Amended soils structure

Oline DK, Grant MC (2002) Scaling patterns of biomass and soil properties an empirical analysis. Landsc Ecol 17 13-26 Perez-de-Mora A, Burgos P, Madejon E, Cabrera F, Jaeckel P, Schloter M (2006) Microbial community structure and function in a soil contaminated by heavy metals effects of plant growth and different amendments. Soil Biol Biochem 38 327-341... 

Compositional and Structural Features of Humic Substances in Amended Soils 151... 

COMPOSITIONAL AND STRUCTURAL FEATURES OF HUMIC SUBSTANCES IN AMENDED SOILS... 

Elemental analysis is a common tool used for the characterization and differentiation of HS isolated from organic amendments and unamended and amended soils. It provides information on the distribution of major elements, typically C, H, N, S, and O, in HS, thus setting limits for HS possible molecular composition. The atomic ratios C/N, C/H, and O/C are also useful in identifying types of HS, monitoring their structural changes, and devising HS structural formulas (Stevenson, 1994 Senesi and Loffredo, 1999). 

Bidimensional fluorescence spectra are commonly obtained in the three modes of emission, excitation, and synchronous-scan excitation, whereas tridimensional fluorescence (or total luminescence) spectra are obtained in the form of excitation-emission matrix (EEM) plots by measuring the fluorescence intensity emitted as a function of the wavelength over a range of excitation wavelengths. This technique allows to obtain more detailed information than that obtained by using conventional monodimensional fluorescence (Mobed et al., 1996). Fluorescence spectroscopy has provided valuable information on the molecular structure, functionalities, conformation, and intramolecular and intermolecular interactions of HS from organic amendments and unamended and amended soils (Senesi et al., 1990,1996, 2007 Mobed et al., 1996 Chen et al., 2003 Senesi and Plaza, 2007). 

Moradi et al. [21] used nonlinear Freundlich isotherm to account for the sorption of cadmium in a sewage-amended soil. Kohne et al. [22] used the nonlinear Freundlich isotherm to incorporate sorption in their multiprocess herbicide transport analysis in structured soils. At low concentration the constant a becomes unity and a linear relation is obtained ... 

GRIFFITHS E. and JONES D. 1965. Microbiological aspects of soil structure. I. Relationships between organic amendments, microbial colonisation and changes in aggregate stability. Plant and Soil, 23, 17-33. 

The results of these experiments have been considered by the Joint Committee for the Co-ordination of the Cathodic Protection of Buried Structures and, in view of the various types of buried structures concerned and the circumstances in which field tests are conducted, the Committee decided not to amend its provisional recommendation that when cathodic protection is applied to a buried structure the maximum permissible potential change in the positive direction on a nearby pipe or cable should be 20 mV. If there is a history of corrosion on the unprotected installation no detectable positive change in structure/soil potential should be permitted. These criteria of interaction have been adopted in the British Standard Code of Practice for Cathodic Protection . 

Ros M, Klammer S, Knapp B, Aichberger K, Insam H (2006) Long term effects of compost amendment of soil on functional and structural diversity and microbial activity. Soil Use Manage 22 29-218... 

The compounds that result from FGD technologies have very different bulk chemical and mineralogical characteristics than those from conventional combustion. They still contain Si, Al, and Fe, but they contain as much as 50-60 wt% Ca and S, much of which is soluble in water. Although many types of FGD products have been used successfully as engineered fill, they may also be utilized as soil amendments, particularly when combined with organic byproducts. Use of FBC ash in structural fill is limited compared to fly ash, bottom ash, and FGD products due to the expansion problems that occur when FBC ash first comes into contact with water. 

The use of surfactant-modified zeolite (SMZ) as a permeable barrier sorbent may offer several unique advantages when dealing with mixed contaminant plumes. Zeolites are hydrated aluminosilicate minerals characterized by cage-like structures, high internal and external surface areas, and high cation exchange capacities. Both natural and synthetic zeolites find use in industry as sorbents, soil amendments, ion exchangers,... 

The presence of acidic functional groups, mostly carboxyl and phenolic OH groups, in the molecular structure of soil HS renders them major players in the acid-base buffering capacity of soils and in the fate, bioavailability, and physico-chemical behavior of macro- and micronutrients, toxic metal ions, and several xenobiotic organic compounds in soil (Ritchie and Perdue, 2003 Senesi and Loffredo, 2005). Consequently, the effects of amendment on the acid-base properties of soil HAs and FAs is a subject of considerable interest. 

Infrared (IR) spectroscopy and Fourier transform IR (FT-IR) have been very useful in studying the molecular structure of HS from organic amendments and unamended soils, as well as the effects of organic amendment on native soil HS (Senesi et al.,... 

Thus, ESR data confirm (a) the lower-ring polycondensation and polymerization degree of HAs and FAs from organic amendments with respect to soil HAs and FAs and (b) the partial incorporation of the amendment on these structural properties into native soil HAs and FAs. 

The mechanism and extent of adsorption are ascertained to depend on several factors, which include (a) the physical and chemical nature and properties of both HS and organic xenobiotic and (b) the conditions of the medium. Organic matter in organic amendments is relatively fresh or little humified, has composition and properties that differ substantially from native soil HS, and affects the composition and structure of native soil HS. Therefore, organic xenobiotics added to soils interact with a complex mixture of applied and native HS, which is expected to affect both quantitative and mechanistic aspects of adsorption phenomena. 

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