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These properties are storativity (S), specific storage (S s) and specific yield (S y). According to Groundwater, by Freeze and Cherry (1979), specific storage, [m −1], of a saturated aquifer is defined as the volume of water that a unit volume of the aquifer releases from storage under a unit decline in hydraulic head. [1]
The specific heat of soil increases as water content increases, since the heat capacity of water is greater than that of dry soil. [89] The specific heat of pure water is ~ 1 calorie per gram, the specific heat of dry soil is ~ 0.2 calories per gram, hence, the specific heat of wet soil is ~ 0.2 to 1 calories per gram (0.8 to 4.2 kJ per ...
Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. The soil moisture curve is characteristic for different types of soil, and is also called the soil moisture characteristic. It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability.
Modelling is essential in theoretical production ecology. Unit of modelling usually is the crop, the assembly of plants per standard surface unit.Analysis results for an individual plant are generalised to the standard surface, e.g. the leaf area index is the projected surface area of all crop leaves above a unit area of ground.
Available water is that which the plants can utilize from the soil within the range between field capacity and wilting point. Roughly speaking for agriculture (top layer soil), soil is 25% water, 25% air, 45% mineral, 5% other; water varies widely from about 1% to 90% due to several retention and drainage properties of a given soil.
The single probe method employs a heat source inserted into the soil whereby heat energy is applied continuously at a given rate. The thermal properties of the soil can be determined by analysing the temperature response adjacent to the heat source via a thermal sensor. This method reflects the rate at which heat is conducted away from the probe.
The term stratification can be traced back to at least 1664 in John Evelyn's Sylva, or A Discourse of Forest-Trees and the Propagation of Timber, [2] where seeds were layered (stratified) between layers of moist soil and the strata were exposed to winter conditions. Thus, stratification became the process by which seeds were artificially ...
Soil temperature regimes, such as frigid, mesic, and thermic, are used to classify soils at some of the lower levels of the Soil Taxonomy. The cryic temperature regime distinguishes some higher-level groups. These regimes are based on the mean annual soil temperature (MAST), mean summer temperature, and the difference between mean summer and ...