Soils waterlogged for a period of about 30 days during the great flood in Poland in July 1997 were examined for total carbon, nitrogen and sulphur, heavy metal concentration, sorption properties and salinity. The aim of the investigation was to characterise the flooded arable soils 5 months after the flood, and to compare the properties of cultivated soils with non-ploughed soils. The investigation revealed that the flood influenced soil properties mainly by depositing a thin layer of sediment containing organic matter and some heavy metals, especially zinc. Five months after the water subsided from the studied area, there were still some non-cultivated fields where the layer of the sediment was recognisable and possible to collect. Zinc concentrations in the surface (0- 20 cm) layer of several non-cultivated soils were higher than the concentrations in cultivated soils, indicating that the flood influenced soil properties. However, the heavy metal contents in soils after the flood did not exceed the natural background. Soils subjected to the flood are characterised by a high saturation of sodium, which could be still observed 5 months after the flood. Despite the high saturation of sodium, investigated soils did not indicate excess salinity.
During the 1997 summer flood of the river Odra, a small cultivated area of 50 km was flooded in the German part of the catchment The flood completely killed the vegetations stands on the fields. Afterwards, the effects of the flood on the ecological properties of the soils and on the conditions for agricultural production had to be evaluated. A study was conducted to estimate the flood effects on heavy metal concentrations and on the nutrient status of the soils. The sediment layer left from the flood had a thickness of less than 3 mm. The heavy metal concentrations within this layer were below legal limits valid in Germany. Thus, no restriction had to be announced for food production purposes. Regarding the nutrient status of the flooded soils, only the mineral nitrogen content was substantially reduced when compared to not flooded soils. This effect could most probably be related to denitrification processes as a result of anaerobic conditions during the flood. Despite the nitrogen losses, the effects of the flood on agricultural management conditons were minor. However, hydrological and land use management concepts have to be developed that help to reduce the probability of such flood events in future.
Oxygen diffusion rates (ODR) were measured in water/sand/air and PEG solution/sand/air mixtures, spanning a range of liquid/solid/air volume ratios. Replacement of water with PEG solution as the liquid phase was found to reduce the ODR within a given mixture by a factor of approximately two. ODR values were compared with limiting values for plant emergence quoted in another study. It was concluded that PEG solutions could be used to control the osmotic potential of a sandy growth medium without adversely affecting seed germination due to oxygen starvation, providing that the pore volume was less than 70% occupied with liquid.
Adsorption and variable surface charge of young sieve roots of triticale and wheat after 24 h aluminium stress were studied using water vapour adsorption isotherms and potentiometric titration data. Root surface areas increased and the amount of variable surface charge decreased after stress. Functions of adsorption energy distribution showed a decrease of the amount of highly energetic surface adsorption centres and an increase of the low energetic ones, which lead to a lowering of average water vapour adsorption energy of the stressed roots. Distribution functions of apparent surface dissociation constants showed a decrease of surface acidity. The observed changes were more pronounced for the roots that were not able to grow further after stress.
Synchrotron X-ray computer microtomography was used to analyze the
microstructure of rose peduncles. Samples from three rose cultivars,
differing in anatomy, were scanned to study the relation between tissue
structure and peduncles mechanical strength. Additionally, chlorophyll
fluorescence imaging and conventional light microscopy was applied to
quantify possible irradiation-induced damage to plant physiology and
tissue structure. The spatial resolution of synchrotron X-ray computer
microtomography was sufficiently high to investigate the complex tissues
of intact rose peduncles without the necessity of any preparation.
However, synchrotron X-radiation induces two different types of damage
on irradiated tissues. First, within a few hours after first X-ray
exposure, there is a direct physical destruction of cell walls. In
addition, a slow and delayed destruction of chlorophyll and,
consequently, of photosynthetic activity occurred within hours/ days
after the exposure. The results indicate that synchrotron X-ray computer
microtomography is well suited for three-dimensional visualization of
the microstructure of rose peduncles. However, in its current technique,
synchrotron X-ray computer microtomography is not really non-destructive
but induce tissue damage. Hence, this technique needs further
optimization before it can be applied for time-series investigations of
living plant materials
In this paper, the spherical mode shapes corresponding to the resonant peaks in the frequency response spectrum were obtained. The apple defect was made by either injecting the reagent HC1 into the apple or by making holes in the apple. It was found that the apple defect may split one S2Q peak into two or even more S^ peaks in the frequency spectrum. The effect relies on the location and size of the defect in the apple as well as the measurement position of the impact and the response sensors. In the presence of the defect, this technique becomes unreliable in firmness evaluation, however it could possibly be used for the indication of the existence of the defect inside the apple.
Postharvest wastes of horticultural produce are enormous in Nigeria, requiring increasing efforts to reduce this spate. Therefore, colourless, blue, red and yellow polyethylene bags impregnated with or without sawdust were used for storing green mature plantain fruits. Control treatment was fruits lined on laboratory bench. Sample fruits enclosed in polyethylene were sealed under ambient laboratory conditions and thereafter opened weekly to assess postharvest changes. Inclusion of sawdust was not in any way more beneficial than without it. Relative light transmission through the four colours was expectedly different. Light intensity reduction by the colourless polyethylene was 3.6%, compared to 30-35% reductions by blue and yellow polyethylene. Variation in light intensity transmitted explained about 90% of weight loss in fruits. After three weeks of storage, weight loss from fruit stored in blue polyethylene was about 7% compared to about 45% in the control. Colour of polyethylene also significantly (P <0.05) influenced ripening pattern. Whereas 67% of fruits stored in colourless, yellow and red polyethylene were still green after two weeks of storage, only 8% of the control samples was still green. Organoleptic assessment of steamed boiled fruits after two weeks of storage revealed that fruits stored in blue and red polyethylene combined relatively high textural and general acceptability ratings, while fruits stored in yellow polyethylene had the highest textural rating. The general acceptability rating of fruits stored in yellow, red and blue polyethylene had highest relationship with flavour, but with taste - for fruits stored in colourless polyethylene. Evidences from the study revealed that blue and yellow polyethylene transmitting lower light intensity ensured lowest fruit weight loss, delayed ripening and enhanced culinary quality traits, and are therefore suggested for further evaluation and use under high temperature environment.
Averages and coefficients of variation of the parameters of the van Genuchten equation were estimated, in relation to a large dataset, for soil particle-size classes differentiated according to the proportions of sand, silt, and clay particles in the inorganic fraction. For each particle-size class, three subclasses (soft, medium, and hard) were differentiated according to the values of the soil bulk density.
A sensory method to evaluate watermelon abrasion was developed on the basis of a 1 to 20 score by visual appearance and by feeling with the finger the surface of the scraped spot on the melon. Different abrasive surfaces produced failure associated with different layers of the watermelon surface. Linear relationships were found between the sensory score and absorbed energy per unit contact area, which were affected by the kind of abrasive surface.
Instantaneous impact shear stress together with the instantaneous energy absorbed were used to predict bruise volume in Golden Delicious apple. The prediction produced a linear relation between the predicted bruise volumes and the measured bruise volumes with a factor of proportionality (K) 1.08 and a coefficient of correlation (R) 0.949. Both the instantaneous impact shear stress and energy absorbed decreased during storage of the fruit, but the value of K was relatively constant. The value of K was also relatively constant for the impact with small drop heights, but it slightly increased with the variation of fruit mass.
The paper presents measurements of the rate of water absorption in wheat grain by the capillary Ã¢Â€Â“ weight method. Measurements were taken for three grain fractions which took water with the characteristic parts, i.e.: groove, germ etc.
The laboratory test for sprouting of wheat grain (cv. Igna and Roma) was used to evaluate the influence of the degree of sprouting on changes in sorption and rheological properties of gluten freshly washed out by means of the Glutomatic device. Lower water additions used for sprouting did not change the water absorption of gluten and the gluten index. A further increase in the water addition caused significant changes in the gluten properties in relation to the untreated grain (control). Gluten index values decreased from about 57 to 35% for cv. Roma and from 94 to 38% for cv. Igna, and contents of the non-absorbed water contents in gluten freshly washed out increased from 4.1 to 13.9% and from 1.2 to 9.6%, respectively. Simultaneously there took place decreases in the absorbed water contents in the gluten from 63.3 to 55.1% for cv. Roma and from 65.8 to 59.0% for cv. Igna.
The new generation of soil improving agents (the so-called soil conditioners) has been suggested for immediate and complex restoration of the soils damaged by the flood in Central and Eastern Europe in 1997. The new ameliorants are prepared on the bases of peat, sapropel, glauconite and other kinds of natural raw materials. Composition of the soil improving agents depends on their application and can be controlled by the ratio between individual components. Effectiveness of the new soil improving agents was estimated in practical application and field tests on the damaged, desert and cultivated soils in Belarus, the United Arab Emirates and Egypt.
Most attempts to predict the effects of climate change on soils, and hence land use, have been made at coarse scales and have made little use of the detailed soil, land use and climatic information available. Much of this information is available in digital form and lends itself readily to manipulation by computer procedures, often within geographic information systems. The ACCESS project was designed to take advantage of this situation. The target was a spatially distributed soil, agro-climatic and soil hydrological model to predict the effects of climate change on land use within the European Community. In the event, the project was extended successfully to Hungary, Poland and Romania, which gave a much wider range of soil, soil hydrological and climatic regimes than originally envisaged. The model structure drew on earlier work, which related simple soil properties, such as might be obtained during soil surveys, to crop suitability. More powerful approaches to the estimation of the soil hydrological state and crop water demands were incorporated into the new model, as are new approaches to land type classification. Much effort also went into deriving robust pedo-transfer functions, which allow the derivation of soil hydrological properties from simple soil survey data. The new model (ACCESS) was purposely designed to run at two levels; a more general approach to utilise the results of the site specific approach to allow extrapolation of the modelling to large areas of land, and a detailed approach to use site specific data for calibration and validation. The most significant difference between the two routes through the model, is that the site specific model operates at a daily meteorological time-step, whilst the broad scale model runs at a monthly time-step.
A trial has been carried out at the experimental site at GrabÃƒÂ³w, which is situated in the Ma-zovian Plain in the Central Polish Lowlands, in order to calibrate the soil /crop water balance model ACCESS-II. The main interest of this site is that it furnishes data for 12 consecutive harvests of winter wheat Firstly, the principles of the model are described. Then the use of the model when the initial water contents are unknown. The first calibration results show that modifications need to be made to allow for the influence of severe winter frosts on crop growth. Following this modification, modelled yields were predicted to within 10 to 15% of measured yields, sufficient to demonstrate the strong link between yield, winter frosts and the amount of snow-cover protection. The discrepancies between measured and predicted values are useful in understanding the reasons for abnormally small yields. At this scale of modelling, the predictions are good enough to classify a region as very good, good or poor for winter wheat production under 'continental' climate conditions.
ACCESS-II contains a detailed model of crop growth and soil water use, for use within small areas and with detailed soil and cropping data. The principles behind the detailed model are described. Validation studies of water movement are shown at two sites in England, and of crop growth in Southern France, together with an example of the impacts of climate change on crop growth.
Assessment of soil structure and still more its changes is impeded by peculiarities of sampling and measurement. Unavoidable local destructions tend to advance use of small numbers of replicates, samples or sampling locations. Ways out of this dilemma are discussed using the results which were obtained in the project 'Qualitative and quantitative assessment of soil structure functions for the sustainable agricultural plant production'. Bulk density(BD) and saturated hydraulic conductivity (CSAT) are the most frequently used primary parameters of soil structure. The stastistical behaviour of these both is most different. High variability of CSAT usually precludes measurement at a sufficient number of replicates for statistic analysis - particularity at soil depths below topsoil. BD has smaller variability but much smaller sensitivity as well. For measurements at greater depths in soils it is preferable nevertheless owing to the lower number of necessary replicates. A two-level outflanking procedure might facilitate sampling problems by first applying an easy-going nondestructive, unspecific method to create a narrow grid of values as a first step which might help to rationalize choice of sampling locations for destructive samplings and in-situ measurements.
In 1932, a nitrogen fertilizer trial was initiated on a loamy Oxyaquic Eutrochrept near Munich (Germany). After 45 years, the sodium nitrate plots showed a much stronger slaking of the soil surface compared to the calcium nitrate plots in 1976. Sampling of the experimental plots to 1 m depth in order to determine bulk density, saturated hydraulic conductivity, soil moisture characteristic, slaking resistance and exchangeable cations was only possible after termination of the experiment in 1998. Comparison of the laboratory results of both plots showed increased contents of exchangeable Na, but no decrease of exchangeable Ca for the sodium nitrate plots. Bulk density at depths >50 cm increased and the slaking resistance decreased on those plots. The other soil structural properties determined were not significantly affected. The reason behind these unexpected findings is the change from sodium nitrate to calcium nitrate + cattle salt as the sodium nitrate fertilizer in 1984, 15 years prior to sampling. The resulting additional supply of Ca2+ was able to remediate the formerly visible deterioration of the soil structure by Na+. The adverse structural effects of an unfavourable fertilizer type (based on monovalent cations) can therefore be reversed by a change to a more appropriate type (based on bivalent cations, preferentially Ca2+).
Leaf transpiration of eight genotypes of Pima cotton was measured in the field of the Maricopa Agricultural Center in August 1994. Photomicrographs of leaf cross-sections and of the leaf surfaces were scanned and analyzed with the image analysis software. The data were used to parameterize the new WALL model, developed in this study to analyze the leaf transpiration with a special emphasis to liquid water movement inside the leaf. The transpiration stream was assumed to go from vein endings in two directions, towards the upper and lower leaf surfaces. These fluxes were presented as two parallel currents driven by the water vapour concentration difference between the atmosphere and the open surface of the vein endings and on the mesophyll and epidermis (inner parts) cells' surfaces as a flow in thin films of water. Simulations were run to estimate quantitatively the contribution of the cuticular transpiration to the total amount of leaf transpiration stream, to evaluate the role of the mesophyll cell walls' surfaces in the water transfer inside the leaf, and to calculate the dependence of transpiration and its components on temperature Simulation results showed (1) a major role of the cuticular transpiration as a leaf cooling mechanism and (2) that the cell wall properties can affect water film characteristics that also affect the transpiration course.
On the basis of a 4–year study, the effect of fertilization methods on the uptake and accumulation of mineral components by maize was evaluated. Two methods were used: by broadcasting over the whole surface and by band fertilization. The applied fertilizer level was gradually increased from 17.4 to 56.7 kg P ha-1 with the use of superphosphate and ammonium phosphate. It was found that the uptake and accumulation of mineral components depended on all the studied factors and their effect was increasing with the advancing vegetation. Band fertilization and the use of ammonium phosphate kept increasing the accumulation of all mineral components from 4-5 to 8-9-leaf-stage, in comparison with broadcast fertilization and superphosphate application, respectively. No distinct effect of phosphorus fertilization level on the uptake and accumulation of mineral components was visible before the stage of 8-9 leaves. Regressions were calculated for the relationship between the mineral components accumulation and the lapse of time from emergence to 8-9-leaf-stage and for the relationship between the uptake of mineral components and the accumulation of dry matter.
The experiment was conducted in the greenhouse of the Institute of Soil Science and Plant Cultivation in PuÃ…Â‚awy. The aim of the studies was the evaluation of some biochemical and physiological changes in faba bean (Vicia faba minor) seeds and the assessment of the dynamics of the accumulation of dry matter in plants grown from seed treated with laser light before sowing. Irra- diation of faba bean seeds of the variety NadwiÃ…Â›lanski, signifi- cantly affected the activity of amylolitic enzymes in the seeds, especially in the germination initial period. Both the three- and five-fold treatment increased enzyme activity to the same degree. It was found that there was a significant effect of seed biostimulation on the scale and rate of dry matter accumulation of particular faba bean organs; the three-fold dose led to an increase in the dynamics in the above- ground part, whereas the five-fold dose, to that in the roots. The weight of vegetative organs intensively reached the pha- se of faba bean flowering; the highest increase of the total above- ground part of the weight was noted during flowering and pod setting, and was followed by a very fast increase in the weight of the generative organs. Irradiation of the seeds significantly influenced plant germination and modified the course of particular develop- ment stages of the faba bean resulting in the accelerated germina- tion and maturity of the plants.
Electroporation was used as a method for Rhodotorula rubra biomass enrichment in selenium. The highest selenium accumulation in yeast cells was achieved after 10 min pulse electric field (PEF) exposure of 16 h shaken culture. Multiple PEF exposure of yeast culture did not favour selenium accumulation. Optimization of selenium concentration in a medium resulted in an over two-fold increase of its accumulation in cells. About three-fold increase of dead yeast cells was recorded in analysed range of selenium concentrations.
The error in the measurement of volumetric water content by the TDR technique results from the correlation imperfections between the directly measured values of soil refractive index, n, and the real value of soil moisture as well as the hardware and software imper- fections of the TDR device and TDR probe installation. On the base of the laboratory measurements of the selected mineral, organic soils and their mixtures, it was confirmed that the soil solid phase significantly influences moisture values as determined by the TDR. Inclusion of the soil bulk density in the TDR calibration formula decreases the absolute error of the TDR determined soil moisture by the factor of two. The relative error of TDR moisture values increases in the lower range of water contents. This is due to a constant absolute error introduced by the measuring device and an increasing role of the soil solid phase in the soil refractive index.
The aim of the study was to determine the effect of acetylene block on the emission of nitrous oxide from soils. The study was conducted on three arable soils of Poland: Haplic Podsol - sandy loam, Eutric Cambisol - loess, and Eutric Cambisol - sandy loam, which differ in the initial concentrations of nitrates: 22, 93 and 52 kg N-NO3- ha-1, respectively. The study was performed with natural samples and enriched with two doses of nitrates (100 and 200 kg N- NO3- ha-1) in treatments with and without acetylene block. It was found that N2O emission without acetylene block was on the level of 0-100% as compared to the emission from samples with acetylene block. The effect of acetylene block was more effective in the soils without nitrate amendment.
The aim of this study was to test the hypothesis that a combined treatment of copper contaminated acid soil with lime and a coal powder decreases copper toxicity due to a synergetic effect of pH increase and association of Cu2+ ions in organo-mineral complexes. A two-year-long pot experiment with alfalfa was carried out on a pseudopodzolic soil contaminated with four Cu levels in the range 0-900 mg kg-1 soil. The amendments applied were lime, coal powder and a precomposted mixture of lime and coal powder. The compost and lime application increased yield and decreased copper content in plants at all levels of copper pollution. Coal powder alone depressed plant growth. The combined application of lime and coal powder maintained soil pH in the optimum range (5.1-5.6) during the whole experiment and had a pronounced effect on yield of the second and next crops, depending on the level of liming.
The effect of intensive soil acidification on the genesis of Fe-, Al- and Mn-oxides and their relation to the soil aggregate stability were investigated in the Vienna Woods. Analyses were carried out on soil samples of 2 sites at 4 depths (0-5, 5-10, 10-20, and 20-30 cm) taken from the infiltration zone of the stemflow (S) of beech trees, which is strongly influenced by acid atmospheric depositions (soil-pH KCl 2.5 to 3.0), and from non-contaminated reference areas (R) between the trees, where the acid input is much lower (soil-pH KCl 5.5). The extreme soil acidification in the infiltration zone of stemflow led to intensive weathering of primary minerals, to neoformation and accumulation of crystallized, amorphous and organic-bound Fe-oxides, to lower concentrations of Al- and Mn-oxides and to a high increase in soil aggregate stability, reflecting the aggregation effect of Fe-oxides, and the concomitant leaching of Mn and Al at a very low soil pH. Moreover, chemical extractions of the fine earth (water saturation extract and BaCl2-extraction) showed that Fe had accumulated in the strongly acidified soils also as water-soluble and exchangeable cation.
The authors characterized selected surface properties of humic acid preparations extracted from three types of Polish soils (degraded chernozem developed from loess, grey-brown podzolic soil developed from loam, grey-brown podzolic soil developed from loess). Based on the isotherms of water vapour adsorption, the specific surface area and the molar energy of adsorption were calculated; the effect of agrotechnical measures in multi-year cultivation on the surface properties of the humic acids under study was determined, and the effect of contamination of humic acids on the form of the isotherms of water vapour adsorption was analyzed.
The object of this study was to determine change of natural buffer
capacity of humic acids by strong buffering agents, which were phosphate
ions. Studies were carried out on the humic acids extracted from peat
soils. Additional information was obtained by determination of water
holding capacity, density, ash and pH for peats and optical parameter
Q4/6 for humic acids. Humic acid suspensions exhibited the
highest buffer properties at low pH and reached maximum at pH ~ 4.
Phosphates possessed buffer properties in the pH range from 4.5 to 8.0.
The maximum of buffering was at pH~6.8 and increased proportionally with
an increase in the concentration of phosphate ions. The study indicated
that the presence of phosphate ions may strongly change natural buffer
capacity of humic acids by shifting buffering maximum toward higher pH
values. Significant correlations were found for the degree of the
secondary transformation with both the buffer capacity and the titrant
volume used during titration.
In order to detect fractures in the plant tissue resulting from deformations, the method of acoustic emission has been applied. Simultaneous measurements of the mechanical parameters and the acoustic emission signal show that the destruction of the cell structure begins at the lower deformation values than the ones at which there is a decrease in the stress level. The results obtained show that the method of measuring the acoustic emission signal allows for an early detection of plant tissue defects arising from the activity of external forces.
The paper presents results concerning ultrasonically assisted extraction of bioactive compounds from roots of valerian. Pulsed ultrasonic field was applied. The investigation was accomplished by varying irradiation time and sonic power. The results were compared with classical (silent) extraction. The study included evaluation of the coefficient of rehydratation, yield of extraction, dry matter content in extract and residue, and unit energy consumption. The utilisation of pulsed ultrasound was proved to be a more efficient technique than the classical method for extraction of bioactive components from dried valerian roots.
A Tandem Scanning Reflected Light Microscope (TSRLM) with computer image analyser and with a structure quantimeter (hardware, software and rotary microtome) are presented and compared to other microscopic methods with respect to new possibilities in visualisation of biological material. Scanning optical microscopes are the most recent constructions in optical microscopy. They offer the rejection of out-of-focus noise and higher contrast than the conventional imaging. The only allowed to reach a detector is the light emitted from the objective focal plane. This cuts off any out-of-focus image blurring. A short history of confocal microscopy from Marvin Minsky to Tandem Scanning Reflected Light Microscope (TSRLM) and Confocal Laser Scanning Microscope (CLSM) has been presented. The use of scanning optical and electron microscope method for the investigation of biological materials is estimated and compared.
Diffuse reflectance spectra from 400 to 700 nm were measured with an integrating sphere from bruised and unbruised, unpeeled and peeled tubers cvs. Desiree, Pentland Dell and Record. Stepwise discriminant analysis was used to determine wavelengths that were sensitive to bruising and to formulate classification al- gorithms to determine whether a tuber from an unknown sample was bruised. Wavelengths selected from unpeeled tubers were dependent on cultivar, while spectra from peeled tubers were independent of cultivar. The accuracy of classifying tubers as bruised or unbruised was between 76 and 91% for unpeeled tubers and 89 and 100% for peeled tubers. When the identity of tubers was unknown to the discriminant program, 70 to 82% of unpeeled and 73 to 83% of peeled tubers were correctly classified as bruised or unbruised. The integrating sphere increased the percentage of spectra correctly classified compared to spectra collected with a bifurcated fibre optic light guide. The increased accuracy was due to a smaller experimental error, greater sampling area and the acquisition of more truly diffuse reflectance.
When a field or a small watershed is repeatedly surveyed for soil water content, sites often can be spotted where soil is consistently wetter or consistently dryer than average across the study area. This phenomenon has been called time stability, temporal stability, temporal persistence, or rank stability in spatial patterns of soil water content or in soil water contents. The temporal stability presents significant interest for upscaling observed soil water contents to obtain average values across the observation area, improving soil water monitoring strategies, and correcting the monitoring results for missing data. The objective of this work was to research the temporal stability in estimated soil water fluxes using extremely frequent multi-depth measurements of soil water content with multisensor capacitance probes installed in soil in multi-year corn production. Data on water contents at 10, 30, 50, and 80 cm depths were collected every 10 min for 20 months of continuous observations from May 2001 to December 2002. Temporal stability was well pronounced for soil water fluxes estimated from soil water balance for the depth of 60 m. Soil water fluxes can be upscaled and efficiently monitored using the temporal stability of soil water patterns.
Soil degradation is occurring over vast areas. The GLASOD and ASSOD projects reflect the present status of human-induced soil degradation and its impact on food productivity related to productivity changes observed in the recent past. However, there is a great need for well-documented, reliable soil information and other related data at national and regional levels to better understand and qualify the impact of changing soil conditions or biomass production.
The effect of spent engine oil on soil pH as well as activity of selected enzymes (catalase and dehydrogenase) was studied. The results indicate that spent engine oil caused a slight change in soil pH relative to the control. There was a significant decrease (p<0.05) in catalase activity in contrast to a significant increase (p<0.05) observed in dehydrogenase activity. On the whole the data suggest that spent engine oil alters soil biochemistry.
Nests habour ants and termites and protect them from harsh environmental
conditions. The structural stabilities of nests were studied to
ascertain their relative vulnerability to environmental stresses.
Arboreal-ant nests were pried from different trees, while
epigeous-termite nests were excavated from soil surface within the
sample area. Soils without any visible sign of ant or termite activity
were also sampled 6 m away from the nests as control. Laboratory
analysis result showed that irrespective of the tree hosts, the
aggregate stabilities of the ant nests were lower than those of the
ground termite, with nests formed on Cola nitida
significantly showing lower aggregate stability (19.7%)
than other antnest structures. Clay dispersion ratio, moisture content,
water stable aggregate class <0.25mm and sand mass were each
negatively correlated with aggregate stability, while water stable
aggregate class1.00-0.50 mm gave a positive correlation. Nest structures
were dominated more by water stable aggregate class >2.00 mm but path
analysis demonstrated that water stable aggregate class <0.25 mm
contributed most to the higher aggregate stability of the termite nest
than the other nest. Nest aggregates had greater structural stability
compared to the control soil. The higher structural stability of termite
nests over other nest and soil was considered a better adaptive
mechanism against body desiccation.
The paper presents the results of a study on the process of moisture diffusion during barley grain storage in a grain storage silo. The moisture migration was caused by concentration gradient. The study was conducted using a model test station and consisted in the measurement of barley grain moisture and temperature in a silo, and in measuring the pressure exerted by the grain bulk on the silo wall. Analysis of the results showed that none of the parameters studied was stable. It was found that when the grain moisture content applied was 16% in the bottom layer and 10% in the upper layer the average value of grain moisture content in the silo increased from 13.2% to 14.1% over the ten days of the process, while with reverse positioning of the layers in the silo the corresponding increase reached 13.8%. This was due to additional precipitation of water in the course of the process of grain respiration. Moisture diffusion caused an increase in the temperature of the grain within the silo (up to 33Ã‚Â°C at ambient temperature of 16Ã‚Â°C). Another important effect of the moisture diffusion was the swelling of grains, which caused an increase in the pressure of the barley grain bulk against the silo wall. The highest increase in the wall load was observed at the boundary line between layers of grain of different moisture content levels. The changes in the values of the parameters under study were described by means of regression equations.
Water vapour adsorption by soil aggregates of humus accumulating soil horizon (fractions Ã…Â0.1, 0.1-0.25, Ã¢Â€Â¦, 5-10 , >10 mm) is found to be adequately described in the range of 0.1Ã…Â p/p0 Ã…Â0.98 by the equation W = Wmh[(p/p0)6-(p/p0)3 + (p/p0)]+Wres, where: Wmh Ã¢Â€Â“ maximum hygroscopic moisture, Wres Ã¢Â€Â“ residual water content or model fitting coefficient. The main parameter Wmh of the dependence W=f(p/p0) of aggregated part of soil is determined by soil type.
The Grand Canonical Ensemble Monte Carlo simulation method is applied to study adsorption of water vapour on external and internal surfaces of sodium montmorillonite. The model uses MINDO water-clay and cation-clay potentials and empirical water-water and water-cation potentials. The results of investigations of thermodynamic and structural properties of adsorbed water are reported.
The results showed that glyphosate is initially adsorbed mostly in the
upper 2 cm. It is than transported and adsorbed after few days in deeper
soil horizons with concomitant increasing content of its metabolite
aminomethylphosphonic acid. Moreover, Fe-oxides seem to be a key
parameter for glyphosate and aminomethylphosphonic adsorption in soils.
This study confirmed previous studies: the analysis showed lower
contents of dithionite-soluble and Fe-oxides for the Chernozem, with
consequently lower adsorption of glyphosate and aminomethylphosphonic as
compared with the Cambisol and the Stagnosol.
Laboratory studies of nitrogen and water vapour adsorption on mucks originating from Lublin Polesie Region are presented. The Brunauer-Emmet and Teller (BET) equation was used to analyze the experimental results and to calculate the specific surface area from both nitrogen adsorption and water vapour sorption isotherms in relation to the degree of mucking (secondary transformation). The existence of relationship between surface area determined from water vapor desorption data and water holding capacity index W1 which characterizes the state of the secondary transformation of peat was proved. The relationships between the specific surface areas determined from water vapour and nitrogen adsorption data, and some important physical properties, eg ash content, bulk density and total porosity of the mucks studied were found. Both classification schemes of the secondary transformation of the peaty-muck soils, that according to Okruszko and W1 index according to Gawlik, should be used simultaneously. In order to characterize the state of muck transformation, simultaneous evaluation of specific surface area from adsorption of polar and non-polar adsorbates is advisable.
Submicroscopic techniques can be broadly subdivided into the study of micromorphology and imaging of the arrangement of the soil particles and voids, and the microchemical analysis of soil components. In the authors opinion, one of the most promising tools in the micromorphology study of soil is the Scanning Electron Microscopy (SEM) operating in Backscattered Electron emission mode (BSE) with the auxiliary Energy Dispersive Spectrometry (EDS) as a microanalytical system. The emission of BSE is strongly related to the atomic number of the target. This allows easy localization of resin in pores and soil mineral particles. Qualitative differences of chemical nature between soil constituents are also distinguishable. The SEM-BSE micrographs have a much higher resolution compared with petrographic micrographs, this permits continued observation of soil structure from the meso and micro to the submicro scale. The polished blocks prepared for SEM-BSE study can be simultaneously examined by microanalytical techniques. Highly contrasted SEM-BSE 2-D images can be easily quantified using image analysis systems. Some examples of application of the BSE imaging in soil micromorphology is given and discussed in the work.
Technological value of grain of new hybrid triticale lines achieved due to crossbreeding X Triticosecale Wittmack with Aegilops sp. was studied as compared to standard triticale varieties to select lines with the best technological value. It was found that the new triticale lines under evaluation were characterized by usually higher 1000-kernel weight than standard Bogo cv., but this value depended on the year of the study when compared to Presto cv. The hybrid strains were characterized by lower volume weight than Presto cv., but exceeded or were similar to Bogo cv. Grain shapeliness and uniformity for the lines studied were usually significantly lower than for standard triticale varieties. Great differentiation of vitreousness within the lines was found; vitreousness of strain 3 and 6 grain even exceeded that for both standard varieties. Total protein content was also higher for both strains than for Presto cv. The hybrid triticale strains were distinguished with lower wet gluten content than the standard varieties. Flour extract from triticale with Aegilops cross- combination grain was significantly lower than from Presto cv., but similar to Bogo cv. Among the strains studied, Nos 4 and 5 were characterized by the highest value of that trait and the best rheological properties of dough. Evaluation of baking and its organoleptic features revealed the superiority of strain 4 over standard Presto cv. Strain 4 deserves attention as a material for the baking industry.
The influence of a variable magnetic field of 30 mT magnetic induction and frequency f = 50 Hz, at different exposure times (8, 15, 30, 60 and 120 s), as well as an electric field of 5 kV cm-1 intensity and the same frequency and exposure times on kernel vigour of triticale with Aegilops hybrids and triticale (cv. Tewo), were studied. The aim of the research has been to choose suitable parameters for kernel biostimulation and find the application for results in further studies. The following methods for vigour evaluation have been used: germination ability, sprout length, germ necroses using the topographic tetrasolin method, electric conductivity of exudates from kernels and a-amylase activity. Positive effects of variable magnetic and electric fields on kernel vigour have been found. Grains subjected to an electric rather than a magnetic field have been characterized as having higher vigour. The best exposure time for kernels in a magnetic field was 60 s and in an electric field 30 s. The cross-combination produced using Ae. crassa 4x was characterized as having higher vigour than that obtained with Ae. juvenalis 6x. Tewo cultivar had a higher power and ability of germination than hybrid lines.
Assessment of aeolian transport in three experimental stations in southern Tunisia showed a prevailing wind direction from the east, the southeast and the north over the winds coming from the south and from the west. The movement of sand (dunes) was towards the Sahara, in particular to the Oriental Erg, and the dune morphology was dynamically orientated to the west and the southwest. For the three stations it was observed that about 70% of the fine sand particles (50 250 Ã„Â¾) were transported beneath 20 cm height above the surface.
Aeration related properties of individual soil layers of three Slovakian soil profiles (Calcaro-haplic Phaeozem, Fluvi-calcaric Phaeozem and Calcaro-gleyic Phaeozem) were characterised with the use of undisturbed soil samples preincubated on water tension plates at 0, 63, 159 and 500 hPa at room temperature. The experiment included measurements of air-filled porosity (Eg), relative gas diffusion coefficient (D/Do), air permeability (k), oxygen diffusion rate (ODR), redox potential (Eh), content of Fe+2 as well as soil dehydrogenase and catalase activities. The soils under investigation showed high resistance to reduction processes. Despite O2 depletion following 2-days water saturation (expressed by the low values of ODR, k, D/Do and Eg), the redox potential was still maintained on a high level and concentration of the reduced iron was relatively low. A close relationship between aeration parameters was found.
A pot experiment with triticale cv. Jago was conducted to test the effect of oxygen deficiency on the content of available macroelements. Oxygen stress (flooded conditions) distinctly conserved all the chemical species content but only at lowest density of soil combined with flooded conditions the decline of uptake of N-NH4+ and P and K was significant. A significant increase in (p <0.001) uptake of the investigated elements occurred in higher values of air filled porosity (Eg). The most sensitive element with respect to Eg value changes was phosphorus, the least one was potassium. The relation between redox potential (Eh) on NH4+, NO3–, P and K uptake was positive in all the investigated cases. The highest relation was observed in P uptake. The parameter of oxygen availability in the soil – ODR (oxygen diffusion rate) showed a typical tendency for changes under differentiated air-water conditions. The critical ODR value (about 35 g m-2 s-1) for uptake of all the studied elements was observed under the investigated conditions. Statistical analysis showed a significant relation between oxygen diffusion rate and NH4+, P and K uptake.
The purpose of this paper was to characterise soil structure from the point of view of its aeration properties and to verify applicability of some methods for the determination of different properties related to aeration. The studies were performed on 15 representative soil samples from Austria, Czech Republic, Hungary, Poland and Slovakia. The paper presents results of measurements of different soil aeration properties such as oxygen diffusion rate (ODR), redox potential (Eh), relative gas diffusion coefficient (D/Do), air permeability (k), air-filled porosity (Eg) and activity of soil dehydrogenase and catalase. All the aeration parameters such as D/Do, ODR, k were correlated with soil water content, air-filled porosity, bulk density and particle density. In most cases the aeration indicators themselves were also intercorrelated. The activity of both studied enzymes was correlated with some of the aeration parameters. Threshold values of soil physical conditions providing satisfactory aeration status in particular soil profiles were determined.
Four horizons (till the depth of 130 cm) of six typical Hungarian soil profiles (Fluvic Gleysol, Vertic Gleysol and Orthic Solonetz) were investigated in order to determine relation between dehydrogenase activity, oxygen diffusion rate (ODR), redox potential (Eh) as well as Fe+2 content and the soil water status, and to relate them to the soil utilisation and cultivation type. The experiments were performed with the use of undisturbed soil samples preincubated on the water tension plates at 0, 63, 159 and 500 hPa at room temperature. All the investigated parameters varied widely in the tested soils. Dehydrogenase activity and reduced iron content decreased but ODR and Eh values increased with increasing soil water tension. A close relationship between oxygenation indicators (ODR, Eh and Fe+2) and dehydrogenase activity was found. The most sensitive oxygenation parameter for describing the relationship between enzyme activity and soil aeration status appeared to be ODR. The studied soils showed a significant decrease of Eh as well as tendency to diminish their ODR, dehydrogenase activity and reduced iron content due to deep-loosening cultivation.