54 



OBSERVATIONS OF TEMPERATURE OF MANURED SOILS IN JAPAN 

 BY GEORGESON. 



Soil temperature must to some extent be aifected by the heat given 

 out by decaying manure and vegetation. On tliis subject Mr. C. C. 

 Georgeson describes some experiments being made at Tokyo, Japan 

 (Agr. Sci., Vol. I, p. 251), from which it appears that the tempera- 

 ture immediately after applying the manure was from 2° to 5° F. 

 higher than in the unmanured soil, and this excess steadily dimin- 

 ished, but was still appreciable at the end of two months. The 2° 

 of excess occurred when the manure was applied at the rate of 10 

 tons per acre, and the 5° of excess when applied at a rate of 80 tons 

 per acre. 



INFLUENCE OF RAIN ON TEMPERATURE OF THE SOIL AT 

 MUNICH. (K. SINGER.) 



The study of the earth temperatures at considerable depths is a prob- 

 lem for terrestrial physics, but for agricultural purposes we need only 

 consider the temperature of the soil within 4 or at most 8 feet. The 

 work of Karl Singer (1890) is sufficiently instructive to justify the 

 presentation of his general results for use in studying the phienolo- 

 gical phenomena of Europe. In a simple diagram Singer sum- 

 marized at a glance the mean temperature of the soil at any depth 

 between 1 and 7 meters for any day of the year, as it results from an 

 average of thirty years of observations at the observatory at Bogen- 

 hausen, near Munich, Bavaria. The series of observations includes, 

 in fact, four sets of earth thermometers, two of which were on the 

 northwest side of the observatory and the other two on the south- 

 east side; the diagram and the following summary of results relate 

 to the average of the pair on the southeast side. Each set of ther- 

 mometers consisted of five, whose bulbs were buried at depths of 4, 8, 

 12, 16, and 20 Bavarian feet, respectively, or 1.2, 2.4, 3.6, 4.8, and 5.9 

 meters, respectively. The lines given in this diagram are thermal 

 isopleths, viz, curves of equal temperature for successive depths and 

 days, the days being represented by vertical lines and the depths by 

 the horizontal lines. The following paragraphs express the general 

 results of Singer's work as far as it bears upon the growth of plants: 



