Soil Genesis

No corrosion occurs in a completely dry environment. In soil, water is needed for ionisation of the oxidised state at the metal surface. Water is also needed for ionisation of soil electrolytes, thus completing the circuit for flow of a current maintaining corrosive activity. Apart from its participation in the fundamental corrosion process, water markedly influences most of the other factors relating to corrosion in soils. Its role in weathering and soil genesis has already been mentioned. 

Soil genesis is the result of four fundamental types of processes simultaneously operating at any part of the Earth s surface. As a soil develops, matter and energy enter the soil, can be transformed or translocated, and can leave the soil. The nature and magnitude of inputs, outputs, transformations, and translocations can vary widely from one site to another and result in numerous different types of soils. 

Vepraskas MJ, Faulkner SP. Redox chemistry of hydric soils. In Richardson JL, Ve-praskas MJ, editors. Wetland Soils Genesis, Hydrology, Landscapes, and Classification. Boca Raton CRC Press, Taylor Francis Group 2001. pp. 85-105. 

Buol, S. W., Hole, F. D. McCracken, R. J. (1989)- Soil Genesis and Classification, 3rd edn. Ames, IA Iowa State University Press. 

Soil classification has been oriented to soil properties in recent years, but still is tempered with concepts of soil genesis, with external associations, and with the use of the soil. The first systematic classification was by Dokuchaiev in Russia in 1882, Based upon field and laboratory characteristics, soils were grouped into three categories—normal soils of the dry-land vegetative zones and moors, transitional soils of washed or dry land sediments and abnormal soils. The system involved properties of the soil with external associations of climate and vegetation. Later, an associate (Sibirtsev) renamed the highest classes zonal intrazonal, and azonal. 

This phenomenon is of practical importance in metallurgy [ 142], in materials science and crystal growth [143], in phagocytosis [144,145], in soil mechanics, soil genesis, and the behavior of vegetation in permafrost and cold regions 1146], and in the separation of various types of solid particles from one another by particle chromatography [147,148]. 

Torrent J. and Nettleton W. D. (1978) Feedback processes in soil genesis. Geoderma 20, 281—287. 

Boyle J. R. and Voight G. K. (1973) Biological weathering of silicate minerals implications for tree nutrition and soil genesis. Plant Soil 38, 191—201. 

Buol SW, Hole FD, McCracken RJ (1989) Soil Genesis and Classification. Iowa State University Press Ames, Iowa, p 446... 

Culminating a long-term international effort, the Soil Survey staff of the Soil Conservation Service (U S. Department of Agriculture) developed a Comprehensive Soil Classification System (CSCS) for world soils (Soil Survey Staff 1975). The CSCS defines soil classes strictly in terms of soil morphology, rather than based on soil genesis. A brief explanation of the 10 soil orders in the CSCS is given in Table 7.4 (see also Bodek et al. 1988). Their temporal relationships are considered in Fig. 7.6. 

Rodin, L. E., Bazilevich, N. L, Gradusov, B. L, Yarilova, E. A. (1977). Arid Savannaofthe Rajaputana (Tar Desert). In Arid Soils Genesis, Geochemistry and Use. Moscow Nauka Publishers, 196-225. 

Bouma, J. (1983). Hydrology and soil genesis of soils with aquic moisture regimes. In "Pedogenesis and Soil Taxonomy I. Concepts and Interactions" (L. P. Walding, N. E. Smeck, and G. F. Hall, eds.), pp. 253-281. Elsevier, Amsterdam, The Netherlands. 

Jackson, M. L. (1960). Structural role of hydronium in layer silicates during soil genesis. Proc. 7th Int. Cong. Soil Sci., Madison, Wisconsin, pp. 445—455. 

As a final item of food for thought, we would like to mention that one sometimes has the impression that pesticide movement into groundwater is an inevitability, especially if the chemical moves beyond the root zone into the subsoil where microbial activities are much lower and degradation would be lessened. We are reminded of the soil genesis process in that a great deal of soluble organic matter has been leached from the surface soil down into the subsoil over centuries and even millennia of soil development. The question is why have we not seen a massive amount of natural organic matter in... 

Soils can be characterized in many ways, depending, for example, on whether primary concern relates to agronomic applications, engineering utility, or soil genesis. From the standpoint of predicting pesticide transport, a series of physical, chemical, and biological... 

With regard to phosphorus, knowledge of the distribution of the different physico-chemical forms of the element in soils is useful for understanding soil biogeochemistry, soil genesis and soil fertility. The... 

Redox potential (Eh) characterises the oxidation-reduction condition of a soil. This in turn provides a means to assess soil genesis, soil fertility and status of soil contaminants (Liu Yu 1984). Redox potential is well known to be difficult to measure precisely with conventional methods, for reasons ranging from slow electrode response to soil condition, especially for poorly poised (redox capacity) soils (Bohn 1971 Ponnamperuma 1972). Usually measurements are made under specified conditions, with values being dependent on the experimental conditions. As the measured value is conditional, it may not be sufficiently precise for some physicochemical studies. Nevertheless, there is unique information about soil condition that can be derived by measuring the redox potential. 

Lyford, W. H. (1963). Importance of ants to brown podzolic soil genesis in New England. Harvard Forest Paper No. 7. Harvard Univ., Harvard Forest, Petersham, Massachusetts 01366. 

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