Silikatbestand und Verwitterungssimulation in den Hochlagenboden des Inneren Bayerischen Waldes

Inventory and weathering of silicate minerals in soils at higher elevations of the Interior Bavarian Forest In order to recognize the importance of the soils on the “new-type” Mg-deficiency disease of Norway spruce at higher elevations of the Bavarian Forest representative pedons were characterized morphologically, chemically and mineralogically. The results of the mineralogical inventory and of weathering experiments in laboratory correspond with the facts of the soil-chemical properties: the replenishment of Mg and Ca by weathering is very unsufficient in contrast to K in all investigated soils (soil pH = 4). Considering the intensive leaching in the flat, rooted zone, this fact explains the inadequate contents of exchangeable Mg and Ca in the upper soil horizons and also the Mg-deficiency of the trees being excellent supplied with K, P and N.     

Mineralselektive K-Freisetzung aus Böden mit Oktodecylammonium-Ionen (nc = 18)

Mineral-selective K release from soils by octodecylammonium- ions (n_c = 18) n_c18-releasable potassium was determined on soils of five different areas. n_c18-releasable K is the potassium which is displaced by octodecylammonium ions (ODA). Because the main sources of this potassium are trioctahedral micas, it is called briefly biotite-K. The investigated soils are from different areas in Bavaria (loess and clay stone derived soils, alluvial soils); partly the locations are K fertilizer trials. Soils of known age are locations from the Niederrhein terraces (Holocene soils). In the 0.2–2 μm (coarse clay) and 2–6 μm (fine silt) fractions the biotite-K content lies between 12 and 40% of total K. At given fractionation the highest amounts of K were released from the coarse clay of the soils. In the loess soils rich in silt the biotite-K pool in the medium and coarse silt fractions was also considerable. Clay soils showing poor K supplying power (K fertilizer trials) in the field are characterized by very low biotite-K quantities in all silt fractions. In the Holocene soils the age of which varies between 4 000 and 8 000 years the ODA releaseable values are greater than in the loess soils. In all fractions of the young Holocene soils the released K is greater than in the same fractions of the old Holocene soils. Calculated to a soil depth of 60 cm the K release in kg/ha reaches from 25 000 (young soil form) to 17 000 (old soil form).     

In situ weathering of rocks or aeolian silt deposition: key parameters for verifying parent material and pedogenesis in the Opawskie Mountains—a case study from SW Poland

Purpose

The aims: (1) to investigate the role of the in situ weathering of bedrock in providing substrate for soil formation; (2) to evaluate the aeolian contribution to the mountainous soils in the vicinity of thick loess cover; and (3) to determine the influence of aeolian silt on further soil development.

Materials and methods

The sampled sites were arranged along the slope toposequence, where an aeolian/silt admixture possibly occurred. Each soil catena started at the top of a hill and ended at its foot. Such an arrangement of the soil profiles ensured the tracking of loess thickness variations and detection of the depth of the residuum-derived materials. One reference soil profile, consisting of aeolian silt deposits, was made. The following soil properties were determined: pH, organic carbon content, soil texture, exchangeable acidity, exchangeable ions and geochemistry. In addition, thin sections were prepared from rock samples to confirm the type of bedrock present.

Results and discussion

The soils in the studied area were classified as Cambisols, Luvisols and Stagnosols, characterised by silt loam texture and a high content of elements indicating an aeolian silt contribution—Hf (7.4 to 14.8 ppm) and Zr (274.4 to 549.0 ppm). These values differ strongly from the residues typical of weathered quartzite, greywacke or catalasite substrates, which generally have low concentrations of Hf and Zr (0.7 to 7.0 ppm and 26.0 to 263 ppm, respectively). Based on the morphological, textural and geochemical data of the studied soils, three layers were distinguished, which show different inputs of aeolian silt: (1) an aeolian silt mantle; (2) a mixed zone in which loess was incorporated into the local material; and (3) a basal zone, free of the influence of aeolian silt. Based on the obtained results, a hypothetical pathway for soil formation in mountainous areas, influenced by aeolian silt admixing, was proposed.

Conclusions

Our study demonstrates that the soils developed in the Opawskie Mountains are characterised by an aeolian silt influence. This differentiates them from weakly developed soils, which comprise materials formed during in situ weathering only. Materials originating from bedrock weathering did not play an independent role as the parent material for the studied pedons. Aeolian silt was admixed with already existing autochthonous substrates, or completely replaced them. This influence on the soil formation resulted in the occurrence of Luvisols, Stagnosols and Cambisols. Such soils cannot be formed from the weathering of quartzites and greywackes, which contribute to a less structure-forming medium.

     

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.     

Aluminiumkonzentrationen und -bindungsformen von Bachwässern und wässrigen Bodenextrakten in den Hochlagen des Inneren Bayerischen Waldes

Aluminium concentrations and -species in streamwaters and water extracts at high elevations of the Inner Bavarian Forest During summer half-years 1986–1988 Al concentrations and Al species were recorded periodically for streamwaters of the Inner Bavarian Forest. Furthermore these analyses were carried out once with water extracts of 5 typical high elevation pedons. Total Al of streamwaters is strongly influenced by the hydrological situation. Highest Al concentrations (up to 1,5 mg/l Al) were found during subsurface flow (interflow) events, when inorganic Al species (Allabil) were predominant. In interflow and water extracts of high elevation sites the average molar ratio of Ca/Al_labil is ≧ 0,5 and the average Mg/Al_labil ratio ≧ 0,4. After Ulrich et al. (1984) and Jorns et al. (1985) these values are above the level of serious Al toxicity and thus they might not be the reason of the widespread Mg-deficiency in high elevation stands of Norway spruce. Water extracts of the examined soils have pK values similar to the mineral Jurbanit (AlOH₂SO₄). Thus in these soils a considerable part of Al should exist in this phase. The differing situation in interflow waters can be explained by an incomplete chemical equilibrium.     

Veränderungen von Dreischicht-Tonmineralen durch natives K in holozänen Lößböden Mitteldeutschlands und Niederbayerns

Changes of three-layer clay minerals by native K in holocene loess derived soils of Central Germany and Lower Bavaria . Transformations of the clay minerals illite, vermiculite and smectite were determined in Central German (31 profiles) and Lower Bavarian loess districts (5 profiles) using 31–36 soil properties. To get significant differences between solum and sediment, the multivariate diskriminant analysis was applied. In the Central German loess district the following properties were crucial, to receive significant separation between solum-horizons and sediments: smectite content, several values of potassium fixation, interlattice potassium. Important were also some parameter of the K-Ca-exchange curve: Activity ratio \documentclass{article}\pagestyle{empty}\begin{document}$ \left({\frac{{{\rm aK}}}{{\sqrt {{\rm aCa}}}}} \right) $\end{document} of a soil solution in equilibrium with a soil (AR_o), buffering capacity of the soil for K at equilibrium (BCKE), labile K(K₁), exchange capacity of the exchange sites with a specific affinity for K minus labile K(EC_x—K₁). The differences of these values can be explained by assuming that (at pH 6–7) the beidellitic layers of smectites of the parent loess were transformed to illitic layers in the solum-horizons. In the Lower Bavarian loess landscape potassium fixation, total K in clay fraction (< 2 μm) and the parameters of the K-Ca-exchange curve indicate the same clay mineral transformation as in Central Germany. Smectite values were not introduced to the diskriminant function, because they were highly significantly correlated with potassium fixation. In this case potassium fixation has caused a better separation between the solum-horizons and the parent loess than X-ray data. From these results, from total -K of the fraction 2–20μm (solum-horizons smaller than sediments) and the vermiculite content fo the clay fraction, it can be concluded, that the rate of potassium release from micas and the rate of potassium fixation by beidellitic sheets during the Holocene period were nearly equal.     

Die Erodibilität ausgewählter Böden der bayerischen Schichtstufenlandschaft

Erodibility of Selected Soils in the Bavarian Scarpland A laboratory rainfall simulator was used to determine the erodibility (K-factor of the USLE) of 6 soils. 3 of the soils were developed from mesozoic sediments (an Ochrept and an Udipsamment from sandstones, an Udorthent from shale), an Udalf and an Udorthent of loessial origin, and an Udorthent, that was developed from a silty-loamy cover. The measured K-values of the loessial soils agreed well with the calculated. But the calculated K-factors for the 3 Jurassic soils underestimated their erodibility. The erodibility of the silty-loamy soil was overestimated. It could be shown that the measured erodibilities agreed better with field data than the calculated.     

Quantitative Mineralbestimmung in der Schlufffraktion von Böden auf der Grundlage der chemischen Analyse und unter Anwendung der Karl-Fischer-Titration. II. Ergebnisse bei Böden aus Geschiebedecksand,Geschiebemergel und Löß

Quantitative estimation of the mineralogical composition from silt-fractions of soils on the basis of the chemical analysis and by application of the Karl-Fischer-titration. II. Results obtained with soils from glacial sand, boulder marl and loess The contents of micas and feldspars were quantified in the silt-fractions from horizons of a podsolic brown earth developed on glacial sand and of lessives on loess as well as on boulder marl by using a method that has been described in detail in part I. Three components each of micas and of feldspars, namely muscovite (Ms), phlogopite (Phl), annite (Ann), orthoclase (Or), albite (Ab) and anorthite (An) were determined. The silt fractions of the three investigated soils are similar in their mineralogical composition. Feldspars are composed of equally high amounts of Or and Ab. Micas are dominated by the Ms-component. Apparently the mica content of the silt fractions is reduced during soil development, whereas no significant changes can be found for feldspars. The loss of micas is responsible for the decreasing potassium content of the silt fractions.     

Schwefelausstattung ausgewählter europäischer Waldböden in Abhängigkeit vom atmogenen S-Eintrag

Sulfur status of selected European forest soils as dependent on the atmospheric S deposition Along a transect from the Pyrenees (SP), over the Vosges Mountains (FR), the Black Forest and the Bavarian Forest (D). and the eastern Ore Mountains to the Iser-Mountains (CR) 10 representative forest soil forms derived from granite regolith and 1 developed from gneiss debris (Dystric Cambisols, Leptic and Ferro-Humic Podzols) at montane and high-montane elevation were analyzed for their concentrations and amounts of total sulfur and various S fractions in order to study the impact of the atmospheric sulfur input, increasing from SW to NE, on the soil sulfur characteristics. Soils receiving low S inputs are generally characterized by low amounts of inorganic (especially water soluble) sulfate. Most of their total S amount consists of organic sulfur. With increasing S deposition, the concentrations of total S and C-S and the ratios S_t/C_org, C-S/C_org and SO₄?S_tor/C_org in the L-. Of- and Oh-horizons increase. The Aeh- and Ah-horizons of Cambisols and Podzols under different sulfur load do not differ with regard to the S parameters. The B horizons of the northeastern soils affected by high sulfur deposition, however, are markedly enriched with adsorbed and water-soluble sulfate and show comparably high ratios of sulfate S versus dithionite-extractable iron.     

Parent material influence on soil distribution and genesis in a Paleudult and Kandiudult complex,southeastern USA

Parent materials greatly influence soil development and the distribution of soils on the southeastern US Coastal Plain. We examined the physical, chemical, and mineralogical properties of 11 pedons in a 1-ha plot on the Upper Coastal Plain of Georgia, USA. Uniformity of parent materials was assessed by sand grain size characteristics. The soils have sandy epipedons of variable thickness and argillic horizons of variable texture. Six of the pedons also have kandic horizons. They are classified (US Soil Taxonomy) in Psammentic, Grossarenic, Arenic, and Typic subgroups of Paleudults and Kandiudults. Loamy pedons possess argillic horizons with two distinct increases in clay and greater differences between eluvial and illuvial horizons than sandy pedons. The upper boundary of the argillic horizon is approximately parallel to the present geomorphic surface, suggesting that it is associated with the contemporary surface. Discontinuities, identified by changes in sand grain size ratios and plots of the third (skewness) and fourth (kurtosis) moments of sand grain distribution, roughly correspond to the bottom of the solum. Our data suggest that there are both eolian and fluvial components in the solum, whereas subjacent horizons are completely derived from fluvial deposits. Sandier pedons have greater gibbsite/kaolinite ratios, possibly because greater permeability has enhanced leaching and Si loss. Our data suggest parent materials largely control soil distribution over this plot.     

Estimation of soil weathering stage and acid neutralizing capacity in a toposequence Luvisol–Cambisol on loess under deciduous forest in Belgium

Soils derived from loess are extensive in Europe and are well suited for forestry. They are suspected to be poor acid buffers, however. We have estimated the weathering stage and acid neutralizing capacity of acid soils under forest in a toposequence on loess in the Belgian silt belt. The soils vary distinctly in morphology and physico‐chemical properties according to their topographic position. Dystric Cambisols have developed in colluvial deposits in the dry valley floors, whereas Dystric Luvisols have formed on the slopes in a rejuvenated material. The Cambisols are more acid and less saturated in bases than are Luvisols. They are strongly depleted of clay and contain less weatherable minerals. Easily weatherable minerals are concentrated mainly in the clay fraction of both soil types. Clay minerals of size < 2 μm therefore act as major sinks for protons in these soils. A simplified expression taking into account the total reserve in bases, total aluminium and iron occluded in silicates is used to estimate acid neutralizing capacity. Our estimates confirm that these acid loessic soils are indeed poor acid buffers. They show that the Dystric Cambisols depleted of clay are sensitive to potential acidification, whether natural or man‐made.     

巫山黄土成因及其发育土壤特征研究

  目的  为探明巫山黄土成因,了解该类母质发育土壤的发生学特征。  方法  以典型巫山黄土及其发育土壤剖面为研究对象,通过野外调查采样和室内分析,详细考察剖面形态、颗粒组成、常量元素地球化学特征及其他相关理化性质,计算探讨硅铝率（ Sa ）、化学蚀变指数（ CIA ）、钠钾比（ Na/K ）、铁游离度等风化指标。  结果  （1）巫山黄土的颗粒组成以粉粒为主,平均含量为53.29%,与典型风尘沉积物相似,同时,巫山黄土与其他区域风成黄土的主要元素硅、铝、铁含量非常接近,上陆壳（UCC）标准化曲线也较为相似;（2）该剖面100 ~ 140 cm深度与其他深度相比,有机碳和硒含量较高,CaCO₃相当物含量和δ13C值较低,推测在此深度堆积过程中的气候较为温湿,并可能出现过植物的生长;（3）巫山黄土剖面的 Sa 为8.73 ~ 9.17、 CIA 为65.96 ~ 69.10、 Na/K 为0.74 ~ 0.89、铁游离度为22.88% ~ 29.74%,与其他地区风成黄土相比,巫山黄土风化程度强于洛川黄土而弱于下蜀黄土和成都黏土,与汉江黄土和甘孜黄土十分接近。  结论  巫山黄土应为风积成因,处于中等化学风化程度,以脱盐基为主,脱硅富铁铝化程度弱,可能与汉江黄土或甘孜黄土同源。     

Effects of silicate weathering and lessivage on K‐content in forest soils derived from Pleistocene sediments

The potassium (K) content of soils developed from Pleistocene calcareous till, glacial sand and loess in NW Germany was investigated in order to characterize stores of K in feldspars (K_feldspar) and mica/illite (K_mica/illite) as well as changes as a function of soil depth. From each horizon, up to seven sand, six silt and three clay fractions were separated. K_feldspar and K_mica/illite were quantified by means of chemical composition and estimation by IR‐spectroscopy. On account of distinct differences in mineralogical composition between different particle size fractions, K‐content of the bulk soil < 2000 μm and the proportion of K_mica/illite and K_feldspar are clearly related to grain size distribution of the sample. Generally, the K‐content of particle size fractions of a soil derived from calcareous till is significantly higher than that of a soil from glacial sands. K_mica/illite of clay and silt fractions increases with depth, reflecting greater mica/illite weathering at the soil surface, whereas K_feldspar shows no noticeable change. Illite accumulates by lessivage in Bt horizons. On a whole‐soil basis, the Bt horizons of Luvisols derived from loess and calcareous till contain more K_mica/illite than either the A or the C horizons. By comparing the K‐content in the different particle size fractions with soil depth, the highest rate of change is found for soils derived from glacial sand. Gains in K in the silt fractions of soils from calcareous till and glacial sand result from weathering of feldspar sand grains. Additionally, decomposition of feldspar‐containing rock fragments of gravel size, and aeolian sedimentation, may also have contributed to these gains.     

Organic carbon in the silt + clay fraction of Tasmanian soils

Organic carbon (C) was measured in the silt + clay fraction of 78 soils from agricultural areas in Tasmania, and the relationship between C in the silt + clay fraction and the percentage by weight of particles in this fraction was compared with similar data for soils from other regions and climates. Most of the cropping soils from Tasmania followed a previously published linear relationship, which is considered an indication of the capacity of soils to store C. The soils which fell the greatest distance below this relationship were sandy soils, consistent with previous evidence that these soils in Tasmania have been degraded. Soils which showed a major positive departure from the relationship were clay loams with >60% silt + clay. Most were also pasture soils. Tasmania's cool‐temperate climate would promote plant growth and C inputs and slow C breakdown, while the high clay content would help protect C. The results for the clay loam soils are consistent with earlier observations that these soils are generally in good health.     

Complex pedogenesis related to differential aeolian sedimentation in microenvironments of the southern part of the semiarid region of Argentina

The aim of this paper is to explain soil genesis and spatial variability in the soil cover of a flat landscape in the southern part of Argentina's semiarid region. Soil survey data indicate random differences in the properties of soils lying within a few hundred meters of one another, as reflected in an intricate distribution pattern which cannot be explained by the climatic theory of soil genesis in a single pedogenetic cycle. This pattern is unrelated to the actual vegetation cover. The soil parent materials consist of a <2-m mantle of aeolian Holocene sediments overlying a thick plio-Pleistocene “tosca” layer (calcrete, caliche). The undulations in the tosca layer are indicative of a paleomicrorelief levelled up to the present surface after the deposition of the Holocene sediments. Soils with fine-textured sandy loess and strong development (Meridiano soil: A–Bw–Ck–2Ckm) occupied a higher position within paleomicrorelief of the tosca layer. Adjacent soils on border or intermediate positions of the petrocalcic paleosurface have more complex profiles with a relict calcic horizon (Vizcachera soil: A–C–2Ck–3Ckm) and coarser texture (silty clayey sand) in the topsoil. In the lower positions of the paleomicrorelief of the tosca layer, the silty clayey sand directly overlie the petrocalcic horizon (El Khazen soil: A–C–2Ckm). The intricate distribution pattern is due to the coexistence of older polypedon (Meridiano soil), remnants of an earlier erosion cycle complexed with two younger soils, one from partial erosion (Vizcachera soil) and the other where total erosion of earlier soils was followed by successive pulses of aeolian deposition (El Khazen soil). The distribution pattern of the three soils thus reflects a complex history involving at least three stages of landscape evolution.     

Dynamik und Elementgehalte von Fichtenfeinwurzeln in Kalkgesteinsböden am Wank (Bayerische Kalkalpen)

Dynamics and nutrient concentration in fine-roots of alpine spruce stands on calcareous soils (Wank-Massif/Bavarian Alps) The dynamics and the concentrations of nutrient elements in the fine roots of two stands of alpine spruce differing in vigour on calcareous soils overlying limestone in the Wank massif of the bavarian alps were measured. Selected root parameters were compared with those obtaining on acid soils. At Wank, the concentration (mg/100 ml soil) of living fine roots and root tips was maximum in the organic surface layer and the mineral horizon immediately underlying the surface layer. There were significantly more fine root biomass (kg ha^?1) on the calcareous site (Walk) than on acid soils (Solling and Fichtelgebirge). There were also marked differences between the two sites in concentration of nutrient elements in the fine roots was strongly influenced by chemical composition of the soil solution.     

Vertikaler Wasser- und Nitrattransport in tiefere Bodenschichten süddeutscher Ackerstandorte

Vertical water and nitrate movement into deeper soil layers on fields located in the south of Germany In Southern Bavaria, selected fields from deep loess and sandy sediments were sampled to a depth of maximum 10 m every 4 months, in order to determine the basic processes of water and nitrate movement in the course of the year. The downward movement of water and nitrate followed the principle of piston flow only in the intermediate vadose zone of loess soils with a leaching distance amounting 0.8 m per year. On the other hand, an accelerated as well as a delayed transport was observed in the zone of evapotranspiration of loess soils and in the whole profile of sandy soils, not being in accordance with the simple simulation model FLOTRA based on the classic theories of transport (Darcy flow, convection-dispersion-equation). Preferential flow led to the leaching of nitrate from the top soil to the lower boundary of the evapotranspiration zone of loess soils in 2 m depth, in winter and spring. In sandy soils nitrate was leached to the groundwater table in 4–6 m depth after extensive rainfall.     

Das Kaliumpotential von Böden des unterbayerischen Hügellandes bei langjährig unterschiedlicher K-Düngung

The K-potential of soils in Lower Bavaria as influenced by long-term K fertilization In a fertilizer trial with P and K established in 1974 on 4 representative soils of the Hallertau (Lower Bavaria) the potential K-supplying power was investigated. To this purpose K-uptake of the crop, K-balance, CAL-soluble K and K-Ca-exchange isothermes were determined once yearly. As K addition increased K uptake by crops increased and this the more the lower the clay content of the soil (3–28%). Labile K was significantly correlateted with K-balance but change in labile K was only one third of change in K-balance. The remaining two thirds of K must have come from interlayer-K. Labile K and CAL-K are sufficiently identical and can be calculated from each other. The K-buffering capacity as taken from exchange isothermes at AR₀ proved to be soil-specific within a wide range of K-balance (positive to negative). AR₀ was closely related to the K-balance and varied the less the higher the K-buffer capacity.     

Auftreten und verbreitung von lösslehmbeimengungen in periglazialen schuttdecken des schwarzwaldwestabfalls

This work was done in three different research areas In order to determine the loess content in the periglacial strata, there has been taken a profile catena on gneis, granite and ignimbrite as solid rock. At first the rock material including the loess of the upper Rhine plain was described. The admixed loess in the layered solifluction profiles was qualitatively and quantitatively determined by its differentiating values By grain-size-distribution the “total loess” including far and local transport was calculated. Because the “far transported loess” differes in geochemical values and heavy minerals it was possible to select it from the local loessThe maximum in loess content was found in the so called Hauptfolge (main series) of the Periglacial. The “Decksediment” (top layer) has got similar contents but is less important because of his minor thickness and smaller spread. The dense “Basisfolge” (basic series) is almost free of loess The amount of far transported loess in a distance of 1 km from the glacial terrace of the Rhine is about 1000 kg/m² (300 m above sea level). It decreases sharp into the mountains and reaches at 1000 m and 12 km from the plain the detection limit of about 30 kg/m². The local component in contrary is not important on the lower slopes and has its maximum of 150 kg/m² at the mountains top (1300 m, 15 km). According to this features total loess has a minimum in an altitude between 800 and 1000 m.At the footslope of Black Forest loess accumulation was favoured at least at the end of the last glacial period. On the mountains kryoclastic silt production and local transport have been more important.

Zusammenfassung

Die Untersuchungen wurden in drei Teilgebieten mit den anstehenden Gesteinen Gneis, Granit und Ignimbrit durchgeführt. Die Lößbeimengung wurde in je einer Catena von Schuttprofilen erfaßt. Zuerst wurden die unveränderten Ausgangsgesteine einschließlich Rheintallöß beschrieben. Mit den hier dargestellten Kennwerten wurden die Lößanteile in den Schuttprofilen qualitativ und quantitativ ermittelt. Mit Hilfe der Korngrößenverteilung wurde der aus Ferntransport und Lokalverwehungen bestehende “Gesamtlöß” bestimmt. Fern- und Lokallöß ließen sich aufgrund ihres unterschiedlichen Chemismus und Mineralbestandes trennen.Die höchsten Lößanteile hatten die als Hauptfolge bezeichneten Schuttschichten. Das Decksediment, welches ähnliche Gehalte erreicht, hat wegen geringerer Mächtigkeit und kleinerem Verbreitungsgebiet weniger Bedeutung. Die meist dichte Basisfolge ist nahezu lößfrei. Die Fernlößmengen, welche in 1 km Abstand von der Niederterrasse des Rheins noch ca. 1000 kg/m² betragen, nehmen gebirgseinwärts rasch ab und erreichen bei 1000 m und 12 km die Nachweisgrenze um 30 kg/m². Die Lokalkomponente ist an den unteren Hängen am niedrigsten und erreicht auf den höchsten Höhen mit 150 kg/m² ihr Maximum. Der Gesamtlöß hat also zwischen 800 und 1000 m sein Minimum.Am Fuße des Schwarzwalds waren die Bedingungen der Lößakkumulation zumindest gegen Ende des letzten Glazials günstig (Vegetation, wenig Bodenfließen). Auf den Höhen dagegen war offensichtlich die Kryoklastik aktiver und lokale Umlagerungen waren stärker begünstigt.     

Beziehungen zwischen Zink- und Kupfergehalt in Haferpflanzen und Böden

Relationship between Zn and Cu Contents in Oat Plants and Soils The Zn concentration in oatplants at the stage of appearing panicles from agricultural fields were higher and more varying on soils of sandy texture than on soils of loess. With the former Zn in plants correlated with n-MgCl₂ extractable Zn in the soil (r = 0.745), and also with 0,5 n-HNO₃ extractable Zn if the pH dependance was taken into account. Zn in plants from soils of loess correlated with HNO₃ extractable Zn only. Cu concentrations in plants were lower on soils of sandy texture. A correlation to 0.5 n-HNO₃ extractable Cu in the soil existed in the group of loess derived soils only (r = 0.474), a negative correlation between Cu in plants and soil pH only with sandy soils (r = —0.500). Zn and Cu concentrations of plants were based on total N contents of plants instead of on dry matter, with the aim of mitigating growth dependent differences in Zn and Cu originating from unequal stage of plant development at harvesting.