Hydrophysical Properties Research Articles

Spatial variability of hydrophysical properties of fallow sandy soils

AbstractSpatial heterogeneity of soil hydrophysical properties was estimated in 2 fallow sandy soils at Csólyospálos and Örbottyán, Hungary. Significant differences in small particle (= silt + clay) content (5.0% vs. 13.7%), organic matter content (1.62% vs. 0.91%), and CaCO

Verification of Appropriateness of Selected Pedotransfer Functions for the Basic Use in Agriculture of the Czech Republic

Soil is a huge reservoir of water used by plants in periods without precipitation and significantly affects the hydrological balance of any territory. To evaluate the hydrological balance of any piece of the land given, it is therefore necessary to carry out the analysis of the hydro-physical conditions. To speed up and simplify the determination of basic hydro-physical properties of soil man developed and began to use the so-called pedotransfer functions (PTF). Comparison of domestic and foreign works, however, faces problems such as the definition of available water supplies in different countries. In the research project “Specification of the available supplies of nitrogen and water in the soil profile and determining the effective depth of crops’ roots” we have dealt with the selection of suitable pedotransfer functions necessary for basic agricultural production with the requirement of minimal amount of input data. For our research we chose several PTFs developed and used in the Czech Republic for a long time, with a minimum of input data, and several new PTFs from foreign authors with greater correlation, but also a greater need of input data, and we compared each other. The best correlation between values and the pedotransfer function for the field water capacity and for the wilting point seems to be the PTF according to Tomasella and PTF according to Batjes. Pedotransfer function according to Váša, in terms of volume of input data, appears better.

Least limiting water range and soybean yield in a long-term, no-till, integrated crop-livestock system under different grazing intensities

Crop-livestock integrated systems possess some uniqueness in soil and plant hydro-physical properties and processes. To obtain a better understanding of these systems, it is necessary to evaluate them with indices that take into account several attributes. Our study aimed to evaluate the efficiency of the least limiting water range in determining the influence of grazing intensities on soybean yield in an Oxisol managed in a long no-till, integrated soybean-beef cattle system. We evaluated an 11 year trial located in southern Brazil, with soybean summer cropping and black oat+Italian ryegrass winter grazing and different winter grazing intensities, namely intensive, moderate and no grazing. Intensive grazing only results in the most superficial soil layer compaction. Long-term moderate grazing, on the other hand, leads to intermediate compaction, not negatively affecting surface or subsurface soil physical properties. The least limiting water range is an inadequate indicator of soil physical quality in integrated soybean-beef cattle system, provided no direct relations with soybean yields. Under normal rainfall conditions, soybean yield depend mainly on rainfall amount and distribution, rather than on soil quality.

The effect of paper sludge and biochar addition on brown peat and coir based growing media properties

Peatlands are crucial sinks for carbon in the terrestrial ecosystem, but they are jeopardized by their use as fuel or as growing media. Much research has been performed aiming to find high quality and low cost substrates from different organic wastes, such as coir, compost, sewage or paper sludges, and thus decrease peat consumption. The main objective of this work is to study the effect on peat and coir-based growing media of deinking sludge (R) and biochar obtained by pyrolysis of deinking sludge at 300°C (B300). For this reason, mixtures of peat or coir with deinking sludge and corresponding biochar were prepared mixing them at 50/50 v/v ratios. The results showed that it is possible to improve the chemical and hydrophysical properties of peat and coir with addition of biochar and deinking sludge. Indeed, biochar increased air space, water holding capacity and total porosity of peat-based growing media whereas for coir, the best hydrophysical properties were obtained after deinking sludge addition. Finally, the use of biochar plus peat as growing media can increase lettuce yield by more than 100% with respect to peat growing media, which can be related with the improvement of hydrophysical growing media properties. This yield increment along with the reduction of the over-exploitation of peat can justify the use of biochar as growing media in spite of the cost associated to the pyrolysis process.

Soil water dynamics and hydrophysical properties of regenerating Sphagnum layers in a cutover peatland

AbstractThe physical and hydrological conditions in extracted peatlands often act as barriers to the regeneration of the keystone peat‐forming genus Sphagnum. Although previous work has suggested that Sphagnum mosses regenerating on cutover peat surfaces quickly become vulnerable to water stress as the thickness of the regenerated layer increases, uncertainties regarding the storage and transmission properties of this layer and how these might evolve over time have made this assertion difficult to evaluate. This study investigates the hydrophysical properties and hydrological behaviour of regenerating Sphagnum layers ranging from 3 to 43 years in age using both field and laboratory methods. The >40‐year‐old regenerated layers had significantly (p < 0.001) higher bulk density and retention capacity in the 5‐cm‐thick basal layer directly overlying the cutover peat than the newer (<10 year old) regenerated layers. Capillarity was a much stronger control on surficial water content (θ) than precipitation, which was poorly retained in the Sphagnum canopy, suggesting that regulation of water table position is an effective method of controlling θ as a means of optimizing productivity. In general, the θ sustained at a given water table position decreased as regenerated layer thickness increased. Analysis of water table position relative to the former cutover peat surface in different areas of the site suggests that the soil water dynamics of the >40‐year‐old regenerated layers may be becoming increasingly similar to those of a natural bog peatland. Copyright © 2015 John Wiley & Sons, Ltd.

Exploring influence of spatial variability of soil hydro-physical properties on crop yield

Utilizing spatial variability in soil properties to make decision of various farming technologies has been explored. The objective of the work is the development of approaches taking into account spatial variability of hydro-physical properties of soils during plant’s production process simulation (wheat crop) using the AGROTOOL – the crop simulation model – in order to support decision making in practical adaptive landscape agriculture. The studies were conducted using a software package, which was based on coupling GIS with AGROTOOL. Impact of spatial variability of soil hydro-physical properties on crop yield has been evaluated.

Burn severity alters peatland moss water availability: implications for post‐fire recovery

AbstractWildfire is the largest disturbance affecting northern peatlands; however, little is known about how burn severity (organic soil depth of burn) alters post‐fire hydrological conditions that control the recovery of keystone peatland mosses (i.e. Sphagnum). For this reason, we assessed the impact of burn severity on moss water availability by measuring soil tension (Ψ) and surface volumetric moisture content (θ) in burned and unburned portions of a peatland complex 2 years after fire. We found that both high and low burn severity decreased post‐fire water availability by altering peat hydrophysical properties (moisture retention and water repellency). Locations covered by Sphagnum fuscum prior to fire exhibited a decreasing post‐fire water availability with an increasing burn severity. In contrast, the lowest water availability (Ψ > 400 cm, θ < 0·02) was observed in feather mosses that underwent low burn severity (residual branches identifiable). Deep burning (>0·20 m) in peatland margins and burn depths >0·05 m in the middle of the peatland exhibited the highest water availability (Ψ < 60 cm). Locations with low surface θ and high Ψ, notably feather mosses undergoing low burn severity, exhibited minimal moss recolonization. Such areas dominate post‐fire surface cover (~40%) within late successional (mature) peatlands or peatlands located in dry hydrological settings. We argue that such environments are under‐represented in conceptual models of post‐fire recovery. A new conceptual model is proposed in which (1) deep burning is counterbalanced by rapid recolonization and (2) pre‐fire species interact with burn severity to produce substantial lags in post‐fire moss recovery. Copyright © 2015 John Wiley & Sons, Ltd.

Experimental study to evaluate the effect of travertine structure on the physical and mechanical properties of the material

Geology, hydrophysical properties, and mechanical behavior of two main varieties of ornamental stones in Algeria have been studied in detail. Travertines and onyx in western Algeria are summarized to two large layers, the Bouhanifia and the Ain Takbalat deposits. Their formation is related to the hydrothermalism following the great fault of Tafna. The travertine formed in water overflow while onyx is set up along the lines of outputs of the sewage of dissolved CaCo3. The results obtained show a good correlation between petrography and the mechanical behavior; the bedding planes and laminations of the travertines give a petrophysical anisotropy across the sample. Two types of mechanical testing: compressive and flexural strength were carried out either parallel or perpendicular to the veins. This test showed that mechanical behavior is guided by the nature, thickness, composition, and orientation of the veins.

Impacts of donor-peat management practices on the functional characteristics of a constructed fen

The reclamation of fen peatlands on post-oil sand development landscapes involves the transfer of peat from a donor fen to form the upper 2m of a sediments-filled pit resulting from open-pit mining. The placed peat serves two major functions of attenuating the upwelling of dissolved solutes from the underlying tailing sediments to the rooting zone, and as fen vegetation establishment substrate. However, the modifications (e.g., decomposition and fragmentation) resulting from salvage and transfer practices (e.g., dewatering and loading/placement with earth-moving equipment) could impact the potentials of the placed peat to support ecohydrological functions in the constructed fen. Thus, we conducted a study to evaluate the impact of these practices on the biogeochemical and hydrologic functioning of a constructed fen. Peat cores were extracted along transects in the donor fen before peat transfer, and after placement in the constructed fen. Cores were also taken from a natural reference site to serve as the nearest possible comparison to donor site conditions prior to dewatering. The cores were subsampled and analyzed for selected physicochemical and hydrophysical properties. Relative to the reference site, our results indicates a higher surface bulk density, and accelerated mineralization of organic-bound nutrients in the dewatered donor peat. Following transfer of peat to the constructed fen, changes in hydrophysical properties were reflected in a reduction of the horizontal/vertical anisotropy ratio from 1.5 to 1, which could impact the vertical fluxes of water. However this impact is likely less than that of the heterogeneity associated with the fragmentation of the placed peat. Hence, we recommend some management practices that can alleviate the modifications resulting from contemporary operational practices.

Ecohydrological controls on water distribution and productivity of moss communities in western boreal peatlands, Canada

AbstractDifferent peatland mosses have varying strategies for water storage and capillary rise mechanisms depending on their particular hydrophysical properties and preferred water sources. To understand these strategies, the retention and redistribution of water from various sources in Sphagnum, feather and Tomenthypnum moss communities were addressed through investigation of the sensitivity of moss moisture dynamics to environmental variables, field surveys and a drought stress experiment. Feather mosses preferred habitats well above the water table, and their relatively low volumetric water content (θ) increased only with precipitation events. The relatively high residual θ (0·22) of Sphagnum capitula helped the moss type maintain conditions suitable for photosynthesis over a range of water table conditions. Tomenthypnum mosses occurred over a broader range of water table positions than Sphagnum or feather mosses because of their ability to use both capillary rise and atmospheric water for growth. While Tomenthypnum had relatively low near‐surface θ (~0·10), evaporative losses were sustained by both small nocturnal additions by condensation of vapour and upward capillary rise. An intermediate layer of partially decomposed mosses supported contact with the underlying peat and helped transport sufficient water to the Tomenthypnum moss surface. However, Tomenthypnum θ and productivity changes were more sensitive to rainfall additions as the uppermost portion of moss shoots can easily desiccate under typical evaporative demand. As a result, nocturnal sources of atmospheric water from dew (~0·15 mm per night) and distillation (~0·10 mm per night) provided temporary relief from desiccation for potentially important early morning photosynthesis and helped drive evaporation and capillary rise. Copyright © 2015 John Wiley & Sons, Ltd.

Hydro-Physical Properties of Soil Treated with Rice Straw-Based Hydrogels

The Present work deals with evaluating rice straw (RS)-based hydrogels, as conditioners for improving the hydro-physical properties of sandy calcareous soils. In this respect, some hydro-physical properties of the soil were examined at the end of three successive growing seasons. Completely randomized field experiments, with three replications for each treatment, were conducted at El-Saff-Giza Governorate, Egypt (summer season 2010 using tomatoes v. cusstle rock, winter season 2010-2011 using wheat v. Seds 1 intercropped with onion v. Giza 20, and summer season 2011 using caw pea v. Bafb as indicator crops), The results obtained show that, applying the RS-based hydrogels provides: (a) Improving in soil structure, which was expressed by water stable structural units (> 0.25 mm in diameter), structural coefficient, dry stable structural units (> 0.84 mm in diameter) and wind erosion parameters. This improvement indicates the high resistance of the soil against both wind and water erosion, as well as destruction of the soil by tillage operations. Moreover, it leads to decrease soil bulk density and macroporosity (drainage pores) on the expense of micro ones. Therefore, water holding pores (the retained moisture in the soil) were increased. Increasing the retained moisture in the soil was noticed at all suctions under study (from 0-15atm). (B) Decreasing the mean diameter of soil pores and in turn its water transmitting properties, namely hydraulic conductivity and transmissivity for vertical flow of water through soil profile. (C) Doubling the rate of applied hydrogels from 2gkg-1 to 4gkg-1 soil leads to great improvement in hydro-physical properties of soil, whereas applying the later rate of hydrogel provides improvement in moisture retention of the treated soil to become over than the requirements of the growing plants. Also, it has adverse effect on the aeration of the root zone as a result of increasing the soil micro-porosity on the expense of its macro ones. Therefore, 2g hydrogel kg-1 soils is recommended dose to get use the RS-hydrogels as benefit soil conditioner, without adverse effects on growth, water and fertilizers efficiency by plants.

Soil water capacity, pore-size distribution and CO2 e-flux in different soils after long-term no-till management

Little is known about the effects of modern soil management practices, especially no-tillage, on soil physical state, soil pore size distribution and soil water capacity after a long-time of successive application on different soil types. The investigations were performed in 2014 at the Institute of Agriculture, Lithuanian Research Centre for Agriculture and Forestry in Central Lithuania’s lowland on a sandy loam-textured Endocalcari-Epihypogleyic Cambisol (CMg-p-w-can) and at the Experimental Station of Aleksandras Stulginskis University on a silt loamtextured Endohypogleyic-Eutric Planosol (PLe-gln-w). The goals of this paper were a) to compare soil water capacity, soil pore-size distribution and CO 2 e-flux in Cambisol and Planosol, b) to evaluate the effect of long-term no-tillage application in combination with and without residue management on hydro-physical properties of soils with different genesis and c) to assess the suitability of such management practice for practical use. Regarding different soils genesis, the lower bulk density and higher total porosity were registered within 0–20 cm depth in Planosol than in Cambisol, while Cambisol was better aerated than Planosol due to a greater space of macropores. A risk of waterlogging condition may occur in Planosol due to a greater share of meso- and microporosity within 5–35 cm soil depth, compared to Cambisol. No-tillage application with crop residue returning was more suitable on Cambisol than on Planosol. This soil management system increased volumetric water content in the soil and CO 2 e-flux. No-tillage with residue removal on Cambisol conditioned soil CO 2 e-flux increase when volumetric soil water content ranged from 0.159 to 0.196 m 3 m -3 . When soil water content increased up to 0.220–0.250 m 3 m -3 , the e-flux peak was reached at which the further CO 2 e-flux sloped down. On Planosol, the soil CO 2 e-flux peak ranges were lower, i.e. approximately 0.170–0.200 m 3 m -3 . Long-term residue returning onto soil surface on Planosol acted as a physical obstruction inside mesopores in 5–10 cm and within macropores in 5–10 and 15–20 cm layers and, finally, causing clogging them. Increase of soil surface volumetric water content in Planosol caused a decrease in soil CO 2 e-flux.

Assessment of the agrochernozem status in trans-Ural steppe under application of No-Till management system

It was shown that the agrochernozems of trans-Ural steppe (Bashkortostan) used under conditions of the No-Till system (NT) from 4 to 19 years are marked by favorable hydrophysical properties for the growth and development of plants and medium and high humus content, but, on the other hand, by the lack of nitrogen and, especially, phosphorus. Slightly eroded agrochernozems occupied by eastern galega for 19 years are similar in their properties to noneroded ones; noneroded chernozems treated with the use of NT technique are similar to the virgin analogues.

Modification of sandy soil hydrophysical environment through bagasse additive under laboratory experiment

Abstract Until now sandy soils can be considered as one roup having common hydrophysical problems. Therefore, a laboratory experiment was conducted to evaluate the influence of bagasse as an amendment to improve hydrophysical properties of sandy soil, through the determination of bulk density, aggregatesize distribution, total porosity, hydraulic conductivity, pore-space structure and water retention. To fulfil this objective, sandy soils were amended with bagasse at the rate of 0, 0.5, 1, 2, 3 and 4% on the dry weight basis. The study results demonstrated that the addition of bagasse to sandy soils in between 3 to 4% on the dry weight basis led to a significant decrease in bulk density, hydraulic conductivity, and rapid-drainable pores, and increase in the total porosity, water-holding pores, fine capillary pores, water retained at field capacity, wilting point, and soil available water as compared with the control treatment

Preparation of molded sorption materials based on peat-mineral compositions

In this work, the use of peat and wastes and products of its processing as sorption materials for the removal of water- and oil-based contamination has been investigated. The negative effect of hysteresis phenomena appearing during drying on the hydrophysical properties of peat has been noted. The use of optimal concentrations of mineral hydrophilic additives in a peat matrix allows the rate and capacity of sorption to be increased. A working hypothesis that explains the physicochemical mechanism of the increase in qualitative parameters of composition sorbents has been suggested. A flow diagram of the formation of peat-based sorption materials that assumes possible transitions between the steps of flow process has been worked out.

Evaluating water balance elements for hydromorphic landscapes by hydrophysical properties of soil cover

A method is proposed for evaluating a dimensionless parameter reflecting the landscape conditions of runoff formation in the method of hydroclimatic calculations. This method allows the hydrological characteristic of landscape to be evaluated at different stages of hydromorphic transformation. The determination of the dimensionless parameter by landscape profile laid through Kruglyi Riam—a growth center of the Bakcharskoe Bog—is based on the known values of field and maximum moisture capacity of the active layer of soil cover.

Improvement of the Wettability Properties of Compost Using Seaweed

ABSTRACT. Composting substrate components from a wide variety of organic materials are becoming more prevalent in ornamental growing medium mixes. Hazelnut husk (HH) and seaweed (HHSW) composts were investigated for their different hydro-physical roles in substrate dynamics. The water repellent material HH was composted either solely or mixed with seaweed (1:1 by volume) and the hydro-physical properties related to the water retention and wettability of the two composts were evaluated using the water drop penetration (WDPT) and molarity of ethanol droplet (MED) tests and contact angle (θ) determination. The addition of seaweed to the HH compost mixture had positive effects on the water holding capacity, water conductivity, air porosity, and wettability characteristics compared to pure HH compost. Although both composts exhibited signs of hydrophobicity under dry conditions, the repellency rate was more severe in the pure HH compost. The wettability tests results indicate that seaweed improved the hydrophobicity of HH compost by at least two ranking classes, from severe hydrophobicity to moderate hydrophobicity. Also, the contact angle reduced from 107° to 103° by composting seaweed. Seaweed was found to have an influence on the hydrological properties when incorporated as a compost component with the HH substrate.

Characterization of maleated vegetable oils for insulation purposes and agricultural applications

Two maleated vegetable oils based on castor and soybean oils (COMA & SOMA) in addition to aliphatic polyester based on propylene glycol and succinic acid (PPS) were prepared and characterized by means of infrared (IR), nuclear magnetic resonance ( 1 H NMR) and thermogravimetric analysis (TGA). TGA data indicates that SOMA is more thermally stable than COMA and PPS. The electrical properties of the prepared materials were investigated through the permittivity ('), the dielectric loss ('') and the elec- trical conductivity () in a frequency range 10-1—10+7 Hz. The obtained data were found to follow the trend COMA > SOMA > PPS. The relaxation mechanisms of such systems were also studied through the dielectric modulus M', including the real and imaginary parts (M' and M''). The effect of the prepared materials on the hydrophysical properties of the sandy soil when supplemented with different concentra- tions (1—5 wt %) was studied by bulk density, total porosity, water holding capacity, field capacity, hyd- raulic conductivity and water stability aggregates. These hydrophysical properties were improved by increasing the concentration of the added materials, which can be explained in terms of the penetration resistance in relation to friction and cohesion forces. These improvements in the hydrophysical properties of the sandy soil render it suitable for plant growth.

Multimedial Study Guide of Field Hydropedological Measurements

Soil hydropedological data measured in situ provide an essential base for basic and also applied research in hydrological, water management, landscape and environmental disciplines. Quality of the measured data is a critical value determining the quality of results and derived conclusions. The knowledge and practical experience of the technician performing the measurements is presenting the human factor, which affects the quality of measured data most. The Multimedial Study Guide of Field Hydropedological Measurements (further referred to as “the Guide”) was created to present and explain selected field measurements determining soil physical and hydro-physical properties in a comprehensive, didactical and user-friendly way. The following topics are introduced: i) Soil sampling (disturbed and undisturbed soil samples), ii) Soil moisture content measurement using indirect non-destructive methods, iii) Determination of tensiometric soil water potential, iv) Measurement of saturated soil hydraulic conductivity in-situ with available groundwater level in measured layer and without available groundwater level in measured layer, v) Measurement of unsaturated soil hydraulic conductivity, and vi) Basic presentation of lysimetry. The Guide was for students, and also for academic workers and other interested members of the public. The English version enables everyone to use these guidelines and carry out each particular measurement, as well as evaluate and present the measured data correctly. The students of the Czech University of Life Sciences Prague use this Guide as a regular learning material in subjects dealing with soil and water relationship since 2012. Now, the 2nd revised edition is presented. The Guide is available on the internet (http://hydropedologie.agrobiologie.cz) and DVD (on request).

Selection of consolidants for the polychrome clay sculptures in the Guanyin Temple, Sichuan, China

Keywords: Polychrome clay sculptures of Guanyin TempleConservation materialsSelectionConsolidationMaterial application關鍵詞 :: 觀音寺彩繪泥塑補塑材料篩選加固材料應用