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61.
Phosphorus NMR spectra were recorded of the A horizons of a soil catena under vital stands of Liberian tropical high forest. Organic P compounds play a major part in the total P reserves (ca. 1/2 of total extractable P which is 1/5 of total soil P). Thereof, between 3.3 and 5.3 kg orthophosphate diester P per hectare participate in the plant available nutrient pool; similar amounts were calculated for the calcium acetate-lactate soluble fraction. Persistent orthophosphate monoester P makes up an even greater percentage of soil P (10 to 25 kg ha?1). Mineral fertilizer requirements are in the range of 25 to 50 kg per hectare for 10 cm depth (based on a 48 hrs. adsorption experiment) when a soil solution concentration of 0.02 mg L?1 is considered adequate for the P supply of plants. P sorption can be explained by the amorphous fractions of Al and Fe hydroxides and the percentage of clay. The apparent vitality and absence of P deficiency symptoms of forest trees suggest the existence of an intact, however delicate, natural P cycle. 相似文献
62.
Uptake of foliar applied copper and manganese by young wheat plants in the course of time Efficiency of foliar applied nutrients depends strongly on the influence of time on the rate of uptake. Rates of uptake of applied elements were determined by dipping shoots of young wheat plants into Cu or Mn sulphate solutions (0,02% Cu; 0,1% Mn) and subsequent washing off the nutrient film in intervals. Initial influx of nutrients was found to be very high, followed by a period of slow uptake after few hours. 28% Cu, but 80% Mn of the applied amounts were absorbed during the 7-day study. 11% of the absorbed Cu and 14% of the Mn were transferred from shoots to roots within two weeks. 相似文献
63.
Wolfgang Thomas 《Water, air, and soil pollution》1984,22(4):351-371
Concentrations of PAH (1.12-benzoperylene, 3.4-benzopyrene, fluoranthene), chlorinated hydrocarbons (α-BHC, lindane, PCB) and trace metals (Zn, Pb, Cu) in bulk precipitation, as well as PAH and trace metal concentrations in atmospheric dust samples from 14 sites in Bavaria, F.R.G. are presented for two vegetation periods (1979 and 1980). The same substances were also analyzed in epiphytic moss (Hypnum cupressiforme var. filiforme) sampled from tree trunks in October 1979 and 1980. Using mean immission values and the amount of precipitation as predictors and concentrations of pollutants in moss samples as criteria, a number of multiple regression models were computed in order to quantify the relationships between absolute air pollution data and accumulated trace substance values. Beta values of all variables help to determine whether bulk precipitation or atmospheric particulate matter has dominant influence on the uptake of trace substances by mosses. The study shows that epiphytic mosses can be used to monitor both heavy-metal, PAH and chlorinated hydrocarbons. 相似文献
64.
Kristina Bachteler Monika Riedel Nikolaus Merkt Wolfgang Schies Jutta Fröhlin Jens Wünsche 《Journal of plant nutrition》2015,38(6):839-853
Berry shrivel and bunch stem necrosis are the economically most important physiological disorders of grapevine. The nutritional status of the plant is considered as one of the main elicitors for the occurrence of these disorders. For foliar fertilization trials, two vineyards that had previously been affected by both diseases were selected in Southwest Germany, one with the variety ‘Zweigelt’ and one with Pinot Blanc. By the use of potassium, magnesium, and calcium foliar fertilizers, a rapid increase of different nutrients in the plants should be caused and the effects on the diseases observed. In 2010, no significant differences in the fertilization treatments were found for both varieties. In ‘Pinot Blanc’, significantly more berries were affected by berry shrivel in 2011 in plots treated with calcium fertilizer compared to those treated with potassium and magnesium. Plots with magnesium fertilizer showed significantly less berries affected by berry shrivel than the untreated control. 相似文献
65.
Sulfur fractions in forest soils of the SO2-polluted Fichtelgebirge The sulfur status of a soil sequence (two Dystric Cambisols, Haplic Podzol, Eutric Cambisol) in SO2-polluted coniferous and hardwood forests of the Fichtelgebirge (North-East Bavaria) is investigated. In the mineral soil layers St fluctuates between 37 to 943 ppm; 11–84% of St is Sp. Layers rich in clay contain up to 79%-SE, whereas in sandy to silty substrates organic bound C?S-S dominates. The organic surface layers show 1.0–2.9‰ St, maximum in the Oh. 69–90% of St are C?S-S. Sp is low with a maximum in the L-horizons (9–19% of St). SE is vice versa, because values increase from L (0–8% of St) to Oh (7–22% of St). The characterization of the sulfur status in a forest ecosystem by investigation of organic layers presumably is more reliable than the results of needle and mineral soil analyses. 相似文献
66.
Formation of Humic Substances during Composting Wheat Straw During composting straw (with and without N-addition) in a model-compostreactor with continuous progress of rotting it comes to an increase of the fraction of humic acids under simultaneousness decrease of their prestages. The synthesis of humic acids is strongly marked in the thermophilic area. Compared with the untreated variant up to 30% more of the humic acids are formed in the N-treated plots. After the maximum temperature the formation of humic acids break down. A direct relation exists between the microbiological decomposition of the organic matter and the formation of humic acids. IR-spectroscopic measurements show no qualitative differences either between or within the compost variants. 相似文献
67.
The photochemical reactions of phosmet, an organophosphorus insecticide used for plant protection and for control of ectoparasites on productive livestock, were studied in the presence of wool wax. Induced by UV light, phosmet features numerous degradation pathways as well as photoaddition reactions with lipid structure moieties. In model irradiation experiments of phosmet in mixtures of solvents (cyclohexane, cyclohexene, 2-propanol) and fatty acid methyl esters (methyl stearate, methyl oleate, 12-hydroxymethyl stearate), both adjusted to the hydroxyl and iodine values of wool wax, half-lives were determined to be approximately 7 and 16 h, respectively. Irradiation of phosmet on crude sheep wool resulted in a degradation rate of 65% after 24 h. In tracer studies with stable isotope labeled phosmet ([15N]phosmet) in commercial lanolin and on raw sheep wool, employing a sunlight simulator and natural sunlight, wool wax bound phosmet was formed. After extraction and measurement by elemental analyzer/isotope ratio mass spectrometry, delta15N values of the phosmet-free wool wax fractions were notably increased as compared to the value of natural lanolin. Calculated from the delta15N values, an average of 13.9/15.6% (sunlight simulator/natural sunlight) was bound to wool wax lipids after irradiation of thin films of commercial lanolin. In experiments with sheep wool, 13.2 and 15.4%, respectively, were detected as wax-bound. 相似文献
68.
Ichikawa Yoichi Hayami Hiroshi Sugiyama Taishi Amann Markus Schöpp Wolfgang 《Water, air, and soil pollution》2001,130(1-4):301-306
In order to contribute to the analysis and solution of regional scale environmental problems in East Asia, we developed a tool for the comprehensive assessment of alternative policy options to improve air quality. This tool projects the future regional energy supply, calculates the emission levels of sulfur dioxide and estimates the geographical pattern of sulfur deposition resulting from emissions. Sulfur deposition in Japan through 2030 was forecasted for various energy supply and emission control scenarios using the analysis tool. Future sulfur depositions were calculated from the source-receptor matrix for 1995 and the growth rate of emission for the source subregion. In the case of the current legislation scenario, anthropogenic SO2 emissions in East Asia would grow by 34 percent and sulfur deposition in Japan would increase by approximately 20 percent between 1995 and 2030. This increase in sulfur deposition over these 35 years is sligthly less than the contribution from volcanic emission to sulfur deposition in Japan. In the case of the hypothetical dirty scenario for China, sulfur deposition in several grids which face the Sea of Japan would double by 2030. 相似文献
69.
Wolfgang R. Müller-Stoll Gerhardt Casperson 《Genetic Resources and Crop Evolution》1987,35(2):441-452
Zusammenfassung Die Trabeculae von Lärche und Zwergwacholder weisen einen Bau auf, der mit Ausnahme des Zentralfadens dem einer normalen Zellwand entspricht. Auf die Mittellamelle folgt zunächst die sehr dünne Primär-, danach eine dreischichtige Sekundärwand; von der Sekundärwand ist besonders die mittlere Schicht (S2) stark verdickt. Die innere Schicht (S3) bildet die Tertiärlamelle, die beiJuniperus mit Warzen versehen ist. Bei Trabeculae-Reihen reicht der Zentralfaden durch die tangentialen Wände der Tracheiden von einer Zelle zur nächsten.
Electron microscopal investigation of intracellular bars (Trabeculae) in wood ofLarix andJuniperus
Summary The Trabeculae ofSanio fromLarix andJuniperus sibirica showed with exception of central or middle core a structure like a normal cell wall. Upon the middle lamella and the central core respectively follows first of all the very thin primary wall, then the three layered secondary wall; of the secondary wall above all the middle layer (S2) is strongly thickened. The inner layer (S3) corresponds with the tertiary lamella which inJuniperus is warty. The rows of Trabeculae only the central core reaches through the tangential walls of tracheids from one cell to the other.
- Larix Juniperus
, , . — . .V (S2). (S3) , Juniperus . , .相似文献
70.
Humic substances from the Ah horizons of five differently calcareous soils from Greece were successively extracted with organic solvents and/or 0.1 N NaOH and they were characterized by UV/VIS/IR spectroscopy and differential thermal analysis (DTA). Diethylether, acetone and dioxane extracts contained non-humic substances such as aliphatic and aromatic ethers, esters, alcoholes and long aliphatic chains, while low molecular weight humic substances were found in the ethanol extracts. All the extracts were found to contain phenolic and ?-acceptor compounds. Some differences in the physical characteristics of the humic substances were associated with the kinds of vegetation. The IR-spectra showed no essential differences between HA's and FA's extracted directly with NaOH or after previous soil extraction with organic solvents. HA's extracted directly by NaOH from soil samples under grass had a higher degree of condensation and thermal stability and generally higher carbon contents than those from soils under pine, cultivation and sedges. 相似文献