516 EXPEEIMENT STATION RECORD. 



the drainage waters and polder soils surrounding Westerkogge, Netherlands, 

 with a view of ascertaining whether sufficient quantities were present to injure 

 vegetation. The salt content in the drainage water varied from 0.1 to 10.82 gm. 

 per liter, that in the surface soil from 0.005 to 0.051 per cent, and that in the 

 subsoil from 0.005 to 0.140 per cent. It is not believed that these quantities 

 were injurious to the vegetation. 



The influence on soil temperature of additions of sand to moor soils, H. 

 VON Feilitzen (Intenutt. Mitt. Bodenk., 2 (1912), No. 1, pp. 45-52, figs. 2) .— 

 Tests of the influence on the temperature of moor soils of a sand layer of 1,500 

 cubic meters per hectare (about 794 cu. yds. per acre), as compared with 

 mixing sand with the soil at the rate of 500 cubic meters per hectare, are re- 

 ported. The results show that the temperature was increased much more 

 markedly by the layer of sand than by mixing. Mixing the sand with the soil 

 increased the temperature early in spring, but thereafter had no effect. 



Soil bacteriolog'y in agriculture, C. B. Lipman (Cal. Cult., 38 {1912), No. 26, 

 pp. 771-773, 770). — This article summarizes concisely and indicates the practi- 

 cal bearing of what investigation has shown to be the relations of bacterial 

 activity in the soil to aeration, water, temperature, humus, manures and fer- 

 tilizers, sulphur and iron, carbon dioxid, soil inoculation, and sterilization. 



Relation of soil bacteria to evaporation, C. Hoffmann (Wisconsin Sta. 

 Resca)-cli Btil. 23, pp. 183-215, fig. i).— Preliminary investigations having shown 

 that Stigell's method of studying the relation of bacterial activity to evapora- 

 tion in the soil (E. S. R., 20, p. 620) gave contradictory results, the author 

 adopted the following method of procedure : 



Five hundred or GOO gm. of air-dried soil, passed through a 12-mesh sieve, 

 was placed in circular dishes either 19.1 or 21 cm. in diameter, making, when 

 uniformly packed and leveled, a soil layer 2.8 cm. deep in the larger dishes and 

 3.2 cm. in the smaller dishes. "To each of the plates were then added by 

 means of a 50 cc. pipette, 150 to 300 cc. of distilled water depending upon the 

 nature and amount of soil employed, the water being applied either pure or 

 modified as indicated under the individual experiments. It was planned to 

 have approximately 30 per cent of moisture present initially in all experiments, 

 thus affording ample moisture for vigorous bacterial multiplication. ... In 

 all cases the total initial weight was recorded and subsequent weighings were 

 then made at more or less frequent intervals to determine the rate of evapora- 

 tion. . . . The results of the individual dishes of each set were then added and 

 the average taken to indicate the loss due to evaporation occurring from period 

 to period." 



A study was made by this method of the evaporation from untreated soil and 

 from that sterilized with mercuric chlorid. Although the results were variable 

 with individual plates, they were uniformly and considerably higher in the 

 inoculated plates than in the sterile plates. 



" One finds the maximum interval variation between sterile and normal sets 

 in the greenhouse and the field clay soils, and the least variation with the 

 sandy soil. On total variations the greenhouse soil exceeds all others, showing 

 as a maximum 19.02 gm. difference in favor of the inoculated set. It is inter- 

 esting to note that in all cases the rate of evaporation was more rapid in the 

 inoculated set than in the sterile set." 



A study of the relation of bacterial multiplication to evaporation apparently 

 indicated that the bacterial activities were responsible for the increased rate of 

 evaporation in the normal or inoculated series. Remoistening the partly dried 

 plates increased the rate of evaporation in the inoculated soils over that ini- 

 tially observed. The addition of 1 per cent blood meal increased evaporation 

 from inoculated soil over sterile soil, but addition of 1 per cent barnyard manure 

 decreased the difference. 



