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The most common models address surface runoff, allowing variation in land use type, topography, soil type, vegetative cover, precipitation, and land management practice (e.g. the application rate of a fertilizer). Runoff models have evolved to a good degree of accuracy and permit the evaluation of alternative land management practices upon ...
Soil formation, also known as pedogenesis, is the process of soil genesis as regulated by the effects of place, environment, and history. Biogeochemical processes act to both create and destroy order ( anisotropy ) within soils.
Soil particles can be classified by their chemical composition as well as their size. The particle size distribution of a soil, its texture, determines many of the properties of that soil, in particular hydraulic conductivity and water potential, [1] but the mineralogy of those particles can strongly modify those properties. The mineralogy of ...
A soil test is a laboratory or in-situ analysis to determine the chemical, physical or biological characteristics of a soil. Possibly the most widely conducted soil tests are those performed to estimate the plant-available concentrations of nutrients in order to provide fertilizer recommendations in agriculture.
At 1 ppm the solution is a very pale yellow. As the concentration increases the colour becomes a more vibrant yellow, then orange, with the final 10,000 ppm a deep red colour. In science and engineering , the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities , e.g. mole fraction or ...
The Unified Soil Classification System (USCS) is a soil classification system used in engineering and geology to describe the texture and grain size of a soil. The classification system can be applied to most unconsolidated materials, and is represented by a two-letter symbol. Each letter is described below (with the exception of Pt):
For standard gamma-ray logs, the measured value of gamma-ray radiation is calculated from concentration of uranium in ppm, thorium in ppm, and potassium in weight percent: e.g., GR API = 8 × uranium concentration in ppm + 4 × thorium concentration in ppm + 16 × potassium concentration in weight percent.
Soil mineral components belonging to a given textural class may thus share properties linked to their specific surface area (e.g. moisture retention) but not those linked to their chemical composition (e.g. cation exchange capacity). Soil components larger than 2.0 mm (0.079 in) are classed as rock and gravel and are removed before determining ...