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Zinc sorption was tested through four mineralogically diverse clay fractions of rendzina soils. The value and mechanisms of Zn sorption are strictly linked to the mineralogical composition of the clay fraction. Analysis of the variation of the buffer coefficient da/dCe, calculated according to the Freundlich isotherm, indicates that the fractions containing prevailing quantities of smectite, illite or kaolinite sorb Zn exchangeably (not specifically). Zn bonding in the smectite fraction is feeblest. The fraction containing opal CT adsorbs Zn permanently (specifically).
In laboratory investigations, 9 methods of sorption ability against phosphorus in 36 soils of southern Poland (loam 7-71% , Corg 0.41-2.0%, Alox 14.7-64.8 mmol kg -1 and Feox 15.7-174.5 mmol kg-1) were compared. Evaluation of the maximum P sorption (Pmax) as well as two ways of buffering capacity against P (PBC) was estimated from multipoint curves according to the data of the Langmuir and Freundlich equation. The indices of P sorption obtained were compared with the single-point indices received by the addition to the soil of one P concentration (PSI1500, IPEC, and PRI200). All the indices of P sorption determined were highly correlated, being the evidence of the usability of the single-point indices in the evaluation of phosphorus sorption in routine soil tests. A significant correlation was found between the indices compared of Alox, Feox, loam concentration and CEC in the soil. The saturation of the soil with phosphorus, estimated by the Pox / (0.5(Feox + Alox ) was low and was in the range in 0.7-8.6 %.
Based on a large number of samples collected from within Polish territory, the concentration of microelements (Fe, Mn, Zn, Cu, B, and Mo) in a soil solution of arable soils of Poland was measured and evaluated, and the possibility of various soil factors as causal agents of this concentration was assessed.
The aim of the study was to estimate some of the microelements (Cu, Zn, Mn, Pb and Cd) in the form available to plants and extracted from the soils of the Bellsund seaboard with DTPA-TEA and to estimate the level of connection between these metals and the soil properties. The study of the microelements was conducted during the polar expeditions of the Institute of Earth Sciences (UMCS, Lublin) to Spitsbergen in the years 1987-2002. The research embraced Gelic Leptosols, Gelic Regosols, Gelic Gleysols, Gelic Cambisols, Gelic Histosols soils occurring in the major physio-graphic units (Dunderdalen, Logne, Dyrstaddalen, Työrndalen, Blomlidalen, Lyellstranda, Calypso-stranda, Tomtoden, Chamberlindalen) of the Bellsund area. The research enables us to draw some general conclusions: (i) the contents of the analysed heavy metals (Cu, Zn, Mn, Pb, Cd) as well as the properties of Bellsund soils are diversified; (ii) statistical analysis shows a negative correlation between the Pb and Cu content with the content of sand ɸ 1-0.1 mm fraction, positive correlation of the Cd and Mn contents with the fine fraction, and of the Pb and Zn contents with organic carbon; (iii) the tested soils are not contaminated with any DTPA-TEA extractable microelemets.
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Chemical criteria in the critical loads concept

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The critical loads concept has been developed under the Convention on Long-Range Transboundary Air Pollution as a scientific basis for the negotiations of its environmentally effect-oriented protocols. The basic idea of this concept is to balance the atmospheric depositions which a given ecosystem is exposed to with the capacity of this ecosystem to buffer the input in the system. Accordingly, a critical loads approach to control acidic emissions in relation to their ecological effects has been introduced. Critical load is defined as "a quantitative estimate of an exposure to one or more pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur according to present knowledge". In this study, the critical loads approach has been applied to the problem of forest ecosystem acidification resulting from sulfur and nitrogen emission. There are several criteria that may be used as critical chemical limits in forest soil solution. These are critical pH, critical Al concentration, critical BC/A1 ratio and Al depletion criterion. The reliability of the calculated critical loads is strongly influenced by the quality of the chemical criteria applied. For abiotic aspects like soil chemistry or ground water quality the critical limits are clear because the dose-effect relations are quite well understood. For biotic indicators like root damage it is more difficult to find critical limits which can be used as threshold levels below which effects are negligible. The process of root damage is quite a complex one and a combination of side factors like droughts and adverse soil chemical condition may contribute to it. So, when a single critical limit such as the ВС/Al ratio is used, this will inherently lead to a considerable uncertainty in the value of this critical limit. Critical limits are based on laboratory experiments during a limited period of time in which sample roots are subject to constantly elevated BC/A1 ratios. One of major problems in applying this kind of criteria is the interpretation of the laboratory bioassay results in relation to field conditions. The aim of this paper is to summarize the current knowledge and to formulate the major questions that should be answered to abate the existing uncertainty in relating the anthropogenically modified soil chemistry and the reaction of forest ecosystems.
The Classical and other long-term experiments at Rothamsted Experimental Station illustrate the causes and effects of soil acidification. One hundred and fifty years of precipitation measurements show how atmospheric deposition has increased, causing acidification of grassland and woodland soils. Where applied, ammonium fertilisers cause very rapid acidification unless their effects are offset by the application of lime. Acidification causes the mobilisation and removal by leaching of base cations to be replaced by aluminium, manganese or iron, the reduction of base saturation and, in the long-term, the reduction of cation exchange capacity by the weathering of clay minerals. Mobilised toxic metals are taken up by vegetation growing on the acidified soils. Some plots of the Park Grass Experiment have acidified to sufficiently to cause the release of aluminium to be taken up in hay in amounts toxic to cattle - a Chemical Time Bomb.
In a present article the results of land fund investigation of Vasylivka Rural Counsil in Onufriivka region of Kirovohrada oblast in Ukraine and agricultural lands productivity monitoring of land use entity Limited Liability Company “Maryivske” are given. It was established that lands are low-yielding (2.5 Mg ha⁻¹of crops and leguminous plants) and ploughed up to 71%. The implementation of measures of agricultural chemicals rational use showed that their productivity reached 100%. It is reasonable to calculate the rates of local fertilizer distribution, taking into account soil chemical characteristics, provided by plants protection products adding and bioactive substances.
Investigations were carried out on the composition and content of amino acids bound in humic acids (HA) isolated from mineral and mineral-organic soils under the shelter-belt (biogeochemical barrier). It was confirmed that the distance from the edge of the shelter-belt and the kind of soil on which the biogeochemical barrier is localized, exerts some considerable influence on the total amount of amino acids bound in HA. The shelter-belt appearing on mineral soils causes a decrease in the total amount of bound amino acids in major periods of sampling. A contrary occurrence was observed in mineral-organic soils.
The rate of broadleaf forest litter decomposition as well as leaching of nitrogen and phosphorus was estimated, on two plots situated in an about 150-year old oak-hornbeam tree stand. In both ecosystems the rate of production and decomposition of litter was approximately the same. There was evidence of the dependence of the decomposition rate on the total precipitation in the vegetative season. The determined quantity of nitrogen leached in the process of litter decomposition reached 50 100 kg per ha in wet years and about 30 kg per ha in dry years. Quantities of phosphorus leached from decomposed litter oscillate between 4 6 kg per ha in wet years and 1 3 kg per ha in dry years.
The research was conducted in 1991-1997 on the soils from arable fields situated near Łódź. To the detailed research there were stated four soil profiles which were different as regards their grain composition (two sand and two silt soils, all shallow) and typology (two profiles of brown leached soils, one pseudopodzolic-gley soil and one fallow glossic grey-brown podzolic soil). Qualification of the directions of the alterations in the content of organic carbon and basic macroelements (P, K, Mg) in soil and hesitation of reaction, hydrolytic acidity and content of the exchangeable basic cations in the soil sorptive complex were the main target of our research. The result of the 7-year-long research showed that different changes took place in the features of the examined soils. However, the exact assignment of the direction of these alteractions is extremely complex and does not warrant getting a satisfying answer. It is the result of taking various agriculture actions which are necessary to the appropriate maintenance of the ecosystems.
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