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PAHs (polycyclic aromatic hydrocarbons) are widespread in the natural environment. They are suspected to have mutagenic, carcinogenic and teratogenic effect on our organisms. Production of wholesome and high quality vegetables does not necessarily involve selection of adequate farmlands or substrates used for vegetable growing. Combustion processes are a source of PAHs in the soil and air. Excessive levels of PAHs are accumulated when the balance between their decomposition in soil and supply from other sources is disrupted. The objective of the present research has been to evaluate the effect of anthracene and pyrene on the concentration of selected trace elements in butter lettuce (Lactuca sativa L.), cultivar Vilmorin, grown on substrates with different nutrient abundance. A pot experiment in four replications was carried out twice in the spring of 2007 and 2008. The pots were maintained in a greenhouse at the University of Warmia and Mazury in Olsztyn. Lettuce was grown under the minimum (optimum) and triple (II fertilization level) substrate abundance in nutrients. In the second variant o the experiment, when the nutrient abundance was elevated, nitrogen was split into two doses: 2/3 of the whole rate were added before planting lettuce seedlings, and 1/3 of the rate was introduced 10 days afterwards. In the first variant, when the nutrient abundance was minimal, all of the nitrogen was added in a single dose. Spraying the lettuce plants with anthracene (ANT), pyrene (PYR0 or their mixture started 10 days after planting. Foliar introduction of the tested PAHs continued for 25 days (in the amount of 1.8 cm3 day–1 at a concentration of 100 mg dm–3) until the vegetative season finished. At the same time, an identical total amount of the PAHs was added to soil as aqueous solution, at 7-day intervals, according to the same pattern. Determinations of the concentrations of heavy metals (Cd, Cu, Ni, Cr, Zn, Mn) was performed with the ASA method, having first mineralised (HClO4+HCl+HNO3) the plant material which had been dried at 60oC. The determinations were compared with certified material (CTA-VTL-2). Concentrations of the trace elements in butter lettuce were significantly varied depending on the experimental factors. A more abundant substrate significantly raised the levels of Cd, Zn and Mn, but had no effect on concentrations of Cu, Ni and Cr. The way the PAHs were applied did not have any influence on modifications in the determined levels of the metals. Out of the two analysed PAHs, anthracene, especially when applied to soil, increased the concentrations of Zn nd Cr in lettuce leaves.
The objective of the experiment was to determine the effect of nutrients (different doses of chlorine, sulphates and calcium as well as different forms of nitrogen fertilizers: Ca(NO3)2 + NH4NO3, NH4NO3, NH4NO3 + CaCl2, NaNO3) on yield and content of N-NO3, Nog., P, K, Ca, Mg and Na in butter lettuce (Lactuca sativa L.) cv. Vilmorin. A pot experiment with four replications was repeated three times in 2007 (from 30th January and from 30th March) and in 2008 (from 31st March). It was established in the ‘Plant House’ of the Chair of Agricultural Chemistry and Environmental Protection UWM in Olsztyn. Lettuce seedlings were planted into pots containing 2 dm3 substratum. Nitrogen was applied three times, every 10 days, each dose consisting of 100 mg N.dm-3 of substratum applied to soil; identical doses of phosphorus, potassium and magnesium were introduced to the substratum before planting lettuce. Irradiation period was 12 hours every day. Lettuce was harvested after 6 weeks. Determinations of Nog (Kjedahl’s method), P (vanadium- molybdenum method), K, Ca, Na (flame photometry – ESA), Mg (atomic absorption spectrophometry – ASA) were performed having wet mineralised plant samples in H2SO4. Concentration of nitrates (V) was determined in fresh matter (potentiometrically, using a ion-selective electrode) in a 0.03 mol.dm-3 CH3COOH according to NOWOSIELSKI (1988). The smallest number of lettuce heads (statistically significant) was obtained after NaNO3 fertilization. The concentration of N-NO3 declined advantageously following an NaNO3 treatment. In contrast, the highest accumulation of nitrates(V) occurred after application of lime saltpetre in conjunction with ammonium nitrate. The composition of minerals in butter lettuce cv. Vilmorin, such as phosphorus, potassium, magnesium and sodium, was more beneficially affected by fertilization with sulphate compounds (K2SO4 + MgSO4) rather than chlorine compounds (KCl + MgCl2). Soda nitre significantly depressed the content of magnesium and calcium in plants, had no effect on the concentration of phosphorus and increased accumulation of sodium and potassium.
The purpose of this study has been to evaluate the effect of foliar application of PAH organic chemical compounds (anthracene, pyrene) on yield, chemical composition and uptake of nutrients by cv. Vilmorin butterhead lettuce (Lactuca sativa L.). Lettuce was grown under minimum and three-fold higher abundance of substrate in nutrients, as determined according to threshold amounts. A pot trial was established in four replicates and performed twice, in the spring of 2008 and 2009, in a greenhouse at the University of Warmia and Mazury in Olsztyn. Lettuce seedlings were planted in pots containing 10 dm3 of mineral substrate. Fertilization (N, P, K, Mg, Na and Cl) was carried out prior to the planting of lettuce. Under the minimum nutrient abundance of the substrate, all the dose of nitrogen was supplied as a pre-sowing treatment, whereas when the abundance in nutrients was raised three-fold, the nitrogen dose was divided (2/3 pre-sowing and 1/3 10 days after planting). Contamination of lettuce plants with anthracene (ANT) or pyrene (PYR) and their mixture started 10 days after planting lettuce. Foliar application of either of the PAHs continued for 25 days until the vegetative growth of lettuce terminated. Determination of the concentration of macronutrients (N, P, K, Mg, Ca and Na) was performed using standard methods on the mineralised (H2SO4+H2O2), previously dried at 60ºC lettuce plant material. The determinations were completed by referring to certified material (CTA-VTL-2). The amount of fresh mass of butterhead lettuce depended primarily on the abundance of the substrate in nutrients. The three-fold increase in the substrate’s abundance in N, P, K, Mg, Na and Cl caused an increment in the yield of lettuce head mass by 13.3%. Foliar application of ANT and PYR caused an increase in the yield of lettuce head mass. The concentration of N, K, Na, Mg, Ca and Mg in lettuce was modified first of all by the abundance of the substrate and, to a lesser degree, by the applied PAHs.
Badania przeprowadzono w latach 2007-2008. Materiałem badawczym była Scabiosa caucasica M.BIEB. - driakiew kaukaska, roślina ozdobna uprawiana na kwiaty cięte. Badania przeprowadzono na trzech odmianach driakwi: ‘Perfecta’, ʻFamaʼ oraz ‘Perfecta White’. Kwiatostany zbierano sukcesywnie, w miarę osiągania dojrzałości zbiorczej. W oparciu o wyniki analiz gleby opracowano dwa warianty nawożenia: I - uzupełnienie składników pokarmowych w glebie do poziomu 100 mg N∙dm-3 i 150 mg K∙dm-3, II - uzupełnienie składników pokarmowych w glebie nawozami mineralnymi do poziomu 200 mg N∙dm-3 i 300 mg K∙dm-3 (zastosowanymi nawozami były saletra potasowa i saletra amonowa). Zastosowano także kombinację kontrolną, bez nawożenia. Na podstawie uzyskanych wyników stwierdzono, iż driakiew kaukaska kwitła bardzo obficie i długo - długość okresu kwitnienia trwała, w zależności od roku badań, od około 3 miesięcy do prawie 4 miesięcy. Liczba kwiatostanów wytworzonych przez jedną roślinę w ciągu całego okresu wegetacyjnego wynosiła nawet ponad 100 sztuk. Liczba uzyskanych pędów kwiatostanowych wzrastała wraz ze wzrostem dawek nawozowych. Najobfitsze kwitnienie driakwi uzyskano po uzupełnieniu składników pokarmowych w glebie nawozami mineralnymi do poziomu 200 mg N∙dm-3 i 300 mg K∙dm-3. W plonie ogólnym większość stanowiły pędy o długości przekraczającej 20 cm, doskonale nadające się na kwiat cięty.
Toxic compounds which belong to PAHs are generated during all types of combustion of fuels and other substances as well as a result of natural processes (mineralisation). Products which appear during the above processes eventually reach soil, where they accumulate. The objective of this study has been to evaluate the effect of anthracene and pyrene accumulated in soil on yield, concentration of macronutrients (N, P, K, Mg, Ca, Na) and their uptake by cv. Vilmorin butter lettuce (Lactuca sativa L.) grown under the minimum and 3-fold enriched abundance of substrate. A pot experiment in four replicates was carried out twice in a greenhouse at the University of Warmia and Mazury in Olsztyn, in the spring of 2007 and 2008. Supplementary fertilisation was applied before planting butter lettuce. At the first rate of fertilisation, nitorgen was introduced in a full dose before planting lettuce, but at the triple rate of nutrients in substrate, it was divided into 2/3 of the dose before planting and the remaining 1/3 applied to soil 10 days after planting. Soil contamination with anthracene (ANT) and pyrene (PYR) or their mixture started 10 days after planting lettuce. Soil application of the two PAHs was performed 5 times at five-day intervals until the end of the growing season of lettuce. Determination of macronutrients (N, P, K, Mg, Ca, Na) was accomplished with standard methods after mineralisation (H2SO4 + H2O2) of the plant material dried at 60oC. The determinations were peformed in comparison to certified material (CTA-VTL-2). Increasing the abundance of substrate in nutrients (N, P, K, Mg, Na, Cl) by three-fold led to a 13.7% increase in yield of lettuce heads. The PAH compounds present in the substrate depressed lettuce yield. This tendency was more evident when anthracene rather than pyrene contaminated soil. ANT and PYR depressed the concentration of nitrogen but raised the concentration of calcium in substrate less abundant in nutrients.
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