scholarly journals Effects of Intercropping on Soil Fractal Dimension and Physicochemical Properties in the Karst Areas

2021 ◽  
Author(s):  
Qin qin Xu ◽  
Kang ning Xiong ◽  
Yong kuan Chi
Keyword(s):  
Fractal Dimension ◽  
Physicochemical Properties ◽  
Soil Water ◽  
Soil Structure ◽  
Salvia Miltiorrhiza ◽  
Chemical Properties ◽  
Spatial Optimization ◽  
Organic Carbon Content ◽  
System Productivity ◽  
Fine Grained

Suitable soil structure and nutrient security are important for plant growth and development, characteristics of soil fractal dimension and distribution of physical and chemical properties and their interactions play an important role in studying the stability of soil structure and water and fertilizer cycles. As a sustainable management model, intercropping has positive benefits for erosion control, spatial optimization of resources, as well as improving system productivity. The effects of four intercropping methods on soil fractal dimension and physicochemical properties were investigated by intercropping Salvia miltiorrhiza with forage and S. miltiorrhiza with forest under typical karst rock desertification habitats in Guizhou. The results showed that soil nutrient content of intercropping was significantly higher than that of monoculture, the organic carbon content of soil grown under forest is higher than other treatments, and there was a non-significant change in soil water content of intercropping compared with monoculture. The soil fine-grained matter of intercropping was significantly higher than that of monoculture, while the soil fractal dimension showed a tendency to become larger with the increase of fine-grained matter. The intercropping planting, due to its component types and spatial and temporal configurations, leads to differences in soil water and fertilizer interactions, which can be combined with other ecological restoration measures to optimize the composite model and jointly promote the restoration and development of ecologically fragile areas.

scholarly journals Effects of Intercropping on Fractal Dimension and Physicochemical Properties of Soil in Karst Areas

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1422
Author(s):  
Qinqin Xu ◽  
Kangning Xiong ◽  
Yongkuan Chi
Keyword(s):  
Fractal Dimension ◽  
Physicochemical Properties ◽  
Soil Water ◽  
Salvia Miltiorrhiza ◽  
Chemical Properties ◽  
Spatial Optimization ◽  
Organic Carbon Content ◽  
System Productivity ◽  
Fine Grained ◽  
Properties Of Soil

Suitable soil structure and nutrient security are important for plant growth and development. The fractal dimension of soil, along with the distribution of physical and chemical properties and their interactions, plays an important role in studying the stability of soil structures and water and fertilizer cycles. As a sustainable management model, intercropping has positive benefits for erosion control, the spatial optimization of resources, and improving system productivity. The effects of four intercropping methods on the fractal dimension and physicochemical properties of soil were investigated by intercropping Salvia miltiorrhiza with forage and S. miltiorrhiza with forest under typical karst rock desertification habitats in Guizhou. The results showed that the soil nutrient content when intercropping was significantly higher than that of monoculture. The organic carbon content of soil grown under forest is higher than other treatments, and there was a non-significant change in soil water content when intercropping compared with monoculture. The soil fine-grained matter when intercropping was significantly higher than that of monoculture, while the soil fractal dimension showed a tendency to become larger with an increase in fine-grained matter. Intercropping planting, due to its component types and spatial and temporal configurations, leads to differences in soil water and fertilizer interactions, which can be combined with other ecological restoration measures to optimize the composite model and jointly promote the restoration and development of ecologically fragile areas.

scholarly journals Influence of humic acid applications on soil physicochemical properties

2015 ◽  
Vol 7 (3) ◽  
pp. 2481-2500 ◽  
Author(s):  
İ. Gümüş ◽  
C. Şeker
Keyword(s):  
Humic Acid ◽  
Physicochemical Properties ◽  
Soil Structure ◽  
Water Movement ◽  
Nutrient Recycling ◽  
Chemical Properties ◽  
Modulus Of Rupture ◽  
Soil Productivity ◽  
Root Penetration ◽  
Incubation Periods

Abstract. Soil structure is often said to be the key to soil productivity since a fertile soil, with desirable soil structure and adequate moisture supply, constitutes a productive soil. Soil structure influences soil water movement and retention, erosion, crusting, nutrient recycling, root penetration and crop yield. The objective of this work is to study, humic acid (HA) application on some physical and chemical properties in weak structured soils investigated. The approach involved establishing a plot experiment in the laboratory conditions. Different rates of HA (control, 0.5, 1, 2 and 4 %) were applied to soil at three incubation periods (21, 42 and 62 days). At the end of the each incubation period, the changes in physicochemical properties were measured. Generally, HA addition increased EC values at the all incubation periods. HA applications decreased soil modulus of rupture. Application of HA at the rate of 4 % was significantly increased soil organic carbon contents. HA applications at the rate of 4 % significantly increased both mean soil total nitrogen content and aggregate stability after at three incubation periods (p < 0.05). Therefore, HA was potential to improve structure of soil in short term.

scholarly journals Effects of Crop and Grass Intercropping on the Soil Environment in the Karst Area

2021 ◽  
Vol 13 (10) ◽  
pp. 5484
Author(s):  
Qinqin Xu ◽  
Kangning Xiong ◽  
Yongkuan Chi ◽  
Shuzhen Song
Keyword(s):  
Correlation Analysis ◽  
Water Content ◽  
Bulk Density ◽  
Soil Water ◽  
Soil Water Content ◽  
Southwest China ◽  
Salvia Miltiorrhiza ◽  
Chemical Properties ◽  
Total Porosity ◽  
Karst Area

The karst area in Southwest China is facing the challenges of environmental degradation and agricultural safety. Intercropping is a green and efficient planting mode that can make full use of the differences in crops’ physiological and ecological characteristics and land and climate resources while considering the environmental and yield benefits. This study selected five treatments: Salvia miltiorrhiza monoculture, Dactylis glomerata intercropped with S. miltiorrhiza, Cichorium intybus intercropped with S.miltiorrhiza, Trifolium repens intercropped with S.miltiorrhiza, and Lolium perenne intercropped with S.miltiorrhiza. Using one-way ANOVA, principle component analysis (PCA), and linear correlation analysis, we analyzed the changes in the soil physicochemical factors and the coupling relationship between them in the intercropping mode. The results showed that at different soil depths, the soil bulk density in the intercropping mode was significantly lower than that in the single cropping mode (p < 0.05), and the soil water content and total porosity were significantly increased (p < 0.05). There were no significant differences in soil pH among the five models (p > 0.05), the content of soil organic matter was significantly higher than that in the single cropping mode (p < 0.05), and the content of nitrogen and phosphorus also showed different changes. The correlation analysis showed that there was no significant correlation between the pH and soil physical properties (p > 0.05); bulk density and chemical properties were negatively correlated, while the soil water content, field water-holding capacity, and total porosity were significantly positively correlated with the chemical properties (p > 0.05). Therefore, it is suggested to strengthen the management of agricultural grass intercropping, improve soil pore structure, regulate the distribution of soil water and fertilizer, and improve the resilience of agricultural systems in the karst area of southwest China.

Using categorical soil structure information to improve soil water retention estimates of tropical delta soils

Soil Research ◽  
2014 ◽  
Vol 52 (5) ◽  
pp. 443 ◽  
Author(s):  
Phuong Minh Nguyen ◽  
Khoa Van Le ◽  
Wim M. Cornelis
Keyword(s):  
Soil Water ◽  
Soil Structure ◽  
Water Retention ◽  
Structural Information ◽  
Mekong Delta ◽  
Pedotransfer Functions ◽  
Organic Carbon Content ◽  
Structural Development ◽  
Soil Water Retention ◽  
Structure Information

Models of soil water and solute transport require input data of soil hydraulic properties (e.g. soil water retention and hydraulic conductivity curves). Lack of such data, especially in tropical delta regions, has usually been the main constraint for the application of simulation models. Direct field or laboratory measurement of soil water retention is costly, laborious and time-consuming; therefore, indirect estimation from other easily measured soil properties has received great interest. However, indirect estimates are often unreliable. In this study, we hypothesise that including basic descriptive information of soil structure such as aspect of presence or absence of pedality can improve the prediction of the soil water retention characteristic (SWRC). Stepwise multiple linear regression was used to develop point pedotransfer functions (PTFs) to estimate soil water retention at eight pressure potentials (e.g. –1, –3, –6, –10, –20, –34, –100, –1500 kPa). Soil structural information was exploited as a preliminary grouping criterion to test our hypothesis. Soil samples were taken from 160 horizons distributed along the Mekong Delta, Vietnam. The results reveal that SWRC of tropical Mekong Delta soils could be satisfactorily estimated by typical predictors of PTFs (e.g. soil texture, organic carbon content and bulk density). Moreover, incorporating soil structure in developing PTFs did improve the prediction accuracy of SWRC, especially in the wet moisture range. Plastic limit was found to be a promising predictor for SWRC-PTFs of soils having a given degree of structural development.

scholarly journals Hydraulic Properties and Their Dependence on Physico-chemical Properties of Soils: A Review

2019 ◽  
pp. 1-7
Author(s):  
Seema . ◽  
Rita Dahiya ◽  
V. K. Phogat ◽  
H. S. Sheoran
Keyword(s):  
Soil Water ◽  
Hydraulic Properties ◽  
Management Strategies ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Stability Index ◽  
Organic Carbon Content ◽  
Physico Chemical ◽  
Use Efficiency ◽  
Chemical Properties Of Soils

In the present day context, the knowledge of the soil, water and its movement in the soil has key importance for optimum plant growth as well as having practical inferences in agricultural, hydrological and ecological situations. Hydraulic properties of soils play a significant role in the adoption of water management strategies capable of improving resource use efficiency and alleviating production constraints of soils worldwide. Hydraulic conductivity is the most important hydraulic parameter to regulate the flow and transport related phenomena in soil. Hence, there is a need for accurate and adequate information regarding the hydraulic properties in relation to soil physico-chemical properties. The aim of this paper is to extend the relationship between the hydraulic properties and other soil physico-chemical properties of soils. Many studies around the world reveal the effect of texture, soil organic carbon content, bulk density, pH, electrical conductivity, sodium adsorption ratio, aggregate stability index and soil water holding capacity on hydraulic properties of soils.

The effects of organic fluids on physicochemical parameters of fine-grained soils

2000 ◽  
Vol 37 (5) ◽  
pp. 943-950 ◽  
Author(s):  
Abidin Kaya ◽  
Hsai-Yang Fang
Keyword(s):  
Dielectric Constant ◽  
Hydraulic Conductivity ◽  
Zeta Potential ◽  
Physicochemical Properties ◽  
Physicochemical Parameters ◽  
Soil Structure ◽  
Pore Fluid ◽  
Diffuse Double Layer ◽  
Fine Grained ◽  
Repulsive Forces

Researchers have shown that properties of fine-grained soils such as hydraulic conductivity change significantly when the pore fluid is replaced with organic liquids. In general, such changes have been reported as a function of the dielectric constant of the pore fluid and attributed to changes in soil structure. However, mechanisms causing changes in soil structure are yet to be understood. In this paper, the physicochemical properties of kaolinite, bentonite, and a local soil are determined as a function of the dielectric constant of pore fluids to evaluate the mechanisms causing changes in soil structure and, in turn, hydraulic conductivity. The physicochemical parameters determined in this study are cation exchange capacity (CEC), zeta potential (ζ), surface charge density, pore-size distribution, and Atterberg limits. Results show that physicochemical properties change as the dielectric constant of the pore fluid changes, such that as the dielectric constant of the pore fluid approaches that of the soil, the repulsive and attractive forces diminish; yet, there is a net increase in the attractive forces, causing aggregation of the particles. Based on the results of this study, it is suggested that as repulsive forces decrease the soil particles tend to flocculate and form aggregates due to attractive forces among particles, leading to a net increase in the effective flow area, resulting in increased hydraulic conductivity of the soil - pore fluid system.Key words: fine-grained soils, diffuse double layer, attractive forces, physicochemical parameters, CEC, zeta potential.

Use of fractals to describe microstructures of porous thick-film platinum electrodes

1992 ◽  
Vol 50 (1) ◽  
pp. 314-315
Author(s):  
Steven D. Toteda
Keyword(s):  
Fractal Dimension ◽  
Power Plants ◽  
Electrical Response ◽  
Cubic Phase ◽  
Platinum Electrodes ◽  
Fine Grained ◽  
Impedance Response ◽  
Platinum Particles ◽  
Energy Surfaces ◽  
Highly Porous

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

Characteristics Of The Structure Formation Of Gypsum Binder Modified With Zinc Hydrosilicates

2020 ◽  
pp. 40-46
Keyword(s):  
Synergistic Effect ◽  
Physicochemical Properties ◽  
Structure Formation ◽  
Silicic Acid ◽  
Chemical Properties ◽  
Crystal Formation ◽  
Ability To Act ◽  
Chemical Factors ◽  
Sorption Characteristics

The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.

scholarly journals Physicochemical characterisation of kafirins extracted from sorghum grain and dried distillers grain with solubles related to their biomaterial functionality

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Umar Shah ◽  
Deepak Dwivedi ◽  
Mark Hackett ◽  
Hani Al-Salami ◽  
Ranjeet P. Utikar ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Physicochemical Properties ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Chemical Properties ◽  
X Ray ◽  
Distillers Grain ◽  
Sorghum Grain ◽  
Dried Distillers Grain ◽  
Polypeptide Profile

AbstractKafirin, the hydrophobic prolamin storage protein in sorghum grain is enriched when the grain is used for bioethanol production to give dried distillers grain with solubles (DGGS) as a by-product. There is great interest in DDGS kafirin as a new source for biomaterials. There is however a lack of fundamental understanding of how the physicochemical properties of DDGS kafirin having been exposed to the high temperature conditions during ethanol production, compare to kafirin made directly from the grain. An understanding of these properties is required to catalyse the utilisation of DDGS kafirin for biomaterial applications. The aim of this study was to extract kafirin directly from sorghum grain and from DDGS derived from the same grain and, then perform a comparative investigation of the physicochemical properties of these kafirins in terms of: polypeptide profile by sodium-dodecyl sulphate polyacrylamide gel electrophoresis; secondary structure by Fourier transform infra-red spectroscopy and x-ray diffraction, self-assembly behaviour by small-angle x-ray scattering, surface morphology by scanning electron microscopy and surface chemical properties by energy dispersive x-ray spectroscopy. DDGS kafirin was found to have very similar polypeptide profile as grain kafirin but contained altered secondary structure with increased levels of β-sheets. The structure morphology showed surface fractals and surface elemental composition suggesting enhanced reactivity with possibility to endow interfacial wettability. These properties of DDGS kafirin may provide it with unique functionality and thus open up opportunities for it to be used as a novel food grade biomaterial.

scholarly journals Abandoned agricultural soils from the central part of the Yamal region of Russia: morphology, diversity, and chemical properties

2020 ◽  
Vol 5 (1) ◽  
pp. 94-106
Author(s):  
Evgeny Abakumov ◽  
Evgeniya Morgun ◽  
Alexandr Pechkin ◽  
Vyacheslav Polyakov
Keyword(s):  
Land Use ◽  
Agricultural Soils ◽  
Anthropogenic Impacts ◽  
Chemical Properties ◽  
Organic Carbon Content ◽  
Active Growth ◽  
Natural Processes ◽  
Agrochemical Properties ◽  
Fallow Lands ◽  
Abandoned Lands

AbstractThe post-anthropogenic and soil cover transformations of former agricultural soils on the abandoned lands in the Russian Arctic territory are poorly investigated due to the active growth of the city complexes and increasing area occupied by agricultural lands. That is lead to an increase in the area of the arable lands surrounding the polar urbanized territories. Today, most of that land allocated for agricultural needs has been abandoned or affected by other types of land use. This study aimed to investigate the abandoned lands surrounding some of the settlements in the central part of the Yamal region. The soil diversity, morphology, and chemical and agrochemical properties were investigated with special reference to the specific transformations that occur to fallow lands under permafrost-affected cryogenic-ecosystem conditions. Analysis of data show that these soils are characterized by features relating to both, previous (and existing), anthropogenic impacts and natural processes such as cryogenic mass transfer. The degradation of the arable humus-enriched horizon was not as pronounced as it has been in more humid boreal environments over recent decades. The organic carbon content in topsoil depends on the land use and varied considerably among the soil types. The former arable topsoil horizon has been stable over time in terms of its morphological features and agrochemical state. Despite the high soil acidity levels, thenutrient content in the anthropogenically impacted soils was still high, even though being abandoned for 20 years.

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