“Preferential flow”: Eine Übersicht über den heutigen Kenntnisstand

Preferential flow: A review of current knowledge Despite intensive research neither suitable methods of measurement, nor complete theoretical statements give an adequate account of preferential flow due to the exceptional complexity and variability of the soil system. In particular it is not possible to make predictions of preferential flow for a given soil due to observations and measurements. In this work we describe theoretical and technical problems of preferential flow and initiate ideas for future work in this field.     

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.     

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.     

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”.     

Beziehungen zwischen “verfügbarem” Bodenphosphat und den Phosphatblattgehalten von Tectona grandis (Teak) in Westafrika

Relationships between “available” soil phosphorus and foliar phosphorus content of Tectona grandis (teak) in West-Africa Significant relationships were analysed between the foliar phosphorus content of Tectona grandis L. and the topsoil phosphorus contents on a broad range of soils in West African plantations of Tectona grandis L. (teak), except for soils very poor in clay or organic matter (< 15% T or < 1% C). Of all methods used (P-H₂O, P-Mehlich, P-CAL, P-Bray-1, P-Soltanpour, P-Dabin, P-Resin, P-H₂SO₄, P-550, P-org) the fraction of soil P (P-550) dissolved in 1 n H₂SO₄ after dry ashing at 550 °C (r = 0.548^***, n = 63) and the method of Bray-1 (r = 0.505^***, n = 63) show the best results. The first reflects 80-90% of the organic P content and is recommended for the evaluation of the phosphorus supply. Using multiple correlation analysis we found a highly significant relationship (R = 0.794^***, R² = 0.63, n = 58) between foliar P as depending variable and P-Bray (positive), the soil sand content (negative) as well as soil pH (positive). A sufficient phosphorus supply of teak foliage (0.2% P) occured at soil levels of 300-320 kg P per ha and 15 cm (or more than 150 mg P/kg in topsoils free of stones (P-550)) in the studied area between Benin and Liberia.     

Submicroscopic characterisation of phosphatic and sesquioxidic nodules of some soils of the “Chaco deprimido” (Argentina): Preliminary results

In this paper two examples are presented of the investigation by submicroscopic techniques, of particular problems in the characterisation and analysis of various pedological features in soils of the “Chaco Deprimido”.

The first concerns nodules seen in an alluvial soil. The techniques established their phosphatic composition and identified them as small bone fragments which are undergoing alteration.

The second relates to study of sesquioxidic nodules and cutans in solodised soils and planosols, and shows them to have a dominantly manganiferous composition; this result enables one to make certain interpretations concerning the physicochemical conditions essential for the formation of such pedological features.     

The role of “effective microorganisms” in the composting of banana (Musa ssp.) residues

“Effective microorganisms” (EM) are a poorly defined mixture of supposedly beneficial microorganisms that are claimed to enhance microbial turnover in compost and soil. In Costa Rica, EM are used to produce organic compost (bokashi) from banana residues (Musa ssp.). Given the scarcity of scientific data about the effects of EM on the mineralization of plant residues, this study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production. To this end, the following non‐EM treatments were compared to EM Bokashi: Bokashi produced with water (W), with molasses (M) as an EM additive, and with sterilized EM (EMst). Subsequently, the effects of the resulting Bokashi treatments on the growth of young banana plants were evaluated. Compared with non‐EM controls, the effect of EM on the mineralization of banana material was negligible. Dry‐matter losses of the composts with different EM treatments were similar, with about 78% over 5 weeks. Ergosterol concentration was highest in EM Bokashi (77 µg (g dry soil)^–1) and lowest in EMst Bokashi (29 µg (g dry soil)^–1). Microbial biomass carbon (C_mic) and microbial biomass nitrogen (N_mic) were both lowest in EM (C_mic = 3121 µg g^–1; N_mic = 449 µg g^–1), while C_mic was highest in Bokashi produced with molasses (3892 µg g^–1) and N_mic was highest in EMst (615 µg g^–1). Treatment effects on adenylate concentrations and adenylate energy charge were negligible. Application of all Bokashi variants to young banana plants significantly increased shoot growth under greenhouse conditions compared to plants grown in a control soil without amendments. However, these effects were similar for all Bokashi treatments, even if EM Bokashi increased the K concentrations in banana leaves significantly compared to Bokashi produced with EMst and the control. Bokashi produced with only molasses and EM Bokashi decreased the number of root nematodes under greenhouse conditions compared to the control. Overall, the results confirmed the expected influence of composting on the degradation of organic material and the effect of compost application on plant growth. Hower, under the conditions of this study, EM showed no special effects in this, except for increasing the K concentrations in the leaves of young banana plants.     

Untersuchungen über einige Böden in der Wüste des „Lut-e-Zangi Ahmed”︁ (Iran)

Investigations on some soils of the Lut-e-Zangi Ahmed desert, Iran ”?Lut-e-Zangi Ahmed”? is a part of the Lut desert, which is located in south-eastern Iran. The Lut desert is one of the warmest and driest deserts of the world. It is very poor in vegetation and water, particularly in useful water. The evaporation is nearly hundred times more than the precipitation during the year (Evap. = 5000), precip. = 50 mm/year. In the research of “Lut-e-Zangi Ahmed”-SW part of the Lut desert-where its soils were entirely unknown, it is tried to get information about the most important properties of the desert-soils and possibility of agricultural use, through the profiles and analyses. The average elevation of the “Lut-e-Zangi Ahmed” is 500 m above the sea-level. The region is very poor in vegetation. There are many large areas on which no vegetation exists. The only useful water (underground water) is found in this part of the Lut desert. There are different zonal-intrazonal and azonal soils in the “Lut-e-Zangi Ahmed” (compare Ganssen 1968) for example: Hamada-desert soils, grey and light-brown saline desert soils, fine textured alluvial soils and sand desert soils. The soils are salty (EC from 11-5 12 mmhos/cm) and neutral to weak alkaline. They are poor in organic matter, phosphor and nitrogen too. The predominating part of the area investigated is not suitable for agricultural use. Only 150 ha are arable land, because it is possible to get here suitable groundwater for desalinization and irrigation.     

Mineralization of “non‐metabolizable” glucose analogues in soil: potential chemosensory mimics of glucose

Glucose is widely used to study the dynamics of easily available organics in soil. Pure culture studies have revealed that many microorganisms can sense and respond to glucose through chemosensory mechanisms that are not directly reliant on energy catabolism. However, the rapid mineralization of glucose by microorganisms makes it difficult to disentangle its energy effects from such non‐catabolic interactions. “Non‐metabolizable” glucose analogues have proven useful in mechanistic studies of glucose in pure culture, but have never been applied to complex microbial communities in soil. We sought to determine how their mineralization in soil differs from that of glucose, and whether they have potential as a new approach for investigating chemosensory mechanisms in soil microbiology. We incubated soil from an agricultural Haplic Luvisol under controlled conditions for 24 d and monitored CO₂ efflux after addition of (1) glucose, and three “non‐metabolizable” glucose analogues: (2) 2‐deoxyglucose (DG), (3) α‐methylglucoside (αMG), and (4) 3‐O‐methyl‐glucose (OMG), at three concentration levels, along with a control. All three analogues did in fact produce a large increase in soil CO₂ efflux, but the dynamics of their mineralization differed from the rapid degradation seen for glucose. At medium and high concentrations, CO₂ efflux peaked between 2.5 and 4 d after amendment with DG and αMG, and was delayed by about one week for OMG. The markedly different patterns of mineralization between glucose and OMG offer a new tool for investigating the behavior of glucose in soil. By using OMG as a glucose model, chemosensory mechanisms could be studied with limited interference from energy catabolism.     

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.     

Genauigkeit von Bodenfeuchtemessungen mit „Time Domain-Reflektometrie” und., Frequency Domain-Sensoren”︁ in heterogenen Waldböden

Precision of soil moisture measurements done with “Time Domain Reflectometry” and “Frequency Domain Probes” in heterogeneous forest soils Using “Time Domain Reflectometry” (TDR) and “Frequency Domain” (FD) technique soil moisture of a homogenized soil- substrate of silty loam was measured in the lab as well as soil moisture of the same silty loam and of two soils with coarser texture and more heterogeneous structure in situ. These measurements were compared with gravimetric soil moisture measurements done at the same measuring sites. Thus the measuring errors caused by soil heterogeneities should be assessed. The standard error of both, the TDR- and the FD- probes amounted to less than 1 Vol%, at the in situ measurements as well as in the homogenized substrate. In the homogenized substrate under relatively dry conditions soil moisture was overestimated to about 2 Vol% by both electronical methods, which is most likely the result of compactions in the contact zone between rods and the soil caused by the insertion of the rods. In the field both electronical methods, however, underestimated the soil moisture up to 14 Vol%. This applied especially to the surface of the mineral soil and under the influence of high stone contents. This deviation is interpreted as an effect of gaps along the rods, caused by the insertion. In loosely packed and stony upper soils we propose therefore to install the rods in homogenized autochtoneous soil material having settled to its natural bulk density instead of inserting them into the natural layered soil.     

Communication of the results of the “Primary Production in the Sahel (PPS)” research project

The main conclusions of the Malian-Dutch “Primary Production in the Sahel (PPS)” research project, which was carried out during 1976–1981 (Penning de Vries and Djitèye, 1982), may be summarized as follows: (1) poor soil quality is just as great a barrier to rural development as water shortage; (2) animal production is high per unit area, compared with similar ecological zones in the U.S.A. and Australia; (3) attempts to increase production without due attention to the shortage of soil nutrients are bound to fail; (4) socio-economic conditions determine the feasibility of productive investments in agriculture in the Sahel. This article presents the PPS approach to publicizing these results and promoting a badly needed revision of development policy in the Sahel.     

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.     

Quantitation of Amines in Cereal Products: Thermal Processes Are Able to Generate “Biogenic” Amines

On the basis of a derivatization with dansyl chloride prior to LC‐MS/MS measurement, a new quantitation method by means of stable isotope dilution analysis was developed for different amines, such as 2‐ and 3‐methylbutylamine, methylpropylamine, and 2‐phenylethylamine. The method was applied both to different cereal products and to a model system, revealing that the amines stemming from the parent amino acids l ‐isoleucine, l ‐leucine, l ‐valine, and l ‐phenylalanine can also be generated by a “thermogenic” pathway besides the well‐established enzymatic formation. A model system simulating the Strecker reaction by heating single amino acids with an α‐dicarbonyl compound (2‐oxopropanal) showed besides the formation of the well‐known desired aroma‐active Strecker aldehydes also the generation of the corresponding Strecker amines, which are undesired in food due to their negative physiological impacts on human health. Thus, a thermal formation of “biogenic” amines was shown, both in cereal‐based foods and in a model system. A contribution of these amines to the overall food aroma is also possible. With this knowledge at hand, mitigation strategies for the formation of amines undesired for health reasons in parallel with a favored generation of the corresponding aroma‐active aldehydes, depending on the processing parameters, can be suggested to food manufacturers.     

Definition of the “Purity Protocol” for Producing Gluten‐Free Oats

Several oat processors in the United States and Canada operate under what is referred to as a Purity Protocol for the provision of gluten‐free oats. This term is derived from a Health Canada position statement that indicated that pure oats, which they defined as oats that are harvested, transported, stored, processed, and manufactured under good manufacturing practices (GMPs) to minimize the presence of gluten, can safely be consumed by some persons with celiac disease. While proprietary definitions of the appropriate GMPs have been used in industry for many years, no independent definition of the requirements to make a Purity Protocol claim has been published. This paper provides a consensus definition of the Purity Protocol requirements based on input from the four largest Purity Protocol oat processors in North America. This definition provides transparency to gluten‐free consumers and allows for auditing of a Purity Protocol claim.