Zu Eigenschaften,Horizontaufbau und Gliederung der „Haftnässepseudogleye”︁

Properties, horizons and classification of the “Haftnässepseudogleye” (Stagnosols periodically waterlogged with capillary water) The term “Haftnässe” (soil wetness due to capillary moisture) can be used in describing soils with Sg-horizons in which long-term waterlogging and anaerobic conditions occur in the absence of gravitational water. “Haftnässe” is caused by water held in pores with an equivalent diameter of 0.2–50 μm by soil-water tension (pF) between 1.8 and 4.2, when the air capacity of the horizons is very low. “Haftnässe” moves primarily by capillary forces and is available to plants (available water). In some soils, the horizon below the Sg-horizon contains large pores, is well aerated and tends to impede the movement of capillary water. This type of horizon is often wetter than the overlying and underlying horizons, due to the presence of capillary water in the immediately overlying Sg-horizon. The symbol “So” is proposed for such horizons. In these soils, in the Sg-horizon reduced iron compounds are oxidized and precipitated, forming rusty mottles. The sequence of horizons developed in the “Haft(nässepseudo)-gleye” (Stagnosols periodically waterlogged with capillary water) typically affects the continuity of the pathways along which capillary water normally moves. The “Haft(nässepseudo)gleye” are divided into two subtypes on the basis of the sequence of horizons in the soil profile:

• Typical “Haft(nässepseudo)gley” (Shn) exhibits a sequence Ah/Sg/(II)So and shows transitions to Luvisol and Glossisol,
• Thick “Haft(nässepseudo)gley” (Shm) exhibits a sequence Ah/Sg and shows transitions to “Stau(wasserpseudo)gley” (Gleysol periodically waterlogged due to perched water), Gleysol, Fluvisol and tidal marsh soil.

     

Quartärgeomorphologische untersuchungen im Nordteil der “Tunesischen dorsale”

Seven Quaternary profiles from the Mediterranean region of northern Tunisia are described and their geomorphological significance assessed. Fifteen radiocarbon datings permit the field observations to be arranged in a chronosequence.The results indicate that the Late Pleistocene period witnessed the production and displacement of coarse debris, a process extending down to low altitudes. Until now, however, the only evidence for this has been found in the vicinity of steep slopes or rock walls. The coarse sediments partly overlie slope deposits derived from reddish soils; to some extent they contain fine reddish pedogenic material, and in part they are covered by it.In the Holocene, the displacement of fine alluvial sediments alternated several times with the formation of humic horizons. Anthropogenic influences on landscape evolution must be admitted as a possibility as from at least three thousand years ago.The aeolian sands of the Late Pleistocene and Middle Holocene are correlated with regressions of high sea levels.     

Die Bewertung der Pedofunktion „Pflanzliche Produktion”︁ in Schleswig-Holstein

Evaluation of the pedofunction “plant production” in Schleswig-Holstein The actual pedofunction “plant production” could be determined by longrunning yield measurements. If we take into consideration the field crops grain, sugarbeet and potatoes, only grain shows a relation between physiographic units and yield. The grain-yield in Schleswig-Holstein has a range of 40% (of maximum yield), about 20% could be explained by different types of soils, further 20% by the water-saturation-deficit of the air (sum of the May and June averages). Decreasing deficits of about one mm go along with increasing yields of about 5%. From a special exploitation of the Specific Crop Estimation results y = ?3,7x + 98 for the relation between relative grain yield and saturation deficit. For winterrye the results of the general exploitation are verified (see above). In contrast winterwheat shows a clear difference: The relative yield scatters about 50%, the relation between relate yield and saturation deficit is not linear, it depends additional on rainfall in summer and the waterholding capacity of soils. Pseudogleys (=Gleyic Luvisols) show a yield depression if the rainfall is less than 350 mm despite decreasing saturation deficits under 8 mm. For Braunerde-Pseudogley-Lessivés (=Cambisol-Gleyic Luvisol- Orthic luvisol) areas this values are 370 mm rainfall in summer and 10 mm saturation deficit. This investigation shows that the pedofunction “plant production” could be determined by the soil type distribution and some few climatic data.     

Der Umsatz von Pflanzenwurzeln im Laufe der Vegetationsperiode und dessen Beitrag zur „Bodenatmung”︁

The Turnover of Plant Roots during the Growth Period and its Influence on “Soll Respiration” Mustard and wheat plants were grown under ¹⁴CO₂, their roots being tightly separated from the shoot sphere. Root formation, root respiration, and root decomposition could thus be followed during the plant development by radiometric methods. The total quantity of organic root matter in soil at harvest time turned out to be 20–50% larger than the amount of root residues as determined by ordinary washing procedures. Depending on the plant and duration of the experiment, an additional amount of up to three times more than this remaining root carbon was already mineralized during the vegetation period. Only one fifth of this ¹⁴CO₂-production could be attributed to the respiration of living root tissue, all the remainder seemed to be due to the microbial decomposition of dead roots, root residues and root excretions. Root respiration and root decomposition together produced almost four fifths of the total evolving CO₂-quantity, whilst the contribution from soil organic matter breakdown did not exceed one fourth of it. According to these data, the total rhizo-deposition amounts to 3–4 times as much organic substance than what can be found as root residues at harvest time. This rich supply of readily decomposable organic matter leads to a most intensive turnover in the rhizosphere, which should be of considerable influence on the dynamic processes in soil.     

Zur Geschichte des Mineralnamens “Goethit”

The history of the mineral name Goethite (α-FeOOH) In 1806 the mining official J.H. Engels found in Eisenfeld near Siegen (Westphalia) two excellent pieces of a “ruby coloured iron mica”, already known as “Rubinglimmer”. He and his friend H.A. Achenbach, a parson, teacher and hobby mineralogist, proposed to J.G. Lenz, professor for mineralogy at Jena, to dedicate this mineral with the new name “Goethenit” to the famous poet J.W. von Goethe, who was also a great natural scientist. Lenz altered this name according to a proposal of F.W. Riemer, the secretary of Goethe, to “Goethit” and published it 1806 in his tables of minerals (printed as “Göthit”). However some years before the mineral was already described by J.C. Ullmann, professor for mining at Marburg, as “Pyrrhosiderit”. “Rubinglimmer” and the other mentioned names designated at that time the γ-form of FeOOH. In 1901 F.A. Lacroix reported, in order to avoid confusions, that the name “Goethit” was transferred to the α-form of FeOOH and that the γ-form had got the name “Lepidokrokit”.     

Die „Baumfuß-Methode”︁, dargestellt anhand einer Untersuchung der Immissionsbelastung von Nordwest-Jugoslawischen Buchenwäldern

The “Trunk Base Method”, Demonstrated by an Investigation on Immission Load of Beech Stands in Northwestern Yugoslavia Due to stemflow, the soil area close to the stem of old beech trees (Fagus sylvatica) differs from the soil farther from the stem as a consequence of higher input rates of all elements. It is postulated that the level of deposition determines the degree of deviation in soil chemical properties of the trunk base area (“Baumfußbereich” = “micro-habitat”) compared with soil which is not influenced by stemflow water (“Vergleichsstandort” = “macro-habitat”). The paper attempts to estimate the relative load of air pollution in 10 beech stands (mainly Rendzinas and Cambisols from limestone and dolomite) of northwestern Yugoslavia. In each plot 10 micro- and macro-habitats were chosen, for analysis of soil samples of Ah horizons for pH and exchangeable cations after percolation with NH₄Cl. The differences in pH, base saturation and saturation of (H+Fe) between trunk base area and related soil are used to determine acid loading. The saturation of (H+Fe) turned out to be the most appropriate indicator to describing the acidification. The results indicate high acid deposition rates at sites 1–5,9 and 10, but low rates at stands 6–8. It is assumed, that the main sources of pollutants reaching the plots 1–5, which are located at the western declivity of Risnjak, are industrial plants in northern Italy and towns at the Adriatic coast. The sources of pollutants reaching the sites 9 and 10, which are located at the eastern declivity of Gorski Kotar, respectively Lika region, are the industrial plants in northern Yugoslavia and Hungary.     

Gefügebildung durch Bodentiere in „konventionell”︁ und „biologisch”︁ bewirtschafteten Ackerböden

Fabric formation by soil animals in “technically farmed” and in “organically farmed” arable land At 4 ecologically different sites in south-western Germany one “organically” and one adjoining “technically” farmed field were investigated. Samples of the Ap horizons of these 4 pairs of comparison were taken before the start of the vegetative period and again after harvest. The fabric formation by earthworms and by Enchytraeid worms (and Collembola) was evaluated on polished blocks by quantitative micromorphologic characteristics. – Significant differences appeared at one pair of comparison only, in part at a second one also. The two pairs of comparison which did not exhibit significant differences were para-brown earthes of loess in somewhat warmer climates. – An increase of Enchytraeid (and Collembola) droppings during the vegetative period was found as a by-result.     

Ertragssimulation mit “Ceres Wheat” an Grundwasserböden gemäßigter Klimazonen. Teil 2: Verifizierung des geänderten Modelles “Ceres Wheat”

Calibration of the simulation model “Ceres Wheat” under conditions of soils with shallow watertable and temperate climate. Part 2: Verification of the modified model “Ceres Wheat” The Ceres Wheat yield model has been adopted to soils under wet conditions and to humide climate. The basic assumptions of the modified model have been checked. The simulated results of the soil water balance, the plant development and the nitrate losses by drain discharge give fairly well agreements to field data from a Calcaric Fluvisol (Speicherkoog, Schleswig-Holstein). The modification improves the model and leads to the opportunity to simulate special aspects in agronomical and ecological advices.     

Einfluß exogen veränderter „source-sink”︁-Beziehungen auf die Anzahl der Endospermzellen und die Kornentwicklung bei Sommerweizen

Influence of an exogenously changed source-sink relationship on the number of endosperm cells and grain development in spring wheat In 2 years pot experiments with spring wheat the source-sink ratio was changed by shading the plants at different times after anthesis, by removal of flag leaf blades, and by phytohormone treatment of the ear. The effect of the different treatments was recorded by determining the number of endosperm cells per grain, the single grain weight and the grain yield. In grains of normally illuminated plants the maximum number of endosperm cells was reached 2 to 3 weeks after anthesis. The storage of assimilates within these cells depends on the intensity of illumination during the entire grain filling period. Shading the plants between anthesis and maturity led to a 23 to 34% decrease in grain yield, but only to a 7 to 16% decrease in the number of endosperm cells. The same drop in the endosperm cell number was observed in plants shaded for only 15 days from the start of anthesis. A subsequent period of normal illumination till maturity led to a marked increase in the single grain weight. No decrease in the endosperm cell number was seen in plants shaded from the 15^th day after anthesis till maturity. There was, however, a 12–13% reduction in the single grain weight and grain yield in these plants as compared with the control. Removal of the flag leaf at anthesis reduced the number of endosperm cells by 6 to 11%, the single grain weight by 10 to 29% and the grain yield by 15 to 25%. CCC and Ancymidol treated plants in the shading trials showed the same decrease in the endosperm cell number but a more pronounced reduction in the single grain weight compared with control plants. Their reactions to the various shading trials followed the same general pattern as the control plants. The results of the shading experiments confirm that the endosperm cell number is not the only determinating factor for the single grain weight. The application of kinetin and abscisic acid to the ear had no effect on the number of endosperm cells and single grain weight. Abscisic acid, however, reduced the number of graines per ear.