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1.
Micromorphology and carbonate dynamics in the Chernozem of Rheinhessen, Western Germany The loess-born Chernozem in Rheinhessen contains carbonate in the whole solum. The presence of pedogenic carbonate indicates a pronounced carbonate dynamic. Lithogenic carbonate was found in all samples and indicates, that the solum never has been completely decalcified. There are microaggregates of double-refracting clay, which are not due to any weathering of silicates during the Holocene, for they belong to a special brown compartiment poor in carbonates and perhaps corresponding to a Wuerm-age loess component.  相似文献   

2.
Transformation and loss of phosphorus in soil chronosequences derived from non-consolidated sediments of the river Lech Phosphorus fractionations were carried out on soils derived from carbonat rich gravel and silt which represent two chronosequences. Results obtained by these procedures indicated an enrichment of Al, Fe-phosphates in nearly all soils. Losses of Ca-phosphates were obtained in all soils. In contrast to other soil chronosequences (viz. Franz-Josef, Manawatu) the PCa-contents did not decline to zero in the oldest soils. The Porg-contents of soils showed a decrease with increasing age of soils of the silt chronosequence. The C/P-ratios of the mineralic soil horizons remained nearly constant during pedogenesis. Losses of total phosphorus amounts to 400g P/m2 in the 20 000 a old soils and to 160g P/m2 in the 10 000a old soils. It must be assumed that the major part of the lost phosphorus has been washed out of the soils.  相似文献   

3.
Chernozems in Austria A general review of the types (Tschernosem, Paratschernosem, Feuchtschwarzerde, Gebirgsschwarzerde) and subtypes of Austrian Chernozems is given. The regional distribution of these soils in the eastern drylands (Pannon) and the dry valleys of the central alpine region is shown and their pedogenetic characteristics, genesis and systematical definition within the Austrian Soil Taxonomy is explained.  相似文献   

4.
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.  相似文献   

5.
Development and Classification of Marsh Soils from the Unterweser Region, West Germany. I. Total Nutrients, Carbonate Content, Exchangeable Cations and Diatom Flora as Indicators of the Role of Sedimentation Conditions in Soil Development This study was carried out to see how much sedimentation conditions determine the properties– in particular the Ca/Mg ratio – of marsh soils (fluvaquents of coastel areas). The following results show, that the marsh soils properties are not determined by different sedimentation conditions: – The vertic fluvaquents don't have a higher clay content than the mollic and aeric fluvaquents – The total (t) contents of P, Ca, Mg, K and Na varied because of different soil development – The Cat/Mgt ratio in soils with CaCO3 was higher than in soils without CaCO3, and – related to the Caa/Mga ratio – it can also be used as a classification characteristic (a = exchangeable) – The Caa/Mga ratio varied greatly because of differences in exchangeable Ca content. Vertic fluvaquents sometimes, but not often, have a higher content of exchangeable Mg than the mollic and aeric fluvaquents. Comparing maps of the Weser area as it appeared at various times in the Holocene with the soil map, shows that the sedimentation pattern is invariably brackish-marine. This is further confirmed by the diotom flora of the soils tested. Thus the properties of marsh soils, long believed to be dependent on sedimentation conditions, are the product of different continuance and intensity of soil development.  相似文献   

6.
Demonstration of the soil development in high flood loam of the Lower Rhine using multiple correlations, regressions and cluster analysis Several characteristics have been examined for 26 soils on high flood loam aged from 500 to 12000 years. Main results of discovered relations between duration of development and degree of characteristics are: Using multiple regression analysis continuous soil development could be stated and quantified. Square regression is better than a linear one. Employing regression being determined among some characteristics and age by means of absolutely dated soils, age of other soils in the same region can be estimated. With cluster analysis it is possible to demonstrate soil development from late pleistocene to youngest holocene too, but the relationship in ages is relative.  相似文献   

7.
A method to determine oxygen partial pressure and oxygen diffusion in single soil aggregates as a function of soil moisture tension Anaerobic zones occur even in unsaturated soils of silty or clayey texture, that are aerated sufficiently in their macropore system. These zones can be related to the inner parts of soil aggregates. To describe the oxygen balances in soils it is necessary to measure not only in soil profiles but as well in single soil aggregates within a range of soil matrix potentials. Therefore oxygen partial pressure in single soil aggregates of different texture was measured continuously as a function of soil matrix potential. For that purpose we developed an oxygen sensitive microelectrode with a tip diameter of 0.5 mm, that is sturdy enough to measure even in sandy soils. One microtensiometer (diameter of the tip < 0.5 mm) and one oxygen microelectrode were placed in water saturated soil aggregates. Soil water potential and oxygen partial pressure were measured continuously during soil drying. The results show an aeration of primarily anoxic soil aggregates at different soil matrix potentials due to different texture and structure. The clayey polyhedral aggregates of the Vertisol were aerated at significantly lower soil matrix potentials than the loamy prisms of the Fluvisol. These show higher values of oxygen partial pressure even at soil water potentials less than 150 hPa. In the aggregates of the Vertisol, that have a fine texture, values of rel. aparent diffusion Ds/Do were in the range of 1 · 10?3 at soil water potentials < ?  相似文献   

8.
Clay mineralogy and K-Ca-exchange properties of surface soils from the nutrient potential trial Hallertau (Bavaria) In soils of four locations of the Hallertau nutrient potential trial, with a soil texture consisting of sand, silty sand, silty loam and sandy clayey loam, clay mineral properties were measured with the standardized glycerol expansion method and with n-alkylammonium (Rnc-NH3+-clay). The expandable minerals of the sandy soils consist exclusively of smectites s.s., (s.s. = sensu stricto) with 0.42 to 0.28 charge equivalents per formula unit (p.f.u.). The expandable minerals of the loams are an assemblage of smectites s.s. and vermiculites. The total layer charge of the smectites s.s. extend from 0.54 to 0.28 charge eq. p.f.u. The fine clay fractions (< 0.1 μm) do not contain vermiculites. The layer charge density of vermiculites with homogeneous charge in the coarse fractions varies between 0.60 and 0.95 charge eq. p.f.u. The immediate K-Ca-exchange was extended with the values of the continued K exchange versus Ca at low K intensity. The Q/I isotherms of sandy soils have a more pronounced curvature than the isotherms of the loams; in all cases, however, the exchange curves have a continuous form. This phenomen is discussed in terms of the clay mineralogy of the soils. After 8 years without K fertilizing, samples gave values between 168 and 497 kg smectite-K/ha for the surface soils. The constant rates of K-desorption vary between 12.8 and 28.7 kg K/ha (surface soil). The rates are better differentiated between unfertilized and fertilized soils for the loams than for the sandy soils. The constant rates of K release were found to be controlled at an AR-level between 1.6 · 10?4 M1/2 (unfertilized sandy soil) and 5.2 · 10?4 M1/2 (fertilized sandy clayey loam soil).  相似文献   

9.
Development and Classification of Marsh Soils from the Unterweser Region, West Germany. II. Importance of Sulfur Metabolism, Methane Production and Ca/Mg Ratio for Classifying Marsh Soils The importance of sulfur metabolism in each step of marsh soil development (Brümmer, 1968) is also confirmed for the marsh soils of the Unterweser region. Sulfur contents and sulfur fractions indicate that soil development has advanced further in brackish marshes than in marine and river marshes. The results give additional evidence that the various properties of marsh soils are only partly caused by sedimentation conditions. – The sedimentation areas (Müller, 1954) apply only to small regions. Thus, methane production predominates in the freshwater area, while sulfate reduction predominates in the marine area. Both processes occur at high rates in the brackish area. Classifying soils on the basis of the Ca/Mg ratio gives the same soil groups as Brümmers classification. Consequently, classifying the marsh soils of Niedersachsen on the basis of Ca/Mg ratio is a suitable method, if the idea that sedimentation conditions cause soil properties – especially the contents of exchangeable Ca and Mg – and the present designations of the soil groups are rejected.  相似文献   

10.
Die für das Niedersächsische Bodeninformationssystem (NIBIS) entwickelten Methoden zur Bewertung des potenziellen Verhaltens von Pflanzenschutzmitteln (PSM) in Böden wurden im Rahmen verschiedener Forschungsprojekte in sächsischen Testgebieten auf ihre Anwendbarkeit untersucht. Die Methoden bieten Ansätze zur qualitativen Bewertung der potenziellen Bindung, Anreicherung, Verfügbarkeit und Verlagerung von PSM auf mittlerer Maßstabsebene. Schutzstrategien oder Meßprogramme zur aktuellen Belastungssituation von Böden und Gewässern können durch die Kennzeichnung großräumiger Gefährdungs schwerpunkte für ausgewählte Stoffe ergänzt werden. Grenzen des Bewertungsverfahrens ergeben sich aus der Verfügbarkeit von Eingangsparametern und dem methodenspezifischen Bewertungsalgorithmus. Die Anwendbarkeit der Methoden erfordert außerdem die lückenlose Aufbereitung der Berechnungsvorschriften sowie die Umsetzung in Computerprogrammen. Methods of the Nether-Saxony Soil Information System (NIBIS) which could estimate the potential behaviour of pesticides in soils are tested in different projects in test areas of Saxony (Germany). The methods offer approaches to assess in quality the potential bounding, enrichment, availability and dislocation of pesticides in mesoscale geographic dimension. Strategies of resource protection or programmes of measuring of the actual pollution of rivers and soils are complemented by the estimation of large-scale risk-areas by different compounds. Problems of the application cause on the availability of modelling-data and the specific characteristics of the calculation-algorithmus. To an expansive using of the methods it would be necessary to complete and programme the instructions of calculation.  相似文献   

11.
Nitrogen compounds in soils and their relation to humus dynamics. 2. Communication: On the determination and attachment of amide-nitrogen The amide-nitrogen fraction in soils – so far very insufficiently defined – has been determined in the hydrolysates of 12 different soil samples. The proposed procedure allows to split this amide-nitrogen fraction into two better befined N-fractions, namely: real amide-N (EAN) and pseudo-amide-N (PAN). This splitting is based on. 1.) a detailed N-fractionation, especially a quantitation of aspartic acid + glutamic acid (AG) and ammonia in the hydrolysate, 2.) on the fact, that pure proteins and ?soil proteins”? do not significantly differ in terms of their amino acid composition (average basis per mol protein) and deductive hereupon 3.) on the assumption, that the calculated NH4/AG- ratio of 0,5 from pure proteins can be transferred to ?soil proteins”?. Methodically the real amide-N (EAN) and the pseudo-amide-N (PAN) are determined as follows: After quantitation of aspartic acid + glutamic acid (AG) in the soil hydrolysate EAN can be calculated by the equation: EAN = (AG) X 0,5. PAN amounts to the difference between Ammonia of the hydrolysate and EAN. For the 12 soil samples the PAN/EAN-ratios are in the range 1,5–11,7.  相似文献   

12.
Rates of deposition, of soil internal production and of turnover of protons in two forest ecosystems The rates of deposition, of turnover and of soil internal production of protons are calculated from the flux balance of chemical elements within two forest ecosystems (Dystic Cambisols from loess/sandstone with beech or spruce). The rates of interception deposition vary significantly throughout the season and determine the rates of total deposition to a large extent. The comparison of the actual rates of proton load with the buffer rates possible in the soils leads to the conclusion that soil acidification up to the level of the Al-buffer range is unavoidable in most forest soils in Middle Europe. The behaviour of the incoming S in the soil is related to the dissolution and precipitation of Al-hydroxo-sulfate. The accumulation of S within the soil of the spruce stand was found to be reversible and was followed by a phase of strong leaching of S and Al from the soil. The processes that account for the rates of soil internal proton-net-production are quantified. More than 70% of the total proton load results from the deposition of air pollutants while only less than 30% is of soil internal origin.  相似文献   

13.
Relationship between soil organisms and soil structure in new reclaimed soils derived from loess under agricultural and forestral use In the Rhenish Browncoal District est of Cologne he question occurs wether forestry or agriculture is the better form of primary use to force structure development in new reclaimed soils derived from loess. The investigations on 10–25 years old reclaimed soils under forestral and agricultural use indicate that humus content, microbiological activities as well as the number of soil meso- and macrofauna individuals like earthworms are increasing with growing age of the forest soils. These processes and the strucutre development are faster under forestral use. Here after about 20–30 years conditions are similiar to those of undisturbed forest soils in comparable substrates. So from the ecological point of view temporal priority should be given to forestral use.  相似文献   

14.
Initial soil development in loess and harbourbasin mud reclaimed by slurry poldering In the Rhenish Brown Coal Strip Mining Area initial soil development was investigated for 6–15 and 15–25 years old loamy-silty loess soils reclaimed by slurry poldering. In the Emden environs the same analyses were applied to 6, 17, and 28 years old silty-clayey harbour-mud soils, also reclaimed by slurry application. The most prominent results when comparing these two types of soil are as follows: The mud soils show higher contents of clay and organic matter. Therefore they reveal more favourable characteristics concerning cation-exchange capacity, soil physical and soil biological properties in comparison to those of the loess soils. In both types of soils cation-exchange-capacity and soil biological activity increase in the Ap-horizon over time. The soil physical characteristics of the mud soils markedly improve in the run of the development, whereas those of the loess soils hardly improve. It remains a subject of discussion, since what stage of development mud soils should be classified as sea-marshes/“Kleimarschen” and loess soils as rendzinas.  相似文献   

15.
The influence of mean annual rainfall and soil texture on the 137Cs vertical distribution in soils from southern Chile The influence of mean annual rainfall and soil texture on the vertical distribution of 137Cs from global fallout was studied in undisturbed volcanic ash soils from southern Chile. The areal concentration and translocation depth increase with the mean annual precipitation. In spite of the high rainfall at the sampled area (970 - 2500 mm a?1), the highest 137Cs contamination was found in the upper 10 cm layer. The vertical migration is reduced by the high adsorption capacity of these volcanic ash soils, but on the other side increased in soils with high large-pore volumen. The translocation depth reaches only up to 26 cm in the clay soils, 35 cm in the silty soils and 70 cm in the sandy soil.  相似文献   

16.
Soil association upon and near to a waste disposal site Soils of a waste disposal site and a moraine slope in the neighbourhood were mapped and analyzed, to see whether they are related soils and that means soil associations after Schlichting. Erosion/sedimentation-processes as well as translocated gases and waste fluids influenced the different soils of the landscape so that these soils are related with each other by soil forming processes.  相似文献   

17.
Formation and properties of amorphous clay constituents in soils of the temperate-humid climate region A review of literature and of some own work was given on formation and properties of amorphous clay constituents which occur along with crystalline clay minerals in soils. By that the importance of soil amorphous material with respect to pedologic-agricultural and social-environmental problems was tried to emphasize. At the beginning some clarification of the different terms used for inorganic amorphous clay constituents and a sort of difinition of the different kinds of amorphous materials seemed to be evident. Then, the occurence and the formation of amorphous material in soils of the temperate-humid climate region was commentated. As a result of this it was stated that amorphous clay constituents occur mainly as coatings on negatively charged surfaces of crystalline layer silicates. From the grouping of amorphous substances around negatively charged cores (layer silicates or AlIV-cores in allophanic soils, respectively) it was deduced that the organisation of amorphous clay constituents and allophanes as well as synthetic aluminosilicates might be due to an unique structural principle, which was tried to explain more detailed. The methods used for determination of amorphous materials, especially allophanes, were discussed. Since the determination of amorphous clay constituents by chemical dissolution techniques is ambiguous with respect to soils containing different weathering stages of crystalline layer silicates as well, some suggestions were made for characterizing amorphous substances in soils by cation exchange and anion adsorption properties. Finally the importance of exchange-reactions caused by specific adsorption of ions and molecules (e.g. nutrients and pesticides) was indicated. Furthermore, the possibility was mentioned that harmful environmental substances might be bound (neutralized) and waste nutrients might be recycled by specific adsorption on amorphous soil constituents.  相似文献   

18.
Prediction of soil strength of arable soils and stress dependent changes in ecological properties based on soil maps Based on a database of at present 160 mechanical soil profile datasets, the site and horizon dependent mechanical soil strength expressed as precompression stress can be predicted by multiple regression analysis and used for documentation in maps at different scales. Stress dependent changes in air permeability or air capacity can be derived for the virgin compression stress range as well as the effect of stress propagation in soils or stress attenuation capacity and depth dependent changes of ecological properties. Thus, areas with defined mechanical sensitivity as a function of depth can be derived and recommendations for site adjusted farming techniques can be given. In addition it allows the agricultural machine industry to develop site adjusted machines to support the ideas of good farming practice, defined by the soil protection law of Germany.  相似文献   

19.
Solubility of the inorganic soil phosphorus and fertilizer phosphate The solubility of the inorganic soil phosphate of different soils was determined in up to 40 consecutive extractions with water and lactate solutions. The graphs showing the relationship between total extracted P, and P concentration in the extract ants (Fig. 1 and 3) were of an exponential type, independent of chemical bonding of the soil phosphorus, and independent of other soil properties. P contents in the first extractions were closely correlated with the sum of the P contents of all extractions with a solubility > 100 μg P/1 (fig. 2). All of the soil phosphate capable of diffusion is plant available. Therefore all phosphate in the soil which originated from fertilizer phosphate will be utilized. This follows from the data of solubility of the soil phosphorus (20–140 μg P/1) after repeated water and lactate (CAL) extractions. The slow adjustment of equilibrium, which is common with phosphate adsorption experiments is due to the influence of diffusion. The relationships between P fertilization, solubility of soil phosphate, and the recommended soil P content for economical P utilization with optimum plant growth (e.g. Tab. 2) is shown.  相似文献   

20.
Estimation of the nutrient distribution around plant roots by separate analysis of rhizo and bulk soil A procedure is described to separate rhizo soil from bulk soil. For this purpose the living plant roots along with the strongly adhering soil are taken out of the surrounding soil. After a short period of drying, roots are separated from rhizo soil by gently sifting. Chemical analysis of the samples has shown that the nutrient content of rhizo soil usually differs markedly from bulk soil. Phosphate and potassium content of the rhizo soil of wheat and maize is lower than in bulk soil. Percentagewise, these differences are higher by using water as an extractant when compared to the slightly acid lactate or formate solutions. The water soluble calcium content of several wheat fields was in most cases higher in the rhizo than in the bulk soil. In sandy soil the depletion zone of phosphate does not exceed the length of the root hairs markedly whereas in the case of potassium it does. This is concluded from data showing that the potassium content, but not the phosphate content, was decreased in the bulk soil if compared to the uncropped soil. In heavier loess soils the nutrient concentrations of rhizo and bulk soil were not always found to be markedly different. It is assumed that the depletion zones are smaller than in sandy soils. In addition, because of aggregation, rhizo soil cannot be separated from bulk soil as neatly as in sandy soils. Therefore, in heavier soils the method does not yield satisfactory results.  相似文献   

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