Wojciech Skierucha | Polish Academy of Sciences (original) (raw)

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Papers by Wojciech Skierucha

The Scientific World Journal, 2015

The paper presents a method for precise estimation of evapotranspiration of selected turfgrass sp... more 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.

The multitude of the research objects, with reference to which the research methods of the physic... more The multitude of the research objects, with reference to which the research methods of the physical sciences are applied, caused the separation of the disciplines, such as: biophysics, geophysics or agrophysics. The prefix in the name of each of these disciplines usually shows the subject of the study. Respectively, agro- in the name of agrophysics in- forms that the objects

Pomiary Automatyka Kontrola, 2010

Vadose Zone Journal, 2016

Sensors, 2016

Time-domain reflectometry (TDR) methods used for measuring the dielectric properties of materials... more Time-domain reflectometry (TDR) methods used for measuring the dielectric properties of materials mostly utilize step or needle electrical pulses of constant amplitudes and shapes. Our novel approach enables determining the dielectric relaxation time of a sample using the analysis of the amplitudes of reflected pulses of two widths, in addition to bulk dielectric permittivity and electrical conductivity commonly obtained by the TDR technique. The method was developed for various values of electrical conductivity and relaxation time using numerical simulations of a five-rod probe placed in a material with complex dielectric permittivity described by the Debye model with an added electrical conductivity term. The characterization of amplitudes of two pulses of selected widths was done with regard to the dielectric parameters of simulated materials. The required probe parameters were obtained solely from numerical simulations. Verification was performed for the probe placed in aqueous KCl solutions with 14 different electrical conductivity values. The determined relaxation time remained roughly constant and independent of electrical conductivity. The obtained electrical conductivity agreed with the reference values. Our results indicate that the relaxation time, dielectric permittivity and electrical conductivity of the tested solutions can be simultaneously determined using a simple analysis of the amplitude and reflection time of two needle pulses of different widths.

Electromagnetic Waves, 2011

Journal of Plant Nutrition and Soil Science, 2009

Irrigation Science, 1989

The principle of operation of a simple, manually controlled Time-Domain Reflectometer (TDR meter)... more The principle of operation of a simple, manually controlled Time-Domain Reflectometer (TDR meter) for soil moisture measurements, which operates with a needle pulse of 300 ps rise-time, is described. A block diagram and constructions are also given. Construction of a switchless multiple sensor probe, having an inherent delay reference, is presented. Results of measurements of the soil dielectric constant as related to water content, for soils having different bulk densities, textures and humus content show a high correlation. The results agree closely with other investigators measurements with different, more expensive, TDR instruments. The general principle of microprocessor-controlled TDRoperated soil moisture meter is considered.

Encyclopedia of Earth Sciences Series, 2011

International Agrophysics, 2000