Allgemeine Merkmale sowie Blei- und Zinkmobilität in urban-industriell überformten Böden des Brücktorviertels in Oberhausen (Ruhrgebiet)

General characteristics as well as the mobility of lead and zinc in soils which were transformed by urban and industrial impact of the Brücktor district in Oberhausen (Ruhr area) This paper presents the results of Urbic Anthrosols from eight different sites which contain partly alkalising material of technological origin in an urban-industrial area in Oberhausen. These results were then compared with those of tests taken of a nearby Cambisol from Oberhausen. The pH-value of the profiles with the deposit layers are almost always in the alkaline range (highest pH = 9,8). More than 50 % of the deposit layers of the tested soils show a coarse texture with a high to very high content of gravel, ashes, cinders, clinker and mining waste. The soils are deep enriched with fossilized and pyrolytic transformed carbon substances which are recorded, as well as the recent humus, by using the Lichterfelder-method to determine the Corg. From the substratum of the deposit layers Na, K, Mg and Ca were moved into deeper horizons which could cause an increase in the pH-value there. The eight tested soils partly show a high accumulation of heavy metals (up to 4,8 g Pb/kg, up to 2,8 g Zn/kg). High heavy metal contents were measured in the deposit layers of ashes. Unlike Na, K, Mg and Ca, it could not be shown that a transfer of mobile Zn and Pb into deeper layers of soil takes place. In spite of a lower background pollution, the acidified Cambisol contains, in comparison to the eight tested soils, a clearly higher mobile Zn-content which could be transferred through the profile.     

Ökologische Gruppierung von Böden nach ihrem chemischen Bodenzustand

Ecological grouping of soils according to their chemical soil state On the base of the solubility of carbonic acid, calcium carbonate, as well as the oxidic compounds of Al and Fe existing in soils, the following buffer ranges are defined and separated from each other by pH values in the soil solution: Carbonic acid/Carbonate buffer range (pH 6.2 to 8.6), Carbonic acid/Silicate buffer range (pH 5.0 to 6.2), Exchanger buffer range (pH 4.2 to 5.0), Aluminium buffer range (pH 2.8 to 4.2), Iron buffer range (pH 2.4 to 3.8). The buffer capacities are calculated and literature indications regarding buffer rates are compiled. The characteristical chemical soil state is demonstrated for the various buffer ranges with aid of a soil collection. With increasing soil acidification the Ca/Al mole ratio in fine roots decreases from values > 1 to values around 0.3; this is taken as evidence for increasing disposition for Al-toxicity. It is suggested to attach soil horizons to buffer ranges on the base of pH(H₂O) measurements made on field fresh samples. The measurement of pH in salt solution is taken as measure for the amplitude of the chemical soil state in case of H-ion or salt stress.     

Untersuchungen über den Einfluß des Bodengefüges für den Eindringwiderstand in Böden

The influence of soil structure on penetration resistance Penetration resistance depends strongly on the soil structure. However, because roots may either penetrate aggregates or grow around them, the value determined for the bulk soil can only be used as a first approximation. If e.g. unconfined aggregates are penetrated, the penetration resistance increases with increasing size. If however, the aggregates are confined by being embedded in gypsum then the penetration resistance is higher but is independent of aggregate size. Thus, the outer skin is stronger than the inner part of the aggregates. When single prisms are penetrated horizontally, then the penetration resistance is smaller than the resistance to vertical penetration. On the other hand, for polyhedral structure the penetration resistance is of the same order of magnitude in both directions.     

Schwermetallanreicherung in den Böden des Abwasserbehandlungsgebietes Braunschweig

The accumulation of heavy metals in the soils of the Braunschweig wastewater irrigation area The concentration of lead, zink and cadmium in the Ap-horizons and subsoils of sandy Podzols and Cambisols were investigated. As compared with same soils outside the irrigation area an accumulation of the heavy metals in the Ap-horizons of the older sprinkler irrigation plots was found. On the rill irrigation area the heavy metals also were concentrated in the subsoils.     

Die Nitrifikation in Böden (Sammelreferat)

Nitrification in soils A literature review is given on the biology of nitrifying organisms, the nitrification process in soil and factors influencing nitrification in soil with special reference to the following aspects:

• 1 Importance of nitrification in the nitrogen cycle.
• 2 Biology of nitrifying micro-organisms.
• 2.1 Chemolithotrophic bacteria and heterotrophic micro-organisms.
• 2.2 Physiology and biochemistry of nitrifying micro-organisms: gain of energy, specifity and concentration of substrate, influence of soil reaction.
• 3. Methods for the measuring nitrification in soil.
• 3.1 Experiments for the determination of nitrification.
• 3.2 Calculation of the nitrification process.
• 4. The course of nitrification in different soils.
• 4.1 Rate of nitrification.
• 4.2 Influence of various environments: soil reaction, temperature, oxygen and water content.
• 4.3 Effect of soil organic matter and vegetation.

     

Genese und Ökologie innerstädtischer Böden aus Bauschutt

Formation and ecology of rural soils from debris Within 30 years Rendzinas have developed on habitats of debris and rubbles in West-Berlin by accumulation of organic substances, carbonate impoverishing, slightly beginning acidity, and biogenic structuring. Their conditions for water, air, and nutrients were investigated for 2 years.     

Protonenpuffersubstanzen in Böden

Proton buffer compounds in soils A classification of solid soil buffer substances according to the type of proton accepting sites, viz. carbonate buffer, variable charge buffer, silicate buffer and hydroxide buffer is proposed. The buffer reactions are discussed in some detail and so are formation and transformation processes of buffer. An association of pH-ranges to various buffer compounds is hampered by an insufficient knowledge of the acid strength of the different functional groups.     

Winterliche N-Mineralisation in sandigen Böden des ‘Fuhrberger Feldes’ (Hannover)

N mineralization in sandy soils of the ‘Fuhrberg well field’ (Hannover) during winter Net N mineralization was measured under field conditions during winter and spring 1991/92 in sandy arable soils (Gleyic Podzols, Mollic Gleysols, Gleyic Arenosols) of the ‘Fuhrberg well field’, a drinking water catchment north-east of Hannover. The aim was to assess leaching losses of nitrate from mineralization processes during the winter on soils formerly used as grassland. Two field procedures were used: the incubation of soil material in polyethylene bags at its original location and rain sheltered fallow plots. Between 6 and 40 (100) kg N ha^?1 were mineralized during 73 days from Dec., 17th to March, 2nd. Mineralisation rates were closely correlated to the organic N and C contents of the soils (r² ± 0.9). In the uncovered soils, the NO₃ was completely leached out. On five out of seven fields the process ‘N-mineralization during winter’ alone was sufficient to exceed the official limit for drinking water (50 mg 1^?1 NO₃^? ) in the uppermost groundwater. It is concluded that even 15 years after converting grassland into arable land the N_org and C_org levels in the soils had not reached a new equilibrium.     

Untersuchungen über einige Böden in der Wüste des „Lut-e-Zangi Ahmed”︁ (Iran)

Investigations on some soils of the Lut-e-Zangi Ahmed desert, Iran ”?Lut-e-Zangi Ahmed”? is a part of the Lut desert, which is located in south-eastern Iran. The Lut desert is one of the warmest and driest deserts of the world. It is very poor in vegetation and water, particularly in useful water. The evaporation is nearly hundred times more than the precipitation during the year (Evap. = 5000), precip. = 50 mm/year. In the research of “Lut-e-Zangi Ahmed”-SW part of the Lut desert-where its soils were entirely unknown, it is tried to get information about the most important properties of the desert-soils and possibility of agricultural use, through the profiles and analyses. The average elevation of the “Lut-e-Zangi Ahmed” is 500 m above the sea-level. The region is very poor in vegetation. There are many large areas on which no vegetation exists. The only useful water (underground water) is found in this part of the Lut desert. There are different zonal-intrazonal and azonal soils in the “Lut-e-Zangi Ahmed” (compare Ganssen 1968) for example: Hamada-desert soils, grey and light-brown saline desert soils, fine textured alluvial soils and sand desert soils. The soils are salty (EC from 11-5 12 mmhos/cm) and neutral to weak alkaline. They are poor in organic matter, phosphor and nitrogen too. The predominating part of the area investigated is not suitable for agricultural use. Only 150 ha are arable land, because it is possible to get here suitable groundwater for desalinization and irrigation.     

Ermittlung des Spannungszustandes von Böden aus Werten des Eindringwiderstandes von Sonden

Evaluation of the soil consolidation state by using data from penetration resistance probes Penetration resistance data (EW) from handdriven equipment are easily obtainable because the equipment is simple, cheap, and easily carriable. Measurements are performed quickly without extensive destruction of the site. It is the only method to measure soil strength directly and in situ. Therefore, it is worthwhile to propose an interpretation of the results in order to obtain more conclusive statements on the structural soil state. The procedure applied in our study consists in assigning EW values to the principal stress σ_x and in using an auxiliary construction for the vertical component (σ_z ) as a function of penetration depth. The EW value obtained at the final soil depth is assumed to represent stresses at rest, i.e., K₀ = σ_x/σ_z = 1. Drawing a straight line from this point towards the origin of the coordinates EW and soil depth supplies values of the hydrostatic condition for each depth; e.g., values for σ_z are available for each depth. The coefficient for the equivalent stress at rest (K_0E) per depth can now be calculated simply by comparing the measured EW values with the assumed (hydrostatic) vertical depth function of EW. From a total volume of 29 sets of EW versus depth relations, means and standard deviation of K_0E are presented for arable and forest soils from central Europe. K_0E of forest soils tends to be close to 1 showing approximately normal compaction. In arable sites, K_0E > 2 prevail, indicating precompation. These results confirm the general feasibility of the approach to evaluate the compaction state of soil from EW data. Examples are given to show the K_0E characteristics for special cases of mechanical stress situations.     

Über die Magnesiumverarmung der Böden in den Hochlagen des Inneren Bayerischen Waldes

On the depletion of magnesium in soils of high altitudes of the Inner Bavarian Forest A widespread magnesium deficiency in stands of Norway spruce, growing at high altitudes of the Bavarian Forest, was the reason for an extensive soil survey and for hydrological-hydrochemical studies of these areas. The prevailing soils are Fragiorthods and Fragiumbrepts (great soil groups after US Soil Taxonomy). Total element contents of soils show clear relation to the respective parent rock. These relations are missing for exchange capacity (CEC_e) and exchangeable elements. This fact can be explained by a consolidated layer in the upper soil and high annual precipitations, which favor episodic interflow with low pH (about 4,0) and high SO₄- respectively NO₃-concentrations. Water of the deeper ground (baseflow) however, shows high pH-values (about 6,5) and low SO₄-concentrations. Increased concentrations of SO₄ and NO₃ in seepage water (interflow) show relation to considerable atmospheric S- and N-input. Furthermore the qualitative evaluation of the nutrient balance in these forest ecosystems revealed a release of SO₄ and NO₃ in soils of the high elevations, which must be followed by an equivalent removal of cations. The balance of element translocations in soil profiles shows, that magnesium is mostly affected by these depletion processes.     

Anthropogener Asbest in Böden

Anthropogenic Asbestos in Soils Fibers of different asbestos types as well as other fibrous minerals, e.g. zeolites, have been found as natural contamination of soils or quarries in numerous countries and regions. Epidemiological studies have shown that inhabitants of these regions have high incidence of calcified pleural plaques and malignant pleural mesotheliomas. Anthropogenic contamination of soils by asbestos as well as asbestos contamination of the soil-near air layer were measured in this study. Soils were contaminated with chrysotile and amphibole asbestos during and after industrial asbestos processing. Asbestos fiber contaminations in the range of 10⁶ to 10¹¹ fibers/g soil and fiber concentrations as high as 5 × 10⁵ fiber/m³ air were measured. Soil contamination by anthropogenic asbestos can produce high or very high contamination of water and of ambient air by very fine fibers and entail carcinogenic risk for the general population, mainly for the inhabitants in the neighbourhood.     

Nitratumverteilung in Böden durch Trocknung

Redistribution of nitrate in soil samples due to drying Soil core samples of 500 cm³ volume were dried at 105°C and divided into 0-1 to 1.0 cm thick layers. The nitrate content of layers from the evaporating upper and lower surface greatly increased as compared with the central parts of the core. This process may take place on drying soil samples in general and may create problems of homogenisation when dried soil samples are analysed on their nitrate content.     

Dicyandiamidabbau in Quarzsand und Böden

Breakdown of Dicyandiamide in quartz sand and soils Under different moisture conditions the breakdown of dicyandiamide (DCD) was investigated in quartz sand with metal oxides and in soils. 1. In quartz sand without metal oxides DCD did not change over 100 days. 2. In the presence of amorphous Fe(III)-hydroxide DCD was transformed to guanylurea after 5 days to 50% and after 40 days to 90%. The transformation rate depended on the kind of metal oxides and increased with low humidity. Other metabolites were not detected in quartz sand medium. 3. In two soils (pH 6.5, 6.3; sandy silty loam and sand) the breakdown of DCD to guanylurea followed the same pattern, but continued to ammonium. About 20–70% of the added amount was transformed within 100 days. 4. With increasing soil moisture the transformation of DCD to guanylurea was slower, but the further breakdown to ammonium increased. 5. As long as DCD was present the formation of nitrate was blocked.     

Schwermetallverteilung und Tongehalte in Böden

Heavy metal distribution and clay contents in soils . In soil profiles differing considerably in horizon pattern and parent material the contents of Mn, Zn, Cu and Co were correlated with those of clay (and CEC), of total Fe (and dithionite soluble Fe) and - after relation to clay - with C. The correlations with clay, CEC, Fe_t and Fe_d were in all cases positive and highly significant, though differing between the different metals and between the references. Deviations for all elements are due to lithogenic differences in soils from mesozoic sediments and for Mn also due to its lower pedogenic stability. The correlations with C were not significant, since O horizons were not yet investigated. The ‘mobility’ of the heavy metals ( = EDTA + NH₄O Ac-extractable in relation to total amount) in topsoils could be more correlated (negative) with the reserves than with other soil features. Relating the ‘immobile’ heavy metal contents to the other soil features considerably improved the correlations.     

Zur Interpretation erhöhter Schluffgehalte in Böden des Bayerischen und des Oberpfälzer Waldes

On the interpretation of raised silt contents in soils of the Bavarian and Upper Palatinate Forest For the Bavarian and Upper Palatinate Forest (Bavaria), 41 representative pedons were examined for aeolian components using grain‐size analysis. Soils derived from loess (three pedons) are only available in the foreland of the Bavarian Forest near to the river Danube. Soils with aeolian fractions (one pedon) also exist in the adjacent part of the Bavarian Forest. No indication for loess components (37 pedons) were found in all other parts of this mountain range: these soils are missing a coarse‐silt maximum in their upper layer as should be expected for loess‐influenced soils. However, 17 of these pedons have a medium‐silt maximum in their upper layer interpreted as a result of intense physical weathering. Therefore, the widely occurrence of soils with aeolian components cannot be confirmed for this low‐mountain range of E Bavaria.     

Kurzfristige pH-Pufferung von Böden

Short-time pH buffering of soils Changes in pH of 60 soils after HCl addition were related to reaction time and soil characteristis. Between 80 and 100% of the added protons were taken up by the soils within a few seconds, resulting in the release of exchangeable Ca, Mg and Al in strongly acid soils. The decrease of proton activity between 0.25 and 30-70 h can be formally described as a diffusion process. pH buffering depended on soil pH and organic C content but not on clay content. Buffering decreased from pH 3.5 to about 6 and increased again up to pH 7. Increase of C_org increased buffering mainly from pH 6-7.