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The physical properties of soil, in order of decreasing importance for ecosystem services such as crop production, are texture, structure, bulk density, porosity, consistency, temperature, colour and resistivity. [ 1] Soil texture is determined by the relative proportion of the three kinds of soil mineral particles, called soil separates: sand ...
The frost line —also known as frost depth or freezing depth —is most commonly the depth to which the groundwater in soil is expected to freeze. The frost depth depends on the climatic conditions of an area, the heat transfer properties of the soil and adjacent materials, and on nearby heat sources. For example, snow cover and asphalt ...
Hardiness zone. A hardiness zone is a geographic area defined as having a certain average annual minimum temperature, a factor relevant to the survival of many plants. In some systems other statistics are included in the calculations. The original and most widely used system, developed by the United States Department of Agriculture (USDA) as a ...
However, evening temperatures are still dropping down to the 40s. Frosting typically occurs between 33 to 36 degrees, according to Iowa State University. While frost generally causes minor damage ...
One possible way of assessing soil thermal properties is the analysis of soil temperature variations versus depth Fourier's law, Q = − λ d T / d z {\displaystyle Q=-\lambda dT/dz\,} where Q is heat flux or rate of heat transfer per unit area J·m −2 ∙s −1 or W·m −2 , λ is thermal conductivity W·m −1 ∙K −1 ; dT / dz is the ...
A taxonomy is an arrangement in a systematic manner; the USDA soil taxonomy has six levels of classification. They are, from most general to specific: order, suborder, great group, subgroup, family and series. Soil properties that can be measured quantitatively are used in this classification system – they include: depth, moisture ...
For a given soil, the greater the void ratio, the higher the value of the coefficient of permeability. Here 'e' is the void ratio. Based on other concepts it has been established that the permeability of a soil varies as e2 or e3 / (1+e). Whatever may be the exact relationship, all soils have e versus log k plot as a straight line.
The most common engineering classification system for soils in North America is the Unified Soil Classification System (USCS). The USCS has three major classification groups: (1) coarse-grained soils (e.g. sands and gravels ); (2) fine-grained soils (e.g. silts and clays ); and (3) highly organic soils (referred to as "peat").