Hydrophysical Properties Research Articles

Increasing the fertility of trans-ural steppe southern chernozems with the use of natural agricultural ores

A three-year field experiment on southern chernozem showed an improvement in its hydrophysical and agrochemical properties and crop productivity as a result of applying natural agricultural fertilizer ores in the series manure-sapropel-floating mat-straw-zeolite-sand.

The role of soil in bioclimatology - a review

Soil’s part in bioclimatology is not defined and formulated yet. We interpret soil together with its plant cover as primary climate modifier for organisms living on, and within it. At the same time evaporating soil together with its transpiring vegetation is affecting the climate, and functioning as secondary climate modifier in context of bioclimatology. Selected Hungarian studies are used to highlight four primary and three secondary soil modifier actions connected to bioclimatology. Both primary and secondary soil modifier roles coupled mainly to soil hydro-physical properties. The first primary soil climate modifier action is the dew formation in the surface of sandy soils. As dew 80 mm of water can annually be transported from the subsoil to soil surface. Positive water resource value of dew is still not completely accepted. The second primary soil climate modifier example presents different amounts of usable soil moisture resource in two oak forest habitats with different species composition of herbs. In the third primary soil example the microclimate of the wetter habitat with deeper soil and denser herb vegetation of the oak forest – estimated by inverse modelling – showed higher shading, air moisture content and lower soil coverage than that of dry one. In the fourth primary soil modifier example forest hydrology is quantified for a Scots pine forest. Amount of transpiration, evaporation, interception, and change in the soil water storage were quantified and modelled. As secondary soil climate modifier role CO<sub>2 emitting of different plant production forms and land-uses is shown. Estimated CO2 production burning fuels for soil and plant cultivation is one to threefold of the organic extensive and intensive plant production farm consecutively in 2001. For the estimative calculations cost data of the farms are used. Amount of CO<sub>2</sub> fixed in the crop biomass is also one to threefold as estimated with the regional scale formula of CEEMA (Canadian Economic and Emission Model for Agriculture). Two secondary soil modifier examples of soil texture and land use pattern’s influence on local weather phenomena and near surface atmospheric processes as storm move and development are presented yet. Both studies demonstrate the significance of site-specific soil hydraulic parameters – as field capacity, usable and actual water storage – in formation of the local weather through the soil evaporation and plant transpiration in modelling studies. Of course variety of soil’s role is much wider as the examples show and even it is not known completely at present. Soil’s role in bioclimatology as new discipline will expectably be formulated in the future.

Drought stress tolerance of two wheat genotypes

Biotic and abiotic stress effects can limit the productivity of plants to great extent. In Hungary, drought is one of the most important constrains of biomass production, even at the present climatic conditions. The climate change scenarios, developed for the Carpathian basin for the nearest future predict further decrease in surface water resources. Consequently, it is essential to develop drought stress tolerant wheat genotypes to ensure sustainable and productive wheat production under changed climate conditions. The aim of the present study was to compare the stress tolerance of two winter wheat genotypes at two different scales. Soil water regime and development of plants, grown in a pot experiment and in large undisturbed soil columns were evaluated. The pot experiments were carried out in a climatic room in three replicates. GK Élet wheat genotype was planted in six, and Mv Emese in other six pots. Two pots were left without plant for evaporation studies. Based on the mass of the soil columns without plant the evaporation from the bare soil surface was calculated in order to distinguish the evaporation and the transpiration with appropriate precision. A complex stress diagnosis system was developed to monitor the water balance elements. ECH<sub>2</sub>O type capacitive soil moisture probes were installed in each of the pots to perform soil water content measurements four times a day. The irrigation demand was determined according to the hydrolimits, derived from soil hydrophysical properties. In case of both genotypes three plants were provided with the optimum water supply, while the other three ones were drought-stressed. In the undisturbed soil columns, the same wheat genotypes were sawn in one replicate. Similar watering strategy was applied. TDR soil moisture probes were installed in the soil at various depths to monitor changes in soil water content. In order to study the drought stress reaction of the wheat plants, microsensors of 1.6 mm diameter were implanted into the stems and connected to a quadrupole mass spectrometer for gas analysis. The stress status was indicated in the plants grown on partly non-irrigated soil columns by the lower CO<sub>2</sub> level at both genotypes. It was concluded that the developed stress diagnosis system could be used for soil water balance elements calculations. This enables more precise estimation of plant water consumption in order to evaluate the drought sensitivity of different wheat genotypes.

Hydro-physical properties of soils developed from different parent materials

The objectives of this study were to compare some selected hydro-physical properties of soils developed from different parent material under the same climate type, similar topography and vegetation cover and to present significant differences in the soil characteristics with numerical values. For this purpose, five different sites with similar topography, vegetation cover, the same climate type, and different parent materials were selected in the northeast part of Turkey where some studies were previously carried out by scientists from the Faculty of Forestry at Istanbul University. The parent materials in the sites were granite, clayey limestone (upper triassic), clayey limestone (upper cretaceous), neocene, and arkose. Results indicated that all properties studied except for saturation capacity and particle density of soils differed significantly with respect to the parent materials. Compared to other soil types developed from the parent materials, granite formed soils with greater sand and lower silt contents, numerically greater porosity, and significantly higher dispersion ratio and organic matter. On the other hand, soils formed on arkose parent materials had the lowest pH value, numerically the greatest available water content and saturation capacity and organic matter percentage.

New Lignin-Based Polymers for Ecological Rehabilitation

It has been shown that the found regularities of the interaction between lignosulfonate and polymeric cations in aqueous media can serve as a scientific basis for chemical modification of lignin by way of the formation of the interpolyelectrolyte complexes. This energy-saving and non-complicated method of modification was applied for obtaining new lignin-based soil improving agents. Water-soluble polymeric products of the interaction of lignosulfonate with three synthetic polymeric cations have been used in order to study the effect of their adsorption at the clay soil surface on the water stability of the artificially soil aggregates formed by the treatment of soil with lignin-based polyelectrolyte complexes (LPECs). The obtained results are explained from the viewpoint of the complex mechanism of soil structure formation, combining simultaneously the flocculation of soil particles and stabilization of the formed aggregates. The conducted field tests have shown that the application of the lignin-based polyelectrolyte complex as a soil conditioner at a deep loosening of heavy clay soil allows the improvement of the hydrophysical properties and the filtration ability of the soil sublayers and, thereby, to enhance the barley yield.

Application of X-ray computed tomography to soil science: A literature review

The study of the spatial configuration of soil, in its complexity, requires an understanding of the interrelations and interactions between the diverse soil constituents, at various levels of organization. Investigations of the spatial arrangement of the mineral and organic components of soil have benefited from the development of techniques for structural analysis. X-ray computed tomography (CT) is a non-destructive and non-invasive technique that has been successfully used for three-dimensional (3D) examination of soil. Valuable information has been obtained by the application of CT for the description and quantitative measurements of soil structure elements, especially of soil pores and pore network features. In many studies, X-ray CT has been used to investigate the hydro-physical characteristics of the soil, in a functional and temporal manner. A dynamic approach has also been utilized in the evaluation of the biotic factor influence on soil. The analysis of soil solid phases, by X-ray CT, has been challenging due to the similar X-ray attenuation of different solid constituents. However, the use of multiple X-ray energy levels has facilitated the discrimination of minerals in soil. The aim of this review and synthesis is to offer a perspective on the major issues related to application of the technique, general attempted solutions and possible directions in the utilization of X-ray CT in soil research. Relevant scanning parameters, procedures for CT image reconstruction, algorithms for the quantification of soil characteristics and results are presented for each type of application. Key words: X-ray computed tomography, energy level, spatial resolution, segmentation, soil mineral and organic constituents, soil physical and hydro-physical properties, soil biota

Moisture dynamics and hydrophysical properties of a transplanted acrotelm on a cutover peatland

AbstractThe natural carbon storage function of peatland ecosystems can be severely affected by the abandonment of peat extraction, influencing peatland drainage, leading to large and persistent sources of atmospheric CO2. Moreover, these cutover peatlands have a low and variable water table position and high tension at the surface, creating harsh ecohydrological conditions for vegetation re‐establishment, particularly peat forming Sphagnum moss. Standard restoration techniques aim to restore the peatland to a carbon accumulating system through various water management techniques to improve hydrological conditions and by reintroducing Sphagnum at the surface. However, restoring the hydrology of peatlands can be expensive due to the cost of implementing the various restoration techniques. This study examines a peat extraction‐restoration technique where the acrotelm is preserved and replaced directly on the cutover peat surface. An experimental peatland adopting this acrotelm transplant technique had both a high water table and peat moisture conditions providing sufficient water at the surface for Sphagnum moss. Average water table conditions were higher at the experimental site (−8·4 ± 4·2 cm) compared to an adjacent natural site (−12·7 ± 6·0 cm) suggesting adequate moisture conditions at the restored surface. However, the experimental site experienced high variability in volumetric moisture content (VMC) in the capitula zone (upper 2 cm) where large diurnal changes in VMC (∼30%) were observed, suggesting possible disturbance to the peat matrix structure during the extraction‐restoration process. However, soil–water retention analysis and physical peat properties (porosity and bulk density) suggest that no significant differences existed between the natural and experimental sites. Any structural changes within the peat matrix were therefore minimal. Moreover, low soil‐water tensions were maintained well above the laboratory measured critical Sphagnum threshold of 33% (−100 mb) VMC, further indicating favourable conditions for Sphagnum moss survival and growth. Copyright © 2007 John Wiley & Sons, Ltd.

Extracellular Polymeric Substances Affecting Pore‐Scale Hydrologic Conditions for Bacterial Activity in Unsaturated Soils

Soil bacterial cells are often found embedded in biosynthesized extracellular polymeric substances (EPS) forming aggregates or stationary colonies attached to solid surfaces. Soil bacterial aggregation and pooling of resources offer a successful adaptation to variations in hydration status and in nutrient availability and enhance cooperative genetic and metabolic exchanges. The ubiquity of such microbially excreted exopolymeric substances across many different environmental conditions and habitats is attributed to their key role in environmental adaptation, including colony architecture and anchoring, nutrient entrapment, and maintenance of favorable hydration conditions. This review focuses on the hydrophysical properties of EPS and its primary constituent, exopolysaccharides, and their role as an interface between living cells and the harsh conditions common to the shallow vadose zone. We review water retention, diffusion, and hydraulic properties of EPS and postulate mechanisms conferring an advantage to embedded bacterial cells. The shrink–swell behavior of EPS for different water potentials affects mean pore size and passage of solutes and colloids of different sizes; we evaluate various water‐related morphological transformations of EPS that influence diffusion behavior in unsaturated soils. We hypothesize that EPS low permeability results in hydraulic decoupling during rapid wetting or drying events, effectively shielding embedded bacterial cells from adverse effects of extreme fluctuations in hydration conditions. We show that the addition of minute amounts of EPS significantly alters the hydrological conditions experienced by microbial colonies and, in some case, may alter macroscopic hydrological and mechanical properties of the host porous medium.

Soil water regime of agricultural field and forest ecosystems

The unsaturated zone of soil is one of the most important and complicated parts considering the water movement in the hydrologic cycle. Water transfer through its upper and lower boundary directly influences the amount of water in this zone. The depth of groundwater table usually delimits the lower boundary. The soil surface with or without plant canopy is the upper boundary. The soil surface reacts directly on meteorological conditions primary through evapotranspiration. It is determining the inflow of precipitation into deeper layers of a soil profile. Both physical and hydrophysical properties of the upper soil layer are changed under the extreme meteorological conditions. In case of such conditions the water can flow along preferential pathways down to the groundwater without filling up the soil matrix. Changes of physical and hydrophysical characteristics of the soil surface layer or of the root zone depend on the vegetation type, too. The water storage of 0–30 cm and 30–60 cm soil layers was calculated from monitored data of soil water contents in two different ecosystems, and the calculated water storages were compared with the integral water contents that are related to hydrolimits (field capacity, point of decreased availability and wilting point) in 1999 and 2000. It should be noted that it was considerably dryer in 2000 than in 1999, and during the vegetation period, it was also warmer in 2000 than in 1999. The higher air temperatures during the vegetation season and the lower cumulative rainfall in 2000 comparing to 1999 resulted in a decrease in the integral water contents in the root zone.

Characteristic of soil hydro-physical properties and water dynamics under different vegetation restoration types

By combining the observation of the soil profile at field and the chemical and physical analysis in laboratory, a study on the hydro-physical properties of soil in six different vegetation types and the dynamics of water content after rain was conducted in Wanchanggou, Guangyuan City to find out the vegetation types with effective water-conservation functions in order to serve the ecological restoration in the low hill heavy rain area upper the Jialing River. Results showed that: the hydro-physical properties of soil in the mixedAlnus cremastogyne andCupressua leyland forest (AcCl) were best. But in the depth of 0–20 cm. The properties of soil in the abandoned cropland (Fm) was better than that in the AcCl. The soil bulk densities varied significantly between the layers of 0–20 cm and 20–40 cm in all the six vegetation types except that in theRobinia pseudoacacia shrub forest (RpII), and the changes of the maximum and the caplillary moisture capacity between layers were significant only in the Fm and in the AcCl. Of these stands, the AcCl had the shortest water-absorbing period and the strongest moisture changes in the upper layer (0–15 cm). In the same stand, the deeper the soil layer, the slighter the soil moisture varied, and the longer the soil moisture accumulating process lasted.

Use of Soil Water Retention Capacity and Hydraulic Conductivity Estimation in the Preparation of Soil Water Management Maps

According to the Hungarian Soil Information and Monitoring System's (HSIMS) database a group estimation method was developed to predict the mean soil hydrophysical properties. The estimation efficiency of the worked out prediction procedures was controlled on a test database, and on a dataset of a study area. It can be established that the water retention and the hydraulic conductivity of soils are sufficiently predictable from the category data of soil maps. The 10-digit map codes of the PWW mapping method were created by different estimation methods, and as a result the PWW map was drawn. However, it is not always possible to estimate the necessary soil hydrophysical properties from the available map information for preparing the PWW map. Sometimes the knowledge gained from the field reports is needed as well. Further studies are planned for integrating these morphological information into our estimations.

Impact of development and cultivation on hydro-physical properties of tropical peat soils

Impact of development and cultivation on hydro-physical properties of tropical peat soils

Approximation of landfill drainage discharge by De Zeeuw-Hellinga model, and its verificationon sanitary landfill of solid domestic waste

The goal of this work is to present a suitable tool or model for the evaluation of the internal landfill water discharge, in relation to the basic design parameters of internal landfill drainage system and other processes. De Zeeuw-Hellinga’s drainage theory fulfils those requirements. De Zeeuw-Hellinga’s drainage intensity factor takes in basic design parameters of internal landfill drainage system and also hydro-physical properties of the collected waste. The drainage theory calculates with landfill internal water recharge to the drainage system within a certain time interval. In practice this method was successfully verified in a sanitary landfill of solid domestic waste in Osecna (a region near Liberec, Czech Republic). The comparison of the real data of the measured values of the internal landfill water discharges with calculated values, demonstrated eligibility of the use of De Zeeuw-Hellinga drainage theory as a good instrument for approximation of the internal landfill water discharges. This tool needs only a minimum of information and can be applied for the evaluation of basic design parameters of the internal landfill drainage system, for the design of the landfill reservoir capacity, and also for description of the landfill hydrology processes.

Evaluation of the soil water regime of an irrigated maize field

This study was carried out to evaluate the soil hydrophysical properties and soil water regime of two irrigated maize fields in order to support irrigation planning and management. The experimental sites were located in Mezohegyes (MZH) and Hódmezovásárhely (HMV) in SE Hungary. In total 11 monitoring stations were chosen, using information from a previously developed, GIS-based agro-geoinformation system. In 2003 and 2004 soil sampling and in situ measurements were performed to determine the soil hydrophysical properties and soil water content dynamics. The hydraulic conductivity of the topsoil was evaluated from double ring infiltrometer measurements. A previously calibrated TDR 300 instrument and a 3T-M capacitance probe were used for quantifying the soil water content. Both types of equipment were found to require calibration and testing under field conditions before use. It was concluded that the study fields could be considered relatively homogeneous in relation to both soil hydrophysical properties and soil water regime. Thus, monitoring stations established for one or two carefully selected soil profiles could provide enough data to ensure proper decisions on irrigation. The results indicate that the soil management system and irrigation strategy used in the experimental fields ensured satisfactory soil and soil moisture conditions.

Hydrophysical properties and evapotranspiration elements of a heavy clay grassland soil

Hydrophysical properties and evapotranspiration elements of a heavy clay grassland soil

Spatial variability studies of soil hydro-physical properties using GIS for sustainable crop planning of a watershed of eastern India and its testing in a rainfed rice area

In this study soil hydro-physical properties such as soil texture, available water capacity, and organic carbon, along with existing land use and topography of a representative watershed of eastern India (Kadalipal watershed, 20.80–20.86°N and 85.54–86.50°E, Dhenkanal district, Orissa), were spatially mapped after collecting data from different sources (ground-truthing, profile survey, remote sensing satellite imagery). Since availability of water is confined to the south-west monsoon period (rainy season, June–September), eastern India is mainly mono-cropped, dominated by rice but second crops can be planned based on the soil hydro-physical properties, mainly water retention and available water of the soil profile utilising residual soil moisture. Keeping the existing land use as a base and considering the potential and prospects of soil hydro-physical properties in different topographies, in this investigation, an alternative land-use plan was developed in different parts of the watershed and tested in its rainfed rice area. Since direct measurement of available water capacity or soil water constants over a large area is time-consuming, pedo-transfer functions were also developed to predict soil water constants using easily measured parameters (e.g. cation exchange capacity, organic carbon, oven-dry bulk density, soil texture, calcium carbonate, etc.) of arable land of the watershed. Results of implementation revealed that the new cropping system was practical for increasing production, productivity, profitability, and sustainability of the rainfed rice area of the eastern India.

The influence of tillage treatments on water infiltration into soil profile

Water infiltration into the soil profile and runoff losses in arable lands are related to the condition of the top layer. The tillage treatment (included no-till) of the top layer plays a key role in changes of the hydro-physical properties, mainly saturated hydraulic conductivity (K) of the treated layer. This paper is focused on the influence of repeated tillage treatments in the same locality on K in a relatively homogeneous soil profile. The field experimental work was conducted in 1997 and repeated in 2000 after three years of repeated treatments in an experimental field of the Research Institute of Plant Production, Prague on Hapludalfs (US Classification)/Orthic luvisol (FAO). The whole experimental site was divided into four tillage treatment areas (TTA) that were maintained using different tillage treatments. A pressure ring infiltrometer (Matula and Kozáková 1997), mounted on the top of a single iron infiltration ring was used to run infiltration tests. The infiltration during the steady state flow (for a long time) was measured, evaluated and K values were calculated. Matula (2002) summarised the theoretical background for the pressure ring infiltrometer and described the final equations for evaluation of the infiltration test results. The conventional ploughing did not give any significant changes in K values after three years. Reduced till treatment and no-till treatment show a significant decrease in the infiltration rate v(t) after three years. The K value decreased approximately three times for reduced till and six times for no-till treatment. The decrease on this type of soil can cause several negative results from the aspect of surface soil hydrology and agriculture (surface runoff increase, water storage decrease, yield decrease, increase in soil compaction of surface layer, soil erosion increase).

Microstructures and physical properties of “backfill” clays: comparison of residual and sedimentary montmorillonite clays

Hydrophysical behaviour of a backfill material produced as a mixture of montmorillonite-rich clays (fine-grained fraction) and ballast material (coarse-grained fraction) is studied. Two different genetic types of clays are evaluated—bentonite, representing the residual weathering type, and sedimentary montmorillonite-rich clay. Hydrophysical properties (liquid and plastic limits, permeability and swelling pressure) were determined for mixtures of mixing ratios from 0% to 100% by weight. The microstructural study focused mainly on pore space and specific surface determination that were employed for the interpretation of the hydrophysical properties. The most favourable results were obtained for activated Ca-bentonite but sedimentary montmorillonite-rich clays yielded good quality backfilling mixtures as well. The transition from fine to coarse-fraction dominated behaviour was established for mixtures containing about 20% of clayey admixture.

Spatial structure of the temperature and salinity fields in the presence of internal waves on the continental shelf of the states of Jalisco and Colima (Mexico)

A method to filter fluctuations in the hydrophysical properties of the continental shelf, caused by intense internal tides, is proposed. The method is based on a smoothing of the field of the properties analyzed with a filter, the parameters of which are determined by the shape of the spatial correlation function of the field pulsations. The filtering method was tested on data from a fast oceanographic survey, conducted in an area of the monitoring polygon of the waters around Barra de Navidad. The survey was conducted on 25 and 26 November 1995, with an undulating CTD. In one day, 86 vertical profiles of temperature and salinity were obtained from nine transects perpendicular to the coast (survey area of 100 · 25 km) to a depth of 100 m. The filtering algorithm of the internal waves is studied in detail. The field measurements present an analytical shape obtained from an equation in which the elements describe the components: low frequency, pulsating and related to daily behavior. The results of the analysis of the initial temperature and salinity fields with respect to homogeneity and isotropy are discussed, as well as the structural peculiarities of the estimates of the spatial correlation functions. It is observed that the temperature and salinity fields along the shelf, within the limits of the polygon scale, are neither homogenous nor isotropic. The correlation functions of the field pulsations analyzed are more clearly observed in the thermocline. The characteristic scales perpendicular to the coast are smaller than along it. Examples of smoothing the temperature and salinity fields in the thermocline are given.

Vegetation, soil hydrophysical properties, and grazing relationships in saline-sodic soils of Central Argentina

Land use and grazing regime can influence the dynamic of soil water and salt in humid areas. In Central Argentina, more than 2 ×106 ha are subjected to either permanent or cyclical processes of land salinization, alkalinization, flooding and sedimentation. In this region, the natural vegetation is the principal resource on which most systems of animal production are based. The objective of this study was to evaluate the effects of plant cover and grazing over some hydrophysical properties of three saline-sodic soils (two Gleic Solonetz in duripan phase and one Mollic Solonetz in fragipan phase), within a catena sequence. The effects on bulk density, saturated hydraulic conductivity, infiltration runoff, superficial salt accumulation and soil salinity distribution were determined in both bare and covered soil conditions, inside and outside of grazing exclosures. The results showed increased bulk density of topsoil for bare conditions, while saturated hydraulic conductivity did not show significant differences. In soils without any cover, the infiltration decreased significantly. Consequently, the runoff coefficient and salinity were greater, as indicated by significant salt accumulation in the topsoil. The soil profile salinity was reduced as a function of exclosure time, showing a trend toward desalinization resulting from a combined effect of soil cover and changes in intensity of land use. A conceptual model of salt and water dynamics in the soil profile for the landscape scale is postulated. The role of vegetation in regulating water and salt movement in poorly drained areas is emphasised as a basis for the development of management strategies. Key words: Saline and sodic soils, infiltration, runoff, grazing, exclosure, model