Brown, earth soils

Figure 11.5 Fourier transform infrared spectra of three brown earth soils under different land use.

Greene, R. S. B., Rengasamy, P., Ford, G. W., Chartres, C. J. Miller, J. J. (1988). The effect of sodium and calcimn on physical properties and micromorphology of two red-brown earth soils. Journal of Soil Science, 39, 639-648. 

The belt is mainly represented by Temperate Forest ecosystems on forest-steppe soils (Brown Earth). The analyses of selenium content in various links of the biogeochemical food web (rock, water, soils, grains, hair, etc.) has shown that these... 

Soils of class 3 include Lateritic Red Earth in the areas southward from the Nanling Mountain, Red Earth and Yellow Earth between the Nanling Mountain and the Changjiang (Yangtzee) River, Yellow-Brown Earth in the lower reaches of the Changjiang(Yangtzee) River, Subalpine Meadow soil and Alpine Meadow soil on the Plateau of Tibet. 

Figure 11.11 Canonical variate plots showing increases in discrimination among three visually similar topsoils as soil attributes (analyses) are combined. A is a cultivated podzol/improved pasture B is a brown earth/improved pasture and C is a brown earth/seminatural grassland. Four replicate values sampled 4 m apart plus 90% confidence ellipses.

Fig. 1-2. Chromium, copper and nickel contents of genetic soil horizons of a brown earth and a podsol. In the podsol there is a marked depletion of metals in A horizons compared with B horizons whereas differences are less pronounced in brown earths (data from Finch et al., 1964 and Swaine and Mitchell, 1960).

Oades J. M., VassaUo A. M., Waters A. G., and Wilson M. A. (1987) Characterization of organic matter in particle size and density fractions from a red-brown earth by sohd-state carbon-13 NMR. Austral. J. Soil Res. 25(1), 71—82. 

Based on the mineralogy controlling weathering and soil development, sensitivity of ecosystem to acid deposition is assessed with a comprehensive consideration on the effect of temperature, soil texture, land use and precipitation. The results show that the most sensitive area to acid deposition in China is Podzolic soil zone in the Northeast, then followed by Latosol, Dark Brown Forest soil and Black soil zones. The less sensitive area is Ferralsol and Yellow-Brown Earth zone in the Southeast, and the least sensitive areas are mainly referred to as Xerosol zone in the Northwest,... 

Tab. 4.2 Sulfur content (gg g ) of sulfur fractions in the humus layer and mineral soil of a brown earth under a spruce stand in the Tharandt Forest. (After Klinger 1995.)...

CLARKE A.L., GREENLAND D.J. and QUIRK J.P. 1967. Changes in some physical properties of the surface of an impoverished red-brown earth under pasture. Australian Journal of Soil Research, 59-69. 

TISDALL J.M. and OADES J.M. 1980. The effect of crop rotation on aggregation in a red-brown earth. Australian Journal of Soil Research, 1, 423-433. 

Radoslovich, E. W., 1958. Clay mineralogy of some Australian red-brown earths. J. Soil Sci., 9 242. 

The occurrence of clay minerals in the great soil groups has been reviewed (Jackson [1959], Grim [1968], Millot [1970]). The abundance and frequently even the predominance of micaceous minerals in the clay fraction of numerous soil types have been confirmed by these articles. Micas and their degraded forms (illite, hydrous mica, mixed-layer minerals with micaceous components) were found to prevail in the clay fraction of arctic raw soils, brown earth s, prairie soils, chernozems, chestnut soils, syrozem, alkali soils, intrazonal mountain soils, and different azonal soils. Remarkable contents of illite have also been observed in the clay fractions of gray-brown, gray, red, and red-yellow podzolic soils. 

Wiklander, L., and D. AJeksandrovic, 1969. Mineral analysis of Swedish soils. I. Brown earths and podsols. Lantbrukshdgskolans Annaler 35 895-919. 

Avery, B. W., I. Stephen, G. Brown, and D. H. Yaalon, 1959. The origin and development of brown earths on clay-with-flints and combe deposits. /. Soil Sci. 10 177. 

The vast loess and till plains are now colonized by grasses and/or forest. They are the home of some of the best soils of the world the black earths . Deep, black Chernozems occupy the central parts of the Eurasian and North American steppe zones. Brown Kastanozems are typical of the drier parts of the steppe zone and border on arid and semi-arid lands. Dusky red Phaeozems occur in slightly more humid areas such as the American prairies and pampas. 

Boron is the 38th most abundant element on Earth. It makes up about 0.001% of the Earths crust, or 10 parts per mdhon, which is about the same abundance as lead. It is not found as a free element in nature but rather in the mineral borax, which is a compound of hydrated sodium, hydrogen, and water. Borax is found in salty lakes, dry lake-beds, or alkali soils. Other naturally occurring compounds are either red crystalline or less dense, dark-brown or black powder. 

Iodine is widely distributed in nature, found in rocks, soils and underground brines. An important mineral is lautarite, which is anhydrous calcium iodate found in nitrate deposits in Chde. The element also occurs in brown seaweeds, in seawater, and in many natural gas wells. Its concentration in the earth s crust is an estimated 0.5 mg/kg and in seawater 0.06 mg/L. 

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