scholarly journals Physico-Chemical Characterization of Soil in a Tropical Landscape Restored by a Vegetal Succession

2020 ◽  
Vol 3 (1) ◽  
pp. 45
Author(s):  
Alfredo Torres-Benítez ◽  
Héctor Esquivel

The objective was to evaluate the physicochemical composition of soils and their relationship with successional vegetation. The study was conducted in the area of influence of fluvial volcanic muds in the central region of Colombia. The physical variables of texture, porosity, humidity, color, apparent density, real density; and chemical variables of pH, organic matter, cation exchange capacity, major elements, minor elements, Al saturation, base saturation, Ca/Mg relation, (Ca+Mg)/K relation, and Mg/K relation were analyzed. A multivariate analysis between variables and descriptive of the soil–vegetation relationship was carried out. Physically, there was a negative correlation between apparent density with %porosity and real density with humidity content. The texture was classified as sandy loam and the structure as granular-crumbly type. Chemically, there was a negative correlation between pH, Mg/K relation, (Ca+Mg)/K relation, and Al saturation; a positive correlation between P, Mn, Ca, Zn, Fe, Mg, and base saturation. Furthermore, Na and K did not show any interaction relationship. The predominant plant species are distributed in the families Fabaceae, Asteraceae, Malvaceae, Euphorbiaceae, Cyperaceae, and Poaceae. The physical and chemical characteristics of the soil present conditions that allow the establishment and continuation of successional vegetation with a dominance of tree and shrub growth habit.

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 325
Author(s):  
Nitin Chandra teja Dadi ◽  
Matúš Dohál ◽  
Veronika Medvecká ◽  
Juraj Bujdák ◽  
Kamila Koči ◽  
...  

This research was aimed at the preparation of a hybrid film based on a layered silicate saponite (Sap) with the immobilized photosensitizer phloxine B (PhB). Sap was selected because of its high cation exchange capacity, ability to exfoliate into nanolayers, and to modify different surfaces. The X-ray diffraction of the films confirmed the intercalation of both the surfactant and PhB molecules in the Sap film. The photosensitizer retained its photoactivity in the hybrid films, as shown by fluorescence spectra measurements. The water contact angles and the measurement of surface free energy demonstrated the hydrophilic nature of the hybrid films. Antimicrobial effectiveness, assessed by the photodynamic inactivation on hybrid films, was tested against a standard strain and against methicillin-resistant bacteria of Staphylococcus aureus (MRSA). One group of samples was irradiated (green LED light; 2.5 h) and compared to nonirradiated ones. S. aureus strains manifested a reduction in growth from 1-log10 to over 3-log10 compared to the control samples with Sap only, and defects in S. aureus cells were proven by scanning electron microscopy. The results proved the optimal photo-physical properties and anti-MRSA potential of this newly designed hybrid system that reflects recent progress in the modification of surfaces for various medical applications.


2018 ◽  
Vol 3 (1) ◽  
pp. 28-44
Author(s):  
Dinesh Khadka ◽  
Sushil Lamichhane ◽  
Amit P Timilsina ◽  
Bandhu R Baral ◽  
Kamal Sah ◽  
...  

Soil pit digging and their precise study is a decision making tool to assess history and future of soil management of a particular area. Thus, the present study was carried out to differentiate soil physico-chemical properties in the different layers of excavated pit of the National Maize Research Program, Rampur, Chitwan, Nepal. Eight pits were dug randomly from three blocks at a depth of 0 to 100 cm. The soil parameters were determined in-situ, and in laboratory for texture, pH, OM, N, P (as P2O5), K (as K2O), Ca, Mg, S, B, Fe, Zn, Cu and Mn of collected soils samples of different layers following standard analytical methods at Soil Science Division, Khumaltar. The result revealed that soil structure was sub-angular in majority of the layers, whereas bottom layer was single grained. The value and chrome of colour was increasing in order from surface to bottom in the majority pits. Similarly, the texture was sandy loam in majority layers of the pits. Moreover, four types of consistence (loose to firm) were observed. Furthermore, mottles and gravels were absent in the majority layers. Likewise, soil was very to moderately acidic in observed layers of majority pits, except bottom layer of agronomy block was slightly acidic. Regarding fertility parameters (OM, macro and micronutrients), some were increasing and vice-versa, while others were intermittent also. Therefore, a single layer is not dominant for particular soil physico-chemical parameters in the farm. In overall, surface layer is more fertile than rest of the layers in all the pits.     


Agro-Science ◽  
2021 ◽  
Vol 20 (3) ◽  
pp. 14-23
Author(s):  
O.N. Ajala ◽  
T.A. Adjadeh ◽  
J.O. Olaniyan ◽  
T.O. Isimikalu ◽  
E.K. Nartey ◽  
...  

A reconnaissance survey conducted at the University of Ilorin Sugar Research Farm (USRF) revealed four dominant soils at Site 1 (USRF1) and one at Site 2 (USRF2). The soils were characterized and classified according to both the Soil Taxonomy (ST) and the World Reference Base for Soil Resources (WRB). Also, the suitability of the soils for sugarcane cultivation was evaluated using the limitation approach. While the USRF1 soils were reddish, the USRF2 soil was greyish due to poor drainage. The USRF1 soils were loamy sand with the AB-horizons of pedons II and III being gravelly. Pedon V had sandy loam surface, sandy clay loam subsurface and clay loam subsoil. The USRF1 soils were moderately acid while the USRF2 soil was slightly acid to slightly alkaline. Exchangeable calcium (Ca2+) content of the USRF2 soil which averaged 4.00 cmolc kg–1 was 2-3 times higher than that of the USRF1 soils. The USRF2 soil also contained higher Mg2+, K+ and Na+, 2-3 folds higher effective cation exchange capacity and > 10 folds higher soil organic carbon (with mean of 11.60 g kg–1) and total nitrogen (mean of 0.94 g kg–1). Under ST, pedons I and IV classified as Typic Haplustepts, II and III as Lithic Haplustepts and V as a Kanhaplic Haplustalf. Under WRB, pedons I and IV classified as Eutric Regosols (arenic), II and III as Endo-pisoplinthic Cambisols (arenic) and V as a Gleyic Lixisol (loamic). Pedon V was highly suitable (85.25%), I and IV moderately suitable (64.53%), II marginally suitable (47.40%) and III unsuitable (35.62%) for sugarcane cultivation.


Clay Minerals ◽  
1976 ◽  
Vol 11 (2) ◽  
pp. 137-146 ◽  
Author(s):  
G. S. R. Krishna Murti ◽  
V. A. K. Sarma ◽  
P. Rengasamy

AbstractThe amorphous mineral selectively dissolved from the clay (<2 μm) fractions of twenty-six ferruginous soils contains considerable iron in addition to silicon and aluminium. SiO2/Al2O3 and SiO2/R2O3 molar ratios are between 2·03-3·52 and 1·72-2·95 respectively. The model of the amorphous ferri-aluminosilicate (AFAS) consists mainly of negatively charged tetrahedrally coordinated silica-alumina phase Si3AlO6(OH)4 containing domains of neutral FeOOH, with an outer positively charged hydroxyaluminium polymeric component [Al(OH)2.5]n.The calculated hydroxyl water content of the AFAS averages 17·8%; cation exchange capacity varies from 48·6 to 112·0 mEq/100 g and shows a negative correlation with the outer hydroxyaluminium octahedral component and a positive correlation with the ratio of the tetrahedral Si-Al component to the octahedral hydroxyaluminium component. The K-fixation capacity (1·9-6·1 mEq/100 g) of the AFAS does not appear to be related to the chemical composition. The genesis of the amorphous mineral is discussed.


2018 ◽  
Vol 106 (11) ◽  
pp. 917-926 ◽  
Author(s):  
Brijlesh Kumar Nagar ◽  
Khushboo Kumari ◽  
Sadhan Bijoy Deb ◽  
Manoj Kumar Saxena ◽  
Bhupendra Singh Tomar

AbstractDysprosium-titanate (Dy2TiO5), being highly refractory in nature, its dissolution using conventional (hot-plate and fusion) methods is very difficult. Hence, for quantitative dissolution, a microwave method has been developed. The instrumental parameters and amount of acids has been optimized. Studies have been carried out for precise and accurate estimation of major elements such as Dy, Ti, and Mo. An anion exchange column has been used to separate Mo, Dy and Ti. Analysis of these elements has been carried out using ICP-MS, UV-visible spectroscopy, and gravimetric methods. In the developed method, precipitation of molybdenum and dysprosium has been done using α-benzoine oxime, and oxalic acid respectively. These precipitates have been converted into their respective oxide form. The purities of these oxides (Dy2O3and MoO3) have been determined using ICP-MS. The method has been validated using synthetic samples where it is found that accuracy of Dy and Mo is >99% and precision is <1 (%RSD). The titanium has been determined using UV-visible spectroscopy with accuracy >98% and precision <2 (%RSD).


2019 ◽  
Vol 8 (1) ◽  
pp. 34
Author(s):  
Rachmad Wunangkolu ◽  
Rismaneswati Rismaneswati ◽  
Christianto Lopulisa

Land potential can be assessed from biophysical land suitability including soil characteristics, climate, and land management. This study aims to determine the potential of paddy fields in Duampanua Sub-District, Pinrang District for irrigated paddy field based on the land biophysical characteristics. The method was qualitative and quantitative approaches. Field surveys use purposive sampling method with 3 object observation. The land suitability class evaluation uses a simple limiting factor approach according to FAO (1976). To support the analysis of rice production data, 30 farmers were interviewed in 3 (three) observation units. The results showed the average rainfall of 2,780.2 mm/year with 9 wet months and 3 dry months categorized as type B2 (Oldeman). The results of soil samples analysis showed the characteristics of the soil with a silty clay texture, silty clay loam and clay; bulk density ranges from 1.36-1.66 g/cm3; cation exchange capacity ranges from 49.64 - 79.75 cmol/kg clay; soil pH ranges from 5.26-5.97; base saturation ranges from 36% - 46.4%; and C-organic ranges from 1.34% - 1.38%. The most dominant types of minerals are orthoclase, biotite, pyroxene, augite, opaque and clay with the symptoms of micropedological concretions and nodules. The land suitability class in the three land units for irrigated paddy rice is classified as S2nr (quite suitability in accordance with the limiting factors for nutrient retention including: base saturation, pH, and C-organic). The average productivity in land units I is 5.1 ton/ha, land unit II is 4.5 ton/ha, and in land units III 5.26 ton/ha.


2006 ◽  
Vol 63 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Zigomar Menezes de Souza ◽  
José Marques Júnior ◽  
Gener Tadeu Pereira ◽  
Diogo Mazza Barbieri

Soils with small variations in relief and under the same management system present differentiated spatial variabilities of their attributes. This variability is a function of soil position in the landscape, even if the relief has little expression. The aim of this work was to investigate the effects of relief shape and depth on spatial variability of soil chemical attributes in a Typic Hapludox cultivated with sugar cane at two landscape compartments. Soil samples were collected in the intercrossing points of a grid, in the traffic line, at 0-0.2 m and 0.6-0.8 m depths, comprising a set of 100 georeferenced points. The spatial variabilities of pH, P, K, Ca, Mg, cation exchange capacity and base saturation were quantified. Small relief shape variations lead to differentiated variability in soil chemical attributes as indicated by the dependence on pedoform found for chemical attributes at both 0-0.2 m and 0.6-0.8 m depths. Because of the higher variability, it is advisable to collect large number of samples in areas with concave and convex shapes. Combining relief shapes and geostatistics allows the determination of areas with different spatial variability for soil chemical attributes.


2019 ◽  
Vol 486 (5) ◽  
pp. 583-587
Author(s):  
A. M. Agashev

The paper presents the results of major and trace elements composition study of garnet megacrysts from Mir kimberlite pipe. On the major elements composition those garnets classified as low Cr and high Ti pyropes. Concentrations of TiO2 show a negative correlation with MgO и Cr2O3 contents in megacrysts composition. Fractional crystallization modeling indicates that the most appropriate melt to reproduce the garnet trace elements signatures is the melt of picritic composition. Composition of garnets crystallized from kimberlite melt do not correspond to observed natural garnets composition. Kimberlites contain less of Ti, Zr, Y and heavy REE (rare earth elements) but more of very incompatible elements such as light REE, Th, U, Nb, Ba then the model melt composition that necessary for garnet crystallization.


Author(s):  
Godwin Okereafor ◽  
Mamookho Makhatha ◽  
Lukhanyo Mekuto ◽  
Vuyo Mavumengwana

In the Blesbokspruit area of Ekuhurleni, South Africa, previous gold mining activities resulted in many tailings dump sites. 20 representative soil samples were used in describing the distribution of metals. The soils were very strongly acidic ranging from 3.86 to 4.34 with a low cation exchange capacity (CEC). Based on X-ray fluorescence (XRF) analysis, elemental composition of the soils revealed average values of major elements such as Na2O (0.18%), MgO (0.63%), Al2O3 (6.51%), SiO2 (81.83%), P2O5 (0.04%), SO3 (3.40%), K2O (1.98%), CaO (0.45%), TiO2 (0.51%), Cr2O3 (0.17%), MnO (0.04%), Fe2O3 (3.59%), NiO (0.04%), As2O3 (0.02%), with Rb2O and SrO falling below 0.01%. Trace metals (TM) contamination levels in the soils were evaluated using various pollution indices which revealed that over 60% of the soils were between the high degree and the ultra-high degree of contamination classes. The concentration of various trace metals varies from 860.3–862.6 mg/kg for Cr; 324.9–328.4 mg/kg for Al; 200.9–203.4 mg/kg for As; 130.1–136.2 mg/kg for Fe; 121.9–125.8 mg/kg for Pb; 27.3–30.2 mg/kg for Co; 23.8–26.8 mg/kg for Ni; 7.2–9.2 mg/kg for Ti; 7.1–9.2 mg/kg for Cd; 4.0–5.6 mg/kg for Zn and 0.1–0.6 mg/kg for Cu.


HortScience ◽  
2007 ◽  
Vol 42 (2) ◽  
pp. 349-352 ◽  
Author(s):  
Janet F.M. Rippy ◽  
Paul V. Nelson

Variations in moss peat cation exchange capacity (CEC) and base saturation (BS) can result in inconsistent initial pH in moss peat-based substrates created using standard formulas for limestone additions and can lead to subsequent drift from the initial pH in those substrates. This study was conducted to determine the extent of such variation. CEC and BS were measured in three replications on 64 moss peat samples that were selected from three mires across Alberta, Canada, to represent maximum gradients in plant species composition within six degrees of decomposition acceptable for professional peat-based substrates. CEC ranged from 108 to 162 cmol·kg−1 (meq·100 g). Averaged overall samples, BS ranged from 15% to 71% of CEC and calcium accounted for 68%, magnesium for 25%, sodium for 5%, and potassium for 1.4% of BS. CEC was positively correlated to the amount of Sphagnum fuscum (Schimp.) Klingrr. in the sample (r = 0.22). BS was positively correlated to the amount of sedge (r = 0.28). Neither CEC nor BS was influenced by degree of decomposition (r = 0.002 and r = 0.08, respectively). Moss peats with high CEC have a greater buffering capacity than those with low CEC, resulting in less pH drift. Moss peats with high BS should have a low neutralization requirement to achieve a target pH. Understanding the species composition in peat-based substrates can alleviate problems of inconsistent initial pH and subsequent pH drift.


Sign in / Sign up

Export Citation Format

Share Document