Soil organic matter, SOM

Table 2 Cumulative CO, Evolution from Root Residues (RM), Soil Organic Matter (SOM), and Glucose During 24 Days of Incubation...

Fig. 3. Soil inventory of carbon in soil organic matter (SOM) (a), A14C of SOM (b), noncrystalline minerals (c), and crystalline minerals (d) versus age of soil substrate. Filled circles, total profiles filled triangle, surface (O and A) horizons (Tom et al. 1997).

The distribution of SOC with depth is attributed mainly to continuous input and decomposition of soil organic matter (SOM), and correlates directly with soil development and SOM turnover (Chen et al. 2005). Regional, continental or global models are useful to understand SOM dynamics according to land use changes and management practices (Cole et al. 

Soil Soil organic matter (SOM) and acidity (pH value) Biological activity Soil structure Erosion Desertification... 

Estimation of Koc Using Aqueous Phase and Soil Organic Matter (SOM) Phase Activity Coefficients Calculated from UNIFAC and ELBRO-FV... 

The natural sources of soil organic matter (SOM) are indigenous plant and animal debris that are decomposed and partly mineralized by soil biota. Any factor that... 

Historically, attention on soil organic matter (SOM) has focused on the central role that it plays in ecosystem fertility and soil properties, but in the past two decades the role of soil organic carbon in moderating atmospheric C02 concentrations has emerged as a critical research area.This chapter will focus on the storage and turnover of natural organic matter in soil (SOM), in the context of the global carbon cycle. 

PAHs in soil may partition into soil organic matter (SOM) or adsorb on soil minerals. The sorptive properties of SOM fractions for organic contaminants in soil play an important role on the transportation of PAHs in soil. Xiao et al. (2004) has reported that soil/sediment organic matter can be fractionated into four fractions with a combined wet chemical procedure and that kerogen and black carbon (BC) are major SOM components in soil/sediment samples collected from the industrialized suburban areas of Guangzhou, China. Phenanthrene and naphthalene were used as the sorbates to study PAH s sorption isotherms on four original and four Soxhlet-extracted soil/sediment samples, 15 isolated SOM fractions, and a char as the sorbents. The sorption isotherms of phenanthrene and naphthalene on all the sorbents were variously nonlinear. The particulate kerogen and black carbon (KB) fractions... 

Soil organic matter SOM Organic materials that accompany soil particles through a 2 mm sieve... 

Soil organic matter (SOM) is made of two major groups of compounds The nonni-trogenous compounds, which are mainly carbohydrates, and the nitrogenous com-... 

Some General Properties of Soil Organic Matter (SOM)... 

These changes in soil C stocks are relatively rapid, due to rapid turnover of soil organic matter (SOM) in these tropical soils. Using radiocarbon derived from atmospheric testing of nuclear weapons in the 1960s as a tracer, Trumbore et al. (1995) estimated that the mean residence time of C in the top 10 cm of soil is about 3 years for 30% of the SOM and 10-30 years for 60% of the SOM. Only about 10% of the C in the top 10 cm of soil cycles on a millennial time scale. This very old C fraction increases to 40-80% in the... 

McGill W. B. (1996) Review and classification of ten soil organic matter (SOM) models. In Evaluation of Soil Organic Matter Models (eds. D. S. Powlson, P. Smith, and J. U. Smith). Springer, pp. 111-132. 

Soils. The structural composition of soil organic matter (SOM) has been determined in 27 soils with different vegetation from several ecological zones of Australia and Pakistan using solid-state CPMAS NMR. Binding of protons, Cu(II) and Pb(II) to a soil fulvic acid, humic acid, and two different size fractions of the humic acid has been investigated solid-state C NMR combined with other techniques. ... 

Figure 7.11 Results obtained for the supercritical extraction of various organochlorine pesticides from contaminated soil and Celite , showing the influence of (a) the soil matrix, and (b) the soil organic matter (SOM) content A, lindane B, aldrin C, dieldrin D, heptachlor E, isodrin (a) B, Celite , soil (b) B, SOM 0.2% , SOM 15% W, SOM 35% [4] (cf. DQ 7.8).

---