Stability in soil

Buser H-R, MD Muller, ME Balmer (2002) Environmental behavionr of the chiral acetamide pesticide metalaxyl enantioselective degradation and chiral stability in soil. Environ Sci Technol 36 221-226. 

Fig. 8.9 Effect of porosity on composition of kerosene during 14 days of volatilization from fine, medium and coarse sand, as seen from gas chromatograph analyses. Reprinted from Galin Ts, Gerstl Z, Yaron B (1990) Soil pollution by petroleum products. IB Kerosene stability in soil columns as affected by volatilization. J Contam Hydrol 5 375-385. Copyright 1990 with permission of Elsevier...

Galin T, Gerstl Z, Yaron B. 1990a. Soil pollution by petroleum products III. Kerosene stability in soil columns as affected by volatilization. J Contam Hydrol 5(4) 375-385. 

While much research on the nature and impact of phytotoxins has been conducted, many questions remain unanswered. Little is known about the rate of phytotoxin production and accumulation, localized concentration, threshold soil concentration for expression of bioactivity, duration of bioactivity, stability in soil, and environmental redistribution. Although the fate of specific chemicals under defined experimental conditions is discussed, it is hoped that the principles involved can be extended to provide a basic understanding of the fate of the wide range of allelochemical substances in the soil. 

A weathering sequence for phyllosilicates has been established which indicates that their relative stability in soils is as follows mica,... 

Lehmann, J., Kinyangi, J., and Solomon, D. (2007). Organic matter stabilization in soil microaggregates Imphcations from spatial heterogeneity of organic carbon contents and carbon forms. Biogeochemistry. 85,45-57. 

In the past, selenium was used in pesticide products, but because of its stability in soils and subsequent contamination of food crops, its use in pesticide products is now restricted. The release of selenium to soil from fly ash settling ponds and hazardous waste sites has not been quantified. 

Environmental fate and pathways photodegradation, stability in water, stability in soil, monitoring data (environment), transport between environmental compartments, distribution, mode of degradation in actual use, biodegradation, BOD5, COD or BOD5/COD ratio, bioaccumulation. 

Results of field experiments confirm that carbon becomes increasingly resistant to decomposition with time. This has led some investigators to conclude that the organic component exists in three major fractions when considered on a dynamic basis (1) decomposing plant residues and the associated biomass, which turn over every few years (2) microbial metabolites and cell wall constituents that become stabilized in soil and have a half-life of 5 to 25 years and (3) the smallest fraction, resistant organic matter, ranging in age from 250 to 2500 years or more. 

The persistence of some enzymic activities in soils, and the possibility that active abiontic enzymes may be stabilized by combination with soil colloids, has led a minority of workers to attempt the characterization of enzymes in soil extracts and in other fractions. Elucidation of the mechanisms by which abiontic enzymes are stabilized in soil may be important in the wider context of understanding the processes which confer biological resistance on soil organic N. 

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