TDR Technique for Estimating the Intensity of Evapotranspiration of Turfgrasses.
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Those parameters are the temperature and the volumetric moisture of soil at the depth of 2.5 cm.Evapotranspiration has the character of a modified logistic function with empirical parameters.It assumes the form ETR(θ (2.5 cm), T (2.5 cm)) = A/(1 + B · e (-C · (θ (2.5 cm) · T (2.5 cm)), where: ETR(θ (2.5 cm), T (2.5 cm)) is evapotranspiration [mm · h(-1)], θ (2.5 cm) is volumetric moisture of soil at the depth of 2.5 cm [m(3) · m(-3)], T (2.5 cm) is soil temperature at the depth of 2.5 cm [°C], and A, B, and C are empirical coefficients calculated individually for each of the grass species [mm · h(1)], and [-], [(m(3) · m(-3) · °C)(-1)].
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PubMed Central - PubMed
Affiliation: Institute of Environmental Protection and Development, Wrocław University of Environmental and Life Sciences, Plac Grunwaldzki 24, 50-363 Wrocław, Poland.
ABSTRACT
The paper presents a method for precise estimation of evapotranspiration of selected turfgrass species. The evapotranspiration functions, whose domains are only two relatively easy to measure parameters, were developed separately for each of the grass species. Those parameters are the temperature and the volumetric moisture of soil at the depth of 2.5 cm. Evapotranspiration has the character of a modified logistic function with empirical parameters. It assumes the form ETR(θ (2.5 cm), T (2.5 cm)) = A/(1 + B · e (-C · (θ (2.5 cm) · T (2.5 cm)), where: ETR(θ (2.5 cm), T (2.5 cm)) is evapotranspiration [mm · h(-1)], θ (2.5 cm) is volumetric moisture of soil at the depth of 2.5 cm [m(3) · m(-3)], T (2.5 cm) is soil temperature at the depth of 2.5 cm [°C], and A, B, and C are empirical coefficients calculated individually for each of the grass species [mm · h(1)], and [-], [(m(3) · m(-3) · °C)(-1)]. The values of evapotranspiration calculated on the basis of the presented function can be used as input data for the design of systems for the automatic control of irrigation systems ensuring optimum moisture conditions in the active layer of lawn swards. No MeSH data available. Related in: MedlinePlus |
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Mentions: A soil column with plant root system was divided into 3 layers with identical volume V. The justification for the number of layers is given at the description of the Figure 2. During a nonrainfall period the water balance equation for the upper layer (j = 1) is as follows:(1)θ1i·V1+E2Δt·F·Δt−ETRΔt·F·Δt=θ1f·V1,where θ1i (θ1f) is volumetric moisture in layer 1 at the initial (final) moment [m3·m−3], V1 is volume of layer 1 [m3], ETRΔt is evapotranspiration [m·h−1], E2Δt is intensity of water flux between layers 1 and 2 [m·h−1], Δt is time step [h], and F is soil column cross-section surface area [m2]. |
View Article: PubMed Central - PubMed
Affiliation: Institute of Environmental Protection and Development, Wrocław University of Environmental and Life Sciences, Plac Grunwaldzki 24, 50-363 Wrocław, Poland.
No MeSH data available.