Properties Of Saline Soil Research Articles

Hiệu quả của phân hữu cơ và vôi trong cải thiện năng suất lúa và đặc tính bất lợi của đất nhiễm mặn trong điều kiện nhà lưới

Saline soils need to be reclaimed to maintain fertility levels for sustaining food production as they are of soil chemical constraints, leading to rice yields reduction. The experiment was established in a greenhouse to evaluate the effect of compost amendment and lime on improving some selected soil properties and rice yield in saline soils. Soil samples were collected from the fields under a shrimp-rice farming system at An Biên district, Kien Giang province. The results showed that application of inorganic fertilizer (60-20–20), 5 ton/ha of sugarcane filter cake compost or Bio-pro and 0.5 ton/ha lime resulted in an improvement of adverse properties of saline soil. The changes were found as reducing exchangeable Na+, Exchangeable Sodium Percentage (ESP), and ECe, increasing of soil available nitrogen and phosphorus. Consequently, the growth rate and rice yield were increased significantly.

Dielectric properties of saline soil based on a modified Dobson dielectric model

Soil salinization is a major concern for agricultural development in arid areas. In this paper, a modified Dobson dielectric model was applied to simulate the dielectric constant of saline soil in the Ugan-Kuqa river delta oasis of Xinjiang Uygur autonomous region, northwestern China. The model performance was examined through analyzing the influences of its parameters on the soil dielectric constant and the relationship between radar backscattering coefficient and the dielectric constant of saline soil. The results of the study indicate that: (1) The real part of the soil dielectric constant is affected by soil water content at low radar frequencies; the imaginary part is closely related with both the soil water content and soil salt content. (2) The soil water and salt contents are related with the coefficient of dialectical loss, which is consistent with the natural conditions of saline soil in arid areas and provides valuable references for the study of soil dielectric properties. (3) The changes of soil water content and soil salt content have instant influences on the dielectric constant of saline soil. Subsequently, the radar backscattering coefficient is affected to respond to the dielectric constant of saline soil. The radar backscattering coefficient is most responsible to the radar’s cross polarization pattern with a correlation coefficient of R 2=0.75. This study provides a potential method to monitor soil salinization and soil water content by using a soil dielectric model and radar techniques.

Dielectric Properties of Saline Soils and an Improved Dielectric Model in C-Band

To retrieve the soil salinity by microwave remote sensing, we must clarify the relation of dielectric properties of saline soils with soil salinity. The objective of this paper was to determine how dielectric properties are affected by soil salinity in the remote sensing range and develop an improved model applying for the saline soil. Laboratory measurements of dielectric constant are made with a microwave vector network analyzer using soil mixture samples of various soil moistures and salinities prepared artificially from natural soils. The results confirmed that the real part is strongly affected by soil moisture, whereas the imaginary part depends on both the soil moisture and salinity, particularly at lower frequencies (1-6 GHz). Thus, as a key factor, soil salinity is introduced into the expression of the imaginary part of dielectric constant in the Dobson semiempirical dielectric mixing model, combining the dielectric model for saline water and the impact of electrical conductivity of soil solution. The improved model yields results, which are in good agreement with the laboratory measurements, the slopes of fitting curves between measurements and simulation nearly being equal to 1, and coefficient R 2 are higher than 0.89. In addition, the improve model is independent of soil-texture parameters. However, it should be noted that the improved model can be applied only to the C-band remote sensing.

Effect of organic materials on the chemical properties of saline soil in the Yellow River Delta of China

A 180-day incubation experiment was conducted to investigate the effect of different organic materials on the chemical properties of coastal soil with high salinity and relatively low pH. Four organic materials (three kinds of plant residues: straw, composted straw, and fresh reed; and one kind of poultry manure: chicken manure) were applied at a ratio of 15 g·kg−1 to samples of costal saline soil from the Yellow River Delta of China. The results showed that the soil pH and exchangeable sodium percentage (ESP) decreased, whereas soil cation exchangeable capacity (CEC) and macronutrient concentrations increased, regardless of the type of organic material used. All treatments showed a remarkable increase in soil soluble organic carbon (SOC) during the 180-day incubation. The peak values of SOC in descending order were chicken manure, reed, composted straw, straw, and control soil. At the end of incubation, the highest level of SOC occurred in the straw-amended soil, followed by composted straw, reed, and chicken manureamended soils. Soil respiration rate and available nitrogen were significantly influenced by the type of material used. Although reed-amended soil had a relatively high SOC and respiration rate, the ESP was reduced the least. Considering the possible risk of heavy metals caused by chicken manure, it is proposed that straw and composted straw are the more efficient materials to use for reclaiming costal saline soil and improving the availability of macronutrients.

Furfural and its biochar improve the general properties of a saline soil

Abstract. Organic materials (e.g., furfural residue) are generally believed to improve the physical and chemical properties of saline soils with low fertility. Recently, biochar has been received more attention as a possible measure to improve the carbon balance and improve soil quality in some degraded soils. However, little is known about their different amelioration of a sandy saline soil. In this study, 56 d incubation experiment was conducted to evaluate the influence of furfural and its biochar on the properties of saline soil. The results showed that both furfural and biochar greatly reduced pH, increased soil organic carbon (SOC) content and cation exchange capacity (CEC), and enhanced the available phosphorus (P) in the soil. Furfural is more efficient than biochar in reducing pH: 5% furfural lowered the soil pH by 0.5–0.8 (soil pH: 8.3–8.6), while 5% biochar decreased by 0.25–0.4 due to the loss of acidity in pyrolysis process. With respect to available P, furfural addition at a rate of 5% increased available P content by 4–6 times in comparison to 2–5 times with biochar application. In reducing soil exchangeable sodium percentage (ESP), biochar is slightly superior to furfural because soil ESP reduced by 51% and 43% with 5% furfural and 5% biochar at the end of incubation. In addition, no significant differences were observed between furfural and biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused by the relatively short incubation time. In general, furfural and biochar exhibited a different effect depending on the property: furfural was more effective in decreasing pH and increasing available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline soil.

The role of humic substances in mitigating the harmful effects of soil salinity and improve plant productivity

The environmental, social and economical reasons indicate that the conventional agriculture constitute a continuous pressure contributing to the progressive worsening of environmental conditions, especially by an increasing apply high level of inputs. In this matter, the increasing use of saline irrigation water is one of the main factors resulting in salt accumulation in the plant rhizosphere influencing both physical, chemical and biological soil properties and agroecosystem productivity. In this situation, soil degradation emphasized the need to develop strategies of salt effected soil reclamation. One of the possible solutions is to use humic substances (HS), since there is an increasing need to their utilization in agriculture. They are the major components of soil organic matter, have multiple roles in plant growth and are the subject of study in various areas of agriculture, such as soil chemistry, soil fertility and plant physiology. Thus, our hypothesis account for a beneficial effect of HS in salt affected rhizosphere likely due to a 'direct' action on the plant together with an 'indirect action' on the metabolism of soil microorganisms, the dynamics of uptake of soil nutrients and soil physical conditions. In this paper we review the HS formation and components and their influences on improving saline soil properties as both direct and indirect effects. Keywords: Humic substance; Salt accumulation; Soil degradation; Plant productivity; Hormone-like activity.

Analysis of Coarse Saline Soil Salt Expansion Characteristics with Different Freeze-Thaw Cycle

Salt expansion deformation of the saline soil is a common form of the roadbed disease in Saline Soil Area. Salt expansion of saline soil refers to volume expansion by the impact of periodic climate changes in nature. Particle distribution characteristics, compaction characteristics, salt composition and salinity and so on are studied to evaluate the basic engineering properties of saline soil in the location of the project. Seven freeze-thaw cycles test and (no) load single-cooling test are designed to clarify the relation between salt expansion and temperature changes, moisture content, overburden pressure. The results provide design and construction experiences for high-grade highway projects in natural coarse saline soil area.

Refinement of the standard basis for computational evaluation of thermophysical properties of saline soils and cryopegs

Procedures are cited for computational evaluation of the freezing point, phase composition, density, pH, and thermophysical properties of saline soils and cryopegs; these methods are implemented using software and approximate formulas, which can be used to develop regulatory documents.

Experimental investigations on the influence of cyclical freezing and thawing on physical and mechanical properties of saline soil

Uniaxial compressive strength experiments were performed on saline loess different water and salt contents, and multiple freeze/thaw cycles at room temperature. The experiments revealed changes to the stress–strain curve and the failure mode of the saline loess. The results indicated that soil strength is intensified or weakened during freezing and thawing due to the injection of sodium sulfate solute. Cyclical freezing and thawing is a process to get a new dynamic equilibrium, and under these experimental conditions, six freeze–thaw cycles are need for loess with sodium sulfate to reach a new dynamic equilibrium.

10.1007/s11487-008-3009-8

The effect of salinity and volume wetness on the dielectric properties of saline sandy soils containing high-hygroscopicity salt CaCl2 are investigated experimentally. A new type of behavior of the dielectric properties of saline soils in the bound-water region is determined.

Effect of high-hygroscopicity salts on the dielectric properties of saline soils in the decimeter wave band

The effect of salinity and volume wetness on the dielectric properties of saline sandy soils containing high-hygroscopicity salt CaCl2 are investigated experimentally. A new type of behavior of the dielectric properties of saline soils in the bound-water region is determined.

The effect of perennial herbs on the physical properties of saline soils

It is shown that the physical and water-physical properties of saline chernozemic-meadow soils improve under the impact of artificially sown perennial herbs: the content of water-stable aggregates >0.25 mm increases, the bulk density of the topsoil decreases, and the soil permeability increases. As the grass cover becomes older, the soil permeability somewhat decreases, though it remains higher in comparison with the soil without the plant cover. The effect of annual crops on the physical properties of the soils is less pronounced. The improvement of soil physical properties under perennial grasses favors the desalinization of the soil profile due to the migration of salts into the groundwater via root paths. Lucerne (Medicago sp.) and sweet clover (Melilotus suaveolens) with deep, well developed root systems have the most pronounced effect on the soil desalinization. A somewhat slighter ameliorative effect is typical of Elymus junceus.

Amelioration of saline‐sodic soils with organic matter and their use for wheat growth

Few reports highlight the effect of organic matter in improving the properties of saline soils. A laboratory study was conducted to determine the effect of adding farm yard manure (manure), Egyptian clover hay (clover hay), and wheat straw, at 1 and 3% of soil weight on water stability of soil aggregates (WSA), water‐holding capacity (WHC), pH, and electrical conductivity of soil extract (ECe) of a normal, saline, and saline sodic soil. After 90 and 180 days, WSA and WHC increased, while pH and ECe decreased. Soil properties improved most by adding 3% manure to all the soils. Wheat grown in these soils indicated significant differences for various growth and yield variables, especially the root growth, number and area of green leaves, and grain yield. Organic matter added to these soils increased WSA and WHC and decreased pH and Ece. The WHC had no correlation with pH, but was negatively correlated with Ece. Increased WSA caused the leaching of excess ions and reduced their toxicity, while enhanced WHC increased the availability of water to the roots and promoted growth. It is concluded that manure ameliorated salt affected soils and promoted wheat growth better than clover hay and wheat straw.

Studies on saline soils in khon kaen region, northeast thailand I. Physical and chemical properties of saline soils

Saline soils occur extensively in Northeast Thailand. As the climate of this region is clearly differentiated into dry and rainy seasons, salts in the groundwater move up and accumulate on the soil surface during the dry season and are leached down with rainfall during the rainy season. In this paper, the physical and chemical properties concerned with salt movement were investigated for the saline soils in the Khon Kaen Region, Northeast Thailand. Changes in the physical and chemical properties with leaching were also studied in order to determine the effect of rainfall on desaltation. The saline soils in the Khon Kaen Region are generally sandy with low CEC, low content of organic matter and low buffering capacity. The dominant salt is NaCI, which facilitates the dispersion of clay. The main types of clay minerals are 1 : 1 type. All the soils contained large amounts of quartz, indicating that they are highly weathered soils. The amount of materials dispersed by water leaching, mainly clay, accounted fo...

PHYSICOCHEMICAL AND MECHANICAL PROPERTIES OF SALINE SOILS DURING TEMPERATURE CHANGE

A series of important changes in physicochemical and physicomechanical properties ofsaline soils occurs during cooling, i. e. the parts of solute migrate towards the colder endof soil column and the parts of the sodium sulphate recrystallize from the soil solution, caus-ing the soil expension in volume or salt heave, which makes the soil decrease in compres-sive strength. The ratio of salt heave of soils decreases with the increase in the coolingrate, surcharge. initial density and the cohesion between soil particles, but increases with anincrease in water content. The fact that soil volume does not reduce obviously during re-warming shows the nonreversibility of salt heave process. During the repeated cycles ofcooling and warming, the salt heave accumulates and the compressive strength of soil de-creases gradually.

Properties of saline soils used in construction : Mikheev, VV Petrukhin, VP Kronik, YA.A. Conference. Session four. 3F, 2T, 9R Proc. Eighth Int. Conf. on Soil Mech. Found. Engng. Moscow, 1973, V2.2, P133–138

Properties of saline soils used in construction : Mikheev, VV Petrukhin, VP Kronik, YA.A. Conference. Session four. 3F, 2T, 9R Proc. Eighth Int. Conf. on Soil Mech. Found. Engng. Moscow, 1973, V2.2, P133–138

Cinstruction properties of saline soils used as foundation beds in industrial and civil construction : Mikheev, VV Petrukhin, VP 1F, 1T, 12R. Soil Mech. Foundation Eng. V10, N1, 1973, P30–36

Cinstruction properties of saline soils used as foundation beds in industrial and civil construction : Mikheev, VV Petrukhin, VP 1F, 1T, 12R. Soil Mech. Foundation Eng. V10, N1, 1973, P30–36

Construction properties of saline soils used as foundation beds in industrial and civil construction

Construction properties of saline soils used as foundation beds in industrial and civil construction

Properties of saline soils in Iraq.

Data on soil texture, lime, gypsum, cation-exchange capacity, salinity, alkalinity, hydraulic conductivity and their interrelations and variations are discussed. An equation expresses the relationship between exchangeable Na and cations soluble in 1: 1 extracts. Special attention is paid to whether alkalization and structure deterioration will occur during reclamation. Gypsum contents seem to be adequate for replacement of Na by Ca during leaching but temporary decrease in permeability in early stages of leaching may occur due to retarded exchange reactions caused by the nature of the clay minerals. (Abstract retrieved from CAB Abstracts by CABI’s permission)