Sierozem soils

Class 5 (the least sensitive) soil include Kashtanozem, Brown soil and Sierozem soil zones in the Plateau of Inner Mongolia and the Loess Plateau, Desert soil zones in He-xi-zou-lang and the Talimu River Basin, Subalpine Steppe soil, Alpine Steppe soil and Alpine Desert soil in the Plateau of Tibet. These kinds of soils, belonging to the soil class of Xerosol or Alpine soil, consist of easy weathering minerals such as carbonate. They show alkaline reactions, with weak leaching and sparse vegetation. Those kinds of soils are insensitive to acid deposition. 

Hydrolysis of parathion in a loessial semiarid soil was investigated by Nelson et al. (1982). They found that Arthrohacter sp. hydrolyzed parathion rapidly in sterilized, parathion-treated soil under aerobic conditions (20% w/w water content). This bacterium was isolated from a silty loam, sierozem soil of loessial semiarid origin (Gilat). It uses parathion or its hydrolysis product, p-nitrophenol, as the sole carbon source. However, when parathion hydrolysis causes the amount of p-nitrophenol to reach a concentration greater than 1 mM or if the concentration is greater than 1 mM in the case of a single application of p-nitrophenol, the hydrolysis product becomes noxious to the bacteria and their growth is inhibited. 

Habitat The chul and adyr zones. Found in combination with ephemeroid vegetation in shallow, loamy, sierozem soil, rocky-clay loams, and hght-clay loams. 

ScHMEHL and Jackson [1955] give examples of broadened basal reflections from soil clays due to complex interstratification. They examined two clays—one derived from a sierozem soil on shale alluvium (Billings clay), the other from a chestnut soil on reddish loess in southwest Colorado (Monticello soil). These clays (Figure 28) are characterized by broad peaks and strong scattering at low angles. This type of pattern is particularly marked with Mg " saturation and is reduced in extent as a result of K saturation, presumably due to reduction in interlamellar hydration. 

Chernozemic and Sierozemic Medium to heavy textured soils of low rainfall area 88 7.20 T = 4.12 -1- 0.82xi -1- 5.12x2... 

Miscellaneous acid soils Selected from the same climatic zone as the Chernozemic and Sierozemic group 65 5.58 Y= 5.13 -H 0.23x, 2.27x2... 

The adyr zone (lowlands and foothills) The adyr zone is abroad belt at an elevation of around 500-1,500 tn (1,640-4,921 ft). This band is found around all the mountains of Central Asia. It occupies the range between two contrasting ecological zones the xerothermic chul (desert) and the meso-thermic tau (mountain region). The soils of the adyr zone contain less salt and more humus than the chul soils and are classified as sierozem (Makhmudov 2001). Bedrock is often found exposed on the surface. 

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