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The paper presents a method for designing a neural speed controller with use of Reinforcement Learning method. The controlled object is an electric drive with a synchronous motor with permanent magnets, having a complex mechanical structure and changeable parameters. Several research cases of the control system with a neural controller are presented, focusing on the change of object parameters. Also, the influence of the system critic behaviour is researched, where the critic is a function of control error and energy cost. It ensures long term performance stability without the need of switching off the adaptation algorithm. Numerous simulation tests were carried out and confirmed on a real stand.

In general, adaptation of cover cropping in crop rotation practices to organic tunnels by methods supporting soil health and quality has not yet been fully optimized. Effect of field pea and pea-oat cover crops to soil physicochemical properties and cash crop quality was assessed in an organic high tunnel in southern Poland in 2016–2017, with the following planting sequence: spring cover crops/tomato/romaine lettuce/green bean/iceberg lettuce. The sole pea produced a lower aboveground biomass (3.06 t ha −1 ) than the pea-oat mixture (4.17 t ha −1 ), and the N content in their biomass was 155 kg N ha −1 and 136 kg N ha −1 , respectively. The results indicated that a high residue input from cover crops was important for soil organic carbon stock, for retaining plant-available N in organic matter, and for improving soil physical properties, especially wet aggregate stability. We observed an increase in soil pH and the availability of some mineral nutrients in the soil under cover crop treatments, especially Ca, Mg, K, and P. N uptake by the subsequent cash crop significantly ( p ≤ 0.05) increased with pea than with pea-oat biculture, and in the green manure formula than with the mulch treatment. Early spring cover cropping depressed the subsequent tomato yield, but enhanced green bean yield in the second year of cropping.

The aim of this research was to recognize the role of landslides and lithology in determining the within-year variability of stream runoff in small forested catchments. The research was conducted in 2022 in three areas located in the Outer Carpathians (Poland). In each of three areas, two small catchments were selected: a catchment with landslides and a control catchment. The presence of landslides increases the within-year variability of stream runoff: the degree of increase depends on the lithology of the catchment and the properties of landslides. These two factors determine the water storage capacity of the catchments. The greatest variability in stream runoff occurs in the catchment where impermeable shale dominates in lithology and landslides are numerous but relatively small. Smaller differences occur in the catchment mainly formed of thin-bedded sandstone, where there is one medium-sized landslide covering about 30% of the catchment area. The smallest differences occur in the catchment formed mainly of thick-bedded sandstone, where the entire landslide catchment is found within one large landslide. The size of landslides determines their depth, and consequently, the depth of landslide fissures: the deeper the system of landslide fissures, the longer the water transit time, and the greater the catchment storage capacity.

The study aimed to determine the linkage between soil exchangeable potassium (K+) concentration and stream water K+ concentration during rainfall and snowmelt events in small catchments with different land use (Carpathian Foothills, Poland). The complementary geochemical and hydrochemical approach used in the study produced new information on the role of particular soil horizons and contributing areas such as hillslope or riparian areas in K+ delivery to stream channels during events. Horizons lying above the nearly impermeable fragipan (Btx) play the most important role in the process of K+ influx to streams during most event types except snowmelts with frozen soils, in all the studied catchments. In the woodland catchment, rapid flushing of K+ from the topsoil Ah horizon with higher hydraulic conductivity (Ksat) and higher exchangeable K+ concentrations than in the lying lower E horizon resulted in a clockwise hysteresis of K+ in stream water during most events. In agricultural catchments, changes in stream water K+ concentration during events were determined by distinct differences between soil exchangeable K+ concentrations on hillslopes and in riparian areas.

The purpose of the study was to determine the role of land use, seasonality, and hydrometeorological conditions on the relationship between stream water potassium (K + ) concentration and discharge during different types of floods—short- and long-duration rainfall floods as well as snowmelt floods on frozen and thawed soils. The research was conducted in small catchments (agricultural, woodland, mixed-use) in the Carpathian Foothills (Poland). In the woodland catchment, lower K + concentrations were noted for each given specific runoff value for summer rainfall floods versus snowmelt floods (seasonal effect). In the agricultural and mixed-use catchments, the opposite was true due to their greater ability to flush K + out of the soil in the summer. In the stream draining woodland catchment, higher K + concentrations occurred during the rising limb than during the falling limb of the hydrograph (clockwise hysteresis) for all flood types, except for snowmelt floods with the ground not frozen. In the agricultural catchment, clockwise hystereses were produced for short- and long-duration rainfall floods caused by high-intensity, high-volume rainfall, while anticlockwise hystereses were produced for short- and long-duration rainfall floods caused by low-intensity, low-volume rainfall as well as during snowmelt floods with the soil frozen and not frozen. In the mixed-use catchment, the hysteresis direction was also affected by different lag times for water reaching stream channels from areas with different land use. K + hystereses for the woodland catchment were more narrow than those for the agricultural and mixed-use catchments due to a smaller pool of K + in the woodland catchment. In all streams, the widest hystereses were produced for rainfall floods preceded by a long period without rainfall.

The purpose of the study was to examine the storage and transport of NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ions through snowpack, soils, and stream water in an acid‐sensitive alpine catchment (Tatra Mountains, Poland) during snowmelt and rain‐on‐snow events. Samples of snowpack layers, near‐surface soil horizons, and stream water were collected in the winter and snowmelt seasons of 2019. A laboratory experiment was conducted to determine the effect of temperature on the rate of soil nitrogen mineralization and nitrification. Our study has shown that snowpack is an important source of NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ions in the catchment. As the snow melts, the release of NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ions from snowpack occurs. A gradual and slow melting of snow starts even before the first snowmelt‐induced increase in stream discharge. NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ions eluted from available snowpack are temporarily stored in soil, which is shown by a large increase in the concentration of water‐soluble NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$in the soil at that time. NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ions are washed out of soils and supplied to streams during the first snowmelt event. This is demonstrated by a large increase in the stream water NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$concentration, termed an “NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$pulse.” The NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ion is a key acid anion responsible for the acidification of the studied stream during snowmelt season, as the NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$pulse coincides with a decrease in bicarbonate alkalinity. Our field research and laboratory experiment have shown a minor role of mineralization and nitrification in NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$production in soils in the winter and NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$pulse formation in stream water during the early stages of the snowmelt season. Key Points NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$ions eluted from snowpack in winter are temporarily stored in soils; they are washed out of soils during the first snowmelt event Large supply of NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$at the beginning of snowmelt forms an NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$pulse in stream water which results in stream water acidification The mineralization and nitrification of organic nitrogen play a minor role in NO3−${\\mathrm{N}\\mathrm{O}}_{3}^{-}$production in soils in the winter season

The purpose of the study was to determine the role of land use, seasonality, and hydrometeorological conditions on the relationship between stream water potassium (K.sup.+) concentration and discharge during different types of floods-short- and long-duration rainfall floods as well as snowmelt floods on frozen and thawed soils. The research was conducted in small catchments (agricultural, woodland, mixed-use) in the Carpathian Foothills (Poland). In the woodland catchment, lower K.sup.+ concentrations were noted for each given specific runoff value for summer rainfall floods versus snowmelt floods (seasonal effect). In the agricultural and mixed-use catchments, the opposite was true due to their greater ability to flush K.sup.+ out of the soil in the summer. In the stream draining woodland catchment, higher K.sup.+ concentrations occurred during the rising limb than during the falling limb of the hydrograph (clockwise hysteresis) for all flood types, except for snowmelt floods with the ground not frozen. In the agricultural catchment, clockwise hystereses were produced for short- and long-duration rainfall floods caused by high-intensity, high-volume rainfall, while anticlockwise hystereses were produced for short- and long-duration rainfall floods caused by low-intensity, low-volume rainfall as well as during snowmelt floods with the soil frozen and not frozen. In the mixed-use catchment, the hysteresis direction was also affected by different lag times for water reaching stream channels from areas with different land use. K.sup.+ hystereses for the woodland catchment were more narrow than those for the agricultural and mixed-use catchments due to a smaller pool of K.sup.+ in the woodland catchment. In all streams, the widest hystereses were produced for rainfall floods preceded by a long period without rainfall.

The study aimed to determine the influence of catchment characteristics and flood type on the relationship between streamflow and a number of chemical characteristics of streamwater. These were specific electrical conductivity (SC), pH, the concentrations of main ions (Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO ₃ ⁻ , SO ₄ ²⁻ , and Cl⁻), and nutrients (NH ₄ ⁺ , NO ₂ ⁻ , NO ₃ ⁻ , and PO ₄ ³⁻ ). These relationships were studied in three small catchments with different geological structure and land use. Several flood types were distinguished based on the factors that initiate flooding and specific conditions during events. Geological factors led to a lower SC and main ion concentrations at a given specific runoff in catchments built of resistant sandstone versus those built of less resistant sediments. A lower concentration of nutrients was detected in the semi-natural woodland catchment versus agricultural and mixed-use catchments, which are strongly impacted by human activity. The strongest correlation between streamflow and the chemical characteristics of water was found in the woodland catchment. Different types of floods were characterized by different ion concentrations. In the woodland catchment, higher SC and higher concentrations of most main ions were noted during storm-induced floods than during floods induced by prolonged rainfall. The opposite was true for the agricultural and mixed-use catchments. During snowmelt floods, SC, NO ₃ ⁻ , and most main ion concentrations were higher when the soil was unfrozen in the agricultural and mixed-use catchments versus when the soil was frozen. In the case of the remaining nutrients, lower concentrations of NH ₄ ⁺ were detected during rain-induced floods than during snowmelt floods. The opposite was true of PO ₄ ³⁻ .

The purpose of the study was to examine the storage and transport of ions through snowpack, soils, and stream water in an acid‐sensitive alpine catchment (Tatra Mountains, Poland) during snowmelt and rain‐on‐snow events. Samples of snowpack layers, near‐surface soil horizons, and stream water were collected in the winter and snowmelt seasons of 2019. A laboratory experiment was conducted to determine the effect of temperature on the rate of soil nitrogen mineralization and nitrification. Our study has shown that snowpack is an important source of ions in the catchment. As the snow melts, the release of ions from snowpack occurs. A gradual and slow melting of snow starts even before the first snowmelt‐induced increase in stream discharge. ions eluted from available snowpack are temporarily stored in soil, which is shown by a large increase in the concentration of water‐soluble in the soil at that time. ions are washed out of soils and supplied to streams during the first snowmelt event. This is demonstrated by a large increase in the stream water concentration, termed an “ pulse.” The ion is a key acid anion responsible for the acidification of the studied stream during snowmelt season, as the pulse coincides with a decrease in bicarbonate alkalinity. Our field research and laboratory experiment have shown a minor role of mineralization and nitrification in production in soils in the winter and pulse formation in stream water during the early stages of the snowmelt season. ions eluted from snowpack in winter are temporarily stored in soils; they are washed out of soils during the first snowmelt event Large supply of at the beginning of snowmelt forms an pulse in stream water which results in stream water acidification The mineralization and nitrification of organic nitrogen play a minor role in production in soils in the winter season

The aim of the study was to identify the factors that influence annual changes in the chemical composition of stream waters. The research area was located in the marginal zone of the Carpathian Foothills (Poland) in the Stara Rzeka catchment (mixed land-use) and its two sub-catchments: Leśny Potok (wooded) and Kubaleniec (farmed). Hydrochemical studies were carried out during the 1998–2004 water years and with separate recording frequencies for individual parameters. Measures used included specific conductance (SC), pH and the concentration of the main ions (Ca2+, Mg2+, Na+, K+, HCO3–, SO42–, Cl–) and nutrient compounds (NH4+ , NO2–, NO3–, PO43–). Tendencies towards changes in chemical parameters were estimated using the Seasonal Kendall Test. Elimination of flow rate impact on the chemical composition of stream waters was achieved using the residuals from the LOWESS analysis. During the analysed period, a statistically significant increase in SC and the concentration of the majority of main ions occurred. Additionally, there was an increase in the concentration of nutrient compounds in watercourses undergoing the anthropogenic impact (Kubaleniec, Stara Rzeka), as opposed to the Leśny Potok stream draining the wooded catchment. The SC changes were determined by a decrease in the annual river run-off and simultaneous ion concentration (natural factor). In the Stara Rzeka catchment, the increase in NH4+ concentration was caused by the increase in sewage discharge into the river (anthropogenic factor). Another factor that contributed to the annual changes of water chemistry was gradually deeper and deeper water-circulation (circulation factor), responsible for an increase in the concentration of Na+ and Cl– and a decrease of HCO3–3– and Ca2+.