Physical properties of soils

Easily observed physical properties of soils often are useful indexes of behavior. These index properties include texture and appearance, specific weight, moisture content, consistency, permeability, compressibility, and shearing strength [37,38]. 

Ralston, C.W. Hatchell, G.E. Effects of prescribed burning on physical properties of soil Prescribed Burning Symp. Proc. USDA For. Serv. Southeast For. Exp. Sta. Asheville, NC, 1971 pp 68-85. 

Irrigation has been practiced from the ancient time it is only in the twentieth century that the importance of the irrigation water quality was recognized [7]. The use of saline water may result in the reduction of crop yields. A high sodicity of water for irrigation may cause the deterioration in the physical properties of soils... 

Handbook of Soil Conditioners Substances That Enhance the Physical Properties of Soil, edited by Arthur Wallace and Richard E. Terry Environmental Chemistry of Selenium, edited by William T. Frankenberger, Jr., and Richard A. Engberg... 

Table 13.1 Physical properties of soils used in MSMA decomposition studies...

Haines, W. B. J. Agric. Science 17 (1927) 264. Studies in the physical properties of soils. IV. A further contribution to the theory of capillary phenomena in soil. 

Jozefaciuk, G. Muranyi, A. Fenyvesi, E. Effect of Randomly Methylated P-Cyclodextrin on Physical Properties of Soils. Environ. Sci. Technol 2003, 37, 3012-3017. 

The nitrogen supplies on land consist of the assimilable nitrogen in the soil VS2 0.19-104tkm-2, in plants (12 1091), and living organisms (0.2 1091). A diversity of nitrogen fluxes is formed here of the processes of nitrification, denitrification, ammonification, fixation, and river run-off. The intensities of these fluxes depend on climatic conditions, temperature regime, moisture, as well as the chemical and physical properties of soil. Many qualitative and quantitative characteristics of these dependences have been described in the literature (Hellebrandt et al., 2003). Let us consider some of them. 

The physical properties of soils and sediments are particularly important in determining infiltration rates in soils as well as groundwater flow velocities. One feature of particular importance is the void space or porosity of soils, rocks, and sediments. Water is capable of moving from one void space to another in these materials thereby allowing the flow of water. Total porosity is defined mathematically by the equation ... 

Haines Extrusion Apparatus—Haines (1925a), in studying the physical properties of soils, developed an extrusion apparatus. This... 

Studies in the physical properties of soil. V. The hysteresis effect in capillary properties, and the modes of moisture distribution associated therewith. Ibid., 20 97-116. 

Lectures on some of the physical properties of soil. Oxford Clarendon Press. 

El-Swaify, S. A. 1976. Changes in physical properties of soil clays due to precipitated A1 and Fe hydroxides. II. Colloidal interaction in the absence of drying. Soil Sci. Soc. Am. Proc. 40 516-520. 

Most comparisons of cerrados and other savannas in the literature focus on cerrado sensu stricto on deep latosols, but these comparisons have several limitations. These comparisons do not, for example, give proper attention to variations in geomorpho-logical aspects, water table flucmations or physical properties of soils. Attempts to correlate vegetation parameters with chemical properties of soils, especially analytical data on available nutrients in the surface layers are more common but should be viewed with caution for several reasons. First of all, such correlations by themselves do not establish a cause-and- effect relationship between soil properties and vegetation parameters. More often, the vegetation... 

However, modern concepts of soil acidity were not developed until the middle of the 20th century. In the U.S.A., Jenny, Stout, Coleman, Harward, and others contributed heavily to a better understanding of the nature of soil acidity and related aspects of soil chemistry and plant nutrition (Coleman and Thomas, 1967). Soil pH has a profound influence on the availability of nutrients to crops, since chemical, microbiological and, to a lesser extent, physical properties of soils are affected by the degree of soil acidity or alkalinity that prevails. 

In partnership with the clay fraction, organic matter has an extremely important influence on the chemical and physical properties of soils. Critical and beneficial functions of organic matter include ... 

Besides these important relations between PZC and ion adsorption by soils, the physical properties of soils may also be sensitive to the PZC. It is a general principle of colloid chemistry that colloidal particles dispersed in water tend to maintain their dispersed state if the particles possess relatively high surface charge, either positive or negative. Conversely, aggregation of these individual particles (i.e., flocculation) is most favored when the surface charge is low. This leads to the rule that ... 

Mielke HW and Heneghan JB (1991) Selected chemical and physical properties of soils and gut physiological processes that influence lead bioavailability. Chemical Spedation Bioavailabdity 3 129-134. 

Badalucco, L., De Cesare, F., Crego, S., Landi, L. and Nannipieri, P. (1997) Do physical properties of soil affect chloroform efficiency in lysing microbial biomass Soil Biology and Biochemistry 29, 1 135-1 142. 

Fortunately, according to De Bano, water repellency appears to be a time-dependent physical property of soil wetting resistance of a hydrophobic soil tends to decrease with time. The addition of wetting agents can also improve wetting of these soils, but no practical use is being made of this fact. 

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