Analysis of plant root properties, texture and porosity that affects landslides in Tangka Sub-Watershed

Abstract Tangka Sub-Watershed in West Sinjai District is one of the sub-watersheds in South Sulawesi, which often experiences landslides. Factors causing landslides were divided into control factors and trigger factors. One of the triggering factors for landslides is the characteristics of soil and plant properties. Several previous research results stated that soil characteristics greatly affect the occurrence of landslides, while plant roots help stabilize soil bonds and slopes. This study aims to determine the triggering factors of the soil (soil texture and porosity) and the distribution of plant roots that affect the occurrence of landslides. Soil texture analysis using hydrometer method. Soil porosity and moisture content using gravimetric and pycnometer methods. The results showed that the soil texture was dominated by silty clay loam impact on low soil cohesion. Intensive land use decreases soil porosity to <50% and increases soil bulk density to 1.4 g/cm3. The soil quickly becomes saturated and could induce the rotting of plant roots. These characteristics increase the vulnerability of the soil, thereby increasing the potential for landslides.

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Silage-corn harvesting machinery traffic effects on soil bulk density and water permeability

Research in Agricultural Engineering ◽

10.17221/2/2013-rae ◽

2013 ◽

Vol 59 (No. 4) ◽

pp. 136-140

Author(s):

I. Ahmadi ◽

H. Ghaur

Keyword(s):

Bulk Density ◽

Water Permeability ◽

Soil Compaction ◽

Field Experiments ◽

Soil Bulk Density ◽

Soil Sampling ◽

Soil Porosity ◽

Silty Clay ◽

Water Permeability Coefficient ◽

Loam Soil

Soil compaction caused by machinery traffic affects the growth of agricultural crops and also has environmental effects like soil damage and erosion. Field experiments were conducted to study the effects of repeated silage-corn harvesting machinery traffic on dry soil bulk density and porosity variations at three different sampling depths, moreover average water permeability coefficient of the examined silty clay loam soil was measured using the falling head method of water permeability test. The examined treatments which were applied while harvesting silage-corn with the combination of tractor, chopper and truck were the number of traffic passes and depths of soil sampling. Significant differences between soil compaction treatments were observed in bulk density and porosity of soil. Numerically, 22% increase in soil bulk density and 19% reduction in soil porosity were recorded due to the effect of two passes of the examined machineries over the field terrain comparing to the non-traffic treatment. Moreover; soil sampling at 0–10 cm and 20–30 cm depths resulted in the highest and the lowest soil porosity respectively.

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Gamma-Ray Attenuation to Evaluate Soil Porosity: An Analysis of Methods

The Scientific World JOURNAL ◽

10.1155/2014/723041 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 7

Author(s):

Luiz F. Pires ◽

André B. Pereira

Keyword(s):

Gamma Ray ◽

Particle Density ◽

Pore Space ◽

Physical Property ◽

Soil Bulk Density ◽

Soil Porosity ◽

Porous System ◽

Soil Pore Space ◽

Gamma Ray Attenuation ◽

Dry Soil

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations ofϕare necessary due to the importance of this physical property in several fields of natural sciences. In the current work, two methods to evaluateϕwere analyzed by means of gamma-ray attenuation technique. The first method uses the soil attenuation approach through dry soil and saturated samples, whereas the second one utilizes the same approach but taking into account dry soil samples to assess soil bulk density and soil particle density to determineϕ. The results obtained point out a good correlation between both methods. However, whenϕis obtained through soil water content at saturation and a 4 mm collimator is used to collimate the gamma-ray beam the first method also shows good correlations with the traditional one.

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Soil Texture Alters the Impact of Salinity on Carbon Mineralization

Agronomy ◽

10.3390/agronomy11010128 ◽

2021 ◽

Vol 11 (1) ◽

pp. 128

Author(s):

Ruihuan She ◽

Yongxiang Yu ◽

Chaorong Ge ◽

Huaiying Yao

Keyword(s):

Soil Texture ◽

Clay Soil ◽

Sandy Loam ◽

Microbial Community Composition ◽

Clay Content ◽

Interactive Effects ◽

Silty Clay ◽

C Mineralization ◽

Negative Effect ◽

Silty Clay Soil

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.

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Model Test of the Reinforcement of Surface Soil by Plant Roots under the Influence of Precipitation

Advances in Materials Science and Engineering ◽

10.1155/2018/3625053 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12

Author(s):

Hengxing Wang ◽

Yulong He ◽

Zufeng Shang ◽

Chunpeng Han ◽

Yilu Wang

Keyword(s):

Water Content ◽

Model Test ◽

Surface Soil ◽

Plant Root ◽

Root Systems ◽

Reinforced Soil ◽

Plant Roots ◽

Interfacial Friction ◽

Negative Power ◽

Pull Out

We present the results of the reinforcement of plant root systems in surface soil in a model test to simulate actual precipitation conditions. In the test, Eleusine indica was selected as herbage to reinforce the soil. Based on the various moisture contents of plant roots in a pull-out test, a fitting formula describing the interfacial friction strength between the roots and soil and soil moisture content was obtained to explain the amount of slippage of the side slope during the process of rainfall. The experimental results showed that the root systems of plants successfully reinforced soil and stabilized the water content in the surface soil of a slope and that the occurrence time of landslides was delayed significantly in the grass-planting slope model. After the simulated rainfall started, the reinforcement effect of the plant roots changed. As the rainfall increased, the interfacial friction between the roots and the soil exhibited a negative power function relationship with the water content. These conclusions can be used as a reference for the design of plant slope protection and reinforcement.

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OPTIMALISASI PRODUKSI ENZIM KITINASE PADA ISOLAT JAMUR KITINOLITIK DARI SAMPEL TANAH RIZOSFER

Edubiotik Jurnal Pendidikan Biologi dan Terapan ◽

10.33503/ebio.v3i01.80 ◽

2018 ◽

Vol 3 (01) ◽

pp. 62-69

Author(s):

Eka Corneliyawati ◽

Massora Massora ◽

Khikmah Khikmah ◽

As’ad Syamsul Arifin

Keyword(s):

Biological Control ◽

Cell Wall ◽

Rhizosphere Soil ◽

Plant Root ◽

Optimal Growth ◽

Chitinase Activity ◽

Fungal Species ◽

Plant Roots ◽

Chitinase Production

The rhizosphere is the zone of soil surrounding a plant root where plant roots, soil and the soil biota interact with each other. Chitinolytic fungi has been effectively used in biological control agens. The chitinase activity causes lysis of the fungi cell wall pathogen. The aim of the research was to find optimization of activity chitinase enzyme from rhizosphere soil was conducted in vitro. Optimal growth chitinase production for TKR3 fungi isolate were concentration of chitin 0,2% (b/v), pH 5,5, temperature 30ºC, agitation 150 rpm and incubation time at four days. The optimum yield of chitinase production is influenced by fungal species and environmental conditions.

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Advances in understanding plant root responses to root-feeding insects

Understanding and improving crop root function - Burleigh Dodds Series in Agricultural Science ◽

10.19103/as.2020.0075.13 ◽

2021 ◽

pp. 231-266

Author(s):

Scott N. Johnson ◽

◽

Ximena Cibils-Stewart ◽

◽

Keyword(s):

Plant Root ◽

Plant Roots ◽

Insect Herbivores ◽

Soil Environment ◽

Knowledge Gaps ◽

Root Herbivores ◽

Mutualistic Fungi ◽

Root Responses ◽

Insect Attack ◽

Root Feeding

This chapter presents an overview of the interactions between plant roots and root-feeding insect herbivores, focussing on changes in growth and physiology and crucially how roots are defended against insect attack. Several reviews have covered the ecology and management of insect root herbivores, together with their interactions with the abiotic and biotic soil environment. Therefore, the chapter focuses particularly on advances in our understanding of how plant mutualistic fungi may affect root-herbivores. This is an emerging area of research, with many attendant knowledge gaps, but we argue that this is an important component of how plants resist attack by belowground insect herbivores.

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Tillage and crop rotation effects on soil carbon and selected soil physical properties in a Haplic Cambisol in Eastern Cape, South Africa

Soil and Water Research ◽

10.17221/176/2018-swr ◽

2019 ◽

Vol 15 (No. 1) ◽

pp. 47-54 ◽

Cited By ~ 4

Author(s):

Mxolisi Mtyobile ◽

Lindah Muzangwa ◽

Pearson Nyari Stephano Mnkeni

Keyword(s):

South Africa ◽

Water Content ◽

Bulk Density ◽

Soil Water ◽

Soil Water Content ◽

Crop Rotation ◽

Soil Bulk Density ◽

Crop Rotations ◽

Soil Porosity ◽

No Till

The effects of tillage and crop rotation on the soil carbon, the soil bulk density, the porosity and the soil water content were evaluated during the 6<sup>th</sup> season of an on-going field trial at the University of Fort Hare Farm (UFH), South Africa. Two tillage systems; conventional tillage (CT) and no-till and crop rotations; maize (Zea mays L.)-fallow-maize (MFM), maize-fallow-soybean (Glycine max L.) (MFS); maize-wheat (Triticum aestivum L.)-maize (MWM) and maize-wheat-soybean (MWS) were evaluated. The field experiment was a 2 × 4 factorial, laid out in a randomised complete design. The crop residues were retained for the no-till plots and incorporated for the CT plots, after each cropping season. No significant effects (P > 0.05) of the tillage and crop rotation on the bulk density were observed. However, the values ranged from 1.32 to1.37 g/cm<sup>3</sup>. Significant interaction effects of the tillage and crop rotation were observed on the soil porosity (P < 0.01) and the soil water content (P < 0.05). The porosity for the MFM and the MWS, was higher under the CT whereas for the MWM and the MWS, it was higher under the no-till. However, the greatest porosity was under the MWS. Whilst the no-till significantly increased (P < 0.05) the soil water content compared to the CT; the greatest soil water content was observed when the no-till was combined with the MWM rotations. The soil organic carbon (SOC) was increased more (P < 0.05) by the no-till than the CT, and the MFM consistently had the least SOC compared with the rest of the crop rotations, at all the sampling depths (0–5, 5–10 and 10–20 cm). The soil bulk density negatively correlated with the soil porosity and the soil water content, whereas the porosity positively correlated with the soil water content. The study concluded that the crop rotations, the MWM and the MWS under the no-till coupled with the residue retention improved the soil porosity and the soil water content levels the most.

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Bacterial Community Members Increase Bacillus subtilis Maintenance on the Roots of Arabidopsis thaliana

Phytobiomes Journal ◽

10.1094/pbiomes-02-20-0019-r ◽

2020 ◽

Vol 4 (4) ◽

pp. 303-313

Author(s):

Noam Eckshtain-Levi ◽

Susanna Leigh Harris ◽

Reizo Quilat Roscios ◽

Elizabeth Anne Shank

Keyword(s):

Arabidopsis Thaliana ◽

Bacillus Subtilis ◽

Crop Production ◽

Crop Yields ◽

Plant Root ◽

Plant Roots ◽

Plant Growth Promoting Bacteria ◽

Bacterial Strains ◽

Root Microbiome ◽

Over Time

Plant-growth-promoting bacteria (PGPB) are used to improve plant health and promote crop production. However, because some PGPB (including Bacillus subtilis) do not maintain substantial colonization on plant roots over time, it is unclear how effective PGPB are throughout the plant growing cycle. A better understanding of the dynamics of plant root community assembly is needed to develop and harness the potential of PGPB. Although B. subtilis is often a member of the root microbiome, it does not efficiently monoassociate with plant roots. We hypothesized that B. subtilis may require other primary colonizers to efficiently associate with plant roots. We utilized a previously designed hydroponic system to add bacteria to Arabidopsis thaliana roots and monitor their attachment over time. We inoculated seedlings with B. subtilis and individual bacterial isolates from the native A. thaliana root microbiome either alone or together. We then measured how the coinoculum affected the ability of B. subtilis to colonize and maintain on A. thaliana roots. We screened 96 fully genome-sequenced strains and identified five bacterial strains that were able to significantly improve the maintenance of B. subtilis. Three of these rhizobacteria also increased the maintenance of two strains of B. amyloliquefaciens commonly used in commercially available bioadditives. These results not only illustrate the utility of this model system to address questions about plant–microbe interactions and how other bacteria affect the ability of PGPB to maintain their relationships with plant roots but also may help inform future agricultural interventions to increase crop yields. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

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Three-dimensional interpolation of soil data: fertility and pedomorphological features in southern Brazil

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832014000400005 ◽

2014 ◽

Vol 38 (4) ◽

pp. 1091-1100

Author(s):

Tales de Campos Piedade ◽

Vander de Freitas Melo ◽

Luiz Cláudio de Paula Souza ◽

Jeferson Dieckow

Keyword(s):

Soil Texture ◽

Graphical Representation ◽

Plant Root ◽

Three Dimensional ◽

Three Dimension ◽

Southern Brazil ◽

Soil Matrix ◽

Continuous Space ◽

Continuous Surface ◽

Three Dimensional Models

The graphical representation of spatial soil properties in a digital environment is complex because it requires a conversion of data collected in a discrete form onto a continuous surface. The objective of this study was to apply three-dimension techniques of interpolation and visualization on soil texture and fertility properties and establish relationships with pedogenetic factors and processes in a slope area. The GRASS Geographic Information System was used to generate three-dimensional models and ParaView software to visualize soil volumes. Samples of the A, AB, BA, and B horizons were collected in a regular 122-point grid in an area of 13 ha, in Pinhais, PR, in southern Brazil. Geoprocessing and graphic computing techniques were effective in identifying and delimiting soil volumes of distinct ranges of fertility properties confined within the soil matrix. Both three-dimensional interpolation and the visualization tool facilitated interpretation in a continuous space (volumes) of the cause-effect relationships between soil texture and fertility properties and pedological factors and processes, such as higher clay contents following the drainage lines of the area. The flattest part with more weathered soils (Oxisols) had the highest pH values and lower Al3+ concentrations. These techniques of data interpolation and visualization have great potential for use in diverse areas of soil science, such as identification of soil volumes occurring side-by-side but that exhibit different physical, chemical, and mineralogical conditions for plant root growth, and monitoring of plumes of organic and inorganic pollutants in soils and sediments, among other applications. The methodological details for interpolation and a three-dimensional view of soil data are presented here.

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The MAD1 Adhesin of Metarhizium anisopliae Links Adhesion with Blastospore Production and Virulence to Insects, and the MAD2 Adhesin Enables Attachment to Plants

Eukaryotic Cell ◽

10.1128/ec.00409-06 ◽

2007 ◽

Vol 6 (5) ◽

pp. 808-816 ◽

Cited By ~ 181

Author(s):

Chengshu Wang ◽

Raymond J. St Leger

Keyword(s):

Metarhizium Anisopliae ◽

Plant Root ◽

Yeast Cells ◽

Plant Roots ◽

Insect Cuticle ◽

Plant Surface ◽

Adhesive Properties ◽

Regional Localization ◽

Expression Of Genes ◽

Ecological Versatility

ABSTRACT Metarhizium anisopliae is a fungus of considerable metabolic and ecological versatility, being a potent insect pathogen that can also colonize plant roots. The mechanistic details of these interactions are unresolved. We provide evidence that M. anisopliae adheres to insects and plants using two different proteins, MAD1 and MAD2, that are differentially induced in insect hemolymph and plant root exudates, respectively, and produce regional localization of adhesive conidial surfaces. Expression of Mad1 in Saccharomyces cerevisiae allowed this yeast to adhere to insect cuticle. Expression of Mad2 caused yeast cells to adhere to a plant surface. Our study demonstrated that as well as allowing adhesion to insects, MAD1 at the surface of M. anisopliae conidia or blastospores is required to orientate the cytoskeleton and stimulate the expression of genes involved in the cell cycle. Consequently, the disruption of Mad1 in M. anisopliae delayed germination, suppressed blastospore formation, and greatly reduced virulence to caterpillars. The disruption of Mad2 blocked the adhesion of M. anisopliae to plant epidermis but had no effects on fungal differentiation and entomopathogenicity. Thus, regulation, localization, and specificity control the functional distinction between Mad1 and Mad2 and enable M. anisopliae cells to adapt their adhesive properties to different habitats.

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