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A simple soil moisture sensor for gardeners. Soil moisture sensors measure the volumetric water content in soil. [1] Since the direct gravimetric measurement of free soil moisture requires removing, drying, and weighing of a sample, soil moisture sensors measure the volumetric water content indirectly by using some other property of the soil, such as electrical resistance, dielectric constant ...
Specific leaf area is a ratio indicating how much leaf area a plant builds with a given amount of leaf biomass: S L A = A M L {\displaystyle SLA\ =\ {\frac {A}{M_{L}}}} where A is the area of a given leaf or all leaves of a plant, and M L is the dry mass of those leaves.
A study of a single winter rye plant grown for four months in one cubic foot (0.0283 cubic meters) of loam soil showed that the plant developed 13,800,000 roots, a total of 620 km in length with 237 square meters in surface area; and 14 billion root hairs of 10,620 km total length and 400 square meters total area; for a total surface area of ...
In the hydrometer tests, the soil particles are mixed with water and shaken to produce a dilute suspension in a glass cylinder, and then the cylinder is left to sit. A hydrometer is used to measure the density of the suspension as a function of time. Clay particles may take several hours to settle past the depth of measurement of the hydrometer.
American Forests, for example, uses a formula to calculate Big Tree Points as part of their Big Tree Program [3] that awards a tree 1 point for each foot of height, 1 point for each inch of girth, and 1 / 4 point for each foot of crown spread. The tree whose point total is the highest for that species is crowned as the champion in their ...
Stomatal conductance, usually measured in mmol m −2 s −1 by a porometer, estimates the rate of gas exchange (i.e., carbon dioxide uptake) and transpiration (i.e., water loss as water vapor) through the leaf stomata as determined by the degree of stomatal aperture (and therefore the physical resistances to the movement of gases between the air and the interior of the leaf).
It is necessary to measure temperatures of both the condensation and evaporation, because the dew point is the equilibrium temperature at which water both condense and evaporate at the same rate. When cooling the mirror, the temperature keeps dropping after it has reached the dew point thus, the condensation temperature measurement is lower ...
Stocking is a quantitative measure of the area occupied by trees, usually measured in terms of well-spaced trees or basal area per hectare, relative to an optimum or desired level of density. [1] It is also used as a measure of the growth potential of a site that may be affected by vegetation in the area along with other nearby trees. Stocking ...