Browsing by Author "Skowron, Piotr"
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Item An overview of plant responses to the drought stress at morphological, physiological and biochemical levels(Instytut Uprawy Nawożenia i Gleboznawstwa – Państwowy Instytut Badawczy w Puławach) Wach, Damian; Skowron, PiotrItem Analiza zmienności składu chemicznego nawozów naturalnych w rejonie środkowo-wschodniej Polski(Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy, 2019) Skowron, Piotr; Wach, Damian; Jadczyszyn, Tamara; Tkaczyk, PrzemysławItem Enterobacteriaceae in Sewage Sludge and Digestate Intended for Soil Fertilization(MDPI, 2024) Wójcik-Fatla, Angelina; Farian, Ewelina; Kowalczyk, Katarzyna; Sroka, Jacek; Skowron, Piotr; Siebielec, Grzegorz; Zdybel, Jolanta Małgorzata; Jadczyszyn, Tamara; Cencek, TomaszSubstances of organic origin are seeing increasing use in agriculture as rich sources of nutrients for plants. The aim of this study was to determine the microbiological contamination of sewage sludge and digestate to assess their safe use as fertilizers in Poland. The assessment of microbial soil, sewage sludge and digestate contamination was based on the total number of mesophilic bacteria and Gram-negative bacteria from the Enterobacteriaceae family. The presence of Escherichia coli and Salmonella spp. was identified via culture and the presence of Enterobacteriaceae species was determined via biochemical and molecular methods. In laboratory conditions, the survival of E. coli in soil fertilized with sewage sludge or digestate inoculated with a reference strain was determined. The average concentration of Enterobacteriaceae in soil, sewage sludge and digestate samples was 1.1 × 104 CFU/g, 9.4 × 105 CFU/g and 5.6 × 106 CFU/g, respectively. Escherichia coli was detected in all sample types. From the soil samples, Serratia, Enterobacter, Pantoea, Citrobacter and Pseudomonas genera were identified the most frequently, while in sewage sludge and digestate, E. coli was predominant. Based on the results of our laboratory experiment, it can be concluded that after three weeks, fertilization with organic waste in acceptable doses does not significantly increase soil contamination with Enterobacteriaceae.Item Genetic diversity, virulence factors and drug resistance of Pantoea strains isolated from samples of fresh fruits, vegetables and soil(Państwowy Instytut Weterynaryjny - Państwowy Instytut Badawczy, 2025-09-13) Farian, Ewelina ; Kowalczyk, Katarzyna; Kłapeć, Teresa; Sroka, Jacek; Skowron, Piotr ; Siebielec, Grzegorz; Jadczyszyn, Tamara ; Zdybel, Jolanta Małgorzata ; Cencek, Tomasz ; Wójcik-Fatla, AngelinaPantoea is a genus of Gram-negative bacteria from the Erwiniaceae family. These bacteria are opportunistic human pathogens which are widely distributed in plants and soil. This study aimed to reveal the genetic diversity of Pantoea isolates from food and soil, characterise them biochemically and evaluate their drug resistance. Material and Methods: Thirty Pantoea strains were isolated from fresh fruit (n = 2), fresh and minimally processed vegetables (n = 12) and soil samples (n = 16). The genomic DNA was isolated from cultures on nutrient agar, and species were identified by amplification of 16S ribosomal RNA and housekeeping gene fragments and confirmed by sequencing. Virulence gene presence was determined by amplification of the hcp (haemolysin-coregulated protein), vgrG (glycine-valine repeat sequence G), acrA (anti–clustered regularly interspaced short palindromic repeat protein A) and acrB genes. Isolate drug resistance was tested using the disc-diffusion and gradient strip methods. The presence of Ambler class C (AmpC) β-lactamase (βL) and extended-spectrum (ES) βL resistance genes was tested for. Results: Five species were identified: P. agglomerans (n = 24), P. ananatis (n = 1), P. eucalypti (n = 1), P. conspicua (n = 1) and P. vagans (n = 2). The hcp and vrgG virulence genes were detected in 7 and 1 strain, respectively. All strains showed high resistance to cephazolin and cephuroxime, and more than half did so to ampicillin. The production of AmpC βL and ESβL was confirmed in 22 and 25 strains, respectively. Three strains of the Pantoea bacteria, including P. ananatis from leeks and P. agglomerans from arugula and soil, showed resistance to three or more antimicrobial classes. Conclusion: Pantoea spp., including multidrug-resistant strains, in fresh foods pose a potential risk of infection to consumers.Item Plan nawożenia jako praktyka promująca racjonalne zarządzanie nawozami i ograniczająca straty biogenów(Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy, 2022) Skowron, Piotr; Jadczyszyn, TamaraItem Productive and Environmental Consequences of Sixteen Years of Unbalanced Fertilization with Nitrogen and Phosphorus—Trials in Poland with Oilseed Rape, Wheat, Maize and Barley(MDPI, 2020) Rutkowska, Agnieszka; Skowron, PiotrTwo factorial field experiments were carried out between 2003 and 2018 in the Experimental Stations in Eastern and Western Poland using four crop rotations with winter oilseed rape, winter wheat, maize and spring barley. The initial value of phosphorus (P) in Grabów soil was 69.8 mg P·kg−1 soil and in Baborówko soil it was 111.3 mg P·kg−1 soil (Egner-Riehm Double-Lactate DL). P fertilizer was added annually at 39 kg P·ha−1 under winter oilseed rape, 35 kg P·ha−1 under maize and 31 kg P·ha−1 under wheat and barley using superphosphate and nitrogen (N), which was added at five levels (30–250 kg N·ha−1) per year as ammonium nitrate in addition to controls with no added fertilizer. Through the several years of the experiment, P fertilizer had no effect on crop N use efficiency (NUE) nor crop productivity. There was significant soil P mining particularly in the high-N fertilizer trials causing a reduction in the content of available soil P by up to 35%. This work recommends that, based on soil P analysis, P fertilizer should not be added to high-P soils. This practice may continue uninterrupted for several years (16 in this case) until the excess soil P has been reduced. This mechanism of removal of “legacy” P from soil has major implications in reducing runoff P into the Baltic Sea drainage area and other water bodies.Item Reconstructing missing data by comparing imputation and interpolation techniques: applications for long-term groundwater monitoring(Nature Portfolio, 2026) Bronowicka-Mielniczuk, Urszula; Mielniczuk, Jacek; Skowron, PiotrMissing data is a pervasive challenge in environmental monitoring, severely hindering reliable analysis and effective water resource management. This study addresses this issue in the context of the EU Nitrates Directive (91/676/EEC), focusing on the proportion of groundwater monitoring sites expected to exceed the regulatory limit of 50 mg NO₃⁻/L. Overall, 57% of observations were missing, with 99% of monitoring stations experiencing data gaps over the 2000–2024 study period. Six reconstruction techniques were evaluated: k-nearest neighbours, multiple imputation by chained equations, missForest, natural neighbour, inverse distance weighting, and indicator kriging. This work presents a novel approach to comparing various imputation techniques for reconstructing threshold overruns and modelling trends in exceedance rates. Moving beyond conventional error metrics, the evaluation is grounded in distributional similarity and monotonic dependence using Hellinger and Kullback-Leibler distances and generalised Lorenz curves. Based on the comparative analysis, indicator kriging was identified as the most robust approach and was subsequently adopted to parameterise the log-linear trend in the proportion of monitoring stations expected to exceed the concentration threshold. This study provides a methodological framework for addressing extreme missingness in environmental monitoring networks, offering actionable insights for EU Member States reporting under the Nitrates Directive.Item Zapobieganie zanieczyszczeniom zasobów wód przez nawozy wykorzystywane w praktyce rolniczej(Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy, 2023) Skowron, Piotr; Wach, DamianItem Zarządzanie nawozami naturalnymi w wybranych krajach Unii Europejskiej(Instytut Uprawy Nawożenia i Gleboznawstwa Państwowy Instytut Badawczy, 2020) Skowron, Piotr; Jadczyszyn, Tamara