Ograniczanie wyników
Czasopisma help
Autorzy help
Lata help
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 377

Liczba wyników na stronie
first rewind previous Strona / 19 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  nitrogen
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 19 next fast forward last
EN
Soil degradation occurs as a result of the ingress and accumulation of excessive amount of pollutants in the soil. The article presents the results of theoretical and experimental studies of the complex effect of soil contamination (concentration of petroleum products, toxic salts, dense residue, sodium ions, sulfate ions, magnesium ions, calcium, chloride ions, bicarbonate ions) on the content of nutrients (alkaline hydrolyzed nitrogen, phosphorus, potassium, humus). A detailed analysis of scientific papers has been carried out, based on which the main scientific tasks solved in the article have been formulated. It has been established that soil-salt processes are insufficiently studied and are the object of scientific research in recent years. At the first stage of research, sampling was carried out and the content of nutrients and pollutants in the soil was determined. Determination of element concentrations was performed by collecting soil samples and their subsequent laboratory testing. At the second stage, a correlation-regression analysis of the obtained data was performed and multiple linear regressions were established. The interaction of substances in the soil was determined by analyzing the obtained multiple linear regressions. Two types of soils were studied: with chloride and with sulfate type of salinization. For soils with chloride type of salinity, dependences have been established for the content of humus, alkaline nitrogen and potassium, while in case of phosphorus multiple linear regression does not exist. For soils with sulfate type of salinization, multiple linear regression dependences of concentrations of alkaline nitrogen, phosphorus, potassium have been determined. It is established that the complex influence of the studied elements is decisive. No regression dependence was found for the humus content, which indicates that the concentration of the studied elements has almost no effect on the humus content in the soil. Comparison of the obtained multiple linear regressions with the results of laboratory studies showed a good correlation between these data series. The obtained regularities of pollutant and nutrient interactions in soils are expected in future to enable creation of scientific bases for development of new methods of desalination of soils polluted by formation waters as well as for planning effective reclamation actions.
PL
W wyniku wnikania i gromadzenia się w glebie nadmiernych ilości zanieczyszczeń następuje degradacja gleby. W artykule przedstawiono wyniki badań teoretycznych i eksperymentalnych złożonego wpływu zanieczyszczenia gleby (stężenie produktów naftowych, toksycznych soli, gęstego osadu, siarczanow, jonów sodu, magnezu, wapnia, chlorków, wodorowęglanów), na zawartość składników pokarmowych (hydrolizowanego alkalicznie azotu, fosforu, potasu, humusu). Przeprowadzona została szczegółowa analiza prac naukowych, na podstawie której sformułowano główne zadania badawcze rozwiązane w artykule. Stwierdzono, że procesy glebowo-solne zbadane są w stopniu niedostatecznym i stanowią one przedmiot badań naukowych w ostatnich latach. W pierwszym etapie badań pobrano próbki i wyznaczono zawartość składników pokarmowych i zanieczyszczeń w glebie. Wyznaczenia stężeń pierwiastków dokonano poprzez pobranie próbek gleb i ich późniejsze badania laboratoryjne. W drugim etapie wykonano analizę korelacyjno-regresyjną uzyskanych danych i ustalono wielokrotne regresje liniowe. Oddziaływanie substancji w glebie określono poprzez analizę otrzymanych wielokrotnych regresji liniowych. Badano dwa rodzaje gleb: o zasoleniu chlorkowym i siarczanowym. Dla gleb o zasoleniu chlorkowym ustalono zależności w odniesieniu do zawartośći humusu, azotu hydrolizowanego alkalicznie i potasu, natomiast dla fosforu regresja liniowa wielokrotna nie wystapiła. Dla gleb o zasoleniu siarczanowym wyznaczono zależności wielokrotnej regresji liniowej stężeń azotu alkalicznego, fosforu, potasu. Ustalono, że decydujące znaczenie ma kompleksowe oddziaływanie badanych pierwiastków. Dla zawartości humusu nie stwierdzono zależności regresji, co wskazuje, że stężenie badanych pierwiastków prawie nie wpływa na zawartość humusu w glebie. Porównanie uzyskanych wielokrotnych regresji liniowych z wynikami badań laboratoryjnych wykazało dobrą korelację między tymi seriami danych. Uzyskane prawidłowości oddziaływania zanieczyszczeń i składników pokarmowych w glebach pozwolą w przyszłości stworzyć naukowe podstawy rozwoju nowych metod odsalania gleb zanieczyszczonych wodami złożowymi, jak również planować efektywne prowadzenie prac rekultywacyjnych.
PL
W artykule zaprezentowano wyniki badań laboratoryjnych wpływu rodzaju gazu napędowego oraz objętościowego natężenia przepływu wody na skuteczność gaśniczą zaprojektowanego i wykonanego stałego urządzenia mgłowego. Jako gaz napędowy zastosowano powietrze sprężone lub azot. Podczas badań mierzono temperaturę i szybkość jej spadku, czas stłumienia płomienia testowego pożaru oraz stężenie tlenu w pomieszczeniu. Do testów pożarowych użyto stosu belek z drewna sosnowego. Największą skuteczność gaśniczą systemu mgłowego otrzymano w przypadku testu, w którym objętościowe natężenie przepływu wody wynosiło 3 dm3/s i czynnikiem napędowym był azot. Uzyskane wyniki pokazują, że rodzaj zastosowanego gazu w systemie mgłowym ma znaczenie, gdyż bierze on udział w gaszeniu, co podważa zapisy normy NFPA 750, która zakłada, że czas gaszenia wymagany przez normę jest tak krótki, że rodzaj gazu nie ma wpływu na proces stłumienia pożaru.
EN
The article presents the results of a laboratory study of the effect of the type of propellant and the volumetric flow rate of water on the extinguishing effectiveness of a designed and manufactured fixed water mist fire protection system. Compressed air or nitrogen was used as the driving gas. During the tests, the temperature and its rate of decrease, the time of suppression of the test fire flame and the oxygen concentration in the room were measured. A stack of pine wood beams was used for the fire tests. The highest extinguishing efficiency of the water mist system was obtained for the test, where the volumetric flow rate of water was 3 dm3/s and the driving agent was nitrogen. The results show that the type of gas used in the water mist fire protection system and takes part in extinguishing, which undermines the provisions of the NFPA750 standard. The standard assumes that the extinguishing time used by the standard is so short that the type of gas does not affect the fire suppression process itself.
EN
This study aimed to investigate how great cormorants and grey herons affect the density and trophic diversity of soil nematodes under breeding colonies located in Stawy Raszyńskie Nature Reserve (central Poland). Soil samples from the colonies were compared to control samples from adjacent areas unaffected by birds. Samples were taken at each site (two colonies and two relevant control sites) to a depth of 20 cm, and the soil cores were split into topsoil (0-10 cm) and subsoil (10-20 cm). A modified Baermann method was used to extract nematodes from the soil. The soil under nests supported more abundant nematode communities, but with a lower trophic diversity compared to the control sites. The cormorants had a greater impact on nematodes than the herons. We found that the external nitrogen input, the higher organic matter content and abundance of ammonifying bacteria, as well as the lower soil pH under the colonies than in the control sites, affected the nematode trophic groups in different ways. Compared to the control sites, there were significantly more bacterivorous nematodes but fewer herbivorous nematodes under the colonies. No predatory nematodes were found under the bird colonies and, in the case of the cormorant colony, no omnivorous nematodes. No significant differences in the abundance of fungivorous nematodes between the impact and the control plots were noticed. The results indicate that allochthonous input under bird colonies promotes microbial activity and the most opportunistic trophic group of nematodes, which may at least temporarily enhance decomposition and mineralisation processes and consequently affect nutrient cycling in the wetland soil.
4
Content available Nitrogen relationships in Polish cropping systems
EN
Based on FAO data, the paper presents trends in nitrogen (N) input and output in Poland. As N input (Ninp), nitrogen from mineral fertilisers, manure application, biological fixation, and deposition was included. The N outputs (Nout) include the N contained in crop harvest (main products and by-products). The trend analyses were carried out for the period before (1961-1989) and after (1990-2018) the changes in the political and economic systems. Additionally, trends in the nitrogen use efficiency (NUE) and nitrogen surpluses (NS) are presented for these periods. In both compared periods, the mean values of N budget indicators in Poland were (kg N∙ha-1 UAA): Ninp 120 and 125, Nout 61 and 84, NS 60 and 41 and NUE 53 and 67%, respectively. The estimated Ymax, which represents the Nout value reached at saturating N fertilisation, reached the values of 127 and 263 kg N∙ha-1 UAA in these periods. The difference in these values suggests a significant impact of agronomy improvement on Nout in the recent period. The trends of nitrogen within 16 regions in period 2002-2019, based on national data, resulted in a significant variation in N indicators. The values found were in the following ranges (kg N∙ha-1 UAA): Ninp 78-167; Nout 62-99; NS 15-83 and Ymax 139-317. The NUE ranged from 50-81%. The obtained results indicate that in Poland and its regions there is still a need to improve of the nitrogen efficiency.
EN
The objective of the study was to trace the variability of the hydrochemical conditions in three lakes of the West Pomeranian Voivodeship (Poland) - Starzyca, Maszewskie and Nowogardzkie in the annual cycle. The research was done in 2018-2019, and samples for analysis were collected 4 times a year. All analyses were performed applying standard methods. Such hydrochemical indices were determined as dissolved oxygen, chemical oxygen demand, content of orthophosphates, total phosphorus, nitrite, nitrate, ammonium, chlorophyll a and iron. The study showed that all lakes in the research cycle were characterised by a polymictic type of water mixing, and the trophic level, based on the adopted criteria, indicated advanced eutrophy, which may also be caused by anthropogenic pressure. Oxygen conditions characterised by deoxidation of the waters in the bottom layer in the spring and summer seasons, and clear oxygenation in the surface water layer (in Lake Maszewskie reaching even 188.5% in the spring) confirm the significant advancement of the eutrophication process. The supply of phosphorus and nitrogen in spring from pelagic waters in the waters of the examined lakes influences concentrations of chlorophyll a in the summer. The influence of “internal supply” (bottom waters and bottom sediments) on the amount of nutrients available for autotrophs is clearly visible in the analysed lakes - an increase in nitrogen and mineral phosphorus concentrations in relation to surface waters was observed in the bottom layer.
EN
The purpose of this study has been to determine the effect of fertilisation with urea-ammonium nitrate (UAN) solution enriched with P, Mg or S on the content of macronutrients in the grain and straw of maize. The following fertilisers were tested in the field experiment: ammonium nitrate, urea, UAN - 32% N; RSM+S - 26% N + 3% S; RSM+P(Medium) - 26% N and 4.80% P; RSM+P(Starter) - 21% N and 7.86% P; UAN + Mg - 20% N + 4% Mg. In each year of the experiment, significant differentiation in the contents of P, K, Ca, Mg and S in maize grain and straw was observed, depending on the applied nitrogen fertilisation. However, considering the average values from each treatment achieved over the three years, it was demonstrated that the fertilisation significantly changed only the content of P and S in grain and K and Ca in straw of maize. The removal of nutrients was the highest in the second year of the research and amounted in kg∙ha-1 : P - about 100, K - about 350, Ca - about 80, Mg - about 35 and S - about 31, which in turn were differentiated over the years of the experiment in the three years. The removal of P, K, Mg and S also significantly depended on fertilisation. Significant differences, however, most often concerned the control treatment relative to the fertilised ones. The contribution of grain to the accumulation of nutrients also varied significantly in the three years of the experiment. Significantly the lowest share of grain in terms of P and S accumulation was noted in maize grown without N fertilisation.
EN
Phytoplankton growth is influenced by the presence of nutrients N (nitrogen) and P (phosphor). Each region has a specific N/P ratio, due to the influence of anthropogenic inputs. This study aimed to assess the response of phytoplankton chlorophyll-a (Chl-a) biomass due to differences in N/P ratio by the influence of river flow in the north coast of Java; Jobokuto Bay (Jepara), the coastal waters of Semarang and the front of the Cisadane river. N-nutrients were analyzed in the form of N-NO3 (nitrate), and N-NH4+ (ammonium ions), and orthophosphate ions (P-PO42-). Nutrient analysis was spectrometric, using the reduction methods (nitrate), ammonium (indophenolblue), and phosphate (molybdenum-blue). Test for site differences using Kruskall-Wallis, followed by a posthoc test. The results showed that Semarang waters had a lower N/P (Stoichiometric) ratio than Jepara and Cisadane, which can be used to predict that P nutrient input is higher than N. This high P input impacts microalgal development (chlorophyll-a). In addition, we also found Semarang waters to have higher speciation of inorganic N in the form of ammonium, which is one of the drivers of eutrophication in these waters. The use of a ratio of N/P is very important in estimating the eutrophication process and can be used to estimate the dominance of nutrients entering the water due to anthropogenic activities in the upstream area.
EN
The primary aim of the current study is to investigate the influence of input parameters of near dry electric discharge machine (ND-EDM) upon the output performances including the MRR, EWR, SR and WLT for the fabricated new metal matrix composite (MMCs) of aluminum A7075 matrix nanocomposites by adding 8% of Microscopic Slide Glass Nanoparticles (MSGNPs) as reinforcements to improve the metallurgical and mechanical properties of Al-7075/MSGNP composites using stir-casting method. In (ND-EDM), the dielectric medium plays a significant role in the procedure responses. In the current work, the vegetable oil with gases, such as air, Ar, mix (Ar+N2), and Freon were used as a dielectric media. The obtained results show that the highest MRR achieved when using the vegetable oil + Freon gas, reached 29.425 mm3/min, and then 26.943 mm3/min when using the vegetable oil + Air as a dielectric. The lowest EWR achieved when employing the vegetable oil + Argon gas, reached 0.120 mm3/min, and then 0.175 mm3/min. The lowest SR values obtained for all the designed experiments reached 3.287 µm when using Ip (10 A), Ton (1600 µsec), and Ar additive gas, followed by 4.567 µm when adding Freon gases to the dielectric. In the ND-EDM, the average of recast white layer thickness in the case of vegetable oil + air, vegetable oil + Ar, vegetable oil + mix (Ar-N2), and vegetable oil + Freon was 1.505, 1.180, 0.456, and 0 μm, respectively. These unique results can be used to increase the service and fatigue life of parts and machines that are exposed to sudden dynamic mechanical or thermal loads, without the need for additional operations to remove this brittle layer, which causes the failure of these parts with a short service life. The created mathematical models displayed a higher value of R-Square and the adjusted R-square, which manifest a better fit. Normal probability plots of the residuals for MRR, EWR, and SR elucidated an obvious pattern (i.e., the points were stabilized in a straight line) which indicates that every factor affects the mentioned responses and the outcomes of these responses from the regression model (predicted value by factorial) and the true values (from the experiments).
PL
Materia organiczna gleby odgrywa istotną rolę w chemicznych, mikrobiologicznych i fizycznych aspektach żyzności gleby. Odpady organiczne przekształcone w humifikowany materiał organiczny w procesie kompostowania można wykorzystać jako organiczne dodatki zwiększające zawartość materii organicznej i poprawiające żyzność gleby. Jakość kompostu różni się w zależności od rodzaju kompostowanych odpadów i technologii procesu kompostowania i jest bardzo istotna, zwłaszcza jeśli chodzi o optymalną zawartość pierwiastków, takich jak fosfor i azot. Przedstawiono wyniki badań zawartości P i N dla czterech różnych rodzajów kompostów.
EN
Four types of compost (household composts, rural compost processed by poultry and 2 composts from the mech.-biolog. treatment plant of municipal waste) were studied for P and N content. The lowest av. P and N content was recorded in rural compost, 1.6 and 1.5% by mass, resp., and the highest in household compost, 3.2 and 2.7% by mass, resp.
EN
This study aims to examine the physicochemical parameters of seawater (temperature, pH, salinity, dissolved oxygen, suspended particulate matter, ammonium-nitrogen, nitrite-nitrogen, nitrate-nitrogen, and phosphate-phosphorus, burnable organic matter in the sediment), and possible effects of pollution in Sığacık Bay where different anthropogenic activities are carried out. Samples of surface seawater (0 m), bottom seawater (2 m), and sediment were collected monthly from four sampling sites between September 2013 and September 2014. Annual mean nutrient values were determined as 1.6 ± 0.14 μg.at.NH4+-N l-1, 0.1 ± 0.01 μg.at.NO2--N l-1, 0.8 ± 0.08 μg.at.NO3--N l-1, 0.7 ± 0.08 μg.at.PO43--P l-1, SPM 21.4 ± 0.33 mg l-1. The BOM content in the sediment was 5.6 ± 0.39%. As a result of the study, it was determined that Sığacık Bay was polluted by anthropogenic point and non-point source pollution. According to the water quality criteria, the bay was found to be in the group of polluted seawater in terms of phosphate phosphorus.
EN
Plant growth-promoting rhizobacteria (PGPR) isolated from the rhizosphere soil of eight field crops at different locations in Egypt were identified. Rhizobacteria strains were identified as Bacillus endophyticus AW1 5, B. filamentosus EM9, ET3, Micrococcus luteus KT2, FW9, FC13, SaW4, Enterobacter cloacae SK18, Pseudomonas azotoformans TPo10, Citrobacter braakii TC3. All isolates solubilised insoluble phosphate and produced IAA, while only six were able to produce siderophores in vitro. Vegetative growth and yield of wheat cv. ‘Sakha 94’ were enhanced after the application of single inoculation of each isolate compared to the control. Grain yield was increased by 20.7-96.5% over the control according to bacterial isolates. Available phosphorus (P) and counts of total bacteria in soil were observed to be significantly increased in treatments than in control. After the wheat harvest, soil pH was observed to be decreased, and a highly significant negative correlation was observed between soil pH and the levels of available phosphorus. Significant increases in grain and straw yields, as well as uptake of nitrogen (N) and P by plants, were observed due to inoculation with PGPR isolates. Levels of photosynthetic pigments, free amino acids, free phenolics, and reducing sugars in flag leaf and spikes were significantly enhanced by the application of all PGPR isolates compared to the control. Thus this study identifies the PGPR isolates for the improvement of the growth, yield, and quality of wheat. The study may be also useful for field evaluation under different soils and environmental conditions before generalising PGPR isolates as biofertilisers.
EN
The application of fertilizers based on sewage sludge significantly affects the formation of the nitrogen fund of sod-podzolic soil, as well as changes in the content of mobile compounds of phosphorus and potassium exchange. The application of such fertilizer under Jerusalem artichoke has a positive effect on the nitrogen content of alkaline hydrolyzed compounds, in particular on increasing the content of mineral and alkaline hydrolyzed nitrogen fractions. The application of sewage sludge at a dose of 20–40 t/ha and the appropriate compensatory dose of mineral fertilizers at the rate of N90P90K90 helps to increase the content of ammonium nitrogen compounds from 16 to 20–22 mg/kg of soil in the upper (0–20 cm) layer – 28% prevails over the control variant, as well as the content of nitrate nitrogen compounds in the layer 0–40 cm from 1.70 to 2.52–2.64 mg/kg of soil. The ratio of the content of alkaline hydrolyzed nitrogen compounds to the nitrogen content of mineral compounds in the experimental conditions changes insignificantly, which indirectly indicates a relatively stable value of this indicator, which changes little under the influence of fertilizers. The application of sewage sludge as a fertilizer significantly affects the change in the content of mobile phosphorus compounds and potassium exchange compounds in the upper (0–40 cm) layer of the soil. However, from a depth of 60 cm, their content decreases sharply and approaches the initial values of the control version. Depending on the application of fertilizers, the indicators of the coefficient of concentration of macronutrients in the soil change significantly, which reflects the ratio of the content of the element in the soil to its content in the control variant. As the rate of sewage sludge increases, the element concentration coefficient increases from 1.27 in the variant with the application of only mineral fertilizers to 2.36 for potassium and for phosphorus – from 1.02 to 1.31. There is a close correlation between the content of phosphorus and potassium in the soil and the coefficients of their concentration. This relationship reflects the multiple coefficient of determination, which for phosphorus and potassium is R2 = 0.69 and R2 = 0.90, respectively. The use of fertilizers in the form of compost with sewage sludge and straw of cereals causes similar trends as the introduction of uncomposted sewage sludge. However, this effect has less radical impact with lower absolute nutrient content compared to the introduction of fresh sewage sludge. The application of sewage sludge in the form of compost and uncomposted form contributes to a significant increase in the content of macronutrients in the soil, providing an improvement in the mineral nutrition of cultivated plants, including Jerusalem artichokes.
EN
Intensive use of the chernozem soils of Northern Kazakhstan since the development of virgin lands has led to soil erosion and loss of humus. Since 1954, according to researchers, 1.2 bln tons of organic matter have been irretrievably lost. During this period, the methods of tillage have changed significantly from surface to subsurface tillage, which led to a change in the method of accumulation of organic residues in the soil. The purpose of this study was the short-term monitoring of spring wheat cultivation technologies to observe their influence on crop productivity and soil agrocenosis. A virgin plot was used as a standard of soil fertility. Determination of nutrients in the soil was carried out by using the method of "wet chemistry" with spectrophotometric termination. An infrared analyzer was used to assess the grain quality. The identification of soil microorganisms was carried out on nutrient microbiological media, such as meat-and-peptone agar, starch-and-ammonia agar, and Czapek-Dox agar. The results of three-year studies showed that the humus content in the variants with permanent wheat decreased to 3.26–3.38%. The greatest decrease in humus content was observed in the two-field grain and fallow crop rotation (2.48%). The decrease in the amount of humus occurred as a result of insufficient intake of plant residues and mineral fertilizers. The content of nitrate nitrogen and mobile phosphorus in virgin soil is low. Soil micromycetes dominate on virgin lands, whereas ammonifiers and immobilizers dominate on cultivated soils. The high level of carbon dioxide emissions on virgin land (3.0 C2 kg/ha/hour) is due to the presence of a large amount of plant biomass. The most optimal variant out the considered technological backgrounds from the point of view of increasing yields up to 15.8 c/ha and preserving soil fertility (3.26% humus content) is the cultivation of permanent wheat with the introduction of fertilizers and herbicides. The use of two-field grain and fallow crop rotation leads to irreplaceable losses of organic matter (2.48%).
EN
The study has investigated the individual and combined effects of nitrogen and potassium on the growth, grain yield, and quality of quinoa in ferralsols and acrisols. The experiments were conducted during the dry season under rainfed conditions in Central Highland, Vietnam. The factorial design was a randomized complete block design with three replications. The results revealed the positive impacts of nitrogen and potassium on the growth and yield of quinoa. However, after the application of an optimum dose of nitrogen, growth, and yield were not significantly changed and even decreased when the dose continued increasing. Higher levels of nitrogen and potassium application resulted in greater protein and fat content, but lower starch and fiber contents, compared to lower levels. The fertilizer practice has to rely on soil fertility. The study shows that the application of 150 kg N and 105 kg K2O ha-1 could be the optimum rate of nitrogen and potassium for quinoa production in ferralsols and acrisols in Central Highland.
EN
The article presents the results of research aimed at determining the catchment areas that pose a risk of nitrogen pollution of the waters of the Mała Panew river. The research was carried out in 13 permanent monitoring points located on the Mała Panew. The location of the points ensured the representativeness of the water quality results for parts of the catchment area with a homogeneous type of land use. Concentrations of nitrate-nitrogen (NO3-N) and total nitrogen (TN) were determined in the samples taken. The content of (NO3-N) in the third quarter of the year and its relation to the value obtained for the first year quarter may be an indicator of the impact of agricultural activities on the quality of water in streams. In the case of agricultural catchments, the lowest concentrations of (NO3-N) and TN occur in the third quarter of the year and are significantly lower than in the first quarter of the year. The demonstrated seasonal variability of nitrate nitrogen concentrations in agriculturally used areas may be used to determine the type of pressure not allowing to achieve good water status in the surface water body. It was shown that the highest unit increments occurred in areas with a high proportion of forest.
PL
Celem pracy było wyznaczenie zlewni cząstkowych, które stwarzają zagrożenie zanieczyszczenia wód Małej Panwi azotem. Podjęto próbę sklasyfikowania typu użytkowania zlewni (rolniczy/leśny) jako potencjalnego źródła zanieczyszczenia wody w rzece. Zweryfikowano hipotezę dotyczącą związku sezonowej zmienności zawartości związków azotowych, szczególnie w formie azotanowej, z rolniczym użytkowaniem obszaru zlewni cząstkowej. Materiał do badań stanowiły próbki wody z rzeki Mała Panew pobrane w 13 stałych punktach monitoringowych. Lokalizację punktów poboru próbek wyznaczono na podstawie analizy przestrzennego zagospodarowania terenu w oparciu o materiały kartograficzne. Ich lokalizacja zapewniła reprezentatywność wyników jakości wody dla fragmentów zlewni o jednorodnym typie użytkowania terenu. W celu określenia ładunków zanieczyszczeń w wodzie Małej Panwi wyznaczono przepływ średni z wielolecia Q (m3·s-1). W pobranych próbkach oznaczono stężenia azotu azotanowego (NO3-N) i azotu ogólnego (TN). W przypadku zlewni rolniczych najniższe stężenia azotu azotanowego (NO3-N) i TN występują w III kwartale i są znacznie niższe niż w I kwartale. Zawartość azotu azotanowego w trzecim kwartale roku i jego stosunek do wartości uzyskanej dla pierwszego kwartału może być wskaźnikiem wpływu działalności rolniczej na jakość wody w ciekach. Wykazana sezonowa zmienność stężeń azotu azotanowego na terenach użytkowanych rolniczo może być wykorzystana do określenia rodzaju presji nie pozwalającej na osiągnięcie dobrego stanu wód w danej jednolitej części wód powierzchniowych. Wykazano, że najwyższe przyrosty jednostkowe występowały na obszarach o dużym udziale lasów.
EN
Influence of thermal modification in nitrogen atmosphere on the gloss of black poplar (Populus nigra L.). Heat treatment of wood is a process to which improve mechanical and physical properties. During this treatment is observed changes aesthetic properties of wood among others gloss. The aim of this research was to conduct the influence of time and temperature on surface gloss of black poplar wood (Populus nigra L.). Wood was modified by heat treatment process in nitrogen atmosphere in temperaturę from 160 °C to 220 °C, and during the following time periods 2 h - 8 h. Under the influence of modification Surface of modified wood change the gloss of black poplar wood. There was correlation between temperaturę and gloss changing and longer time of treatment. In temperaturę 220 °C decrease og gloss was 45 % for radial section and 52 % for tangential section. Influence of time and temperature on modified black poplar wood was different and depend on section. Temperature of modification was in 20 % accountable for gloss change on radial section and in 38 % for gloss change on tangential section. Influence of time during the proces was much smaller then temperaturę parameters and was 3 % and 5 % respectively for radial and tangential section.
PL
Wpływ modyfikacji termicznej w atmosferze azotu na połysk drewna topoli czarnej (Populus nigra L.). Modyfikacja termiczna drewna przeprowadzana jest w celu poprawy właściwości fizycznych oraz mechanicznych. Pod wpływem obróbki następuje zmiana właściwości estetycznych drewna, w tym również połysku. Celem prowadzonych badań było określenie wpływu temperatury i czasu modyfikacji na połysk drewna topoli czarnej (Populus nigra L.). Drewno topoli czarnej było modyfikowane termicznie w atmosferze azotu w temperaturze od 160 °C do 220 °C, od 2 h do 8 h. Pod wpływem procesu modyfikacji nastąpiła zmiana połysku drewna topoli czarnej. Zmiany były intensywniejsze im wyższa była temperatura i dłuższy czas obróbki. W temperaturze 220 °C uzyskano spadek wartości połysku o 45 % oraz o 52 % odpowiednio dla przekroju promieniowego i stycznego. Wpływ parametrów modyfikacji na połysk drewna topoli czarnej był różny w zależności od analizowanego przekroju. Temperatura modyfikacji w 20 % odpowiadała za zmienność połysku na przekroju promieniowym, natomiast w 38 % za zmienność połysku na przekroju stycznym. Wpływ czasu modyfikacji był znacznie niższy niż wpływ temperatury i wynosił 3 % i 5 % odpowiednio dla przekroju promieniowego i stycznego.
17
PL
W doświadczeniach polowych z odmianami pszenżyta jarego Mazur, Milewo, Puzon, Sopot określono wskaźniki wykorzystania azotu z nawozów w zależności od sposobu uprawy gleby i dawki azotu. Stwierdzono zmniejszenie efektywności rolniczej i fizjologicznej przy wzroście nawożenia azotem z 70 do 100 kg/ha. Wzrost wykorzystania azotu z nawozów i istotnie wyższy plon ziarna wystąpił na obiekcie nawożonym dawką N 70 kg/ha, w uprawie uproszczonej i u odmiany Sopot.
EN
The N content was detd. in the crops of 4 spring triticale cultivars (grain and straw) obtained at various doses of N fertilization and with different methods of soil cultivation. The degree of N utilization from fertilizers was 86 and 73% in field expts. fertilized with N at a dose of 70 and 100 kg/h, resp. A decrease in agricultural and physiol. efficiency was found along with an increase in the dose of N fertilizer from 70 to 100 kg/ha.
EN
Models describe our beliefs about how the world functions. In mathematical modelling, we translate those beliefs into the language of mathematics. Mathematical models can yield prognose on the base of applied fertiliser dose. In this work results of finding yield mathematical model according to fertiliser (nitrogen) dose for perennials (willowleaf sunflower Helianthus salicifolious, cup plant Silphium perfoliatum and Jerusalem artichoke Helianthus tuberosus) on marginal land are presented. Models were described as normalised square equations for dependence between yield and fertiliser doses. Experiments were conducted in lisymeters and vases for willowleaf sunflower and cup plant. For Jerusalem artichoke experiments were done in vases only. All experiments have been doing during two years (2018 and 2019) for different fertilisers doses (45, 90 and 135 kg N∙ha-1) in three repetitions. From simulations maximal yield could be achieved for following fertiliser doses – willowleaf sunflower 104 kg N∙ha-1, cup plant 85 kg N∙ha-1 and Jerusalem artichoke 126 kg N∙ha-1.
EN
For the purposes of research and this resultant publication, the water quality was tested in three reservoirs differing in operating times. It was assumed that the study period covering autumn, spring and early summer was the period with the most visible changes in the concentrations of pollutants. The samples taken from the reservoirs were analysed by determining biological oxygen demand (BOD5), ammonia concentration (NH4), phosphate concentration (PO4) and total suspended solids. The use of indicators allowed for assessing the quality of water in these reservoirs and comparing it in terms of different periods of their operation. It was also observed that the water flowing into the Roszków and Jeżewo reservoirs (two oldest reservoirs) was of worse quality than the outgoing water. In the case of the newest reservoir, the water quality at the outflow deteriorated in relation to all indicators.
EN
Plant nutrition is one of the significant factors determining the quantity and quality of crop production. Therefore, the objective of the experiment was to express the dependence numerically (statistically) of the selected yield parameters of radish on the contents of ammonium and nitrate nitrogen occurring in the soil growing medium in different periods of radish vegetation. The experiment was performed in the plastic greenhouse with aeration and irrigation manually operated. It had three variants and was established by the method of random plot arrangement with a threefold repetition of variants. The variants differed in the quantity of vermicompost in the soil growing medium (0%, 10%, 20%). The achieved results indicate that the yield parameters of radish were more dependent on the contents of N–NO3- than on the contents of N–NH4+ occurring in the soil substrate. The quantity of N–NO3-, occurring in the soil growing medium in the initial period of the growing season, had impact on the quantity of yield. The quantity of N–NO3-, present in the soil substrate in the second half of the growing season, had impact mainly on the content of vitamin C and content of nitrates in roots. As the N–NO3- content of the soil growing medium increased, the content of nitrates was increased and content of vitamin C was decreased. The dependence between the contents of N–NH4+ in the substrate and root yield was insignificant. The quantity of radish root yield depended predominantly on the contents of Nin occurring in the soil growing medium at the beginning of the growing season. On the contrary, the content of nitrates and vitamin C (influencing the yield quality) was dependent mostly on the contents of Nin present in the soil substrate in the second half of radish growing season. Along with the increase in the content of Nin, the root yield and the content of nitrates in roots also increased, while the content of vitamin C was decreased.
first rewind previous Strona / 19 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.