scholarly journals Changes in the profile properties and chemical weathering characteristics of cultivated soils affected by anthropic activities

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiangwen Li ◽  
Jing Du ◽  
Shouqin Zhong ◽  
En Ci ◽  
Chaofu Wei
Keyword(s):  
Chemical Weathering ◽  
Chemical Properties ◽  
Natural Evolution ◽  
Soil Taxonomy ◽  
Forming Process ◽  
Genetic Characteristics ◽  
Reference Base ◽  
Pedogenic Process ◽  
Diagnostic Characteristics ◽  
The Future

AbstractThe study of the pedogenic process in response to natural evolution, gradual anthropogenic shifts and engineering upheavals is of great significance for understanding, utilizing and transforming nature in the future. Although scholars have considered anthropic activities to be an important factor affecting pedogenesis, research on how and how much anthropic activities influence the soil-forming process is scant. This paper was conducted to analyse pedogenic characteristics dominated by anthropic activities. In this study, the parent materials and soils undergoing natural evolution (NE), tillage perturbation (TP) and engineering perturbation (EP) were selected as research objects. The genetic characteristics of soils undergoing NE, TP and EP are investigated mainly from three aspects: soil profile macromorphological characteristics, soil physical and chemical properties and chemical weathering characteristics. The results indicated that the influence of anthropic activities (TP and EP) on the process of pedogenesis is complicated. First, compared with NE, TP decreases the thickness of topsoil from 22.2 to 21.2 cm, while EP increases the thickness of topsoil from 22.2 to 23.2 cm, and EP causes the soil to have a high profile development index. Second, compared with TP, EP can improve bulk density (BD), soil organic carbon (SOC), total nitrogen (TN) and cation exchange capacity (CEC), Finally, the chemical weathering intensity differed among NE, TP and EP and followed the order of TP > NE > EP. Therefore, in the future, the genetic characteristics of soils dominated by anthropic activities should be considered. This will help us systematically understand the genesis and evolutionary characteristics of soil and lay a foundation for further perfecting the diagnostic horizon and diagnostic characteristics of the Soil Taxonomy and World Reference Base.

scholarly journals Classification and assessment of agricultural potential of the lower Niger floodplain soils of Atani, Southeastern Nigeria

Agro-Science ◽  
2020 ◽  
Vol 19 (3) ◽  
pp. 51-61
Author(s):  
F.C. Okenmuo ◽  
C.O. Anochie ◽  
M.E. Ukabiala ◽  
C.L.A. Asadu ◽  
P.K. Kefas ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Soil Classification ◽  
Exchange Capacity ◽  
Available Phosphorus ◽  
Soil Taxonomy ◽  
Southeastern Nigeria ◽  
Reference Base ◽  
Anambra State ◽  
Agricultural Potential ◽  
Capability Evaluation

The soils of Atani floodplain in Anambra State of Nigeria contribute significantly to the food production of the State, hence the need to understand their behavior in order to enhance their management and productivity. Profile pits were sited along three physiographic units viz: levee crest, levee  slope and flood basin. Soil samples were collected from the profile horizons and subjected to standard laboratory procedures. Characterization of the soils was based on their morphological, physical and chemical properties. Soil classification was carried out using the USDA Soil Taxonomy and correlated with FAO/IUSS World Reference Base. Its agricultural potential was assessed using the fertility capability classification. The soils were deep. Topsoil colour was dominantly blackish black (10YR 3/2). Mottles were pervasive; an indication of impeded drainage conditions. The soils were predominantly fine textured. Soil pH values ranged from 4.8 to 6.2. Exchangeable Calcium was low to moderate (2.6-8.2 cmol kg−1); Magnesium was moderate to high (1.6-6.8 cmol kg−1); Sodium was high to very high (1.0-2.5 cmol kg−1), while potassium was high (1.2-4.2 cmol kg−1). Cation  exchange capacity values ranged from 11.6 to 42.6 cmol kg−1. Total nitrogen was very low to low (0.14-1.12 g kg−1), while organic carbon was low to moderate (0.4-15.2 g kg−1). Available phosphorus was very low to high ranging from 0.93 to 31.71 mg kg−1 while base saturation ranged from 64 to 93%. The soils were classified as Typic Fluvaquents (Typic Fluvisols), Fluvaquentic Endoaquepts (Endostagnic Cambisols) and Fluventic Endoaquepts (Endostagnic Cambisols) according to the USDA and FAO/IUSS. The fertility capability evaluation of the soils revealed that the pedons were Lgn in classification due to limitations in drainage. Key words: alluvium, cambic horizon, Inceptisols, lithologic discontinuity

Brunisolic soils of Canada: Genesis, distribution, and classification

2011 ◽  
Vol 91 (5) ◽  
pp. 695-717 ◽  
Author(s):  
C. A. S. Smith ◽  
K. T. Webb ◽  
E. Kenney ◽  
A. Anderson ◽  
D. Kroetsch
Keyword(s):  
Boreal Forest ◽  
Forest Cover ◽  
Reference Group ◽  
The Arctic ◽  
Soil Taxonomy ◽  
Reference Base ◽  
Podzolic Soils ◽  
Discontinuous Permafrost ◽  
Pedogenic Process ◽  
Wide Range

Smith, C. A. S., Webb, K. T., Kenney, E., Anderson, A. and Kroetsch, D. 2011. Brunisolic soils of Canada: Genesis, distribution, and classification. Can. J. Soil Sci. 91: 695–717. Brunisols are considered as moderately developed soils formed under forest cover. They have a wide range of physical and chemical properties and no single dominant pedogenic process drives the development of these soils. Brunisols are some of the more common soils in Canada, occupying over 1.2 million km2 of land, roughly equivalent to the area of Podzolic soils, and about half the area of the most common soil order in Canada, the Cryosols. Brunisols occur mainly within the boreal forest regions, but extend across the country with the exception of the Arctic and prairie regions. Within the zone of discontinuous permafrost they co-exist on landscapes with Cryosols. In humid regions of both eastern and western Canada they form a continuum of soil development with Podzolic soils. Within subhumid to semi-arid regions they often co-exist with Luvisolic soils, occurring on parent materials too coarse to enable Luvisolic soil formation. Brunisols equate closely to the Cambisol reference group in the World Reference Base taxonomic system and to several suborders of the Inceptisol order in Soil Taxonomy. Both Melanic and Sombric Brunisols are important agricultural soils in British Columbia, Ontario and the Maritime provinces. Eutric and Dystric Brunisols support commercial forest stands throughout the boreal forest and western cordillera of Canada.

scholarly journals COMPARATIVE ASSESSMENT OF TROPICAL RAINFOREST SOILS FORMED FROM DIFFERENT GEOLOGIC FORMATIONS IN SOUTHEASTERN NIGERIA

2021 ◽  
Vol 5 (1) ◽  
pp. 47-57
Author(s):  
Chike Onyeke Madueke ◽  
Ikokwu Kalu Okore ◽  
Ebubechukwu Chizoba Maduekeh ◽  
Akudo Ogechukwu Onunwa ◽  
Maduabuchi Johnbosco Okafor ◽  
...  
Keyword(s):  
Land Use Planning ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
United States Department ◽  
Soil Taxonomy ◽  
Southeastern Nigeria ◽  
Reference Base ◽  
Clay Shales ◽  
World Reference Base ◽  
Study Sites

Data on the nature, properties and potentials of soils is grossly inadequate in the rainforest belt of southeastern Nigeria. As such, policymakers and other land users have tended to subscribe to unduly generalized ideas about the soils of the region. This has led to improper land use planning and aggravated land degradation. This necessitated the need for the comparative evaluation of the nature and potentials of the soils of the region to determine their degree of variability. Profile pits were dug in four towns underlain by different geologic formations: Umungwa (Benin Formation), Umuawa Ogii (Nsukka Formation), Ikpem (Igbaku Sandstones) and Amuro (Imo Clay Shales). The soils were characterized and classified using the World Reference Base for Soil Resources (WRB), United States Department of Agriculture (USDA) Soil Taxonomy and land capability classification. The variability of soils across the different sites was subsequently analysed using the coefficient of variation (CV). The results show that the variability of sand across the study sites was moderate (20 – 21 %), silt was high (63 %), clay ranged from moderate (34 %) to high (52 %), while hydraulic conductivity was very high (128 – 144 %). Similarly, with regards to the chemical properties, soil pH and base saturation ranged from moderate (20 – 49 %) to high (52 %), while effective cation exchange capacity (ECEC) and aluminium saturation were high (70 – 77 %). It was concluded that the soils of southeastern Nigeria are very heterogeneous. Undue generalization should consequently be discouraged.

Characteristics and genesis of two strongly weathered soils in Samar, Philippines

Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 153 ◽  
Author(s):  
Ian A. Navarrete ◽  
Victor B. Asio ◽  
Reinhold Jahn ◽  
Kiyoshi Tsutsuki
Keyword(s):  
Clay Fraction ◽  
Chemical Properties ◽  
Morphological Characteristics ◽  
Clay Content ◽  
Parent Material ◽  
Parent Rock ◽  
Soil Taxonomy ◽  
Reference Base ◽  
Weathered Soils ◽  
World Reference Base

Very limited data have been published on the nature of strongly weathered soils in geologically young humid tropical islands. The study evaluated the characteristics and formation of 2 strongly weathered soils in the island of Samar, Philippines, one developed from slate (Bagacay soil) and the other from ultrabasic rock (Salcedo soil). Results revealed that the soils have generally similar morphological characteristics, particularly in terms of colour (2.5 YR-10 R), solum thickness (>5.0 m), and structure (granular to subangular blocky), although the Salcedo soil has much higher clay content than the Bagacay soil. Both soils have similar chemical properties (e.g. acidic, low exchangeable bases) except that the Salcedo soil has lower CEC values but higher exchangeable Na content, resulting in a higher base saturation. They also have high dithionite-extractable Fe contents and very low oxalate/dithionite ratios and are dominated by halloysite, kaolinite, gibbsite, goethite, hematite, and quartz in the clay fraction. Apparently as a result of its more weatherable ultrabasic parent rock and more stable geomorphic surface, the Salcedo soil shows more advanced weathering and soil development than the Bagacay soil. Salcedo soil is classified as Haplic Ferralsol (Dystric, Clayic, Rhodic) in the World Reference Base or very fine, sesquic, isohyperthermic, Rhodic Hapludox in the Soil Taxonomy. Bagacay soil is a Haplic Acrisol (Alumic, Hyperdystric, Clayic, Rhodic) or fine, kaolinitic, isohyperthermic, Typic Paleudult. The Salcedo soil has very high Ni and Cr contents inherited from its ultrabasic parent material. The study reveals that on the geologically young humid tropical island of Samar, the characteristics and genesis of strongly weathered soils are greatly affected by the geochemical characteristic of the parent rock material.

Identification of the Location of Conductive Filaments Formed in Pt/NiO/Pt Resistive Switching Cells and Investigation on Their Properties

2012 ◽  
Vol 1430 ◽  
Author(s):  
Tatsuya Iwata ◽  
Yusuke Nishi ◽  
Tsunenobu Kimoto
Keyword(s):  
Resistive Switching ◽  
Chemical Properties ◽  
Cell Resistance ◽  
Forming Process ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Size And Shape

ABSTRACTExact locations of conductive filaments formed in NiO-based resistive switching (RS) cells were detected by C-AFM, and their electrical as well as chemical properties were investigated. After a forming process, a part of top electrodes of Pt/NiO/Pt RS cells is deformed. NiO layers are also deformed, and conductive spots, i.e. filaments have been found preferentially along the edges of deformations. Detailed C-AFM investigation has revealed that variation of cell resistances originates from differences in size and shape of filaments, not their resistivity. Furthermore, cross-sectional TEM analysis has demonstrated that filaments determining cell resistance consist of reduced NiO with an inclusion of Pt.

Fake News im Wahlkampf

2021 ◽  
Author(s):  
Jessica Flint
Keyword(s):  
Social Networks ◽  
Public Opinion ◽  
Fundamental Rights ◽  
Election Campaigns ◽  
Fake News ◽  
Forming Process ◽  
Private Companies ◽  
The Future

The urgency of regulating fake news on social networks regarding election campaigns is more evident than ever. This poses considerable difficulties for legislative practice. It is important to consider the fundamental rights of the parties involved without the state's influence on the formation of public opinion becoming too great. The current options of reacting to fake news do not suffice to ensure a free opinion-forming process. This publication makes an innovative proposal as to how social networks – especially Facebook – can be regulated in the future in such a way that the discourse is strengthened and the alarming influence of private companies on the formation of opinion is limited.

The Future of Soil Taxonomy

2014 ◽  
pp. 317-320
Author(s):  
James G. Bockheim
Keyword(s):  
Soil Taxonomy ◽  
The Future

scholarly journals Characterization, classification and suitability evaluation of soils under sugarcane (Saccharum officinarum L.) cultivation at the Sugar Research Farm, University of Ilorin, Nigeria

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 ◽  
...  
Keyword(s):  
Sandy Loam ◽  
Saccharum Officinarum ◽  
Exchange Capacity ◽  
Clay Loam ◽  
Soil Taxonomy ◽  
Reference Base ◽  
Suitability Evaluation ◽  
Reconnaissance Survey ◽  
World Reference Base ◽  
The University

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.

scholarly journals Chemical properties and fertility analysis of dredger-fill silt during soil formation: The tianjin dredge–fill project

2017 ◽  
Author(s):  
Huijun Gu ◽  
Xin Sui ◽  
Guogang Zhang ◽  
Meiqing Jia
Keyword(s):  
Nitrate Nitrogen ◽  
Chemical Properties ◽  
Soil Formation ◽  
Principal Component ◽  
Available Phosphorus ◽  
Forming Process ◽  
Factors Affecting ◽  
Ecological Problems ◽  
Dredger Fill ◽  
Fertility Analysis

Dredger-fill silt has been used in the port of Tianjin, China to reclaim land; however, the dredger-fill silt has no soil ecological function. Translating the silt into soil rapidly and accelerating the soil-forming process are key to solving the ecological problems of the Dredge–Fill project. This study measured 15 chemical properties of the dredger-fill silt for 8 years of the soil forming process to explore fertility changes and the critical factors affecting soil formation. The results showed that: (1) the salinity of silt changed from severe to mild with a reduction in Na+ and Cl- concentration. Other ion concentrations changed slightly. (2) Effective nutrients significantly decreased during soil formation. Soil organic matter (SOM)，the nitrate-nitrogen, available phosphorus (A-P) and available potassium (A-K) decreased by 26.22%, 86.23%, 45.92%, 33.61% respectively, indicating severe nutrients loss. (3) Principal component analysis showed that silt fertility decreased significantly and the total soil fertility loss was severe. This study has significance for the artificial improvement of silt.

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