C- und N-Festlegung in Böden Südostniedersachsens nach Krumenvertiefung

Enrichment of C and N in soils of southeastern Niedersachsen after deepening of top soil In a comprehensive study, the effects of deepening of top soil during the last 20 years on C-organic-and N-total-masses of some selected arable land sites have been analyzed. The sampling sites represent soil groups predominating in southeastern Niedersachsen. In 145 plots of 22 agricultural farms with the rotation sugar beets/winter wheat/winter barley, sugar beets/winter wheat/winter wheat respectively, the actual depth of plow horizon varies from 32 to 38 cm in summer. Organic matter has been analyzed in 125 soils. A C-org.- and N-total-balance sheet has been prepared for the time after deepening of the top soils. In luvisols with a top soil deepening of about 10 cm a period of 15 years has been necessary for aquirement of the C-content before deepening. A C-enrichment up to 15 t/ha was recorded with incorporation of plant residues in the last 15 years. During this period up to 1,5t of N/ha accumulated assuming constant C/N-ratios. For chernosems, a similar rate has been determined. In sandy cambisols, the short period of observation of 10 years and less after top soil deepening did not permit a complete reenrichment with organic matter. The ”?potentially”? possible enrichment with organic C amounts to 14–17 t/ha (= 1,4–1,7 t N). Furthermore, luvisols gave a significant correlation between clay- and C-amounts of non deepened soils. A weak interrelation has also been found between clay content and the enrichment potential of organic matter in these soils.     

PH-Verteilung und Pufferung von Böden

PH-distribution and buffering of soils A frequency distribution of the pH values of 927 soils clearly reflects the three soil buffer ranges (carbonate, pH-dependent charge and aluminium release) by higher frequencies within these ranges and lower frequencies between them.     

Einfluß des Jahresniederschlags und der Bodenart auf die 137Cs-Tiefenverteilung in Böden Südchiles

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.     

Die Adsorption von HCB und DDD in Böden

The Adsorption of HCB and DDD by soils A method for studying the adsorption of substances with low water solubility by soils has been set up. The method has been verified by two chemicals (HCB, DDD) and a number of different soils. The results have shown a significant correlation between the distribution ratio and the content of organic carbon.     

Stickstoffumsatz in einigen obstbaulich genutzten Böden Südwestdeutschlands

Nitrogen turnover in some orchard soils of South West Germany Investigations in several orchards in South West Germany led to the following results: The actual content of mineral nitrogen as well as the rate of mineralization showed a marked dependence on the nature of soil, weather and soil management. Frequently the rate of mineralization had a distinct annual course following soil temperature. During summer additional oscillations partially were related to water and air contents of the soils. As a rule under old sward the rate of mineralization was distinctly higher than in the same soil being cultivated or treated with herbicides. Under mulched sod not only higher rates of mineralization, but also distinctly higher actual contents of mineral nitrogen could be found as compared with data under cropped sod. This ran parallel with higher nitrogen supplies to the trees and distinctly higher yields, but also with a worse storage quality of the fruits and conspicuously increased wash-out rates of nitrate (provided that manuring was continued with the primary amount of nitrogen). The total content of soil nitrogen depended much more on the method of soil management (swarded or not swarded) than on the amount of nitrogen fertilizers. It seems that the total nitrogen content of a soil tends towards a certain level corresponding to the conditions of site and soil managements and that this level cannot be raised constantly by manuring. From these results the following conclusions for practical fruit growing can be drawn: With modern forms of commercial fruit growing using mulched sward for soil management the nitrogen output is much less than with cultivating the same soil as arable land or intensive grassland. Due to cropping of the grass in former times nitrogen deficiency of fruit trees was not unusual, but since the grass under the trees has been mulched there is more danger of excessive nitrogen supply if manuring has been left as it was. Unlike the situation known of sand cultures with low nitrogen reserves in orchards with high mineralization rates the time of manuring is not of great consequence.     

Adsorption und Desorption von Methabenzthiazuron in verschiedenen Böden

Adsorption and desorption of methabenzthiazuron in various soils A method investigating adsorption and desorption of pesticides using radioactive tracers and a computer programme is described. The adsorption and desorption of the herbicidal substance methabenzthiazuron in 7 soil samples is investigated. The adsorption of methabenzthiazuron decreases from the A_p- to the C-horizons. A good correlation exists between the adsorbed amount of the herbicidal substance and the C- and N-content of the soils. The relatively highest desorption was found with nearly humusfree soils. The amount of adsorbed herbicide residues, not desorbable by water in 5 desorption cycles, is much higher in the humic soils than in the nearly humusfree soils. From the relationship found between adsorption and corresponding herbicide concentrations proper adsorption values can be predicted for any herbicide concentration within the investigated concentration range by using one single adsorption measurement as a basis of calculation.     

Die Messung der Katalaseaktivität von Böden

The determination of Catalase Activity in Soils by Dr. Beck 1. The elaboration of a method for the determination of the activity of catalase in soils is described. The method envolves the gasvolumetric determination of oxygen released by decomposition of a H₂O₂-solution by soils, suspended in buffers in the presence and absence of the catalase inhibitor NaN₃. 2. The influences of the following factors on catalase activity were studied: Methods for the determination of developed oxygen, enzyme- and substrate concentration, inhibition of catalase by NaN₃, pH- and temperature-optima of catalase and the presence of plant residues in soils. 3. It was found, that there was only a little decrease in catalase activity when fresh or dried samples of soils were stored over a periode of 4 months under laboratory conditions. The catalase activity of different soils showed very good correspondence to the dehydrogenase activity of the soils and less correspondence to the amount of soil respiration and the amylase activity. No relation could be found to the number of microorganisms in soil.     

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.     

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.     

Unterschiede von Toneigenschaften in Tonstein der fränkischen Lias- und Doggerlandschaften und ihren Böden

Distinctions of Clay Properties in Claystone of the Franconian Lias-and Doggerlandscape and Their Soils Pelosols and Pseudogleys derived from the sediments of the Amaltheen Clay (lias δ), Posidonia Shale (lias δ) and Opalinus Clay (dogger æ) formations in the forelands of the Alb Mountains in Franconia were separated using 16 properties (seven textural and nine chemical properties, the latter of which indicate clay specific properties). Multivariate discriminant analysis was able to distinguish sediments from sediments, sediments from soils and soils from soils. Eight properties were important for discriminating the samples into several groups. Properties with the greatest discriminating quality were the effective buffering capacity for K (BCKe in mval/100 g soil and 100 g clay/M^1/2), the K-fixation (mg K/100 g soil and clay), and the labile K (mval K/100 g soil). The mobile K (ARo in M^1/2) was also an important property. The Pseudogleys were most significantly separated from the Amaltheen Clay and Opalinus Clay sediments. Furthermore, the Pelosols could be significantly separated from Amaltheen Clay and Opalinus Clay on one side and Posidonia Shale on the other. The statistically significant increase of the BCKe and the decrease of ARo as well as some X-ray diagrams suggest that in Pseudogleys derived from Amaltheen Clay and Opalinus Clay and in Pelosols derived from Posidonia Shale expandable forms of 2 : 1 minerals were formed from 10 A-minerals.     

Der Einfluß von Niederschlag und Höhenlage auf den Humusgehalt ostafrikanischer Böden

The influence of precipitation and altitude on the humus content of East African soils Positive correlations were found between the log of the carbon and nitrogen content of the 0–15 cm soil layer, altitude and average annual precipitation of 20 grassland soils, 13 forest soils and 21 cultivated soils at altitudes of 10–2840 m and a precipitation of 380–2410 mm in Kenya, Tanzania and Uganda. For each of the soil groups equations with the two variables altitude and precipitation were derived, which accounted for 76–93 per cent of the variation of the carbon (0,42–5,62%) and nitrogen (0,04–0,71%) content. There was no correlation between altitude, precipitation and the C/N ratio of the soils.     

Stickstoffdynamik von Böden mit Abwasserverrieselung

Nitrogen dynamic of soils with wastewater irrigation The nitrogen status of a Sandy Cambisol and a Loamy Luvisol of Berlin, which were flooded with wastewater over a period of 100 years were studied. The two-year examination of the water, redox and nitrogen dynamics showed great differences in nitrogen leaching and the intensity of nitrification and denitrification processes.     

Differenzierte Erfassung der Bioaktivität von Pilzen und Bakterien zweier Böden unter Fichte

Differential determination of fungal- and bacterial bioactivity in two spruce forest ecosystems To determine the general bioactivity and the contribution of actinomycetes and fungi in organic and mineral horizons of two spruce forests (Luvic Cambisol and Dystric Podzoluvisol) different physiological methods were utilized and compared. According to microbial measurements (ATP-quantity, heat output) the activity in Ebersberger Forst surpassed that of Höglwald in each horizon. The measurements of ergosterol and chitin delivered contradictory results. A similarity between the amount of glucosamine and that of fluorescein diacetate hydrolysis was observed. In the activity of lignin degrading fungi and ethylene production both soils differed entirely.