1919] SOILS — FERTILIZE] 417 



Activity and the climate of the Far East i iiius. i, by K. Beklguchl (Aba.) 



ie p. 410); Cumulus ClOUdS of Hawaii (iiius. i, by A. M. Hamrick ; and 



Some New Facts About the Centers of Typhoons (illus), bj Co-Chlng Chu. 

 \</. tO. Halo Phenomena Observed during October, 1918, by Vf. EL Gn 

 Forecast Service for Aviators Begins; a B£ucb Needed Change of Emphasis in 

 Meteorological Research, by w. S. Franklin (see p. U6) ; Dynamic Heating of 



Air as a Cause of Hot Volcanic Blasts (illus.), by G. N. Cole; Sm an 



Indicator of Gustiness and Convection (illus.), by P. \v. Etkes ami 0. F. 



Brooks; The Structure of Gusts, by C. C. Turner (Abs.) ; A Virginia Tornado 

 (illus.), by A. w. Giles; Abnormal Change of Air Temperature at Tokyo uud 

 Sinagawa, by K. Slgetoml (Abs.) ; and Major Controls of the Climates of the 

 United Stales, by K. I >eC. Ward. 



Meteorological records for the year ending November 30, 1917, E. Bukke 

 {Montana Sta. lipt. 1917, pp. iib3-dGG). — Observations at Bozeman, Mont., on 

 temperature, precipitation, frosts, and cloudiness are summarized and the 

 general character of the weather of the year is described. The Iii^li.-st tem- 

 perature recorded in 1'JIT was 93° F., July 8, '12, and "JO; lowest, — 25°, Jan- 

 uary '1- and 31; mean, 40.87°; total rainfall, 15.0S in.; days with 0.01 in. or 

 more precipitation, 90; last killing frost in spring, June 3; first killing frost 

 in fall, October 17; and number of clear days in year, 140. The weather was 

 the coldest of which there is any record, ami was characterized by unusually 

 heavj snowfall and the absence of chinook winds. The precipitation for the 

 growing season was below normal, and the hot months of July and August, 

 combined with a low precipitation, made the season extremely unfavorable for 

 the growing of dry-land crops. 



SOILS— FERTILIZERS. 



Relation of inorganic soil colloids to plowsole in citrus groves in southern 

 California, C. A. JENSEN (Jour. Ayr. Research [l . s.\. 15 (WIS), No. V. pp. 

 505-519). — The plowsole, which was the subject of the investigations reported 

 in this article, a contribution from the Bureau of Plant Industry of the V. S. 

 Department of Agriculture, is the hard soil layer which usually forms imme- 

 diately under the soil mulch in cultivated citrus groves in southern California. 

 " It often seriously Limits the root system of the shallow-rooted citrus trees, 

 and seriously interferes with penetration of Irrigation water. After being 

 broken up with a subsoiler, it re-forms when cultivation is resumed. . . . 

 Mechanical packing is not necessary for its formation. . . . 



"No greater accumulation of water-soluble iron, calcium, magnesium, or 

 silica was found in the plowsole than in the soil mulch or subsoil. No greater 

 accumulation of total ammonia-soluble silica, iron, aluminum, or phosphoric 

 acid was found in the plowsole than in the soil mulch or subsoil, after the 

 calcium had been removed with hydrochloric acid. The humus extract . . . 

 contained more colloidal silica, iron, and aluminum than either the soil mulch 

 or subsoil, but no more colloidal phosphoric acid. Both the organic and in- 

 organic colloidal material in the humus extract moved toward the positive 

 pole in an electric current. . . . 



" Plowsole contained a markedly higher percentage of inorganic colloid sus- 

 pension than the soil mulch, and usually a higher percentage than the sub- 

 soil. When soils were placed in pots in the laboratory. Irrigated, and allowed 

 to dry, the percentage of colloid suspension was found to be appreciably greater 

 in the surface soil layer than in the subsurface layer, indicating that the 

 colloids moved with the capillary soil moisture. No relation could i>c observed 



