Hydrophysical Properties Research Articles

Comparative analysis for three models of hysteretic water retention capacity using data on silty soil

The most important of the hydrophysical properties is the water-retention capacity of the soil. This property is formulated as a relationship between the volumetric moisture of the soil and the capillary pressure of soil moisture. Three hysteresis models of soil water-retention capacity are presented. The parameters were identified by point approximation of experimental data (from an authoritative literary source) on the main (boundary) drying and wetting branches of the soil «2003 Silt of Nave-Yaar» using the «SoilHysteresis-v.1.0» computer program developed by the authors. Applying the condition of equality of the values of the exponential parameter for the branches of draining and moistening eliminates the undesirable (methodical) «pump effect». A comparative analysis of hysteresis models based on the identification of significant differences between the errors of the point approximation of the experimental data by the Williams-Kloot test. The advantages of models in which an additional additive parameter is used are revealed. The use of physically justified models of hysteresis of the water-retention capacity of the soil has prospects in the development and application of resource-saving technologies in precision reclamation agriculture.

Comparison of three systems of soil hydrophysical functions on example of silt loam

Three systems of functions are used to describe the water-retention capacity and the ratio of the hydraulic conductivity of the soil to the moisture filtration coefficient (relative hydraulic conductivity of the soil). Each of the three systems uses an appropriate set of parameters. These parameters are common to each pair of functions that make up the corresponding system. The parameters of the first system of functions are formal in nature and are used in the Mualem-Van Genuchten method. The parameters of the second and third systems have a physics-statistical interpretation. The main purpose of the considered systems is to predictively evaluate the values of the relative hydraulic conductivity function using parameters identified by the point approximation of data on the water-retention capacity of the soil. Using the soil example «3304 Touchet silt loam» from the Mualem catalog, three systems of functions are compared. In order to identify significant differences between the errors of the compared function systems with respect to the point approximation of data on water-retention capacity, as well as for predictive estimates of the values of the function of the relative hydraulic conductivity of the soil, the Williams-Kloot test is used. The influence of the additive parameter describing the capillary pressure of the «air inlet» on the errors of the second and third systems is estimated. The results of the study indicate the advantages of the second and third systems over the first system, the functions of which are used in the Mualem-Van Genuchten method. The third system is formulated in the form of fairly simple relationships using elementary mathematical functions and is recommended for modeling the hydrophysical properties of the soil and solving problems of ameliorative farming.

Correction: Effects of conversion of native cerrado vegetation to pasture on soil hydro-physical properties, evapotranspiration and streamflow on the Amazonian agricultural frontier.

[This corrects the article DOI: 10.1371/journal.pone.0179414.].

Testing the effect of AQUASORB and nitrogen rates on yield, nitrogen and water use efficiencies of wheat and hydro-physical properties of soil in Sudan Savanna, Nigeria

The effect of supplementary irrigation (SI) rate and planting date on water use efficiency of potato (Solanum tuberosum L.) was conducted during the 2017 and 2018 cropping seasons at the Research Farm of the National Root Crops Research Institute (NRCRI) Kuru, Jos in Plateau State, Nigeria. The treatments consisted of two planting dates (2nd week of April, 2nd week of May) and four levels of water application (W1 = Control, W2 = SI of 200 m3 W3= SI of 400 m3, W4 = SI of 600 m3). The factors were combined to give 8 treatment combinations that were laid out in a 2×4 split plot arrangement in a Randomized Complete Block Design (RCBD) and replicated three times. Water use efficiency of potato was computed using formulae. Crop and water use efficiency data collected were subjected to Analysis of Variance (ANOVA. Planting of potato in April uses water more efficiently and also gave higher potato yield. Interaction effect of planting in April x 400 m3 SI gave higher water use efficiency of potato. It is recommended that potatoes should be planted in the second week of April and rainfall augmented with 400 m3SI rates, especially at the period of dryspell.

Does the Process of Passive Forest Restoration Affect the Hydrophysical Attributes of the Soil Superficial Horizon?

There has been an increase in the area of secondary tropical forests in recent years due to forest restoration in degraded areas. Recent analyses suggest that the success of passive forest restoration is highly uncertain and needs to be better understood. This study aimed to investigate the behavior of saturated hydraulic conductivity (Ks) and some hydrophysical soil attributes between agricultural land uses, restored forests, and a degraded forest fragment. The areas evaluated are located in the municipality of Rio Claro, São Paulo, Brazil, under different types of land use: (i) two areas in the process of passive forest restoration: one of 18 and another of 42 years (NR18 and NR42); (ii) a degraded forest fragment (FFD); (iii) pasture (P), and (iv) sugarcane (SC). The hydraulic soil conductivity characterization was performed using the Beerkan method. Dry soil bulk density (BD), total porosity (Pt), macroporosity (Mac), microporosity (Mic), penetration resistance (PR), mean aggregate diameter (MWD), and soil organic carbon (OC) were also determined. The comparative analysis of the hydrophysical attributes of the soil superficial horizon in agricultural land uses (P and SC), restored forests (NR18 and NR42), and a degraded forest (DFF) confirms that the recovery of soil hydrological functioning in ongoing forest restoration processes can be a relatively slow process. In addition, the intensity of previous land use leaves footprints that can affect passive restoration areas for decades after agriculture abandonment, increasing the time for the recovery of Ks and soil hydrophysical attributes.

Impact of Tillage and Residue Management on Hydro-physical Properties of Clay Soil under Rice-wheat Cropping System in Indo-Gangetic Plains of India

A field experiment on the residual impact of tillage operations and organic residues incorporation on hydro-physical properties of clay soil under the rice-wheat cropping system in split-plot design with three replications was carried out at the experimental farm of BAU, Sabour. The treatments of tillage operations and application of organic residues, along with their interactions, significantly decreased the soil strength/compaction and consequently bulk density of the soils over control. It was confirmed by the positive and highly significant correlation of soil strength with the bulk density (r = 0.802**). The maximum decrease was noted under T3 (Mould board plough) and C6 (GM + rice husk) and their interactions. A significant decrease in clod size was observed under treatments T3 and C6 and their interactions over control. The maximum increase in stable water-stable aggregates was estimated under treatments T3 and C6 and their interactions (T3 x C6) due to an increase in porosity and decrease in compaction of the soils which led to increasing in hydraulic conductivity. This was further confirmed by a positive and highly significant correlation of hydraulic conductivity with MWD (r = 0.788**) and negatively and highly significant correlation with compaction (r = -0.646**) and BD (r = -0.846**). It was revealed that the soil moisture content showed a variable increase with variable depth and observed their maximum values in T4 (28%) and C6 (29%) treatments at 45-60 cm depth of the soils. The increase in yield of wheat grain was highest under the influence of treatments (MB) T3 and C6 (GM + rice husk) and their interaction. These observations were further confirmed by the positive and highly significant correlation of yield of wheat grain with MWD (r = 0.514*) and HC (r = 0.482*) and negative and highly significant correlation with soil strength (r = -0.649**). The most effective treatments were T3 and C6 and their interactions, while minimum improvements were noted under T1 (desi plough) and C3 (paddy straw) and their interactions.

Polymerasphaltconcrete together with the use of modified effective components

In this paper, we consider the possibility of joint use of polystyrene, its block copolymers and transformer oil to produce polymerasphaltconcrete. It is established that the properties of bitumen change when different polymers and their quantity are introduced into its composition. It was found that the introduction of polystyrene together with a plasticizer expands the temperature range of operation, which leads to an improvement in the physical-mechanical and hydrophysical properties of polymerasphaltconcrete. The regularities of the influence of the composition and quantity of polymers on the physical, mechanical and operational properties of asphalt concrete based on modified binders are revealed. It was found that the optimal amount of polymers and plasticizer is 3.5% and 10% of the mass of bitumen.

Intensive Ways of Producing Carbonate Curing Building Materials Based on Lime Secondary Raw Materials

The article is dedicated to the research and development of intensive methods for curing products by capturing and binding CO2. It aims to improve and increase the productivity of technologies for the production of artificially carbonated building materials and products. Soda production wastes, limestone dust and finely dispersed limestone dust were used as the research objects. Secondary raw materials have been investigated using modern methods of phase composition and granulometry test. Intensive methods of production of accelerated carbonation of systems consisting of soda wastes were tested using multi-parameter optimization methods. The effects of recycled lime materials on the strength and hydrophysical properties of the obtained material were determined. The secondary raw materials effect depended on the composition of the raw mixture, molding conditions, CO2 concentration applied to the carbonate curing chamber, and the duration of exposure to environments with high CO2 content. It was found that the most effective way of providing accelerated carbonation curing of construction materials and products is a combined carbonation method, combining the principles of dynamic and static methods. It was concluded that the optimal CO2 concentration in the gas-air mixtures used for carbonate curing is 30%–40%.

Evaluating the Effects of Biochar and SAP Polymer on Soil Physical Quality Indices

ABSTRACT The aim of this study was to examine the effects of soil amendments to sandy loam and soil physical indices, mainly soil aggregates, soil retention curve, and pore size distribution. Date palm waste biochar at rates 2% (B1), 4% (B2), 6% (B3), and 8% (B4) and sorbent adsorption polymer (SAP) at rates 0.2% (P1), 0.4% (P2), 0.6% (P3), and 0.8% (P4) (w/w). In addition, the combination of both as B1:P1, B2:P2, B3:P3, and B4:P4, were added to the soil as amelioration materials. The results revealed that on the average, soil water content increased by 7.3%, 3.3%, and 15.0% with the addition of biochar, polymer, and the combination, respectively. The location parameters dmode, dmedian, and dmean decreased by 6.4%, 8.8%, and 10.6% for the biochar, and increased by 2.3%, 4.6%, and 3.4% for the polymer treatments, decreased by 4.8%, 4.4%, and 4.2% for the combination treatments, respectively. Shape parameters such as standard deviation (SD), (spread) skewness (asymmetry), and kurtosis (peakedness) were 2.2, – 0.27, and 1.6 for the biochar treatments, 2.17, – 0.27, and 1.6 for the polymer treatments, and 2.17, – 0.23, and 1.6, for the combination treatments, respectively. The aggregate stability (SA) of soils of size 0.25 and 0.13 mm increased by 50.8% and 50% with the application of biochar (B2 = 4%) and polymer (P2 = 0.4%) B2:P2 and polymer (P4 = 0.8%) P4 treatments, respectively. This study recommends using combination of biochar with polymer treatments on sandy loam soil in arid area due to its strong hydro-physical properties.

Soil hydrophysical properties as affected by kind of added polymer.

Laboratory experiments were carried out to clarify the impact of different types of natural and synthetic polymers on some hydrophysical properties (soil hydraulic parameters) of a sandy soil. Adding 0.5% (w/w) of each treatment to soil significantly increased water retention at saturation, field capacity, total available water and readily available water. This treatment decreased the value of inflection point on water retention curve as result of enhancing water behavior in the soil. The obtained results revealed that soil water storage significantly increased from 0.271 in control treatment (without adding polymer) up to 0.414 in treatment [T10] (Acrylic acid + Xanthan) while, field capacity increased significantly from 0.078 in control up to 0.242 of the abovementioned treatment (T10). Regarding the effects of polymer application in total available water and readily available water, data revealed significant increases in the above mentioned parameters. Total available water increased from 0.044 in control treatment up to 0.153 in T10 and readily available water increased from 0.057in control treatment up to 0.185 in T10. Concerning values of inflection point on soil water retention curve, the obtained results revealed that, inflection point of control treatment (1000 mbar) decreased to 590 mbar, as a result of adding a mixture of polymer acrylic acid + xanthan (T10 ).Soil depletion rate decreased as due to polymer application by 25% up to 75% depending on type of polymer and wether it was added individually or in combination with another polymer. This effect led to significant differences among control treatment (control) and the other treatments. Generally, there were significant effects of all polymers on the concerned hydrophyical properties of the studied sandy soil, i.e. storage capacity of soil water, depletion rate of soil water, soil field capacity , soil available water, readily available water and inflection point on the soil water retention curve. Acrylic acid recorded the best results concerning soil water behavior if it was added individually to the sandy soil (Treatment 2) or in combination with Xanthan (Treatment 10) or with Lignosulphonate (Treatment 11).

Hydrophysical properties of sandy clay contaminated by petroleum hydrocarbon

The aim of the presented research was to assess the changes in hydro-physical properties of sandy clay under the influence of petroleum hydrocarbon contamination. An understanding of these changes is fundamental in the right remedial actions and for further use of soil. Laboratory tests of inherently wettable sandy clay showed that the petroleum hydrocarbon induced potential soil water repellency (SWR) of extremely repellent class at the contamination of 18 g kg−1. The relationship between soil water potential (pF) and SWR determined by the WDPT test for given hydrocarbon contamination, i.e., 6, 12, 18, 30, 100 g kg−1, showed that the critical soil moisture value (CSMC) corresponds to the pF = 1.0 ÷ 1.5. Soil retention characteristic (pF) showed that an increase in hydrocarbon contamination from 0 to 100 g kg−1 caused a reduction of total available water for plants from about 0.19 to 0.06 cm cm−3. At the same time, in the pF = 1.5 ÷ 2.0 range, intensive soil pore drainage was observed. Statistically, significant effect of hydrocarbon contamination and soil moisture potential on SWR was found. Soil hydrophobicity limits the addition of soil retention, because a significant part of the precipitation can be transformed by surface runoff. The carried out tests showed that at a hydrocarbon contamination of 30 g kg−1, total rainfall amount 14 mm with an intensity of 2 mm h−1 was transformed into a surface drain in approx. 40%. The conducted studies demonstrate the adverse impact of hydrocarbon contamination on the soil’s hydro-physical properties. The soil water retention reduction and launching of the surface outflow, as a result of limiting the water penetration process resulting from SWR, change the agrohydrological conditions of the contaminated area. It can result as the imbalance of the flow of energy and matter in the ecosystem. The scenarios of environmental effects, among others, depend on the type of soil, the degree of its pollution, the type of ecosystem, and supporting activities undertaken by man. It should be taken into account that the increasing frequency of drought occurrence associated with climate change is conducive to the phenomenon of SWR regardless of the reasons for its occurrence.

Modeling the hydrophysical soil properties and comparative analysis for three systems of functions

A functional description of the hydrophysical properties of the soil as a capillary-porous medium is presented. The described functions of water retention capacity and hydraulic conductivity of the soil have common parameters, which are interpreted within the framework of physical and statistical concepts. The practical significance of the proposed functions lies in the fact that the volume of labor-intensive field measurements necessary, for example, for modeling the dynamics of soil moisture, is significantly reduced. To identify the parameters of these functions, it is sufficient to use data only on the water retention capacity of the soil. The parameters identified in this way can be used to predict the ratio of the hydraulic conductivity of the soil to the moisture filtration coefficient. The presented system of the hydrophysical functions of the soil is compared with world analogues using literature data on soils of different texture.

СТРОИТЕЛЬНЫЕ МАТЕРИАЛЫ НА ОСНОВЕ ИЗВЕСТКОВОЙ ПЫЛИ И МЕЛКОДИСПЕРСНОГО ИЗВЕСТНЯКА

The paper presents research on the development of building materials with low CO2 emissions based on industrial man-made materials. The optimal recipe-technological parameters for the production of materials based on lime dust generated by mechanical deposition in cyclones and bag filters of shaft furnaces, as well as finely divided marble-like limestone with a fraction of up to 5 mm were determined. Studies have shown that it is possible to obtain a building material with compressive strength of more than 40 MPa from this recycled material by forced carbonization for three hours. Moreover, to obtain such strength indicators, the optimal content of lime dust in the raw materials is in the range of 35-40% wt. when the water content of the mixture is 6-7% wt. The carbonized material obtained at the indicated technological parameters will have an average density of 1.95-2.0 g / cm3 and water absorption by weight of not more than 12%. Accordingly, the data obtained make it possible to judge the possibility of obtaining high-quality construction products with physico-mechanical, physico-chemical, hydrophysical, and other properties sufficient for building materials.

Stabilization to prevent soil erosion using vetiver (Chrysopogon zizanioides L.) in slopes: a field case study of selected grounds at Guatemala

The effects of Chrysopogon zizanioides (vetiver) on the hydrophysical properties of soils and infiltration rate have been determined. Thus, it has been examined the stabilization to prevent soil erosion using vetiver in slopes, studying a field case of selected grounds at Guatemala. The particle size analysis of the soil samples showed a predominant sand fraction and a plasticity index of 7.9 %. The results indicated that these soils were fairly acid with worthless salinity and non-swelling. The specific surface area, determined by nitrogen adsorption-desorption analysis, ranged from 11.7 - 15.5 m2 /g and the pore sizes between 17-160 µm, which changed to 20-100 µm, with predominant pore size around 40 µm after cultivation. The characteristics of the soils showed the presence of cohesion (2.05 t/m2) and an internal friction angle Ф = 31.69º. After the plantation, it has been found a decrease in the cohesion and an increase of the internal friction angle. The sowing of vetiver affected the infiltration characteristics of the soil. An analysis using the Kostiakov-Lewis classical model, with a mathematical fitting, has been performed. From these results, it has been deduced that the slope protected using this plant diminished its infiltration rate, being associated to the compaction caused by the plant roots. The present results demonstrated that the plantation of vetiver is effective to stabilize and prevent slopes from the soil erosion caused by severe rainfall events.

Sodic land reclamation for livelihood security in Central Indo-Gangetic Plains of Uttar Pradesh

The problem of salt affected soils has been reported from many parts of the world from ancient times. The widespread occurrence of these soils in about 120 countries encompassing all continent poses a serious threat to agricultural production in both irrigated and rainfed areas. Based on FAO/UNESCO Soil Map of the World, a total of 9530 lakh ha covering about 7–8% of the surface are suffering from this problem. India has estimated area 67.3 lakh ha of the salt affected soils out of which 13.7 lakh ha land spread over in Central Indo-Gangetic Plains of Uttar Pradesh. These soils have abundance of sodium carbonate, bicarbonate, chloride and sulphate, which stimulated various kinds of geochemical processes within these soils and promotes poor hydro-physical properties. In the soil profile, the level of native soil organic matter is very less due to its high solubility, decomposability and accessibility within the sodic soils. Holistic management practices using one time gypsum (50% of Gypsum Requirement) ameliorant along with salt tolerant cultivars and locally available inputs like dhaincha (Sesbania sp., pressmud) proved to have a significant impact in improvement of soil health and crop productivity. In Uttar Pradesh 3.61 lakh ha lands had been reclaimed by Bhumi Sudhar Nigam, Lucknow, Uttar Pradesh during 1993–2018 with technological backup of Central Soil Salinity Research Institute. Implementation of these management practices considerably reduced soil pH and increased cropping intensity from baseline of 46 to 185 percent during III phase of reclamation programme. The reclamation program of the salt affected soils helped in the upliftment of the economic status of marginal and small farmers.

STUDY OF HEAVY METAL DYNAMICS IN SOIL

The paper covers the results of a study, carried out during 2005 and 2018, regarding the impact of sludge dump of a wastewater treatment plant from Iasi city, Romania, on the soil characteristics. Experimental research was conducted to highlight the evolution of the heavy metal content of both the material in the storage site and the soil in its proximity. The following heavy metal concentrations were analyzed with atomic adsorption spectrometry method: Zn, Ni, Cr, Pb, Co, Cu and Cd. Research has also addressed other physical (particle size composition and soil moisture) and chemical (pH, sludge and soil reaction, organic carbon content, nitric nitrogen concentration, total nitrogen, mobile phosphorus and potassium content) properties that influence the mobility and retention of chemical compounds in the soil. The results of this study showed that the material consisting of sludge, on the depth of 0-20 cm, shows well-developed structural aggregates, with a structure between granules and subangular polyhedra, with a medium level of development. The analyzed material has good hydrophysical properties that give it mechanical and hydronic stability. Following the analyzes carried out during 2005 to 2018, we can say that there has been an increase in the humidity and the zinc content in the soil due to the sludge dump from the wastewater treatment plant in Iasi. Research results can be used as a scientific basis for developing an appropriate soil management system in the study area.

АНАЛИЗ СИСТЕМЫ «ОСАДКИ-ПОЧВА-ДРЕНАЖ» В УСЛОВИЯХ ИЗМЕНЕНИЯ КЛИМАТА НА СЕВЕРО-ЗАПАДЕ РОССИИ

Purpose: to analyze the soil-climatic and anthropogenic reasons of decreasing drainage efficiency of closed pottery tubular drainage on the reclaimed lands of the North-West of Russia under the observed local weather conditions against the background of global climate changes. Materials and methods. The objects of research are seasonal precipitation regimes, reclaimed lands and drainage systems of closed tubular drainage. The methods of applied mathematical statistics, the ensemble method of processing and generalization of climate forecasts of the Intergovernmental Panel on Climate Change (IPCC), modernized by the authors were used in research. Monitoring data on changes in the physical properties of soils of reclaimed lands during their long-term operation were obtained using laboratory agrophysical methods for studying samples taken in the field. Results. It is shown that under the conditions of the observed climatic changes, the frequency, intensity and extremeness of atmospheric precipitation are increased. Long-term exploitation of lands with a leaching drainage regime is accompanied by changes in the hydrophysical properties of soils, for example, the coefficient of heterogeneity of the subsurface horizons of soils texture of automorphic genesis decreased from 26 to 6. The system “precipitation – soil – drainage” in climatically abnormal weather conditions exceeding the initial calculated precipitation level mode by 10–20 %, is unable to ensure the removal of excess moisture from the root layer. Conclusions: when creating and reconstructing such reclamation drainage systems it is recommended to take into account the tendencies of changes in the spatial-temporal statistical structure of precipitation and to design technologies for regulating the water regime with systems for intercepting and diverting surface runoff on such reclaimed lands.

ИНТЕНСИВНЫЕ СПОСОБЫ ПОЛУЧЕНИЯ СТРОИТЕЛЬНЫХ МАТЕРИАЛОВ КАРБОНАТНОГО ТВЕРДЕНИЯ НА ОСНОВЕ ИЗВЕСТКОВОГО ВТОРИЧНОГО СЫРЬЯ

the article is dedicated to the research and development of intensive methods for curing products by capturing and binding CO2. It aims to improve and increase the productivity of technologies for the production of artificially carbonated building materials and products. Soda production wastes, limestone dust and finely dispersed limestone dust were used as the research objects. Secondary raw materials have been investigated using modern methods of phase composition and granulometry test. Intensive methods of production of accelerated carbonation of systems consisting of soda wastes were tested using multi-parameter optimization methods. The effects of recycled lime materials on the strength and hydrophysical properties of the obtained material were determined. The secondary raw materials effect depended on the composition of the raw mixture, molding conditions, CO2 concentration applied to the carbonate curing chamber, and the duration of exposure to environments with high CO2 content. It was found that the most effective way of providing accelerated carbonation curing of construction materials and products is a combined carbonation method, combining the principles of dynamic and static methods. It was concluded that the optimal CO2 concentration in the gas-air mixtures used for carbonate curing is 30%–40%.

Morphological features of the irrigated soils in Central Fergana

The aim of the study. To describe the morphology of the irrigated meadow saz soils (Calcic Gypsisols (Aric, Gleyic, Siltic). Location and place of the study. Central Fergana, Uzbekistan, 2019 year. Materials and methods. Morphogenetic comparative method developed by V.V. Dokuchaev. Result. The pedolithic horizons with carbonate-gypsum accumulation were described. The hydrophysical properties of the horizons, formed due to the specific hydrological processes due to irrigation, do not favour plant growth and development.

Investigation of functional properties of metal surfaces after laser treatment

This article presents the results of the study of the processes of formation of the metal surface, which has different hydrophysical properties and high chemical resistance to acidic media. The dependence of the contact angle of the surface (θ) on various parameters of laser processing material, the density of arrangement of the scanning vectors, the depth of the heated layer, the presence of oxide layer, etc. Determined optimum modes of laser processing, with which it is possible to obtain the greatest hydrophobicity, and maximum adhesion to the metal surface.