SOILS FEETILIZERti. 521 



Temperature of the soil, C. Flammarion iBul. Mens. Off. Rcnseig. Agr. 

 [Paris], 8 {1909), No. 8, pp. 1106-1117, flys. 3).— The results of several years' 

 observatious on the temperature of the soil at various depths down to 1 meter 

 as compared with the temperature of the air are reported. The data are 

 analyzed by Fourier's method and illustrated graphically. 



It is shown that the diurnal variation of temperature decreases with the 

 depth in the soil and with the season of the year. The temperature changes 

 in the soil lag behind those of the air and this lag increases with the depth. 

 For example, the maximum temperature of the air occurred on the average at 

 about 2 o'clock p. m., of the surface soil at 1 o'clock, of the soil at a depth of 

 0.0.5 meter at 2.30, at 0.1 meter at 3.15, and at 0.2.5 meter at 6 o'clock p. m. 

 The minimum temperature of the air and of tlie surface soil occurred a little 

 before sunrise, at 0.05 meter a little after sunrise, at 0.1 meter 1 hour after 

 sunrise, at 0.25 meter 4 hours after sunri.se. In winter all layers of the soil 

 were warmer than the air. The surface soil was warmer than the air during 

 the period from May to November, the greatest difference in this respect 

 occurring in July. The temperature of the surface soil declined toward the 

 end of September to a point below that of the soil at a depth of 1 meter, in 

 October below that at 0.5 meter, and in November below that at 0.25 meter. 



The diagrams given show certain regular annual variations in the tempera- 

 ture of the soil during a series of years, following that of the air regardless of 

 casual disturbing conditions. In December, Januai-y, and February there was 

 a series of increasing temperatures with the depth in the soil ; in May, June, 

 and July a series of decreasing temperatures. The first inversion of tempera- 

 ture occurred in March to April, when the temperature of the soil was greatest 

 at the surface and decreased to a depth of 1.5 meters, and the second in autumn, 

 when the temperature of the surface layers was lowest and increased to a depth 

 of 1.5 meters. The general character of the diurnal variation was the same 

 in bare and sodded soil, but the upper layer of the sodded soil was warmer in 

 winter and colder in summer than that of the lower layers. 



Soil temperatures in upland moors and the soil air of different types of 

 moors, P. Vageler {Mitt. K. Bayr. Moorktdturanst., 1901, No. 1, pp. 1-51, pi. 

 1, figs. 3). — This article describes the methods employed and reports the results 

 of a large number of observations on moors of different kinds. The general 

 conclusion reached was that temperature and air conditions as well as the de- 

 composition processes in moor soils are interdependent and are modified by the 

 moor vegetation. On the other hand, the vegetation is modified in composition 

 by the physical and chemical conditions in the soil, so that there results a suc- 

 cession of plants, ending in the formation of the moor soils when the climatic 

 conditions are favorable. 



A classified bibliography of the literature of the subject is given. 



The relation between vegetation, chemical composition, and fertilizer 

 requirements of moors, E. Gully {Mitt. K. Bayr. Moorkulturanst., 1909, No. 

 3. pp. 1-38). — The results of detailed studies of the vegetation and chemical 

 composition of South Bavarian moors of different types are reported, and an 

 attempt is made to trace the relationship between the vegetation and chemical 

 composition. 



Contribution to the niti'ogen assimilation of forests, G. Zemplen and G. 

 Roth {Erdeszeti Kiserletek, 10 {1908), No. 1-2, pp. 1-6.1). — Microscopic exami- 

 nations of a number of different kinds of forest trees by the methods described 

 by Jamieson showed the existence in all cases of the hair-like organs to which 

 Jamieson has ascribed the power of fixing free nitrogen. The authors believe 

 that this furnishes an explanation of the fact that the amount of nitrogen is 



