equal periods of time in solution cultures. " It would seem 

 that better aeration may not be the only factor contributing to intensive nitrifi- 

 cation, but that change of local environment is in some way associated with it." 



Nitrate production in soil as affected by the crop and cultivation, W. A. 

 Albrecht (Missouri Sta. Bui. 163 (1919), pp. 61, 68). — In studies of the In- 

 fluence of crops and cultivation on nitrate production in soils, it was found 

 during the first year that " the most significant influence of the crops is that of 

 removing the nitrates. A reduction of nitrates takes place when the crop 

 makes its rapid growth. For corn, nitrates accumulated until late In June but 

 decreased very df^cidedly thereafter. For the grasses, including oats and tim- 

 othy sod, no significant accumulation ever occurred, although there was slight 

 increase after the crops were harvested. 



" Cultivation failed to have any significant favorable effect. The greatest 

 accumulation was obtained in the plat which was plowed in the spring and 

 scraped to remove the weeds. The next highest accumulation resulted where 

 the soil was left entirely undisturbed save that the weeds were pulled by hand. 

 No appreciable difference was given by plowing 4 in. deep as compared to 

 plowing 8 in. deep. Plats left uncultivated were higher in nitrates than those 

 cultivated regularly during the year. 



" The straw mulch had a decidedly depressing effect on nitrate accumulation. 

 No significant accumulations occurred. Apparently the high moisture was re- 

 sponsible, since the curve of moisture percentage bears a negative correlation 

 to that of nitrate accumulation." 



A possible case of partial sterilization in soil, P. Knowles (Nature [Lon- 

 don], 103 (1919), No. 2585, p. 205; abs. in Chem. Abs., 13 (1919), No. 15, p. 

 1736). — A very favorable growth was observed In crops of potatoes, dwarf 

 peas, and dwarf beans grown on a garden soil that had been Idle for at least 

 three years and that had received by chance a light top-dressing of a mixture 

 of charcoal and brick earth impregnated with potassium carbonate and hexa- 

 methylenetetramln. It is suggested that the unusually good growth of the crops 

 149863°— 20 3 



