Characteristics of soils

Table 4-1 Characteristics of soils and their rating number Z (DIN 50929, Pt 3 and DVGW worksheet GW 9).

Table I. Characteristics of soil and annual plant vegetation under shrub canopies and in intershrub spaces. Data from references 12, 27, 28, and 29.

U.S. EPA requires that soil liners be built so that the hydraulic conductivity is equal to or less than 1 x 10 7 cm/s. To meet this requirement, certain characteristics of soil materials should be met. First, the soil should have at least 20% fines (fine silt and clay-sized particles). Some soils with less than 20% fines will have hydraulic conductivities below 10-7 cm/s, but at such low fines content, the required hydraulic conductivity value is much harder to meet.5... 

FIGURE 48 A soil profile. Many of the characteristics of soils vary with depth. A convenient way of representing its varying characteristics is by dividing the soil into layers, usually referred to as horizons, identified by letter symbols. The surface layer, which is known as the A horizon, is generally rich in organic matter. Next come the B and C horizons, each of which may have compositional characteristics and modifications. The deepest soil horizon (R) is solid rock. The illustration identifies clearly defined horizons, although in most soils the horizons are not as clear and in some they may be very diffuse. 

All physical and chemical characteristics of soil have a pronounced effect on its analysis. The intention here is to first investigate some of the most important characteristics of soil and its extracts that impact its analysis, as well... 

Soils develop by the action of the soil forming factors on soil parent materials including material transported by different agents. The result of these soil forming factors is the formation of soil horizons, different colors, and peds. Each of these factors has a pronounced effect on a soil s chemistry. Knowledge of the soil type and profile description can provide the soil chemist, analyst, or researcher with valuable information about the characteristics of soil relevant to the development of extraction, analytical, and instrumental analytical procedures. It also is the place to start when investigating the failure of a procedure. 

It is reasonable to assume the effect of plant roots and tops on the soil would be the same. However, this is not the case. Plant roots profoundly affect the chemical characteristics of soil. Because they are in intimate contact with the soil, roots are constantly extracting nutrients and water from the soil and exuding materials into it. The intimate relationship, which includes physical, microbiological, biochemical, bioorganic, and chemical interactions between roots and soil, is illustrated in Figure 4.3. 

Explain how animals can change the physical characteristics of soil. Give some examples. 

Although all characteristics of electricity have been used to investigate soil and its properties, only a limited number are used routinely. The most common are those used for the determination of pH, salt content, and soil water content. Of these three, pH is the most common measurement and frequently the first measurement made prior to all other determinations. Although pH can be determined by many methods, for soil, the most common is to use a pH meter and electrode. Conductivity or resistance is used to measure soil salt content, while several different electrical characteristics of soil are used to determine... 

Knoll (40) in a study similar to that of Rhodes (33) demonstrated that percolation of organic acids through the soil did not influence the exchange characteristics of soil with respect to plutonium waste. However, hydroxyacetic acid removed 50% of the plutonium from soil and in the case of americium this value was raised to 100%. 

An important characteristic of soil is its level of alkalinity or acidity, known as pH. The pH scale runs from 1, extremely acidic, to 14, extremely alkaline. Most soils range from 4 to 8, with the majority of plants growing in the range of 5.5-75. Ornamentals tend to tolerate... 

Table 16.9 Physicochemical characteristics of soils used in experiments (Wahid et al. 1980)...

Characteristics of soil Quantity of waste Utility/fuel rates Moisture content of soil Initial contaminant concentration Characteristics of residual waste Waste handling/preprocessing Target contaminant concentration Amount of debris with waste Labor rates... 

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