Lexikon
soil texture is a soil property used to describe the relative proportion of different grain sizes of mineral particles in a soil. Particles are grouped according to their size into what are called soil separates. These separates are typically named clay, silt, and sand. Soil texture classification is based on the fractions of soil separates present in a soil. The soil texture triangle is a diagram often used to figure out soil textures.
| Name of soil separate | Diameter limits (mm) (USDA classification) |
| Clay | less than 0.002 |
| Silt | 0.002–0.05 |
| Very fine sand | 0.05–0.10 |
| Fine sand | 0.10–0.25 |
| Medium sand | 0.25–0.50 |
| Coarse sand | 0.50–1.00 |
| Very coarse sand | 1.00–2.00 |
(Source: Wikipedia)
soil value marks are used in a Hungarian system for the characterisation of agricultural soil quality by a decimal mark system. 0−9 marks for the characteristics, and further 0−9 marks for the quality within each characteristics. The highest value is 100 and the productivity of the soil which is characterised by the marks is equivalent with the % of the maximum.
soil vapor extraction SVE is used to remediate unsaturated vadose zone soil. A vacuum is applied to the soil to induce the controlled flow of air and remove volatile and some semivolatile organic contaminants from the soil. SVE usually is performed in situ; however, in some cases, it can be used as an ex situ technology.
soil washing is an ex situ soil or sediment treatment technology. Contaminants sorbed onto fine soil particles are separated from bulk soil in a water-based system on the basis of particle size. The wash water may be augmented with a basic leaching agent, surfactant, or chelating agent or by adjustment of pH to help remove organics and heavy metals. Soils and wash water are mixed ex situ in a tank or other treatment unit. The wash water and various soil fractions are usually separated using gravity settling.
Soil washing is an ex situ soil or sediment treatment technology. Contaminants sorbed onto fine soil particles are separated from bulk soil in a water-based system on the basis of particle size. The wash water may be augmented with a basic leaching agent, surfactant, or chelating agent or by adjustment of pH to help remove organics and heavy metals. Soils and wash water are mixed ex situ in a tank or other treatment unit. The wash water and various soil fractions are usually separated using gravity settling.
soil water is held in the pore spaces between particles of soil. Soil water is the water that is immediately available to plants. Soil water can be further sub-divided into three categories, 1) hygroscopic water, 2) capillary water, and 3) gravitational water.
Hygroscopic water is found as a microscopic film of water surrounding soil particles. This water is tightly bound to a soil particle by molecular attraction so powerful that it cannot be removed by natural forces. Hygroscopic water is bound to soil particles by adhesive forces that exceed 31 bars and may be as great as 10,000 bars (Recall that sea level pressure is equal to 1013.2 millibars which is just about 1 bar!).
Capillary water is held by cohesive forces between the films of hygroscopic water. The binding pressure for capillary water is much less than hygroscopic water. This water can be removed by air drying or by plant absorption, but cannot be removed by gravity. Plants extract this water through their roots until the soil capillary force (force holding water to the particle) is equal to the extractive force of the plant root. At this point the plant cannot pull water from the plant-rooting zone and it wilts (called the wilting point).
Gravity water is water moved through the soil by the force of gravity. The amount of water held in the soil after excess water has drained is called the field capacity of the soil. The amount of water in the soil is controlled by the soil texture. Soils dominated by clay-sized particles have more total pore space in a unit volume than soils dominated by sand. As a result, fine grained soils have higher field capacities than coarse-grained soils.
There is a relationship between soil texture, wilting point, field capacity, and available water. The difference between the wilting point and the field capacity is the available water. The smallest amount of available water is associated with the coarsest soil texture, sand. The amount of available water increases where soils with a mixture of different sized particles (loamy soils) are found. The available water then drops off toward the fine textured soils on the right. How does one explain the relationship between available water and soil texture? Coarse soil does not have much available water because it doesn't hold much water to begin with. At the other end of the spectrum, low available water in fine soils is due to strong bond between soil particles and water. Plants have a harder time pulling water away from the soil particle under these conditions.
soil is generally defined as the top layer of the earth’s crust. It is formed by mineral particles, organic matter, water, air and living organisms. Soil is the interface between the earth (geosphere), the air (atmosphere) and the water (hydrosphere). While soil is the physical upper layer of what is usually referred to as “land”, the concept of “land” is much wider and includes territorial and spatial dimensions. It is difficult to separate soil from its land context. (Source: EUGRIS)
steam heating of the soil is one specific method where soil or solid wastes are heated by means of stream and is a category within the umbrella term of “thermally enhanced recovery”. It mens the enhanced recovery of volatile or volatilized contaminants from contaminated soil. I can be applied ex situ or in situ.
soil texture is a soil property used to describe the relative proportion of different grain sizes of mineral particles in a soil. Particles are grouped according to their size into what are called soil separates. These separates are typically named clay, silt, and sand. Soil texture classification is based on the fractions of soil separates present in a soil. The soil texture triangle is a diagram often used to figure out soil textures.
| Name of soil separate | Diameter limits (mm) (USDA classification) |
| Clay | less than 0.002 |
| Silt | 0.002–0.05 |
| Very fine sand | 0.05–0.10 |
| Fine sand | 0.10–0.25 |
| Medium sand | 0.25–0.50 |
| Coarse sand | 0.50–1.00 |
| Very coarse sand | 1.00–2.00 |
(Source: Wikipedia)
the World Reference Base for soil resources is a two-level system of soil classification with 30 Soil Reference Groups and a series of uniquely defined qualifiers for specific soil characteristics.
For describing and defining soils the WRB exploits the following nomenclature:
- soil characteristics comprise single observable or measured parameters;
- soil properties are a combination of characteristics indicating soil-forming processes;
- soil horizons represent three-dimensional bodies containing one or more soil properties