RUSSIAN SOIL INVESTIGATIONS. 815 



If the second horizon is near to the surface or the whole soil is 

 transformed into podzol the land is, of course, very poor. In sandy 

 soils the second horizon contains much less of the alkalis, lime, mag- 

 nesia, iron oxid, alumina, and phosphoric acid than is found in clayey 

 soils of this class. 



The relation of sand to tine earth in podzol soils varies from 5:1 to 

 7:1. The capacity for water is only from one-half to two-thirds that 

 of chernozem, while its permeability is 2 to 6 times as great. On the 

 better class of podzol soils, when well provided with moisture, the 

 crops, although not large, are more uniform and constant than on 

 the chernozem, especially if well fertilized. In the true silty podzol, 

 however, there is frequently more than TO per cent of tine earth in 

 the form of quartz dust. It absorbs moisture with avidity and retains 

 it for a long time, turning into a sticky dough-like mass. On drying 

 it breaks up into dust or hardens and forms crusts. This is one of 

 the worst and most unproductive soils, both on account of its poverty 

 in fertilizing constituents and of its unfavorable physical properties. 



Soils of the podzol type are found in Siberia, northern Germany, 

 France (the landes), Holland, Denmark, and Scandinavia, and North 

 America (mainh^ in the British possessions). 



Tundra xoils. — The soils of the arctic tundra of pAiropean Russia 

 and Siberia may be classified as rocky, turfy, clayey, and sandy. The 

 level surface and the treeless condition of the tundra of the basins of 

 the Petchora, Obi, and Yenisei Rivers impart to it a steppe-like appear- 

 ance. The vegetation consists of lichens, mosses. Arctostaphylos, 

 Andromeda, Empetrum, Eahun cliaiitmmm'us, Vaccinium, Carex, etc. 

 Betuhi nana and the polar dwarf willows appear as almost the only 

 representatives of bushes. The humus is crude and accumulates only 

 in the surface horizon of the clayey or sandy soil, to a depth of 3 to ,5 

 cm.; ever^^where can be seen denuded places, surrounded by mosses or 

 lichens. The temperature fluctuations are striking. The summer is 

 very short; even in July the temperature falls at night to + 3-' C, and 

 at the end of the month even to —2°; in August it snows, and soon the 

 long winter, with its icy winds, begins. The perpetuall}^ frozen layer 

 l)egiTis in the clayey tundra at a depth of 0.7 to 1 meter and in the 

 sandy at a depth of about 1^ meters. The turfy tundras are charac- 

 teristic mounds of turf, frozen inside, which are 15 to 20 meters in 

 length and \ metei-s in height. The forest penetrates into the tundra 

 from the south, along the river banks, where the perpetually frozen 

 horizon is deeper than in other places. 



INTRAZOXAL SOILS. 



Alkali -soils. — Alkali lands are found in the southern part of Euro- 

 pean Russia, in southwestern Siberia, in the Transcaspian region, and 

 in Turkestan. In the territor}^ of the chernozem they occur in spots, 



