TDR Technique for Estimating the Intensity of Evapotranspiration of Turfgrasses

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 ETRθ2.5 cm,T2.5 cm=A/1+B·e-C·θ2.5 cm·T2.5 cm, where: ETRθ2.5 cm,T2.5 cm is evapotranspiration [mm·h−1], θ2.5 cm is volumetric moisture of soil at the depth of 2.5 cm [m3·m−3], T2.5 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·h1], and [—], [(m3·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 Use of World Water Resources in the Irrigation of Field Cultivations

The paper concerns evaluation of the exploitation of the world’s water resources for irrigating field crops. It was determined that the volume of water used in 2020 in all sectors of the economy in relation to the world’s freshwater resources will amount to 31 to 38% of the available resources. It has been found that globally, in the period 1900–2100, the agricultural sector has the highest consumption of fresh water. Therefore, there is a need for rational use of water, especially when irrigating field crops. Hence, the paper describes the methods of evaluating the effectiveness of irrigation. The indicators from the Water use efficiency group, which consider the yield obtained from a given area and the sum of irrigation doses, were considered the most reliable form of evaluation. Determining the indicator should also be accompanied by a presentation of the scope of work related to irrigation, water quality, cultivation techniques, fertilization and environmental conditions of the growing season. The work characterizes the selected pressure irrigation systems, considering their advantages and disadvantages. On this basis, the paper presents the adaptation of the SWOT analysis for two irrigation systems: a reel sprinkler with a water cannon and a drip tape

Dynamics of Volumetric Moisture in Sand Caused by Injection Irrigation—Physical Model

The study was aimed at the determination of the dynamics of spatial distribution of moisture front, caused by pointwise application of water under conditions of high pressure. This was effected through a series of simulations of water injection to a porous material with particle size distribution corresponding to that of sand. The study was composed of six independent experimental series in which the sand monolith was supplied with water doses of 250, 500, 750, 1000, 1250, and 1500 cm3 under pressure (4 bar). At the same time, measurements of volumetric moisture were conducted with the use of TDR sensors, which were positioned within the soil in a regular grid pattern. It was demonstrated that the primary cause of water movement at the moment of injection is the pressure potential gradient of water molecules. The spatial reach of moisture change in relation to the injected water dose was also defined. It was also observed that in the course of water injection there is a risk of disturbing the structure of the porous material. The correctness of the adopted method was verified through the calculation of the water balance

Ocena dokładności powierzchniowego rozkładu wilgotności objętościowej w wierzchniej warstwie gleby sporządzonego metodami geostatystycznymi

W pracy wykazano wpływ gęstości pomiarów na dokładność wyznaczania powierzchniowego rozkładu wilgotności objętościowej w wierzchniej warstwie gleby. Do analiz zastosowano metody geostatystyczne, których wykorzystanie poprzedzono wstępną oceną klasycznych miar statystycznych. Po sprawdzeniu warunku stacjonarności zbudowano semiwariogramy empiryczne z najlepiej dopasowanymi modelami matematycznymi. Wykorzystano je podczas procedury krigingu, w celu sporządzenia powierzchniowych rozkładów wilgotności. Na podstawie badań polowych przeprowadzonych w miejscowości Sarbinowo położonej na terenie gminy Mielno wykazano, że zwiększenie dokładności określenia rozkładu wilgotności jest istotne, gdy „oczko” siatki punktów pomiarowych maleje do 1 m. Powierzchniowe zagęszczanie pomiarów wiąże się ze zwiększeniem pracochłonności badań i nie powoduje istotnych zmian w dokładności wyznaczenia rozkładu wilgotności

BONITATION ANALYSIS OF TURF ON CITY STADIUM IN WROCLAW IN THE SEASON OF EURO 2012

In 2012–2013, a study was conducted, consisting in a bonitation analysis of turf on the City Stadium which is located in the north-west part of Wroclaw and was a sport arena of the European Championships Euro 2012. The experiment was made with the complete randomisation method for 2 factors, on 5 dates in the growing season. On the turf of the pitch 12 points were selected, and at each of them an evaluation of utility features was performed, in 4 replications, on surface area of 1 m2. Based on the observation of the condition of the turf, during subsequent analyses it was found how the selection of the mixture of grasses, intensity of use and pratotechnic treatments affect the bonitation quality of sport turfgrass. The results are shown in relation to the whole object, separating each of the features under analysis

Influence of variation in the volumetric moisture content of the substrate on irrigation efficiency in early potato varieties.

Potato is a plant with high water requirements. This factor affects not only the weight of potato tubers but also their quality parameters. In order to achieve quantity and quality goal, it is helpful if we apply the principles of precision agriculture, which also contributes to sustainable management of environmental resources. Accurate identification of the water requirements of crops is the basis for determining optimal irrigation doses and dates. After their application, it is possible to assess the effectiveness of irrigation treatments and their impact on the air-water conditions in soil with a root system. The aim of the presented study was to analyse the influence of volumetric soil moisture diversity on the vegetation of early potato varieties. Two potato varieties were subject to investigation: Denar and Julinka. Pot experiments were carried out at the Department of Horticulture of Wroclaw University of Environmental and Life Sciences. Three variants were analysed: one with a low water content in the soil (pF 2.7), one with the optimal water content (pF 2.5) and one with a high water content (pF 2.2). The basis for the selection of the frequency and application rate of water doses was soil moisture measured with an SM150-Kit set. Volumetric moisture was measured with a TDR apparatus. It was found that the water requirements of both potato varieties differ and increase along with the development of the aboveground and underground parts. Moreover, it was shown that the irrigation requirements of cv. Julinka are higher than those of Denar (31.4-33.0% higher), depending on the adopted variant. The research also showed that the most effective method of potato cultivation is to maintain soil moisture at a lower level. This should be taken into account in regions where the cultivation of this species uses supplementation of the water requirements by irrigation