Soils, nature

Table 6 shows the result of predicted environmental concentration in air, soil (natural, agricultural, and industrial), freshwater, and sediment for regional scale (Guiyu region). 

Singh B.R., Almas A., Jeng A.S., Narwal R.P. Crop uptake and extractability of cadmium in soils naturally high in metals at different pH levels. Commun Soil Sci Plant Anal 1996 26 2123-2142. 

Bird MI, Chivas AR, Head J (1996) A latitudinal gradient in carbon turnover times in forest soils. Nature 381 143-146... 

A more recent study of the effect of drying on various species of phosphate in soil showed that drying had little effect on some species while having a pronounced effect on others [13]. In nature, soil is never heated to the temperatures used in oven drying, and thus the results of analysis of oven-dried soils are not considered representative of the soils natural conditions. 

Patrick WH, Ir. 1966. Apparatus for controlling the oxidation-reduction potential of waterlogged soil. Nature 212 1278-1279. 

Pearsall WH, Mortimer CH. 1939. Oxidation-reduction potentials in waterlogged soils, natural waters and muds. Journal of Ecology 27 483-501. 

Jones JG, Knight M, Byrom JA. 1970. Effect of gross pollution by kerosine hydrocarbons on the microflora of a moorland soil. Nature 227(263) 1166. 

Phenolic compounds have also been oxidatively polymerized to humic substances by clay minerals (29) and by the mineral fraction of a latasol (66). After a 10-day equilibration period, montmoril-lonite and illite clay minerals yielded 44 to 47% of the total added phenolic acids as humic substances whereas quartz gave only 9%. Samples of a latasol yielded over 63% of the total amount, from mixtures in varied proportion, of mono-, di- and trihydroxy phenolic compounds as humic substances (66). Extractions of the reaction products yielded humic, fulvic, and humin fractions that resembled soil natural fractions in color, in acid-base solubility, and in infrared absorption spectra. Wang and co-workers (67) further showed that the catalytic polymerization of catechol to humic substances was, enhanced by the presence of A1 oxide and increased with pH in the 5.0 to 7.0 range. Thus the normally very reactive products of Itgnin degradation can be linked into very stable humic acid polymers which will maintain a pool of potentially reactive phytotoxins in the soil. 

Maher, B.A. Taylor, R.M. (1988) Formation of ultrafme-grained magnetite in soils. Nature 336 368-370... 

Schwertmann, U. (1964) DifFerenzierung der Eisenoxide des Boden durch Extraktion mit Ammoniumoxalat-Ldsung. Z. Pflanzener-nahr. Diing. Bodenk. 105 194-202 Schwertmann, U. (1966) Inhibitory effect of soil organic matter on the crystallization of amorphous ferric hydroxide. Nature 212 645-646 Schwertmann, U. (1971) Transformation of hematite to goethite in soils. Nature 232 624-625... 

M. E. Hines, and R. C. Harriss, Rapid Degradation of Atmospheric Methyl Bromide in Soils, Nature, 377, 717-719 (1995). 

Tegen, I., A. A. Lacis, and I. Fung, The Influence on Climate Forcing of Mineral Aerosols from Disturbed Soils, Nature, 380, 419-422(1996). 

Alvarez et al. [73] compared the performance of LDA and ANNs to classify different classes of wines. Metal concentrations (Ca, Mg, Sr, Ba, K, Na, P, Fe, Al, Mn, Cu and Zn) were selected as chemical descriptors for discrimination because of their correlation with soil nature, geographical origin and grape variety. Both LDA and ANNs led to a perfect separation of classes, especially when multi-layer perceptron nets were trained by error back-propagation. 

Geoghegan, M. J., and Brian, R. C. (1946). Influence of bacterial polysaccharides on aggregate formation in soils. Nature (London) 158, 837. 

Schlesinger, W. H. (1990). Evidence from chronosequence studies for a low carbon-storage potential of soils, Nature 348, 232-234. 

Figure 4.1. Balance of organic matter in soils. Reprinted from Schulze, E. D., and Freibauer, A. (2005). Carbon unlocked from soils. Nature 437,205-206, with permission from Macmillan Publishers Ltd.

A survey of OCPs in surface soils was carried out recently in the PRD (Li et al, 2006). A total 74 soil samples containing crop, paddy and natural soils were collected. The concentrations and enantiomeric compositions of HCH, DDT, and chlordane were analyzed. Detailed information on the concentrations in the soils is shown in Table 6.2. The mean concentrations of total HCHs and DDTs in descending order were crop soils > paddy soils > natural soils whereas, only pesticides in the natural soils were significantly (p < 0.001) lower than crop soils and paddy soils. The spatial distribution of HCHs and DDTs was similar, with higher levels found at the center of the PRD. The DDT concentrations in crop (mean 54ngg-1 dw) and paddy soils (mean 47ngg-1 dw) in the PRD were similar to those reported in paddy soils in Dehradun of... 

Tegen, I., Lacis, A.A. and Fung, I. (1996) The influence on climate forcing of mineral aerosols from disturbed soils. Nature, 380, 419-422. 

Briggs, G.G. (1969) Molecular structure of herbicides and their sorption by soils. Nature 223, 1288. 

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