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Lecture Notes on the Major Soils of the World
Abstract
These lecture notes describe the major soils of the world (Histosols, Anthrosols, Andosols, Arenosols, Vertisols, Fluvisols, Gleysols, Leptosols, Regosols, Cambisols, Plinthosols, Ferralsols, Alisols, Nitisols, Acrisols, Lixisols, Solonchaks, Solonetz, Gypsisols, Durisols, Calcisols, Chernozems, Kastanozems, Phaeozems, Podzols, Planosols, Albeluvisols, Luvisols, Umbrisols, and Cryosols), their properties, genetic formation and regional distribution. All soils are discussed with due attention being paid to their management and associated land use. The World Reference Base for Soil Resources is used as the correlation system throughout the text. It is intended to facilitate the study of soils and the exchange of soil information, and provides a common language for soil science
... Mulugeta and Sheleme (2010) also reported that soils on slopes that have never been saturated with water had reddish and brownish subsoil colors while soils on poorly drained locations tended to have grey-colored B-horizons. However, the greyish subsurface soils color at the summit could be due to the limited weathering of smectite clays that remain stable as long as the pH is above neutral and result in subsoils with a lower red hue and weaker chroma because of the less free ferric ions (Driessen et al., 2001). Besides, the blackish/greyish sub-surfaces at the shoulder could be due to the leaching accumulation of weathered smectitic clays that impede internal drainage upon cementation of subsoil particles while providing reddish soil color owing to Fe 3+ compounds left behind in the surface horizon (Driessen et al., 2001). ...
... However, the greyish subsurface soils color at the summit could be due to the limited weathering of smectite clays that remain stable as long as the pH is above neutral and result in subsoils with a lower red hue and weaker chroma because of the less free ferric ions (Driessen et al., 2001). Besides, the blackish/greyish sub-surfaces at the shoulder could be due to the leaching accumulation of weathered smectitic clays that impede internal drainage upon cementation of subsoil particles while providing reddish soil color owing to Fe 3+ compounds left behind in the surface horizon (Driessen et al., 2001). ...
It is imperative to understand and predict the nature and distribution of soils along a given physiographic condition. However, the hitherto practices of collecting basic soil information at a site-specific level seem inadequate to assure sustainable agricultural production via proper utilization and effective management of soil resources. Therefore, this research was conducted to characterize, classify, and map soils along the toposequence of Qenberenaweti sub-watershed, Central Highlands of Ethiopia. A total of 91 auger inspections were made up to a 120 cm depth to define soil mapping units with their boundaries. Then, six pedons were opened at typical slope positions along the toposequence. The depth of the pedons varied between 135 and 200+ cm, whereas the thickness of A-horizons showed an increasing trend down the slope by excluding the back-slope position. All the soils at surface and subsurface horizons had clayey texture with pH ranging from 5.59 to 6.23 and 5.31 to 7.65, respectively. The OC contents throughout the entire horizons varied from 0.22 to 2.03%. The highest CEC values were found at the middle slope position followed by pedons at the upper and bottom parts. The exchangeable cations of most pedons were in declining order of Ca, Mg, K, and Na except for the Mg dominance over Ca at the back slope and bottom depression. Hereby, six soil types were identified; and their distribution was mapped. The results of this research revealed that the extent of variations in key topographic features resulted in the formation, development, and distribution of diversified soils along the toposequence. Consequently, such detailed soil characterization, classification, and mapping work is vital for proper planning, management, and utilization of the soil resources at local topographic conditions. However, further research should be done to ensure sustainable agricultural production in the study area.
... High Fe/K is thought to indicate high soil erosion or chemical weathering, pointing to increased precipitation (Govin et al., 2012) in southern South Africa. The type of soil has a notable impact, for instance the Kwa-Zulu Natal province is extensively covered by lixisols, which has a high Fe oxide content, while the 425 eastern Cape and western Cape have a high proportion of luvisols which is lower in Fe oxide, and durisols and leptosols that are even lower in Fe oxide (Driessen et al., 2001;Garzanti et al., 2014). The relationship between Fe/K and river catchment precipitation can also be affect by other factors, notably vegetation cover, where low cover increases soil erodibility (Ludwig and Probst, 1998), organic acids released by vegetation which can increase the dissolution rate of minerals (Benedetti et al., 1994), high temperatures accelerating chemical weathering in subtropical humid regions (Driessen et al., 2001), and 430 diagenetic Fe remobilisation in marine sediments due to redox processes linked with changes in sedimentation rates or turbidites (e.g., Thomson et al., 1996). ...
... The type of soil has a notable impact, for instance the Kwa-Zulu Natal province is extensively covered by lixisols, which has a high Fe oxide content, while the 425 eastern Cape and western Cape have a high proportion of luvisols which is lower in Fe oxide, and durisols and leptosols that are even lower in Fe oxide (Driessen et al., 2001;Garzanti et al., 2014). The relationship between Fe/K and river catchment precipitation can also be affect by other factors, notably vegetation cover, where low cover increases soil erodibility (Ludwig and Probst, 1998), organic acids released by vegetation which can increase the dissolution rate of minerals (Benedetti et al., 1994), high temperatures accelerating chemical weathering in subtropical humid regions (Driessen et al., 2001), and 430 diagenetic Fe remobilisation in marine sediments due to redox processes linked with changes in sedimentation rates or turbidites (e.g., Thomson et al., 1996). ...
During the late Quaternary the past climatic conditions of southern South Africa underwent fluctuations, influenced by various climatic factors, such as the impacts of both the Indian and Atlantic Oceans, as well as the effects of the southeasterly trade winds and Southern Hemisphere Westerlies (SHW), influenced by changes in orbital parameters. At the same time, this region exhibits some of the most abundant Middle Stone Age (MSA) archaeological sites containing records of Homo sapiens behavioural and technological evolution. Consequently, there is a pressing need for precise climatic reconstructions that can provide climate constraints during the MSA in this area. However, there is a lack of continuous high-resolution climate records covering the majority of the MSA, which spans from ~300 to ~60 ka. In this study, we present data obtained from a marine sediment core (MD20-3592) that spans approximately the last 260,000 (from m8 to 1) aiming to expand the spatial and temporal coverage of available climate archives. This marine sediment core documents both terrestrial and ocean hydroclimate variability because it is strategically positioned close to the South African coastline receiving terrestrial sediments via riverine input as well as being located under the marine influence of the Agulhas Current at the same time. X-ray fluorescence (XRF) core scanning, calibrated with discrete samples analyzed by XRF spectroscopy, was used to determine the variability of the bulk elemental composition of the core over time. Principal component analysis was performed to facilitate the interpretation of the data. Statistical analyses including frequency analysis, gaussian filtering, and wavelet analysis reveal that the regional hydroclimate was affected mostly by local insolation changes caused by orbital precession, and high latitude forcing that varies on timescales associated with orbital obliquity and eccentricity. Increased fluvial input was associated with a high precession index, during times of high local insolation, due to the effects of precession on local convergence and seasonal rainfall. Comparison with regional climate archives confirmed the dominant influence of precession on precipitation in southern South Africa. On glacial-interglacial timescales, lower precipitation observed during glacial intervals could be explained by a northward shift of the Southern Hemisphere Westerlies (SHW) and South Indian Ocean convergence zone (SIOCZ). Finally, the data from core MD20-3592 can provide a climatic context for the appearance of behavioral complexity in South Africa between ~ 120 ka and ~ 50 ka. Humid conditions in the river catchments going through the south coast and south-east coast of South Africa were present at approximately 117 ka, 93 ka, and 72 ka, alternating with dry conditions at approximately 105 ka, 83 ka, and 60–50 ka.
... Plant communities in this region include gallery forests, woodlands and tree and shrub savannas (Nacoulma 2018). The region experiences temperatures from 16°C in the coolest months to 40°C in the hottest months (Driessen 2001). Cassou Forest was selected for its high biodiversity and rich vegetation, providing an ideal setting to study how structural diversity influences AGB-productive, forested savanna areas. ...
The role of plant diversity and biomass in ecosystem functioning and management is well recognized. However, the structural drivers of aboveground biomass (AGB) and their influence across savanna ecosystems remain understudied, particularly in semi‐arid regions. Here, we hypothesized that (i) species richness and structural diversity would positively influence AGB across vegetation strata and (ii) environmental factors would play a secondary role compared to diversity metrics. We tested these hypotheses using data from 160 systematically established plots (0.1 ha each) in two savanna sites (Cassou and Kongoussi) in Burkina Faso. We examined how taxonomic diversity, structural diversity (CV‐DBH, CV‐height) and environmental factors contribute to AGB and aboveground carbon (AGC) stocks. A total of 97 woody species from 66 genera and 26 families were identified. Species richness had a significant positive effect on AGB in both strata, with a more pronounced influence in shrub layers. Structural diversity, particularly CV‐DBH and CV‐height, also contributed significantly to AGB, especially in Cassou. Elevation negatively influenced AGB at both sites, while NDVI and EVI2 were positively correlated with AGC in Kongoussi but not in Cassou. Species richness and structural diversity, especially in shrub strata, were the primary drivers of AGB, underscoring their importance for carbon sequestration. The study highlights the important role of structural diversity and taxonomic richness in determining AGB, particularly in shrub‐dominated savannas. Management strategies focusing on the conservation of species diversity and enhancement of structural diversity are essential to optimize biomass accumulation and ecosystem functioning in semi‐arid savanna ecosystems.
... The yearly mean air temperature is estimated at 22.5˚C, ranging from 18˚C to 26˚C, with the mean maximum ranging from 25.5˚C to 32.5˚C, and the mean minimum from 10.5˚C to 20˚C (MAE, 2005). Lixisols are the predominant soils in the area (Driessen et al., 2001), which are strongly weathered soils with clay accumulation at depth, often requiring recurrent inputs of fertilizers and lime for arable farming. Examples of the sampled soil profiles are displayed in the supplemental material ( Figure S1). ...
Coffee (Coffea L.) agroforestry systems (CAFS) and wooded grasslands (WG) have been pointed out as having high soil organic carbon (SOC) storage potential compared to monoculture systems. Studies analyzing the response of soil bulk density (BD) and SOC to the conversion of WG to slash‐and‐burn agriculture (SBA) and to CAFS are lacking in southern Africa. This study was conducted in the buffer zone of Gorongosa National Park (Mozambique), where depth profiles of BD and SOC were estimated to 0‐ to 100‐cm soil depth in WG, SBA, and CAFS sites, with coffee shrubs aged 3, 5, and 8 years after planting. The stratification ratio (SR) was used as an indicator of soil quality and recovery from disturbance. BD and SOC stocks varied significantly among land use systems and coffee ages only in the surface soil layer (0–20 cm). SOC stocks of the surface soil and SR increased with increasing coffee age. Compared to SBA, significant increases in SOC stocks were only observed 5 years after implementation of CAFS. WG conversion to SBA did not alter SOC stocks in any soil layer; however, it led to decreased SR. Surface SOC stocks were 25.6 and 33.7 Mg ha⁻¹ in WG and SBA, and 28.0, 41.9, and 61.1 Mg ha⁻¹ in 3‐ and 5‐ and 8‐year‐old CAFS (mean SOC accumulation of 6.65 Mg ha−1 year⁻¹). This study reveals that CAFS have the potential to increase belowground carbon sequestration when compared to SBA and WG over comparable soils, making it a practical option for climate change mitigation.
... Tropical soils are acid, with mineralogy formed mainly by kaolinite and oxides, which have surface groups Si-OH, Fe-OH, and Al-OH (Melo and Aleoni, 2009), in which P can be strongly adsorbed through the exchange of ligands with the establishment of covalent bonds (Machado and Souza, 2012;Vinha et al., 2021). Thus, most of the P added to the soil is fixed and does not remain readily available for crops to take up (Sanchez, 1976;Driessen et al., 2001). Studies show that wood ash can contribute to increased soil P availability (Tan and Lagerkvist, 2011;Melese and Yli-Halla, 2016). ...
It is estimated that the livestock sector accounts for about 40% of the value of global agricultural production. Livestock plays an essential role in maintaining food security as the sector contributes around 13% of calories and 28% of protein demands required by humans worldwide. Fertilization of tropical pastures with wood ash emerges as a sustainable practice that can contribute to better nutrient cycling, increased production, and reduced dependence on mineral resources. In this context, the aim of this study was to evaluate the production characteristics of two Panicum maximum grass cultivars fertilized with ash from wood grown in tropical soils of the Brazilian Cerrado. The experimental design was in randomized blocks in a factorial arrangement 5x2 with five doses of wood ash (0, 8, 16, 24, and 32 g kg-1) and two cultivars of Panicum maximum (cv. BRS Zuri and cv. Mombasa), with six replications. The experiment was carried out in 5 dm 3 pots for 120 days. The wood ash used in the experiment comes from the combustion of eucalyptus (Eucalyptus sp.) logs in a boiler. The application of wood ash in acidic tropical soils increased leaf area, tillering, leaf dry mass, stem dry mass, and root volume in Mombasa and BRS Zuri cultivars of Panicum maximum grass, with maximum production at a dose of 32 g kg-1. The application of wood ash in acidic tropical soils offers potential as a sustainable strategy to increase production in forage production area for animal consumption in grazing, given the growing demand for beef. In addition, it properly and safely disposes of waste and recycles nutrients extracted by the crops.
... Lime accumulations will occur deeper and deeper in the profile with an increase in the AI (more humid conditions). Lime accumulations can also be due to restricting soil layers which hinders leaching (Driessen and Deckers, 2001;Netterberg, 1978). ...
Ferrolysis. A hydromorphic soil-forming process. Thesis abstract
A hypothesis was proposed explaining clay decomposition and interlayering in acid, seasonally wet soils, under the influence of the periodic reduction and oxidation of iron. This process, termed ferrolysis, is as follows. In the wet season, reduction of ferric oxides produces dissolved ferrous iron, which displaces and mobilizes exchangeable bases. The bases (and dissolved ferrous iron) are partially removed by leaching. In the dry season, oxidation of exchangeable ferrous iron produces ferric oxides and exchangeable hydrogen leading to partial decomposition of the clay and release of aluminium and silica. Aluminium interlayers with trapped ferrous iron are formed in 2:1 clays by partial neutralization of exchangeable aluminium together with reduction of ferric oxides in the wet season; thus the cation exchange capacity decreases further.
The implications of ferrolysis were tested by morphological, chemical and mineralogical analysis of several acid, seasonally wet soils from South-east Asia and different parts of Europe. The effects of various other processes, e.g. cheluviation and clay translocation, were also identified in some of these profiles.
Until now, ferrolysis was not clearly distinguished from cheluviation (podzolization sensu stricto), clay translocation and desilication. Therefore, criteria are given to differentiate between the effects of these processes.
Free descriptors: surface-water gley soils, pseudogley soils, podzolic soils, paddy soils, Planosols, Gleyic Acrisols, Aqualfs, Aquults, Albic horizon.
FULL TEXT: library.wur.nl/WebQuery/clc/103366, click 'full text', next screen click 'Proefschrift' (Thesis). (download button below defective)
Fifteen separate delta lobes have been formed by the Mississippi River in the past 6,000 years. Fourteen are included in the Teche, St. Bernard, and Lafourche deltaic complexes; the fifteenth includes the present birdfoot delta, which is an extension of the initial lobe of the Plaquemines-Modern complex. Each deltaic complex is genetically related to a major Mississippi River trunk stream, whereas delta lobes within each complex are the result of different distributary networks extending from the trunk stream. The delta lobes were defined by detailed facies analyses of sediment cores from hundreds of shallow borings combined with lithologic and faunal data from several hundred additional borings. Each lobe consists of a basal fine-grained prodelta facies, an overlying sandy delta-front facies, and an uppermost fine-grained delta-plain facies. The latter deposits include peat accumulations and nonorganic flood-basin and natural-levee deposits. More than 100 radiocarbon age determinations have been used to establish the chronology of major deltaic complexes and their subsidiary delta lobes. These data, together with the facies relations, indicate that growth of each deltaic complex was sporadic; progradational phases were interrupted by transgressions resulting from local shifting of sediment influx and from subsidence. Similar deltaic sequences, prevalent in Tertiary outcrops along the northern flank of the Gulf Coast geosyncline, extend basinward as massive subsurface clastic wedges, which constitute a major part of the peripheral basin fill. End_of_Article - Last_Page 2164------------