摘要:

Plutonium in vegetables, fruits, and soilsThe plutonium content of fruits and vegetables from the Karlsruhe area in the years of 1971 ‐ 1975 was determined. In vegetables the Pu‐239 and Pu‐240 activities were highly different, fluctuating between 64 fCi/kg fresh weight and values below the detection limit of about 6 fCi/kg. The activity of most of the vegetables and of all fruits was not higher than 10 fCi/kg. The nuclide Pu‐238 could be identified in a qualitative way only, i. e. all measuring values remained below the detection limit of about 17 fCi/kg. The total‐alpha‐activities which were simultaneously determined in the vegetable and fruit ashes were in the range of 0.5 ‐19 pCi/kg fresh weight. Soil samples taken from the same region had a mean Pu‐239 and Pu‐240 activity of 5.9 ± 1.4 fCi/g and a total‐alpha‐activity of (10 ± 1.5) · 103fCi/g. Samples taken from the immediate vicinity of the Karlsruhe Nuclear Research Centre did not show i

ISSN:0044-3263    

DOI:10.1002/jpln.19781410302

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Examination of the risk of contamination by polycyclic aromatic hydrocarbons in the harvested crops of carrots and fungi after the application of composted municipal wasteInvestigations were conducted to determine if the often high, naturally‐occuring concentrations of polycyclic aromatic hydrocarbon (PAHs) present in municipal waste composts could cause hazardous contamination of plants when the composts are used as soil conditioners in agriculture and gardening. Carrots (Daucus carota) and mushrooms (Agaricus bisporus), used as representatives of higher and lower plants, respectively, were cultivated on compost‐free or compost‐amended substrates. To determine concentrations of PAHs in soils and plants a gas‐chromatographic method was employed which allowed benzo(a)pyrene and 12 other PAHs to be determined singly or as isomeric mixtures.In the experiments withAgaricusit was found that fruiting bodies, even though grown in a substrate with very high concentrations of PAHs (i‐ e., 1000 ppb benzo(a)pyrene), contained no detectible quantities of these compounds. In contrast to this, experiments with carrots showed that there was a direct correlation between PAH concentrations in the substrate and PAH concentrations in both below‐ and above‐ground portions of the plants. The 25 to 40 fold increase of the PAH concentration in the substrate containing waste compost caused an increase of these compounds in the carrot roots by the same factor. The only 2 to 4 fold increment of the PAHs in the corresponding foliage was thought to be mainly due to a relatively great portion of air contamination by which the increase of the PAH quantities entering from below ground to the foliage was not so evident.The concentrations of benzo(a)pyrene used in the present series of experiments with composted waste are 7 to 10 times higher than those found in soil to which compost has been added as in practical agricultural application. Relating the result of the described experiments to actual practice, it could be suggested that the normally very low concentrations of PAHs in below ground plant parts would increase with the use of composted municipal waste, but they would not become greater than the concentrations in above ground plant as caused by contamination from naturally occuring PA

ISSN:0044-3263    

DOI:10.1002/jpln.19781410303

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Uptake of adsorbed monolinuron by oat plantsThe uptake of soil adsorbed14C‐ureido‐labelled herbicide monolinuron by oat plants was investigated. After a growing period of 9 weeks 35 to 57 % of the initial14C‐radioactivity was found in the shoots. An incubation period of 16 weeks of soil and monolinuron reduced the uptake by plants in contrast to either short term adsorption or the addition of monolinuron in solution. Changes in the herbicide soil ratio had no influence on the plant availability of freshly adsorbed monolinuron or monolinuron added in solution. However, after 16 weeks of incubation the availability of monolinuron was reduced by a narrow herbicide soil ratio. Monolinuron was identified in the soil solution by mass‐spectrometry.As much as between one half and two third of the total monolinuron was taken up by the plants in the first 3 weeks.14C‐radioactivity was also found in the roots as well as in shoots of untreated control plants. The amount of14C‐activity adsorbed on soil after harvest was

ISSN:0044-3263    

DOI:10.1002/jpln.19781410304

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Influence of chelating agents on calcium translocation in the shoots of higher plantsUsing 28‐day‐old plants and shoots of bush beans as well as isolated haulms of barley taken from the field 24‐hour experiments were carried out to investigate how equimolar additions of the chelating agents Na2H2EDTA (EDTA) or citric acid to the45CaCl2uptake solution (0.5–1.0 mM/l) influenced Ca‐translocation in the shoot. The following results were obtained:1If Ca2+was taken up by the intact root system, equimolar additions of EDTA to the CaCl2‐uptake solution reduced Ca‐uptake, and therefore the translocation of Ca to and within the shoot was also lowered.2Chelating agents favoured Ca‐translocation in the shoots only when Ca‐uptake as a chelate by the plasmalemma of the root cells was prevented using DNP or when the roots were by‐passed by injecting chelates or by removing the roots themselves.3Additions of MgCl2(0.5 mM/l) or DNP (10−5‐10−4M/l) to the45CaCl2uptake solution (0.5 mM/l) of isolated shoots reduced the favourable effect of equimolar EDTA‐levels on Ca‐translocation because Mg2+and DNP themselves increased Ca‐translocation.4From the effects of Mg2+and DNP it was concluded that the favourable influence of chelating agents on Ca‐translocation within the shoot can be explained on the one hand by the reduction in adsorption of Ca2+on negatively charged cell walls of the xylem and on the other hand by the diminished accumulation and precipitation of Ca in the xylem‐surrounding tissue.5On the basis of the results obtained here, stem injections of chelating agents or treatments which influence the content of native chelating agents in the plants appear to be possible starting points for the improvement o

ISSN:0044-3263    

DOI:10.1002/jpln.19781410305

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Characterization of the nutritional system of carrot tissue cultures: Photosynthesis, carbon and nitrogen nutrition, uptake of mineral nutrientsDuring a culture period of 28 days qualitative and quantitative changes in the nutritional system of carrot tissue cultures can be observed. Investigations on sugar uptake, CO2fixation, and uptake of amino acids and nitrate indicate a succession of 3 periods, i.e. a heterotrophic period at the beginning of the culture period (up to 10 days), a mixotrophic period (till about the 20th day) followed by an autotrophic period. The transition into the autotrophic period could be only observed in treatments supplemented with kinetin. Uptake of potassium, phosphorus, calcium and magnesium was closely correlated to cell division activity of the explants as induced by m‐inositol, IAA and kineti

ISSN:0044-3263    

DOI:10.1002/jpln.19781410306

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractFor a loes soil with sugar beets (Beta vulgarisL.) a model was developed with which the difficult‐to‐measure components of the water balance equation can be determined. Basic component of the model is the unsaturated soil moisture flow equation. This equation is solved numerically by a finite difference method. As boundary condition at the soil surface, expressions for the potential and the actual transpiration and for the potential and the actual evaporation are used. Besides the hydraulic functions of the soil, standard meteorological measurements, together with leaf area index and root distribution data of the crop, enter the model. For a period of 316 days, calculated and measured soil suction values in 10 different soil depths, are compared as well as transpiration and seepage vaules. The comparison shows that the model provides acceptable results. The model calculations indicate that of the 519 mm of precipitation received during the 316‐day period, 503 mm were used for evapotranspiration and 119 mm left the soil profile as internal se

ISSN:0044-3263    

DOI:10.1002/jpln.19781410307

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Filtering of Sulfur compounds from air by beech forestIn a mature beech (Fagus silvatica) forest the amounts of sulfate‐S per ha and year in open land precipitation, throughfall, stem flow and seepage in 100 cm soil depth have been measured from 1969 to 1976. From the fluxes measured quantitative data on plant leaching and dry deposition in the form of plant filtering are derived. Dry deposition amounts to 26kg S · ha−1· y−1and is of the same size as wet deposition (24 kg). The leaching of sulfate takes place only in autumn and amounts to ca. 3 kg S. The acid soil in the range of Al‐buffering increases its sulfate storage annually by ca. 1

ISSN:0044-3263    

DOI:10.1002/jpln.19781410308

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Gypsum solubilities in aqueous systems containing NaCl, MgCl2, Na2SO4, and MgSO4Solubilities of Gypsum (CaSO4·2H2O) have been determined within the systems MgSO4–MgCl2–NaCl–H2O and MgSO4–Na2SO4–NaCl–H2O at 21 different compositions of solutions per concentration range (0.01, 0.05, 0.1, 0.15, 0.5, and 1.0mol/l) of total easily soluble salt. Lines of equal solubilities of gypsum can be constructed form these data. They make possible to estimate gypsum solubility in solutions of similar composition. Small quantities of KCl or KNO3may be taken as NaCl. Solubilities measured under percolation conditions deviate sometimes to lower, those measured at supersaturation to higher values. The tendency to supersaturation lowers with increasing content of crystal‐solution interfaces within the system. At concentrations of easily soluble salts from 0,01 to 0,15mol/l the solubility of gypsum is governed by the CL−:SO=4‐ratio. Concentration of solution or Na+:Mg++‐ratio are

ISSN:0044-3263    

DOI:10.1002/jpln.19781410309

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

Phosphatasen — Aktivitäten in der Rhizosphäre verschiedener Leguminosen und Nicht‐LeguminosenDie Aktivitäten an saurer, neutraler und alkalischer Phosphatase in der Rhizosphäre 16 verschiedener Kulturpflanzen (Leguminosen und Nicht‐Leguminosen) wurden ermittelt. Mit Ausnahme von der Karotte (Daucus carota) waren die Aktivitäten der drei Phosphatasen in der Rhizosphäre stärker als in den umgebenden Böden. Im Schnitt war die Phosphatase‐Aktivität in der Rhizosphäre von Leguminosen höher als bei den Nicht‐Leguminosen. Unter den 3 Phosphatasen wurde die neutrale Phosphatase am

ISSN:0044-3263    

DOI:10.1002/jpln.19781410310

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY

摘要:

The influence of fertilization with straw and sewage sludge on the humic system of a brunizem and a chernozemThe influence of fertilization with straw, sludge and mineral nitrogen on the humic system of a black and a brown soil was determined. Soil samples from a polyfactoriel pot experiment lasting two years were analyzed using a photometric analysis of the humic system.Sewage sludge increased extractable humic substances in both soils; straw increased chernozem humic substances but not brunizem humic substances. The other factors tested had no influence.Fertilization with straw, sludge and mineral‐N each caused a degradation of the humic system of both soils, as was the case with the combined treatmetns on the brown soil. On the black soil, however, the combined treatment with straw and sludge caused a pronounced aggregation of the humic system. Additional fertilization with mineral‐N resulted in an aggregation already with the lower sludge‐trea

ISSN:0044-3263    

DOI:10.1002/jpln.19781410311

出版商:WILEY‐VCH Verlag    

年代:1978

数据来源: WILEY