Soils bulk density

Bulk density, soil - Mass of dry soil per unit bulk volume (combined volume of soil solids and pore space). 

Volume of parent material Volume of soil Parent material bulk density Soil bulk density... 

Soil physical properties most likely to be altered by biomass burning are soil structure, soil wettability, and clay mineralogy (Table HI) (43). The destruction of organic matter results in losses of soil structure, increases in bulk density, diminished aggregate stability and decreases in macropore space (44). 

Fig. 7. Root and shoot dry weight of wheat after 22 days of growth (5-leaf Stage) at various soil penetrometer resistances. Variations in penetrometer resistance were obtained by varying soil bulk density and water content. Symbols are as follows. Shape refers to bulk density (g cm ) 0,1.17 A, 1.29 , 1.37 <0, 1.41 V, 1.45. Shade refers to water content (g g dry soil) open symbols, 0.22 or 0.23 half-shaded, 0.25 closed, 0.27. Points are means s.E. (n = 6). Modified from Masle Passioura (1988).

Polyvinyl chloride cylinders -1- nylon gauze -1- device for continuous water supply Soil slices at measurable distance from soil-root interface. High bulk density of soil sampled. Nutrient uptake through an induced root hairs surface. Study of rhizosphere effect over a time and distance gradient from the soil-root interface. 47, 67, 127-129... 

For example, the expected zero-time soil concentration (Co) of a compound applied at a rate of 2.2kga.i.ha would be calculated by dividing the application rate (mga.i.ha ) by the total weight of a 15-cm depth of soil. Assuming a soil bulk density of 1500 kg m , the total weight of a 15-cm layer of soil is 2.24 x 10 kgha ... 

Total soil weight per given depth per hectare assumes a bulk density of 1500 kg soil m. Calculations are based on a nominal application rate of 0.168kga.i.ha . Soil core sectioning techniques are discussed in Section 3. 

G.R. Blake and K.H. Hartge, Bulk density, in Methods of Soil Analysis Part 1 Physical and Mineralogical Methods, ed. A. Klute, Second edition, American Society of Agronomy and Soil Science Society of America, Madison, Wl, pp. 363-375 (1986). 

Infiltration rate Water content Particle size distribution Frozen soil Bulk density Clay mineralogy Macro porosity... 

The order of the mobilities of alachlor, butylate, and metolachlor in columns of various soils was metolachlor > alachlor > butylate. This correlates directly with the water solubilities and inversely to the adsorption coefficients and octanol/water partition coefficients of these compounds. Diffusion of these compounds in soil thin-layers was as follows butylate > alachlor > metolachlor, which correlates directly with the vapor pressures of these compounds. Significant soil properties affecting diffusion appeared to be bulk density and temperature. Soil moisture is also probably important, but its effect on the diffusion of these compounds was not determined. 

K = Freundlich adsorption coefficient from TABLE IV. ds = bulk density of soil from TABLE I. 

Physico-chemical characteristics of the soils were summarized in Table 1. The values were comparable to that described in the previous reports about the SERS (Doi and Sakurai 2003 Doi et al. 2004 Sakurai et al. 1998). The one-way ANOVA indicated that most of the soil variables significantly reflected the land degradation with high values of bulk density, sand content and exchangeable acidity, and low values of moisture content, pH, OM, base (K, Ca, Mg) contents, EC, CEC, base saturation rate, TN and TC contents, available phosphorus and MPN on the glucose medium with no antibiotics. These results also told that the human activities induced several soil environmental gradients. 

Comparison with observations Soil and vegetation are only represented as single layer (topsoil) surfaces in the MPI-MCTM, hence their contamination is expressed as a mass per surface area. Soil burdens were converted into concentrations by dividing them by soil dry bulk density and a fixed soil depth of 10 cm. The average DDT concentration in soil between 40 °N and 60°N was compared to measured soil and sediment concentrations from Northern North America and Great Britain [Dimond and Owen (1996), Meijer et al (2001), and others compiled by Schenker et al (2008a)]. For intercomparison reasons only relative soil concentrations are compared to observational data. Each set of observations was normalised to its 1990 value. 

In soils, the bulk density is an indication of the degree of compaction and also the capacity for holding water, air, and nutrients. Highly compacted soils with low porosity (voids) are desirable for roadbeds and dams, but are not suitable for plant growth. The actual density, or particle density, of soils is determined by the displacement of water of a given mass of soil. 

Knowing the particle size distribution for soils provides information about many of the soil properties, such as how much heat, water, and nutrients the soil will hold, how fast they will move through the soil, and what kind of structure, bulk density, and consistency the soil will have. The texture of the soil, how it feels, is based on the relative amounts of sand, silt, and clay present. Particles larger than 2.0 mm are called stones or gravels and are not considered soil material. Sand varies in size from 2.0 to 0.05 mm. Silt varies from 0.05 to 0.002 mm. Clays are less than 0.002 mm. 

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