The contamination of soil with petroleum products is a major environmental problem. Petroleum products are common soil contaminants as a result of human activities, and they are causing substantial changes in the biological (particularly microbiological) processes, chemical composition, structure and physical properties of soil. The main objective of this study was to assess the impact of soil moisture on CO2 efflux from diesel-contaminated albic podzol soils. Two contamination treatments (3000 and 9000 mg of diesel oil per kg of soil) were prepared for four horizons from two forest study sites with different initial levels of soil water repellency. CO2 emissions were measured using a portable infrared gas analyser (LCpro+, ADC BioScientific, UK) while the soil samples were drying under laboratory conditions (from saturation to air-dry). The assessment of soil water repellency was performed using the water drop penetration time test. An analysis of variance (ANVOA) was conducted for the CO2 efflux data. The obtained results show that CO2 efflux from diesel-contaminated soils is higher than efflux from uncontaminated soils. The initially water-repellent soils were found to have a bigger CO2 efflux. The non-linear relationship between soil moisture content and CO2 efflux only existed for the upper soil horizons, while for deeper soil horizons, the efflux is practically independent of soil moisture content. The contamination of soil by diesel leads to increased soil water repellency.

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The aim of the studies was the assessment of the usefulness of selected pedotransfer function for calculating the water retention of alluvial soils in Żuławy Wiślane. Żuławy Wiślane are an important area, both as far as agricultural production and environmental values are concerned. The analysis accounted for three models, i.e.: van Genuchten-Wösten, Varellyay and Mieronienko, Hewelke et al. Based on 122 dataset of alluvial soils from the Żuławy area, the statistical relationships between the measured values of total available water and values calculated for individual models were analysed. The studies carried out indicate that the analysed pedotransfer functions are characterized by different compatibilities with results obtained by means of direct measurement. The lowest average errors of fit were obtained for the Hewelke et al. and van Genuchten models.

Retencja gleb leśnych w znacznym stopniu decyduje o bilansie wodnym zlewni i przebiegu zjawisk hydrologicznych, wpływa na kształtowanie się określonego typu siedliska lasu, skład florystyczny i jakość drzewostanu. Zdolności retencyjne gleb leśnych są znacznie mniej rozpoznane niż retencja gleb użytkowanych rolniczo. Retencja może być wyznaczona zarówno metodą bezpośrednią, jak i pośrednio za pomocą tzw. funkcji pedotransfer opisującej jej związek z określonymi właściwościami fizycznymi gleby. Analizę prowadzono dla modelu regresyjnego opracowanego dla wybranych gleb leśnych z obszaru Polski oraz dla modeli van Genuchtena i Wöstena oraz Varallyaya i Mironienki. Do oceny dopasowania modeli zastosowano niezależną serię gleb leśnych. Analiza pomierzonych i obliczonych wartości potencjalnej retencji użytecznej wskazuje na dobre dopasowanie modelu regresyjnego opracowanego dla badanej grupy gleb leśnych bielicowych i brunatnych. Modele opracowane dla gleb użytkowanych rolniczo nie dają akceptowalnego statystycznie dopasowania dla analizowanych gleb leśnych. Przeprowadzone badania potwierdzają lokalny charakter funkcji pedotransfer.

Dynamic simulation of sustainable farm development scenarios using cognitive modeling. The paper presents a dynamic simulation system of sustainable development scenarios on farms using cognitive modeling. The system incorporates relevant variables which affect the sustainable development of farms. Its user provides answers to strategic issues connected with the level of farm sustainability over a long-term perspective of dynamic development. The work contains a description of the model structure as well as the results of simulations carried out on 16 farms in northern Ukraine. The results show that the process of sustainability is based mainly on the potential for innovation in agricultural production and biodiversity. The user is able to simulate various scenarios for the sustainable development of a farm and visualize the infl uence of factors on the economic and social situation, as well as on environmental aspects. Upon carrying out a series of simulations, it was determined that the development of farms characterized by sustainable development is based on additional profi t, which serves as the main motivation for transforming a conventional farm into a sustainable one. Nevertheless, additional profi t is not the only driving force in the system of sustainable development. The standard of living, market condition, and legal regulations as well as government support also play a signifi cant motivational role.