scholarly journals Moisture, Temperature, and Salinity of a Typical Desert Plant (Haloxylon ammodendron) in an Arid Oasis of Northwest China

2021 ◽  
Vol 13 (4) ◽  
pp. 1908
Author(s):  
Li Zhao ◽  
Wanjing Li ◽  
Guang Yang ◽  
Ke Yan ◽  
Xinlin He ◽  
...  
Keyword(s):  
Soil Water ◽  
Salt Content ◽  
Chemical Properties ◽  
Northwest China ◽  
Water Sources ◽  
Desert Plant ◽  
Haloxylon Ammodendron ◽  
Type Curve ◽  
Ecological Protection ◽  
Physical And Chemical

The physical and chemical characteristics of soil and water sources affect desert plants’ growth, which is essential for the ecological protection in arid areas. The typical patch patterns of Haloxylon ammodendron in the oasis-desert ecotone in the southern margin of the Manas River Basin consists of bare patches (BP) and vegetation patches (VP). The water sources of H. ammodendron were studied using stable isotope technology, and the soil physical and chemical properties were monitored and analyzed. The results showed that the soil moisture presented a reversed “S” type curve, and the total salt content of the soil presented an “S” type curve. A “wet island” and “cold island” were formed in the low salt area with H. ammodendron at the center. NaCl was most abundant in the BP soil, and the milligram equivalent of Cl− was 80–90%, while CaSO4 was most abundant in the VP soil, in which the milligram equivalent of SO42− was 80–100%. Before the rain, H. ammodendron mainly relied on the soil water from a deeper layer (≥60 cm) to maintain its growth. However, after the rain, H. ammodendron mainly relied on shallow soil water (<60 cm) to maintain its growth.

Water source and transmission in Haloxylon ammodendron in the desert margin of the Manas River Basin, China

2021 ◽  
pp. 1-12
Author(s):  
Wanjing Li ◽  
Li Zhao ◽  
Guang Yang ◽  
Ke Yan ◽  
Xinlin He ◽  
...  
Keyword(s):  
Soil Water ◽  
Ecological Restoration ◽  
Moisture Transfer ◽  
Water Source ◽  
Desert Plant ◽  
Contribution Rate ◽  
Haloxylon Ammodendron ◽  
Water Transportation ◽  
Stem Flow ◽  
Average Contribution

Abstract Analysis of water source and moisture transfer characteristics of desert plants is of great significance for ecological restoration in arid areas. In this study, the water source utilized by the desert plant, Haloxylon ammodendron, was analysed using the stable isotope technique, and the water transportation characteristics were obtained based on the proportional heat balance method under different weather conditions. The results showed that (1) before raining, the moisture of H. ammodendron mainly relied on groundwater (the average contribution rate was 34.14%) and on soil water located at a depth of 120–180 cm (the average contribution rate was 29.87%). After the rain, H. ammodendron mainly absorbed soil water from a depth of 60–120 cm (the average contribution rate was 33.19%) and groundwater (the average contribution rate was 30.67%); (2) the stem flow of H. ammodendron showed an obvious diurnal variation, showing a “midday rest” phenomenon. The stem flow showed a peak value, and in sunny days, it was ~2 fold higher than that in cloudy days. (3) The stem flow rate of H. ammodendron varied regularly overtime as follows: August > July > September > June > May, and the meteorological factors affecting its stem flow were solar radiation (0.826) > atmospheric temperature (0.598) > humidity (-0.573). The results provide basic support for the ecological conservation of the desert plant H. ammodendron, while also having important implications for ecological restoration in arid regions.

scholarly journals Niche analysis of dominant species in alpine desert grassland communities in Qaidam Basin

2021 ◽  
Vol 257 ◽  
pp. 03021
Author(s):  
Jiancai Sun ◽  
Yonghui Li ◽  
Deting Deng ◽  
Sha Yang ◽  
Yukun Wu ◽  
...  
Keyword(s):  
Plant Communities ◽  
Dominant Species ◽  
Qaidam Basin ◽  
Chemical Properties ◽  
Niche Overlap ◽  
Desert Plant ◽  
Desert Grassland ◽  
Qinghai Province ◽  
Physical And Chemical ◽  
The Relationship

Community dominant plants and their ecological niche research is the focus of community ecology research. To explore the niche characteristics of desert dominant plants and the relationship between them and soil factors in Qaidam Basin, and to provide a basis for the construction of desert plant communities and the sustainable management of natural resources in Qaidam Basin. Taking 13 desert plant communities in Qaidam Basin, Qinghai Province as the research objects, this paper analyzed the characteristics of desert plant communities and dominant species based on soil physical and chemical properties, and calculated the niche width and niche overlap of dominant plants. The dominant plants are, Haloxylon ammodendron, Tamarix chinensis, Achnatherum splendens, Poacynum hendersonii, Reaumuria songonica, Phragmites australiss, Sympegma regelii, and Ajania Tenuifolia, Artemisia sphaerocephala, Ceratoides latens, Pearl russianthistle, Scirpustriquter. There were different degree of niche overlap among species in the community. In addition, CCA sequencing showed that different species had different requirements on the environment, and the distribution of dominant species was mainly affected by soil total nitrogen and soil organic matter.

scholarly journals State-space approach to evaluate the relation between soil physical and chemical properties

2004 ◽  
Vol 28 (1) ◽  
pp. 49-58 ◽  
Author(s):  
L. C. Timm ◽  
K. Reichardt ◽  
J. C. M. Oliveira ◽  
F. A. M. Cassaro ◽  
T. T. Tominaga ◽  
...  
Keyword(s):  
State Space ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Clay Content ◽  
State Space Approach ◽  
Physical And Chemical ◽  
Space Approach

The state-space approach is used to evaluate the relation between soil physical and chemical properties in an area cultivated with sugarcane. The experiment was carried out on a Rhodic Kandiudalf in Piracicaba, State of São Paulo, Brazil. Sugarcane was planted on an area of 0.21 ha i.e., in 15 rows 100 m long, spaced 1.4 m. Soil water content, soil organic matter, clay content and aggregate stability were sampled along a transect of 84 points, meter by meter. The state-space approach is used to evaluate how the soil water content is affected by itself and by soil organic matter, clay content, and aggregate stability of neighboring locations, in different combinations, aiming to contribute to a better understanding of the relation among these variables in the soil. Results show that soil water contents were successfully estimated by this approach. Best performances were found when the estimate of soil water content at locations i was related to soil water content, clay content and aggregate stability at locations i-1. Results also indicate that this state-space model using all series describes the soil water content better than any equivalent multiple regression equation.

Effects of subsoil amendments on soil physical properties, crop response, and soil water quality in a dry year

Soil Research ◽  
2010 ◽  
Vol 48 (2) ◽  
pp. 140 ◽  
Author(s):  
T. M. McBeath ◽  
C. D. Grant ◽  
R. S. Murray ◽  
D. J. Chittleborough
Keyword(s):  
Soil Water ◽  
Chemical Properties ◽  
Crop Productivity ◽  
Residual Effects ◽  
Physical And Chemical Properties ◽  
Deep Placement ◽  
Growing Seasons ◽  
Texture Contrast ◽  
Physical And Chemical ◽  
And Chemical Properties

In southern Australia the ability of field crops to extract soil moisture and nutrients from depth depends on the physical and chemical properties of the subsoil. In texture-contrast soils accumulation of water and nutrients in the E or A2 horizon, immediately above a clay B horizon of much lower hydraulic conductivity (herein called the interface), may generate lateral flows and enhanced nutrient and solute transfer to water bodies. Evidence that deep-ripping with addition of subsoil nutrients can increase crop productivity in regions having hostile, alkaline subsoils led to experiments to test whether this response was related to an increase in the use of water and nutrients in the subsoil. Our study measured the effects of deep-ripping with and without amendments on soil physical and chemical properties of the A and upper B horizons of 2 South Australian soils. Deep-ripping and deep-placement of nutrients increased grain harvest weight even in an exceptionally dry season. The greater yield was accompanied by significantly lower field-penetration resistance to 0.35–0.50 m depth, which we hypothesise enabled the crop to better access stored soil water and deep placed nutrients in the subsoil. Residual effects from deep-ripping were minimal after 4 growing seasons; therefore, ripping will need to be practiced at regular intervals to maintain treatment effects. The ripping and nutrient amendments had no significant effect on exchangeable sodium percentage, electrical conductivity, and readily extractable phosphorus and nitrate-nitrogen, despite changes in these soil properties between spring and harvest sampling.

scholarly journals Flocculation Settling Characteristics of Ultra-Fine Iron Tailings with Rich Gypsum

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Daiqiang Deng ◽  
Guodong Cao
Keyword(s):  
Yangtze River Basin ◽  
Average Particle Size ◽  
Chemical Properties ◽  
Average Particle ◽  
Technological Support ◽  
Ecological Protection ◽  
Iron Mine ◽  
Fine Tailings ◽  
The Yangtze River Basin ◽  
Physical And Chemical

Because of the uniqueness of geological mineralization, tailings obtained from Chenchao Iron Mine have low SiO2 content of only 27.80%. Content of Al2O3 and MgO is 13.31% and CaSO4 is 22.09%. The fineness modulus of the ores is large enough for convenient mineral separation, thus resulting in 16.03% −5 μm particles and 27.76% −10 μm particles in the tailings, respectively. The average particle size is only 69.36 μm; it belongs to the category of very fine tailings. The natural sedimentation of tailings is extremely slow due to the comprehensive effects of their physical and chemical properties. Hence, sedimentation tests using four types of flocculating agents are conducted to accelerate the sedimentation of the tailings of Chenchao Iron Mine. Compared with natural sedimentation, the flocculating sedimentation is considerably quicker. Among the four flocculants, the sedimentation of sample using the special BASF flocculant is the fastest. When the tailings of 1 ton add this flocculant of 20 g, the maximum settling concentration reaches 60.98% after 40 min and its special gravity is 1.577 g/cm3, thus it fulfills future requirements of filling technologies. As the largest iron mine in the mid-southern region of China, Chenchao Iron Mine must turn to filling mining. This study can provide technological support for goaf management and environment-friendly treatment of solid waste in the Yangtze River basin, which plays important roles in ecological protection.

Influence of water potential on production of ethylene in soil

1977 ◽  
Vol 23 (6) ◽  
pp. 811-817 ◽  
Author(s):  
R. J. Cook ◽  
A. M. Smith
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Ethylene Production ◽  
Soil Water Potential ◽  
Chemical Properties ◽  
High Water ◽  
Wheat Field ◽  
Influence Of Water ◽  
Physical And Chemical ◽  
The Relationship

Ethylene production at different soil water potentials was studied in a high organic matter, red basaltic soil from a rain forest avocado grove of Queensland, Australia, and in a Latah silt loam from a recropped wheat field of Idaho, U.S.A. The soils were sealed under air or N2 in glass vials and incubated at 25 and 35 °C, respectively. Although the two soils differed in physical and chemical properties, in water content – water potential relationships, and in amount of ethylene produced, the relationship between ethylene production and water potential was virtually identical for both soils: maximal at saturation, reduced by −1 bar, and nearly prevented by −5 bars or slightly lower. Onset of ethylene production was earlier under N2, but total ethylene produced and the water potential–ethylene production relationship were about the same under both N2 and air. Osmotic adjustments of the soil water potential with KCl solutions resulted in more ethylene production between −1 and about −15 bars, but little or no ethylene production below −22 bars.The need for high water potential for ethylene production indicates that soil bacteria are more important than fungi in the ethylene production process in soil. The results further indicate that, because ethylene production is possible even to −5 bars or slightly lower, soil water availability should be no more directly limiting to this process in nature than it is, for example, to nitrification or other bacteriological processes in soil.

scholarly journals Profiles of relative permittivity and electrical conductivity from unsaturated soil water content models

2016 ◽  
Vol 59 (3) ◽  
Author(s):  
Roberta Porretta ◽  
Fabio Bianchi
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Relative Permittivity ◽  
Chemical Properties ◽  
Geophysical Investigation ◽  
Empirical Relations ◽  
Different Types ◽  
Physical And Chemical

<p>A mathematical model of water diffusion in the vadose zone has been implemented for different types of soil textures in order to determine the soil water content (SWC) profiles in dependence of depth and time. From these profiles, obtained for different soils, we derived the characteristic electrical parameters, such as relative permittivity (<span class="gt-card-ttl-txt">epsilon</span><span><sub>r</sub></span>) and electrical conductivity (<span>sigma</span>), and their variation in time, employing empirical relations available in the scientific literature. The simulation through mathematical models has been performed taking into account different types of soils characterized by the percentage composition of sand, clay and silt in the textural triangle, which provides some physical and chemical properties that affect the water retention in the soil. The resulting simulated profiles of SWC and consequently permittivity and conductivity profiles, span over a certain range of values suggesting the best techniques and the limits in geophysical investigation. Moreover this a-prior knowledge helps in the elaboration and interpretation of permittivity and conductivity data obtained by the measurements. Permittivity and conductivity profiles are particularly useful in some environmental applications when the soil textures are (or supposed to be) known as in the typical case of landfill leachate dispersion. Since the soil textures beneath or nearby a disposal waste are characterized by a SWC, the values of (<span class="gt-card-ttl-txt">epsilon</span><sub>r</sub>) and (sigma) at various depth can be directly inferred.</p>

scholarly journals Review on uranium in soil: levels, migration

2020 ◽  
pp. 117-132
Author(s):  
N. I. Sanzharova ◽  
A. N. Ratnikov ◽  
S. V. Fesenko ◽  
D. G. Sviridenko
Keyword(s):  
Soil Water ◽  
Natural Radionuclides ◽  
Chemical Properties ◽  
Soil Types ◽  
Physical And Chemical Properties ◽  
Additional Source ◽  
Phosphorus Fertilizers ◽  
And Migration ◽  
Physical And Chemical ◽  
And Chemical Properties

The problems of radioactive contamination of biosphere with the 238U in recent years have attracted a large number of experts in various fields of knowledge. Natural radionuclides are an integral part of the biosphere. They are concentrated everywhere: in rocks, in soil, water, air and food. Various types of phosphorus fertilizers and other natural ameliorants used in agriculture are also an additional source of heavy natural radionuclides. The review describes the behaviour and migration of 238U in biosphere, which depend on various factors acting simultaneously. It is noted that the behaviour of 238U in the soil depends on the forms of its presence in it and the physical and chemical properties of the soil. The processes of sorption and desorption of 238U by different soil types are significant indicators.

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