Einfluß der Kalkung und Düngung auf den Ionenaustausch und die chemische Zusammensetzung der Bodenlösung am Beispiel von vier Waldstandorten im Hessischen Bergland

Impact of liming and fertilization on ionic exchange and chemical composition of soil solutions from four forest sites in the colline region of Hesse Between February 1985 and July 1987 soil seepage experiments were carried out on fertilizer trial plots in mature beech stands of four forest districts of Hesse. Encompassed by this study are in addition the most important results from soil-chemical analyses of the subsequent years 1988 to 1991. Aim of the investigations was to study the influence of liming and K/Mg-fertilization on the chemical composition of soil and soil solution under different site conditions. In the percolated soil solution liming did not led to a significant pH increase in subsequent years. In contrast, in some cases the pH level dropped by 0.1 to 0.2 units on average and Al-concentration increased correspondingly. In most cases, fertilization led to a significant increase in soil solution concentrations of the metal cations potassium, calcium and magnesium, especially at a depth of 50 cm. On those trial plots where a pH decrease was observed, the concentrations of K, Ca and Mg exhibited either a slight or no increase at all. Furthermore on some trial sites with freely drained soils, liming led to a faster mineralisation of the humus layer and thus to an increase of nitrate contents in the percolated soil solution from about 1–2 mg/l to 10–20 mg/l on average. Increased concentrations of sulfate and in most cases also of heavy metals (Mn, Zn, Cu. Cd) were observed in the soil solution which was attributed to the mobilizing effect of Ca-fertlization. In general, the mobility of most chemical parameters showed a slight increase following liming and soil tillage. Even after 5 to 8 years considerably higher pH-values and base saturation were evident in limed and fertilized soils, especially in the top 15 cm of soil profiles.     

Der Einfluß der natürlichen organischen Substanzen auf die Metallverteilung zwischen Boden und Bodenlösung in einem sauren Waldboden

The influence of organic matter in the translocation of metals between soil and soil solution of an acid forest soil Water extracts were prepared from soil samples which were collected from a soil profile showing very little variation in the texture down to a depth of 120 cm and thus only little translocation of clay in the soil profile. The aim of the study was to describe the distribution between soil and soil solution of several metals like Cu, Pb, Cd, Zn, Al and Mn as a function of humic substances, electrolyte concentration and pH. From the experimental results the following hypothesis on the reaction mechanisms involving metals and humus derived substances has been deduced. The metals Cu, Fe, Al and Pb are mobilized through complexation by soluble humus substances in addition to the usual pH dependent desorption and dissolution of hydroxides. This mobilization determines the solution concentration of Cu and Fe at pH > 3.7 and Al and Pb at pH > 4.2. Al, Fe and Pb are complexed selectively by high molecular weight humus derived substances which undergo adsorption on soil mineral surfaces. Cu interacts with low molecular weight humus derived substances which are not easily adsorbed by the mineral surfaces. Zn, Cd and Mn primarily undergo sorption and are thus controlled by pH and electrolyte concentration of solutions because their complexation with humus derived substances seems to be weak or nonexistant. It is further postulated that the humus derived substances mobilize Al³⁺ and Fe³⁺ ions. By this, other metals like Cd, Zn, Mn, Ca and Mg can occupy the free exchange sites.     

Einfluß von Bodeneigenschaften,Bodennutzung und Bodentemperatur auf die N-Mobilisierung von Kulturböden

Influence of soil characteristics, agricultural use and soil temperature on the N-mobilization of cultivated soils A new N-mobilization model, which considers also the short term and seasonal N-supplying capacity of soil is presented. At a fixed time the potential mobilizable N (N-MOB) is a sum of difficultly mobilizable N (N-MOB_s) originating from the pool of difficultly mobilizable N (N_s) and the easily mobilizable N (N-MOB₁) originating from the pool of easily mobilizable N (N₁). It is possible to characterize soil according to their M₁, N-MOB_s and v (N-MOB_s per day) values. Usefulness of these parameters in N-nutrition and ground water burden from N has been discussed. Basic parameters of this model have been experimentally determined independently with the help of two different experiments i. e. laboratory incubation and column lysimeter using surface soil samples. The easily mobilizable N pool (N₁) values were found in the range of 142 to 814 kg N ha^?1 which corresponded to 1.2 to 7.4 % of organic N content of these soils. The difficultly mobilizable N per day (i. e. v = N-MOB_s per day) in an incubation experiment (35°C) were found in the range of 1.5 to 24kg N ha^?1. However, in the column lysimeter experiment, in contrast, these values at 10°C ranged between 0.05 to 0.9 kg N ha^?1. These values correspond to N-MOB_s values in the range of 11–182 kg N·ha^?1 for a period of 200 days which approximate to a vegetation period. For practical purposes, the N₁ and v values could be calculated by just measuring 3–4 points after 14 days of incubation at 35°C. The results show that N-MOB_s values strongly correlated compared to N₁ values to total N, organic carbon and clay content and non significantly to pH and silt content. The results of an laboratory incubation experiment carried out to assess the effect of temperature on N-mobilization show that even at 0°C there was N-mobilization. The results revealed that in the temperature range of 0–8°C (a range of soil temp. usually observed in winter months) and in the range of 25–40°C (range of summer months temp. for surface arable soil), a small change in the soil temperature would result in enormous increase in the quantity of mobilized N. The highest mobilized N quantity was found above 60°C.     

Einfluß der Probenvorbereitung auf die Adsorption von Cd und Cu in sauren Waldböden

Influence of Soil Sample Preparation on Cd and Cu Adsorption in Acid Forest Soils The influence of soil sample preparation on Cd and Cu adsorption was investigated using six acid forest soil samples and comparing adsorption isotherms for fresh and air-dried samples. While no influence of sample preparation on Cd adsorption capacity was found, air-drying resulted in a significant decrease in Cu adsorption density in all six soil samples under investigation at ecotoxicologically relevant concentrations in the soil solution.     

Kurzmitteilung Einfluß der Qualität der organischen Substanz auf die Konsistenz landwirtschaftlicher Böden

Influence of organic matter quality on consistency of agricultural soils The soil organic matter of two samples similar in the texture and approximately in the organic C contents, but very differently in the consistency properties, were investigated by pyrolysis-field ionization mass spectrometry (Py-FIMS). The shifts of the values of the liquid and plastic limits towards higher moisture contents are explained by a different quality of soil organic matter, in particular by higher amounts of longchained lipids (C_8-32 alkanes, alkenes, fatty acids), N-compounds and lignin dimers.     

Wirkungen organischer Substanzen auf Boden- und Düngerphosphat Teil 1: Einfluß von Stroh- und Maiswurzelextrakten auf die Löslichkeit von Boden-und Dünger-P

Effects of organic substances on soil- and fertilizer phosphate Part 1: Influence of straw or maize-root extracts on the solubility of soil and fertilizer P The effects of straw and maize-root extracts on the solubility of soil and fertilizer phosphate were tested in incubation trials. The following results were obtained. 1. Addition of an extract of unrotted straw (10 g straw/100 g soil) to incubate a brown-earth soil, (high or low in P) for 1–14 days did not have any significant effects on the H₂O and CAL P-fraction as compared to a KH₂PO₄ control, but markedly increased transformation of ‘easily soluble’Fe- and Al-phosphates (?15 to ?40 ppm) into ‘less soluble’forms (+15 to +20 ppm). Addition of an extract of rotted straw decreased the amounts of water extractable P and ‘easily soluble’Fe- and Al-phosphates but CAL-extractable P and ‘less soluble’Fe- and Al-phosphates were increased. 2. Incubation of the same soil (P-enriched) with an extract of maize roots (roots: soil = 1:3) for 1 day resulted in a reduction in the fixation of fertilizer phosphate (34 as compared to 42%) and in a decrease of fertilizer P recovered as ‘less soluble’Fe- and Al-P (from 31 to 11%); however, fixation was markedly increased after 14 days.     

Einfluß löslicher organischer Inhaltsstoffe auf die photometrische Analyse von Nitrat,Chlorid und Sulfat in Sickerwässern

Influence of DOC on the photometric analysis of nitrate, chloride and sulfate in seepage water Investigations on the applicability of photometric sulfate and chloride analysis in seepage water are showing strong influences by DOC, causing a raised detection of these anions. Interactions can be reduced, but not completely removed by solid phase extraction with reversed phase material. The photometric detection of nitrate is not influenced by DOC.     

Einfluß von Stickstoff- und Cytokiningaben auf die Entwicklung des Fahnenblattes und der Karyopsen von Weizen

Influence of nitrogen and cytokinin applications on the development of flag leaves and grains of wheat In two experiments spring wheat cv. Solo was grown in hydroculture under greenhouse conditions. The influence of cytokinin applications during grain filling period (Cy: 0 – 100 μg BA/l nutrient solition) combined with different nitrogen supply (N: 0, 0.25, 0.50 and 4.0/1.3 mMol/l) was studied in regard to the development of flag leaves and grains. As to flag leaf, only N was capable to increase specific fresh and dry matter and delay the decrease during development. Similar changes in the chlorophyll content, photosynthesis and N-content of leaves and grains, resp., could be induced by either N or Cy. Grain growth and grain N-content was favoured by N, with the first effect becoming visible early and the second late in the grain filling period. At maturity Cy gave the same effects, but time course was slightly modified. At high doses of N (4.0/1.3 mMol/l) Cy-applications reduced chlorophyll content, photosynthesis and N-content of leaves and grains. This gave rise to the conclusion that cytokinins limit the corresponding physiological processes only if nitrogen nutrition is low.     

Einfluß von Ammonium- und Nitratstickstoff auf die Entwicklung von Buchenjungpflanzen

Influence of ammonium and nitrate nitrogen on the growth of young beech plants Young beech plants were grown in aerated nutrient solutions with NH₄ or NO₃ nitrogen for a period of 12 weeks. pH-changes caused by the source of nitrogen were corrected every second day. Absorption of NH₄-N was higher than of NO₃-N. NH₄-N was superior for shoot growth and development of lateral roots, NO₃-N for growth of the main root. Nutrient solution containing both sources of nitrogen was the most favorable.     

Die Beeinflussung der Bodenlösung durch Saugkerzen aus Ni-Sintermetall und Keramik

Influencing soil solution by suction cup material (Ni, ceramics) The influence of suction cup material (ceramics, Ni) on the chemical composition of the soil solution was tested in the laboratory by percolating soil solutions of different concentration (pH ～ 4.0). Ceramic cups of P 80 material can be used for the collection of soil solution and its determination for the concentrations of H, Na, K, NH₄, Ca, Mg, Mn, Al, S, Cl and NO₃. They can't be used to determine P-concentrations. The cups must be prepared and preconditioned by leaching large amounts of equilibrium soil solution which should not be oversaturated with respect to the solubility product of AlOHSO₄. The changes in the concentration of extracted soil solution when it passes through the cups depend upon the extracted volume. The lower the volume, the greater are the changes. Sintered Ni-cups show many severe disadvantages (decreasing permeability, insufficient resistence against acid solutions, large variability among single cups), and can only be used for cases where Na, Ca, K, and S are to be determined. Ceramic cups of the type ‘Czeratzki’ are comparable with those of P 80. However, they can only be used, when the concentrations don't vary too much and large amounts of water can be extracted.     

Einfluß der Bodeneigenschaften auf die Freisetzung der gelösten organischen Substanz (DOM) aus dem Oberboden

Influence of Soil Properties on the Release of Dissolved Organic Matter (DOM) from the Topsoil A percolation experiment over a period of three month with small monoliths from forest and grassland soils varying in their anthropogenic changes was carried out to identify, to weigh and to quantify important soil properties for DOM release from the topsoil. Quality of soil organic matter determines the amount of DOM released from the topsoil if the soils have a low ability to adsorb and to precipitate DOM. Favorable conditions for high DOC concentrations in the soil solution are wide C/N ratios in the soil and in the hot water soluble fraction, a high soil content of hot water soluble organic carbon and a high portion of hot water soluble organic carbon in the total organic carbon content. Anthropogenic changes of the soils are effective to DOM release via changing quality of soil organic matter. Long dry periods and large water fluxes can further increase DOM release. The effects of soil organic matter can be disguised in soils with a high DOM retention capacity (high CEC, high content of exchangeable bases, Fe_ox and Fe_d). Then adsorption and precipitation determine DOM release from the topsoil and contribute to a decrease of DOM release.     

Einfluß der Löslichkeit verschiedener Phosphatdüngemittel auf die Phosphataufnahme und den Ertrag von Sommerweizen

Solubility of various phosphate fertilizers in a brown podzolic soil and their effect on phosphate uptake and yield of spring wheat. The solubility of various phosphate fertilizers (Superphosphate, Rhenaniaphosphate, Novaphos, Carolonphosphate and Hyperphosphate) was studied in an incubation experiment, and P uptake and yield effect of these fertilizers were investigated in a pot experiment. The soil used was a carbonate free brown podzolic earth (C horizon) with a neutral pH and low in available phosphate and humus. The quantities of P extracted from the soil by the EUF technique were the lower, the higher the amount of non processed phosphate of the incubated P fertilizers. This clear differentiation in the solubility of the various P-fertilizers was not obtained by the DL extraction. The P uptake of plants was highly correlated with the P quantities extracted by EUF (r = 0,95***), while the correlation between P uptake and the P of the DL extract was less narrow (r = 0,64*). The yield, particularly the grain yield, decreased with an increase of the non processed P in the fertilizers tested. Grain yield and EUF extractable P were highly correlated (r = 0,86***); while the relationship between grain yield and the DL extractable P was poorer (r = 0.62*). The experiments have shown that mainly the easily soluble phosphate is of decisive importance for the yield formation.     

Einfluß von Natriumchlorid und Mycostatin auf den Mineralstoffgehalt im Blattgewebe und die Feinstruktur der Chloroplasten

Effect of Sodium Chloride and Mycostatin on the Mineral Content of Leaf Segments and on the Fine Structure of Chloroplasts Leaf segments of bean, barley and sugar beet were treated for several hours with 25 meq NaC1 or with the antibiotica mycostatin. The effect of these treatments on the content of potassium, sodium, calcium, magnesium and chloride in the leaf segments and on the fine structure of chloroplasts was studied. In bean sodium chloride treatment induced strong efflux of potassium and swelling of the chloroplasts. Sodium sulfate or mycostatin had the same effect. Despite of the strong efflux of potassium the content of calcium and magnesium in the segments was practically unaffected. Addition of 1 meq calcium to the external solution prevented the effect of sodium chloride on efflux of potassium as well as on the fine structure. In barley sodium chloride or mycostatin also induced efflux of potassium and swelling of the chloroplasts. These effects, however, were less pronounced than in bean. Again the content of calcium and magnesium in the segments was practically unaffected, and the addition of 1 meq calcium compensated the effect of sodium chloride. In sugar beet both mycostatin and sodium chloride did not induce efflux of potassium, despite of a strong influx of sodium in the sodium chloride treatment. In both treatments no change in the fine structure of the chloroplasts was observed. It was proved by isolation of chloroplasts that the typical sodium chloride induced differences in efflux of potassium from the leaf segments is also reflected in efflux of potassium from the chloroplasts. The results indicate the causative connection between efflux of potassium and change in the fine structure of the chloroplasts. Differences between the three plant species with respect to efflux of potassium induced by sodium chloride or mycostatin are reflections of different membrane properties. The presence of calcium in the external solution is much more important for the membrane stability of bean than it is for sugar beet e. g. The results obtained with leaf segments are a good reflection of the different tolerance of these three plant species to high sodium chloride concentrations under field conditions.     

Der Einfluß der Fauna auf die Stoffverlagerung sowie die Homogenität und die Durchlässigkeit von Böden

The influence of the fauna on displacement and on homogeneity and permeability of soils The influence of the most important soil animals (mammals, ants, termites, woodlice and earthworms) on displacement and on homogeneity and permeability of soils is discussed in reference to both older and more recent literature. Nearly all soil animals cause displacement of organic and mineral soil particles. The quantity, intensity and direction of this activity depends upon the morphological characters of the species involved. The homogeneity of soils is positively influenced only by the earthworms (and related forms) whereas the activity of the other soil fauna mostly has a contrary effect as far as shorter periods are concerned. The permeability of soils increases in different dimensions due to the activity of all species discussed. Permanent vegetation and non-tilling for the most part favour the activity of the soil fauna. Recent field experiments dealing with minimum or zero tillage have made this fact fairly evident.     

Wirkungen organischer Substanzen auf Boden- und Düngerphosphat. Teil 2: Einfluß verschiedener organischer Stoffe auf die Mobilität von Dünger-P

Effekt of various organic substances on the mobility of fertilizer P Using model trials, studies were carried out on the influence of long-term organic manuring as well as incubation with rotted straw, maize roots, and slurry, on both the diffusion of ³²P from added (NH₄)₂H³²PO₄ in a ‘soil block’and the fixation rate of fertilizer phosphate in the soil. 1. In the “soil block experiment”, preincubation for 7 days with slurry (added to a low-P brown earth soil at a rate of 5% D. M.) increased diffusion of P as compared to an equivalent amount of added inorganic P. Preincubation with rotted straw resp. maize roots had only insignificant effects. 2. Long-term organic manuring with farmyard manure (P-long-term field trials Weihenstephan) had a significant positive effect on the diffusion of P in the soil block in contrast to annual application of mineral P. Effects of straw manuring were markedly less. 3. Addition of maize roots (5% D. M. to a non P-treated or P-enriched brown earth soil) resulted in a reduced fixation of labelled fertilizer phosphate (by 2–8%), longer preincubation periods, however, increased fixation. Preincubation with rotted straw increased P fixation by 2 to 4% as compared to an equivalent addition of inorganic P (diammonium phosphate).