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IR-Spectra of Microbial Biomass and Humic Acid from Podzol IR-examination of soil samples from podzol with or without different pretreatments was carried out in order to check the possibility of humic acid and microbial biomass detection. Pure humic acid and microbial biomass, both isolated or enriched from the soil under controle, showed distinct absorption bands or shoulders at 1730cm?1, 1620cm?1 and 1380cm?1. Only weak absorption bands at the respective wave numbers were detected in the untreated soil sample.  相似文献   

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Reduction of stalk length in winter and summer rye by Ethrel (2-chloroethylphosphonic acid) . In pot experiments with winter and summer rye Ethrel (2-chloroethylphosphonic acid) considerably reduced stalk length so that a favourable effect on lodging can be expected. The shortening effect strongly depends on the time of application. Grain yield is scarcely affected. The experiments give indication for the optimal concentration and the amount of active substance required.  相似文献   

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Comperative study of the mineral content of damaged and visibly healthy red beeches (Fagus sylvatica) on limestone soils in the Saarland 50-80 years old red beeches from a limestone region in the Saarland, differentiated in apparently healthy and diseased trees, were investigated on their mineral content beginning with the roots over stem up to the leaves. Macro- and microelement contents were different between healthy and diseased trees. Magnesium content in the roots of the latter was markedly reduced. Also zinc and phosphorous were decreased in the damaged trees, while manganese was partially accumulated. On the other side, a high sulphur content was observed in the crown area of both types of trees.  相似文献   

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Estimation of organic carbon deposition into forest ecosystems by determination of the spectral absorption of rainwater in range of ultraviolet radiation (SAC254) Organic compounds are mostly neglected within deposition measurement programs because their determination is expensive and complicated. A very simple and rapid estimation of total organic carbon (TOC) is possible by determination of the spectral absorption coefficient in the range of ultraviolet radiation at 254 nm wave-length (SAC254): TOC (mg/1) = 0,5 SAC254 (m?1) - 0,15  相似文献   

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Intersite estimation of biological activity of soils by determination respiration and cellulolytical activity in the field A temperature differentiated scale of estimation is presented, which is derived from long-term investigations of respiration and cellulolytic activity. This is suitable for intersite comparison of different soil-ecosystems. Investigations in spring are representative and could be done during mapping the soil-ecosystems. It exists a strong correlation to the quality of the humus body and to the available nutrients.  相似文献   

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Dynamics of organic matter during the degradation of Chernozems In the course of pedogenesis especially the amount and the composition of soil organic matter changes. This is investigated in the presented paper at 6 different developmentstages of a Chernozem-degradation-sequence from Hildesheim region. The mechanisms of this process can be deduced from the ‘degradation products’, found in the different soils. Using several methods for extraction of organic substances by successively stronger reagents or conditions, different amounts of fulvic and humic acids were got. The findings give indications to the different stability of bondings between mineral and organic substances in the soils and their change during degradation. The ascending exhaustive fractionating method was found to be the best for obtaining and-simultaneously - separating completely the organic matter in distinct franctions and also to earn a humus-clay and a silica humic acid component. Using this method, 5 fractions of the humus complex at any of profile-horizons were got in greater amounts and quantitative as far as qualitative determined. It was found that the loss of organic matter is differently distributed to the single humus fractions in the profiles and in the horizon-zones. Therefore it is not sufficient to determine only the total C- and N-content. Comparing the increase or decrease of humic substances in the upper resp. lower zones of the profiles of the sequence, the degradation process can be pursued retrospectively.  相似文献   

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Heavy metal- and nutrient contents of plants and soil samples from metal liferous waste dumps in Bleiberg (Carinthia, Austria). I. herbaceous plants Lead and zinc concentration in the fine fraction (< 0,2 mm) of mine dump material were twice as high as in coarser fraction (2–0,2 mm) (table 1). Due to high metal levels in roots of several mine dump plants (table 3) interactions between plants and soil-microorganisms are assumed. Furthermore root originating exsudates (organic acids) are probably responsible for an increase in heavy metal availability in soil in spite of a general high pH of soil solution. The low mobility of lead within intact plants is caused by a selective affinity of this metal to cell wall pectines. On the other hand a physiological barrier (endodermis/pericycel) in primary roots of these plants is assumed, which partly prevents lead from upward transport into the shoots. Heavy metal compartmentation may be part of a tolerance mechanism diminishing a surplus of toxic metals within plant metabolism.  相似文献   

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Phytotoxicity of Thallium (Tl) in Culture Solution Part 2: Effects of Tl(III) on the Growth and Heavy Metal Contents of Pea and Field Bean Plants The effects of Tl(NO3)3 and Tl(III)EDTA on growth and heavy metal contents of pea plants (Pisum sativum L. cv. Aromata) and field bean plants (Vicia faba L. cv. Hangdown) were compared in hydroponic culture experiments. In the presence of Tl(NO3)3, the essential heavy metals were available to the plants in their ionic forms. When Tl(III)EDTA was present the essential heavy metals were available as chelated complexes. Dry matter production of the pea plants was inhibited to a greater extent by TI(II1)EDTA than by Tl(NO3)3. The distribution of TI within the plant was unaffected by the accompanying anion, however an increase of the TI content of the stems and the leaves was observed in the presence of TI(II1)EDTA. The micronutrients exhibited different interactions with TI(II1). In the presence of increasing concentrations of Tl(NO3)3 the Mn content of each organ and the Zn content of the roots were lowered, but the Zn content of the stems was increased. Increasing concentrations of TI(II1)EDTA resulted only in a decrease of the Mn content of the roots, but in an increase of the contents of Fe and Mn within the stems, and Fe, Mn, Zn, and Cu within the leaves. The increases may be due to concentration by growth inhibition. In contrast to pea plants, growth of field bean plants was inhibited only by TI(N03)). The field bean plants retained most of the TI within the roots independent of the TI compound in the solution. Chelation of TI(II1) resulted in higher TI contents of both the roots and the stems, but equal or reduced TI contents of the leaves. Whereas increasing concentrations of Tl(NO3)3 reduced the Mn content of each organ as well as the Zn content of the roots and the leaves, TI(II1)EDTA only reduced the Mn content of the roots.  相似文献   

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Effect of copper and nitrogen deficiency on phenol oxidase activity and content of phenols in leaves of sunflower (Helianthus annuus) In sunflower leaves of different insertion height the activity of phenol oxidase during the course of the whole vegetation period was determined. In leaves of normal plants this activity reached its maximum during the period of most intensiv growth and decreased continuously with increasing age. The highest activity was found in cotyledons. In normal leaves this maximum decreased with increasing insertion height. Copper deficiency led in cotyledons to a small, in leaves to a severe inhibition of the phenol oxidase activity. Here the decrease of copper content always led to an unproportional decrease of the enzyme activity. After the middle of July, no phenol oxidase activity in leaves of copper deficient plants could be determined. Nitrogen deficiency decreased the yield considerably, while it was lowering the phenol oxidase activity only slightly. Orthodihydroxyphenols, as substrates of phenol oxidase, showed a negative correlation to the enzym activity: The stronger the suppression of the phenol oxidase activity, the higher was the rise of the orthodiphenol content in full expanded leaves. With unsufficient copper supply the plants showed only week deficiency symptoms, although the phenol oxidase activity was completly inhibited. Therefore it is presumed that in sunflower leaves the role of phenol oxidase can partly be taken over by other enzymes.  相似文献   

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Nitrogen nutrition and Al toxicity with young beech plants. I: Development of young beech plants in relation to the source of nitrogen and the Al content of the nutrient solution Young beech plants were grown in aerated nutrient solutions with different Al concentrations over a period of 14 weeks. Nitrogen was supplied in either NO3- or NH4-form. pH-changes of the solutions were either corrected to the initial pH of 4 after two days, or not corrected over a period of two weeks. Root growth of the beech seedlings was inhibited by Al. Reduction of root length and dry matter production was more severe if the plants were fed with ammonium nitrogen compared to nitrate nitrogen. Detrimental effect of Al on root growth was also influenced by the pH of the solution. NH4-N-nutrition led to pH decrease and therefore to increased solubility and toxicity of aluminium. On the contrary, NO3-N-nutrition weakened Al toxicity because of pH increase at the root surface and in the AFS. This led to an inactivation of Al in the form of insoluble hydroxy aluminium polymers. Compared to NO3-N-nutrition NH4-N promoted shoot growth. During 14 weeks no detrimental effect of Al on shoot growth was observed.  相似文献   

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Nitrogen nutrition and Al toxicity with young beech plants. II: Mineral contents of young beech plants in relation to the source of nitrogen and the Al content of the nutrient solution Young beech plants were grown in aerated nutrient solutions with different Al concentrations over a period of 14 weeks. Nitrogen was supplied in either NO3 or NH4-form. pH-changes of the solutions were either corrected to the initial pH of 4,0 after two days, or not corrected over a period of two weeks. The cation contents of the roots and shoots were greater if the nitrogen was supplied in NO3-form. Increasing Al concentrations in the nutrient solutions led to an increase in Al contents and a decrease in Ca- and Mg-contents in roots and shoots.  相似文献   

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Litho- and Pedogenesis of slope positions of the Sandstone Odenwald Hilly slope positions of the Odenwald in SW-Germany are characterised by solifluction deposits which were formed from mesozoic sandstone during the glacial age. The evaluation of texture and heavy mineral analysis showed different amounts of loess in different layers of the solifluction deposits. Clay migration seems to be the main reason for differences in clay content between soil horizons and took place mainly in deposits with low loess contents. These are also the deposits in which a pronounced podzolization took place.  相似文献   

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Heavy metal enrichment and mobility in the infiltration zone of stemflow from beech (Fagus sylvatica) in the Vienna woods Filtering action of beech crowns in a polluted atmosphere produces acidic stemflow enriched with heavy metals. Series of soil profiles through the infiltration zone of stemflow waters were analyzed in three old growth beech stands on pseudogley (aqualf) soils of the northeastern Vienna Woods to study soil acidification and heavy metal accumulation and mobility: + In the infiltration zone of stemflow soil pH can be less than pH 3 and thus more than 2 pH units lower than in profiles more distant from the stem base. + Heavy metal contents of the soil peaked near the stembase. Maximum values for lead were 500 to 1.200 mg·kg?1 soil, for copper 70 to 150 mg·kg?1 soil and for zinc 250 to 500 mg·kg?1 soil. + Manganese was not enriched but leached out from the soil profile. + The proportion of AED-complexable lead and copper to total lead and copper decreased under stemflow influence in the topsoil but increased in the subsoil. These results indicate that significant amounts of heavy metals are deposited with stemflow in beech stands of the Vienna Woods. Strong soil acidification enhances heavy metal solubility and thus promotes leaching into deeper soil strata.  相似文献   

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