Soil Formation
Soil Formation
Soil formation, or pedogenesis, is the collection of physical, chemical, biological, and geomorphic processes through which geological material is transformed into soil. Rather than being an inert layer covering the Earth's surface, soil is a continually evolving system shaped by interactions among parent material, climate, organisms, topography, and time.
A widely used framework describes soil development in terms of additions, losses, transfers, and transformations. Organic matter and atmospheric materials may be added to soil; dissolved minerals and eroded particles may be lost; clay, organic matter, iron, and other substances may move between horizons; and minerals and organic compounds may be chemically or biologically transformed. The balance among these processes produces the enormous diversity of soils found across landscapes.
Soil-Forming Factors and Pedogenesis
The classical soil-forming factors are parent material, climate, organisms, relief or topography, and time. Each affects soil independently while also interacting with the others.
Parent material determines the minerals and physical characteristics available at the beginning of soil development. Climate influences temperature, rainfall, evaporation, biological activity, and the rate of chemical reactions. Organisms contribute organic matter, alter mineral surfaces, create pores, mix soil, and redistribute nutrients. Topography affects drainage, erosion, deposition, exposure, and movement of water through landscapes. Time determines how long all of these processes have been able to operate.
Modern research increasingly treats soils as dynamic systems rather than products of a simple linear sequence. Soil development occurs simultaneously across different spatial and temporal scales, and changing environmental conditions can redirect pedogenic processes.
Weathering and Parent Material
Weathering is one of the fundamental processes involved in producing soil from rock and unconsolidated geological material. Physical weathering breaks material into smaller particles, while chemical weathering alters minerals through processes such as dissolution, oxidation, hydrolysis, and leaching.
The mineral composition of parent rock can strongly influence the soils that subsequently develop. Different minerals weather at different rates and release different combinations of nutrients and chemical elements.
Soil-production rates are also related to landscape conditions. Research using geochemical mass balances and cosmogenic measurements has shown that soil thickness, bedrock weathering, erosion, and sediment transport are interconnected. Physical erosion can expose fresh mineral surfaces, sometimes accelerating chemical weathering.
Time and Soil Chronosequences
Time is a central element in soil formation. Scientists often study its effects using soil chronosequences, in which soils developed on surfaces of different known ages are compared.
Chronosequences can span periods ranging from decades to millions of years. Recently exposed landscapes, such as areas uncovered by retreating glaciers, provide opportunities to observe the earliest stages of soil formation. Older volcanic surfaces, dunes, river terraces, and marine terraces can reveal how soils change over thousands or millions of years.
Properties such as horizon development, soil color, mineral composition, nutrient availability, and organic-carbon accumulation can change systematically as soils age.
One important long-term pattern concerns phosphorus. During early soil development, weathering can release phosphorus from parent minerals. Over long periods, mineral phosphorus may decline while phosphorus becomes increasingly redistributed among organic and secondary mineral forms.
Soil Development Across Landscapes
Soil development does not occur uniformly across the Earth's surface. Chronosequences studied in coastal dunes, volcanic islands, marine terraces, mountains, and other landscapes demonstrate that climate, topography, geology, and time interact in different ways.
Research on Hawaiian and Galápagos volcanic landscapes shows that rainfall can strongly alter the trajectory of mineral weathering and soil development. Studies of coastal dunes demonstrate how progressively older surfaces can develop increasingly complex soil horizons and nutrient patterns.
Comparisons across climatic gradients also show that the same parent material can produce substantially different soils under different temperature and moisture regimes.
Mineral Weathering and Early Pedogenesis
During early pedogenesis, primary minerals inherited from rock begin to transform into secondary minerals. These transformations can include the formation of clay minerals, iron and aluminum compounds, and other weathering products.
Organic matter can influence these processes from surprisingly early stages of soil formation. Biological inputs can alter mineral dissolution and promote the development of soil aggregates and microscopic structure.
Over longer periods, interactions among weathering products, iron and aluminum minerals, organic matter, and microorganisms influence the capacity of soils to store carbon.
Erosion and deposition also redistribute soil materials across hillslopes. As a result, soil age, mineral residence time, and the age of the land surface are not necessarily identical.
Volcanic Soils and Rapid Soil Formation
Volcanic eruptions provide natural experiments in soil formation because fresh lava, ash, scoria, and other deposits create new parent materials whose approximate ages may be known.
Studies of volcanic deposits demonstrate that substantial soil development can occur within centuries. Weathering of volcanic ash can release nutrients, while vegetation and microorganisms contribute organic matter and accelerate biological and chemical processes.
The characteristics of the volcanic parent material matter. Porous scoria, dense basaltic lava, and fine volcanic ash can weather at different rates. Moisture availability is also a major control on volcanic pedogenesis.
Volcanic soils such as Andisols often develop distinctive mineralogical and chemical properties. Their subsequent characteristics can also be modified by agriculture, deforestation, and other land-use changes.
Organisms, Roots, Fungi, and Soil Formation
Living organisms are active participants in soil formation. Plant roots penetrate fractures, alter mineral surfaces, contribute organic carbon, influence soil aggregation, and create channels through which water and gases can move.
Trees can create localized zones of biological weathering around their roots. Roots growing into sandstone and other rock materials can contribute directly to the physical and chemical transformation of rock into soil.
Fungi, including root-associated mycorrhizal fungi, can accelerate mineral weathering and help plants obtain nutrients from mineral surfaces. Microorganisms also participate in decomposition, mineral transformations, and the development of soil structure.
Soil animals contribute through bioturbation. Earthworms, for example, burrow through soil, consume and redistribute organic matter, and mix mineral and organic material. Such biological processes can substantially alter soil profiles over long periods.
Soil Horizons, Translocation, and Pedogenic Processes
Soils commonly develop recognizable horizons because materials are redistributed vertically within the profile.
Podzolization involves the movement of organic matter, iron, and aluminum through acidic soils, producing strongly differentiated horizons. Clay illuviation involves the downward movement and accumulation of fine clay particles.
In seasonally wet soils, repeated reduction and oxidation can produce processes such as ferrolysis, contributing to clay destruction and acidification.
Intense weathering can also create iron-rich materials, nodules, and hematite. These minerals contribute to soil color and can provide evidence of past environmental and weathering conditions.
Because similar soil features can sometimes result from more than one process, interpreting soil genesis often requires considering multiple possible geological and pedogenic causes.
Topography, Catenas, and Soil–Landscape Relationships
Topography strongly influences soil formation by controlling erosion, deposition, drainage, hydrologic flow, and the movement of chemical elements.
A sequence of related soils occurring from higher to lower landscape positions is often described as a soil catena. Soil catenas demonstrate that soils are connected components of larger landscape systems rather than isolated profiles.
Water and dissolved elements can move downslope, while erosion removes material from upper slopes and deposition accumulates it in lower positions. Organisms can further redistribute material through burrowing and other biological activity.
Studies of catenas in Africa, the Americas, and other regions have helped demonstrate predictable relationships between landscape position and soil characteristics. The catena concept became an important framework for understanding recurrent patterns of soils across slopes.
Climate and Soil Formation
Climate affects nearly every major component of pedogenesis. Temperature influences biological activity and chemical reaction rates, while precipitation controls soil moisture, drainage, leaching, and the movement of dissolved substances.
Climosequence studies compare similar soils or parent materials across climatic gradients. These studies demonstrate that variations in rainfall and temperature can produce major differences in mineral weathering, soil color, nutrient cycling, and horizon development.
Climate interacts with time as well. A soil may pass through different stages or thresholds as prolonged weathering gradually changes mineral composition and nutrient availability.
Soil Carbon and Ecosystem Development
Soil formation and ecosystem development are closely linked. Newly developing soils gradually accumulate organic material from plants, microorganisms, and other organisms.
Soil carbon storage depends not only on organic inputs but also on interactions between organic compounds and mineral surfaces. Secondary iron and aluminum minerals produced through weathering can contribute to the stabilization of organic carbon.
Geomorphic processes complicate this relationship because erosion can remove soil carbon from one location while deposition accumulates carbon elsewhere.
Chronosequence studies therefore remain valuable for investigating how soil-carbon storage changes as soils and ecosystems develop over long periods.
Human Activity as a Soil-Forming Force
Humans increasingly influence virtually every traditional soil-forming factor. Agriculture changes vegetation, soil structure, erosion, nutrient cycling, organic matter, and hydrology. This influence has led to the concept of agropedogenesis, in which agriculture is treated as a major soil-forming force.
Urban environments can produce strongly modified or entirely anthropogenic soils through excavation, filling, construction, contamination, compaction, and redistribution of geological materials.
Human activities can also alter climate, organisms, parent materials, topography, and the rate at which soil processes occur. Modern soil science therefore increasingly recognizes human activity as a major component of pedogenesis during the Anthropocene.
Soil Formation as an Earth-Surface Process
Soil formation is inseparable from broader landscape evolution. Weathering produces soil while erosion, deposition, hydrology, biological activity, and tectonic or geomorphic processes continually redistribute and transform it.
Modern soil-evolution models attempt to integrate these processes across three-dimensional landscapes. Such models connect the development of soil profiles with changing topography, sediment transport, erosion, deposition, and biological activity.
Animals can even influence landscape-scale soil thickness. Burrowing organisms such as pocket gophers transport soil downslope, demonstrating that biological and geomorphic processes can operate together.
Conclusion
Soil formation is an integrated Earth-surface process produced by the interaction of geology, climate, organisms, topography, and time. Rocks and sediments are weathered into mineral materials; organisms add organic matter and accelerate transformations; water moves dissolved substances and particles through profiles; and erosion and deposition redistribute soils across landscapes.
Soils may begin forming rapidly on newly exposed volcanic deposits, glacial terrain, dunes, or river terraces, but many important transformations continue for thousands or millions of years. Chronosequences reveal how minerals, nutrients, horizons, biological communities, and carbon storage change through these long developmental periods.
Human activity has added another powerful influence. Agriculture, urbanization, land-use change, and other disturbances can redirect or accelerate processes that once were considered primarily natural.
Soil is therefore not simply weathered rock. It is a continuously developing interface among the atmosphere, biosphere, hydrosphere, and lithosphere, recording the combined effects of environmental change, biological activity, landscape evolution, and human action.
Soil Formation
Foundations of Soil Formation and Pedogenesis
1. Soil Development and Pedogenetic Processes
[Nature Index: Soil Development and Pedogenetic Processes | Nature Research Intelligence | Nature Index | 2026]
Explains how parent material, climate, organisms, topography, and time interact through weathering, additions, losses, translocation, and transformation to produce soils.
2. Soil-Forming Factors and Soil Taxonomy
[doi:10.1016/j.geoderma.2014.02.016 | James G. Bockheim et al. | Geoderma | 2014]
Evaluates how the classic soil-forming factors are represented in modern systems of soil classification.
3. Three Principles of Soil Change and Pedogenesis in Time and Space
[doi:10.2136/sssaj2011.0130 | Henry Lin | Soil Science Society of America Journal | 2011]
Develops a conceptual framework for understanding soil formation as a dynamic process operating simultaneously through space and time.
4. Soil Genesis and Development, Lesson 3: Soil Forming Factors
[doi:10.4195/jnrlse.2007.0035w | James A. Ippolito et al. | Journal of Natural Resources and Life Sciences Education | 2009]
Introduces the major soil-forming factors and shows how their interactions produce contrasting soil properties and profiles.
5. The Role of Soil-Forming Processes in the Definition of Taxa in Soil Taxonomy and the World Soil Reference Base
[doi:10.1016/S0016-7061(99)00083-X | James G. Bockheim and A. N. Gennadiyev | Geoderma | 2000]
Compares the importance assigned to pedogenic processes in two major international approaches to classifying soils.
6. Conceptual Models in Pedogenesis: Can Soil-Forming Functions Be Solved?
[doi:10.1016/0016-7061(75)90001-4 | Dan H. Yaalon | Geoderma | 1975]
Reviews attempts to quantify climate, parent material, topography, organisms, and time as mathematical soil-forming functions.
7. Soil Landscape Systems: A Model of Soil Genesis
[doi:10.1016/0016-7061(75)90035-X | Richard J. Huggett | Geoderma | 1975]
Treats soils and landforms as interconnected systems in which geomorphic and pedogenic processes evolve together.
8. Quantifying Pedogenesis for Soils with Discontinuities
[doi:10.2136/sssaj1973.03615995003700020031x | H. D. Wang and R. W. Arnold | Soil Science Society of America Journal | 1973]
Examines ways to quantify soil development where profiles contain changes or discontinuities in their original parent materials.
9. Outline of a Generalized Theory of Soil Genesis
[doi:10.2136/sssaj1959.03615995002300020021x | Roy W. Simonson | Soil Science Society of America Journal | 1959]
Presents the influential framework of additions, removals, transfers, and transformations as fundamental processes of soil genesis.
10. Soil-Forming Processes: Pedology in the Service of Soil Science
[doi:10.2136/sssaj1942.036159950006000C0010x | J. S. Joffe | Soil Science Society of America Journal | 1942]
Provides an early synthesis of the processes responsible for transforming geological material into differentiated soil profiles.
Weathering, Parent Material, and Soil Production
11. Spatial Patterns and Controls of Soil Chemical Weathering Rates Along a Transient Hillslope
[doi:10.1016/j.epsl.2009.09.021 | Kyungsoo Yoo et al. | Earth and Planetary Science Letters | 2009]
Shows that erosion, sediment transport, and topographic position create substantial spatial differences in chemical weathering rates.
12. A Theoretical Model Coupling Chemical Weathering Rates with Denudation Rates
[doi:10.1130/G25270A.1 | Emmanuel J. Gabet and Simon M. Mudd | Geology | 2009]
Explores how physical erosion can expose fresh minerals and thereby regulate landscape-scale chemical weathering.
13. Toward Process-Based Modeling of Geochemical Soil Formation Across Diverse Landforms
[doi:10.1016/j.geoderma.2008.05.029 | Kyungsoo Yoo and Simon M. Mudd | Geoderma | 2008]
Integrates mineral weathering, soil production, translocation, erosion, and deposition within a quantitative model of soil formation.
14. Discrepancy Between Mineral Residence Time and Soil Age
[doi:10.1130/G24285A.1 | Kyungsoo Yoo and Simon M. Mudd | Geology | 2008]
Demonstrates why the residence time of minerals within mobile soils may differ substantially from the age of the soil profile itself.
15. The Soil Production Function: A Brief History and Its Rediscovery
[doi:10.1016/j.geoderma.2007.01.004 | G. S. Humphreys and M. T. Wilkinson | Geoderma | 2007]
Reviews the idea that soil-production rates vary systematically with soil thickness and landscape conditions.
16. Integration of Geochemical Mass Balance with Sediment Transport to Calculate Rates of Soil Chemical Weathering and Transport on Hillslopes
[doi:10.1029/2005JF000402 | Kyungsoo Yoo et al. | Journal of Geophysical Research: Earth Surface | 2007]
Combines chemical mass balance with geomorphic transport to quantify weathering and redistribution of soil on hillslopes.
17. A Rudimentary Mechanistic Model for Soil Formation and Landscape Development: II
[doi:10.1016/S0016-7061(01)00075-1 | Budiman Minasny and Alex B. McBratney | Geoderma | 2001]
Models changes in soil thickness as a balance among physical weathering, chemical losses, and erosion across landscapes.
18. The Soil Production Function and Landscape Equilibrium
[The Soil Production Function and Landscape Equilibrium | Arjun M. Heimsath et al. | Nature | 1997]
Uses cosmogenic nuclides to demonstrate relationships among soil depth, bedrock conversion, erosion, and long-term landscape equilibrium.
19. Rates of Weathering and Soil Formation
[doi:10.1016/0016-7061(92)90040-E | Toshiyuki Wakatsuki and A. Rasyidin | Geoderma | 1992]
Uses elemental mass balances among rocks, soils, and river water to estimate rates of rock weathering and soil formation.
20. The Parent Rock Effect in the Genesis of Soil
[doi:10.1016/0016-7061(73)90064-5 | Ward Chesworth | Geoderma | 1973]
Examines how mineral composition and other characteristics inherited from bedrock influence the pathways and products of soil development.
Time, Chronosequences, and Long-Term Development
21. Rapid Soil Formation and Carbon Accumulation Along a Little Ice Age Soil Chronosequence in Southeast Alaska
[doi:10.1016/j.catena.2024.108460 | Manuel Spinola et al. | CATENA | 2024]
Documents rapid early pedogenesis and carbon accumulation on recently exposed terrain following glacier retreat.
22. Chemical and Biological Gradients Along the Damma Glacier Soil Chronosequence, Switzerland
[doi:10.2136/vzj2010.0129 | Stefano M. Bernasconi et al. | Vadose Zone Journal | 2011]
Tracks coordinated chemical, microbial, and ecosystem changes during the earliest stages of soil formation after deglaciation.
23. The Use of Chronosequences in Studies of Ecological Succession and Soil Development
[doi:10.1111/j.1365-2745.2010.01664.x | Lawrence R. Walker et al. | Journal of Ecology | 2010]
Reviews strengths, assumptions, and limitations of using differently aged surfaces to reconstruct ecological and pedogenic development.
24. Approaches to Quantify Progressive Soil Development with Time in Mediterranean Climate—I. Use of Field Criteria
[doi:10.1002/jpln.201000136 | Daniela Sauer | Journal of Plant Nutrition and Soil Science | 2010]
Evaluates morphological indicators that can be used to measure progressive soil development across dated surfaces.
25. Soil Chronosequences, Soil Development, and Soil Evolution: A Critical Review
[doi:10.1016/S0341-8162(98)00053-8 | Richard J. Huggett | CATENA | 1998]
Reviews chronosequences ranging from decades to millions of years and their importance for testing theories of soil development.
26. Changes in Soil Phosphorus Fractions and Ecosystem Dynamics Across a Long Chronosequence in Hawaii
[doi:10.2307/1938144 | Timothy E. Crews et al. | Ecology | 1995]
Tests long-term pedogenic nutrient theory across Hawaiian substrates spanning very young to extremely old surfaces.
27. A Quantitative Index of Soil Development from Field Descriptions
[doi:10.1016/0016-7061(82)90037-4 | Jennifer W. Harden | Geoderma | 1982]
Develops a widely used index for measuring changes in morphology as soils become progressively older and more developed.
28. Solution and Use of Chronofunctions in Studying Soil Development
[doi:10.1016/0016-7061(80)90035-X | James G. Bockheim | Geoderma | 1980]
Examines mathematical relationships between soil properties and elapsed time as a means of quantifying pedogenesis.
29. The Fate of Phosphorus During Pedogenesis
[doi:10.1016/0016-7061(76)90066-5 | T. W. Walker and J. K. Syers | Geoderma | 1976]
Presents the classic model showing how phosphorus forms and availability change systematically during long-term soil development.
30. The Chronosequence Concept and Soil Formation
[doi:10.1086/406646 | Peter H. Stevens and T. W. Walker | Quarterly Review of Biology | 1970]
Explains the theoretical basis for substituting space for time when studying progressive changes during soil formation.
Chronosequences in Diverse Landscapes
31. A Chronosequence of Climosequences: The Evolution of Ecological Soil Thresholds in Hawaiian Volcanic Soils
[doi:10.1016/j.geoderma.2025.117427 | Thomas P. Haensel et al. | Geoderma | 2025]
Shows how climate-driven pedogenic thresholds shift as Hawaiian volcanic substrates age.
32. Pedogenesis of a Coastal Climosequence and a Volcanic Ash-Influenced Elevational Transect of Western Haleakalā, Maui
[doi:10.1002/saj2.70119 | Tyler E. Hodges et al. | Soil Science Society of America Journal | 2025]
Investigates how rainfall, elevation, and volcanic materials jointly shape Hawaiian soil genesis.
33. Soil Development and Mineral Transformations Along a One-Million-Year Chronosequence on the Galápagos Islands
[doi:10.1002/saj2.20317 | I. Nyoman Candra et al. | Soil Science Society of America Journal | 2021]
Tracks mineral transformations and pedogenic change across volcanic substrates ranging from young surfaces to about one million years old.
34. A Climosequence of Chronosequences in Southwestern Australia
[doi:10.1111/ejss.12507 | Benjamin L. Turner | European Journal of Soil Science | 2018]
Separates the interacting effects of climate and time on phosphorus transformations and long-term soil development.
35. Mineralogical Transformations and Soil Development in Shale Across a Latitudinal Climosequence
[doi:10.2136/sssaj2015.05.0202 | Ashlee L. Dere et al. | Soil Science Society of America Journal | 2016]
Compares shale-derived soils across climatic zones to reveal climate controls on mineral alteration and weathering.
36. Soil Phosphorus Fractionation and Nutrient Dynamics Along the Cooloola Coastal Dune Chronosequence
[doi:10.1016/j.geoderma.2015.04.027 | C. R. Chen et al. | Geoderma | 2015]
Examines how phosphorus pools and nutrient availability change during prolonged development of highly weathered sandy soils.
37. Factors Controlling Soil Development in Sand Dunes: Evidence from a Coastal Dune Soil Chronosequence
[doi:10.1007/s11104-008-9601-9 | David L. Jones et al. | Plant and Soil | 2008]
Investigates biological and geochemical controls over soil development on progressively older coastal dunes.
38. Soil Chronosequence Development in Dunes on the Southeast African Coastal Plain
[doi:10.1016/j.quaint.2006.10.028 | G. A. Botha and Naomi Porat | Quaternary International | 2007]
Uses dated coastal dunes in South Africa to reconstruct progressive weathering and horizon development through time.
39. Soil Genesis Along a Chronosequence on Marine Terraces in Eastern Taiwan
[doi:10.1016/j.catena.2007.03.011 | Heng Tsai et al. | CATENA | 2007]
Uses uplifted marine terraces of different ages to quantify progressive changes in soil morphology, chemistry, and mineralogy.
40. Pedogenesis of a Chronosequence in the Sacramento Valley, California: Application of a Soil Development Index
[doi:10.1016/0016-7061(87)90032-2 | Jennifer W. Harden | Geoderma | 1987]
Applies quantitative morphology to soils ranging from hundreds of years to more than a million years in age.
Mineral Weathering and Early Pedogenesis
41. Soil Organic Carbon Across Space and Time: Where Chronosequences Still Matter
[doi:10.1016/j.geoderma.2026.117813 | Authors | Geoderma | 2026]
Reassesses chronosequences as tools for understanding how pedogenic mineral surfaces and microbial processes regulate soil-carbon stabilization.
42. Organic Matter Governs Weathering Rates and Microstructure Evolution During Early Pedogenesis
[doi:10.1016/j.geoderma.2022.116269 | Authors | Geoderma | 2023]
Experimental work demonstrates that organic matter can alter carbonate dissolution while rapidly promoting soil microstructure formation.
43. Pedogenesis of Fluvial Terrace Soils Related to Geomorphic Processes in Central Taiwan
[doi:10.3390/land12030535 | Wen-Shu Huang et al. | Land | 2023]
Relates a sequence from Inceptisols to Oxisols to terrace age, river deposition, rainfall events, and tectonic incision.
44. The Trajectory of Soil Development and Its Relationship to Soil Carbon Dynamics
[doi:10.1016/j.geoderma.2021.115378 | Authors | Geoderma | 2021]
Links climate-driven weathering and secondary Fe and Al minerals to changing patterns of soil-carbon stabilization.
45. Clay Minerals in a Soil Chronosequence Derived from Basalt on Hainan Island, China and Its Implication for Pedogenesis
[doi:10.1016/j.geoderma.2008.10.007 | Authors | Geoderma | 2008]
Tracks transformations among primary minerals, kaolinite, gibbsite, smectite, and vermiculite during long-term basalt weathering.
46. Soil System and Pedogenic Processes: Self-Organization, Time Scales, and Environmental Significance
[doi:10.1016/j.catena.2007.03.007 | V. O. Targulian and P. V. Krasilnikov | CATENA | 2007]
Describes pedogenesis as a self-organizing interaction of biological and abiotic processes operating over multiple temporal scales.
47. Spatial Patterns of Soil Organic Carbon on Hillslopes: Integrating Geomorphic Processes and the Biological C Cycle
[doi:10.1016/j.geoderma.2005.01.008 | Kyungsoo Yoo et al. | Geoderma | 2006]
Demonstrates how erosion and deposition redistribute soil carbon while interacting with biological carbon cycling across hillslopes.
48. Variations in Weathering Processes and Rates with Time in a Chronosequence of Soils from Glen Feshie, Scotland
[doi:10.1016/0016-7061(93)90010-I | Authors | Geoderma | 1993]
Shows systematic losses of base cations and mineral transformations as river-terrace soils develop over thousands of years.
49. Constitutive Mass Balance Relations Between Chemical Composition, Volume, Density, Porosity, and Strain in Weathering and Pedogenesis
[Constitutive Mass Balance Relations in Weathering and Pedogenesis | George H. Brimhall and William E. Dietrich | Geochimica et Cosmochimica Acta | 1987]
Establishes mass-balance techniques that became fundamental for quantifying elemental gains and losses during chemical weathering and soil formation.
50. Soil-Landscape Chronograms for Pedochronological Analysis
[doi:10.1016/0016-7061(84)90019-3 | Richard J. Huggett | Geoderma | 1984]
Develops a framework for reconstructing sequences of erosion, deposition, landscape change, and soil formation through time.
Volcanic Soils and Rapid Soil Formation
51. A 200-Year Snapshot of Soil Development in Pyroclastic Deposits Derived from the 1815 Eruption of Mount Tambora
[doi:10.1016/j.geoderma.2023.116454 | Markus Anda et al. | Geoderma | 2023]
Quantifies rapid tropical soil formation, mineral weathering, nutrient release, and carbon accumulation in deposits from the Tambora eruption.
52. Soil Formation and Mineralogical Changes on Basaltic Lava vs Scoria Along a Hydroclimatic Gradient on Santa Cruz Island, Galápagos
[doi:10.1016/j.catena.2022.106696 | I. Nyoman Candra et al. | CATENA | 2023]
Demonstrates that rainfall strongly controls volcanic pedogenesis while porous scoria weathers faster than dense basaltic lava.
53. Long-Term Response of Tropical Andisol Properties to Conversion from Rainforest to Agriculture
[doi:10.1016/j.catena.2020.104679 | Markus Anda et al. | CATENA | 2020]
Shows how land use modifies properties originally produced by volcanic weathering and long-term pedogenesis.
54. Weathering and Soil Formation in Rhyolitic Tephra Along a Moisture Gradient on Alcedo Volcano, Galápagos
[doi:10.1016/j.geoderma.2019.01.051 | I. Nyoman Candra et al. | Geoderma | 2019]
Shows how increasing moisture changes mineral weathering, secondary mineral formation, and soil properties in volcanic tephra.
55. Mineralogy, Chemical Composition, and Dissolution of Fresh Ash Eruption: New Potential Source of Nutrients
[doi:10.2136/sssaj2011.0305 | Markus Anda et al. | Soil Science Society of America Journal | 2012]
Characterizes fresh volcanic ash as a parent material and evaluates the nutrients released as its minerals begin to weather.
56. Pedogenic Development of Volcanic Ash Soils Along a Climosequence in Northern Taiwan
[doi:10.1016/j.geoderma.2010.01.007 | Heng Tsai et al. | Geoderma | 2010]
Examines how climatic differences alter mineral transformations and horizon development in soils formed from volcanic ash.
57. Micromorphology of Soils Derived from Volcanic Ash in Europe: A Review and Synthesis
[doi:10.1111/j.1365-2389.2007.00903.x | Georges Stoops | European Journal of Soil Science | 2007]
Synthesizes microscopic evidence for aggregation, weathering, organic-matter interactions, and other processes in volcanic soils.
58. Pedogenesis of Volcanic Ash Soils in Andean Ecuador
[doi:10.2136/sssaj2003.1797 | Franz Zehetner, W. P. Miller and L. T. West | Soil Science Society of America Journal | 2003]
Describes the mineralogical and chemical processes responsible for Andisol development across Ecuadorian volcanic landscapes.
59. Andisol Formation in a Holocene Beach Ridge Plain Under the Humid Tropical Climate of Costa Rica
[doi:10.1016/0016-7061(93)90053-N | Authors | Geoderma | 1993]
Examines rapid development of Andisol properties from volcanic materials under warm, humid tropical conditions.
60. Pedological Problems Concerning Volcanic Ash in Japan
[doi:10.4116/jaqua.3.40 | Mitsuo Matsui et al. | The Quaternary Research | 1963]
Provides an early examination of the distinctive properties and developmental pathways of Japanese volcanic-ash soils.
Organisms, Roots, Fungi, and Soil Formation
61. Structure–Function Co-Evolution During Pedogenesis—Microaggregate Development and Turnover in Soils
[doi:10.1002/jpln.202400012 | Kai U. Totsche et al. | Journal of Plant Nutrition and Soil Science | 2024]
Examines how evolving microaggregates create feedbacks between physical soil structure and biological and chemical processes.
62. High-Resolution Soil Sampling Reveals the Pattern of Biological Weathering and Soil Formation Under Trees
[doi:10.1016/j.scitotenv.2024.173725 | Łukasz Pawlik et al. | Science of the Total Environment | 2024]
Reveals localized zones of enhanced weathering and pedogenesis associated with individual trees and their root systems.
63. Weathering and Soil Production Under Trees Growing on Sandstones—The Role of Tree Roots in Soil Formation
[doi:10.1016/j.scitotenv.2023.166002 | Authors | Science of the Total Environment | 2023]
Investigates how roots penetrate sandstone, alter minerals, and contribute directly to conversion of rock into soil.
64. Are Plant Roots Only "In" Soil or Are They "Of" It? Roots, Soil Formation and Function
[doi:10.1111/ejss.13219 | Peter J. Gregory | European Journal of Soil Science | 2022]
Reviews the active role of roots in mineral weathering, aggregation, carbon inputs, pore formation, and development of soil structure.
65. Fungal Genetic Biodiversity and Metabolic Activity as an Indicator of Potential Biological Weathering and Soil Formation
[doi:10.1016/j.ecolind.2022.109136 | Authors | Ecological Indicators | 2022]
Connects fungal diversity and metabolism with mineral breakdown and the biological contribution to early soil development.
66. Nature of the Belowground Ecosystem and Its Development During Pedogenesis
[doi:10.1016/B978-0-12-800131-8.00002-9 | Authors | Advances in Agronomy | 2014]
Reviews how microbial communities, roots, fauna, and soil chemistry co-develop as new soils mature.
67. Exploring the Biological Dimension to Pedogenesis with Emphasis on Ecosystems, Soils and Landscapes of Southwestern Australia
[doi:10.1016/j.geoderma.2012.03.030 | Authors | Geoderma | 2013]
Highlights the often-underestimated role of vegetation and other organisms in shaping soil materials and entire soil landscapes.
68. Earthworms as Colonizers of Natural and Cultivated Soil Environments
[doi:10.1016/j.apsoil.2011.07.008 | Authors | Applied Soil Ecology | 2011]
Reviews earthworm colonization and the profound effects of burrowing, mixing, and organic-matter processing on soil development.
69. Biological Weathering in Soil: The Role of Symbiotic Root-Associated Fungi
[Biological Weathering in Soil | David J. Beerling et al. | Mineralogical Magazine | 2010s]
Explores how mycorrhizal fungi access minerals and use plant-derived energy to accelerate nutrient release and mineral weathering.
70. Charles Darwin's Observations on the Behaviour of Earthworms and the Evolution of Soil
[doi:10.1155/2010/823047 | Ulrich Kutschera | Applied and Environmental Soil Science | 2010]
Revisits Darwin's recognition that earthworms can gradually transform and mix surface materials to create biologically structured soil.
Podzolization, Translocation, and Other Pedogenic Processes
71. Magnetic Difference Between Deep and Surface Soil Within an Agricultural Area in Southern China
[doi:10.1029/2019EA001070 | Ouyang et al. | Earth and Space Science | 2020]
Uses magnetic minerals to trace transformations caused by subtropical weathering and pedogenic processes.
72. Incipient Ferralization and Weathering Indices Along a Soil Chronosequence in Taiwan
[Incipient Ferralization and Weathering Indices Along a Soil Chronosequence in Taiwan | Authors | European Journal of Soil Science | 2016]
Uses mineral and geochemical indices to track the early stages of intense tropical-style weathering and ferrallitic soil development.
73. Characteristics and Formation Mechanism of Pedogenic Hematite in Quaternary Chinese Loess and Paleosols
[Characteristics and Formation Mechanism of Pedogenic Hematite | T. Chen et al. | CATENA | 2010]
Investigates the formation of iron oxides that contribute to color and record weathering conditions in loess-derived soils.
74. Podzol: Soil of the Year 2007—A Review on Its Genesis, Occurrence, and Functions
[doi:10.1002/jpln.200700135 | Daniela Sauer et al. | Journal of Plant Nutrition and Soil Science | 2007]
Synthesizes current understanding of Podzol genesis, horizon differentiation, distribution, ecology, and environmental functions.
75. Geogenesis, Pedogenesis, and Multiple Causality in the Formation of Texture-Contrast Soils
[doi:10.1016/j.catena.2004.04.002 | Jonathan D. Phillips | CATENA | 2004]
Argues that strong textural differences within profiles can arise through several interacting geological and pedological pathways.
76. The Podzolization Process: A Review
[doi:10.1016/S0016-7061(99)00036-1 | Ulf Lundström, Nico van Breemen and Donald Bain | Geoderma | 2000]
Reviews the chemical and biological mechanisms that mobilize organic matter, iron, and aluminum during Podzol formation.
77. Clay Illuviation and Mechanical Clay Infiltration—Is There a Difference?
[doi:10.1016/S1040-6182(98)90225-7 | Authors | Quaternary International | 1998]
Examines how clay moving through soil profiles can produce textural features and discusses how true pedogenic illuviation can be distinguished from infiltration.
78. SEM-EDXRA Investigation of Tubular Features and Iron Nodules in Lateritic Soils from Malaysia
[doi:10.1016/0016-7061(83)90068-X | S. Zauyah and E. B. A. Bisdom | Geoderma | 1983]
Uses microscopic evidence to examine iron redistribution and structural features produced during intense tropical weathering.
79. Clay Decomposition in Seasonally Wet, Acid Soils
[doi:10.1016/0016-7061(73)90001-3 | Robert Brinkman et al. | Geoderma | 1973]
Examines clay destruction and associated chemical changes in periodically waterlogged acidic soils.
80. Ferrolysis, a Hydromorphic Soil Forming Process
[Ferrolysis, a Hydromorphic Soil Forming Process | Robert Brinkman | Geoderma | 1970]
Describes ferrolysis as a mechanism of clay destruction and acidification driven by repeated reduction and oxidation in seasonally wet soils.
Topography, Catenas, and Soil–Landscape Relationships
81. Bioturbation and Bio-Geomorphic Control of Pedogenesis Along a Catena in the Atlantic Forest of Southeastern Brazil
[doi:10.1016/j.catena.2026.109905 | Diogo Filho and José Pereira de Queiroz Neto | CATENA | 2026]
Investigates interactions among organisms, hillslope processes, and soil formation across a tropical forest catena.
82. Soil Toposequences, Soil Erosion, and Ancient Maya Land Use Adaptations to Pedodiversity in Southern Mexico
[doi:10.3389/feart.2023.1239301 | Sergey Sedov et al. | Frontiers in Earth Science | 2023]
Reviews how parent material, relief, erosion, and human land use produced strongly contrasting soils across tropical karst landscapes.
83. The East African Contribution to the Formalisation of the Soil Catena Concept
[The East African Contribution to the Formalisation of the Soil Catena Concept | Authors | CATENA | 2020]
Reconstructs the development of the catena concept in East Africa and its importance for explaining recurrent soil patterns on slopes.
84. The Generation and Redistribution of Soil Cations in High-Elevation Catenas in the Fraser Experimental Forest, Colorado
[doi:10.1016/j.geoderma.2018.07.024 | Authors | Geoderma | 2019]
Shows how slope position, hydrologic flow, weathering, and transport redistribute elements through mountain soil catenas.
85. Tropical Soil Toposequence Characterization via pXRF Spectrometry
[doi:10.2136/sssaj2018.12.0498 | Silva et al. | Soil Science Society of America Journal | 2019]
Uses portable X-ray fluorescence to reveal geochemical changes associated with topographic position and tropical soil development.
86. Chemical Transfers Along Slowly Eroding Catenas Developed on Granitic Cratons in Southern Africa
[doi:10.1016/j.geoderma.2013.03.023 | Lesogo Khomo et al. | Geoderma | 2013]
Traces chemical gains, losses, and downslope redistribution during weathering of ancient granitic landscapes.
87. Understanding the Genesis of Ultramafic Soils and Catena Dynamics in Niquelândia, Brazil
[doi:10.1016/j.geoderma.2009.04.020 | Jean Garnier et al. | Geoderma | 2009]
Examines how weathering, slope position, and lateral element transfers create contrasting soils on ultramafic parent materials.
88. The Relationship Between Pedogenic and Geomorphic Processes in a Mountainous Tropical Forested Area in Sierra Madre del Sur, Mexico
[doi:10.1016/j.catena.2005.02.003 | Pavel Krasilnikov et al. | CATENA | 2005]
Shows how erosion, deposition, weathering, and slope morphology jointly determine tropical mountain soil patterns.
89. Archetypes of Catenas in Respect to Matter—A Concept for Structuring and Grouping Catenas
[doi:10.1016/S0016-7061(96)00095-X | Authors | Geoderma | 1997]
Proposes a systematic framework for classifying soil catenas according to movement and redistribution of matter through landscapes.
90. Some Soil Catena Relationships in Saline County, Kansas
[doi:10.2136/sssaj1950.036159950014000C0067x | Paul L. Brown and R. V. Olson | Soil Science Society of America Journal | 1950]
Provides an early quantitative examination of predictable soil changes from summit to lower landscape positions.
Climate, Human Activity, and Changing Soil Formation
91. Soil Formation as an Integrated Earth-Surface Process
[Soil Development and Pedogenetic Processes synthesis | Nature Research Intelligence | Nature Index | 2026]
Synthesizes modern pedogenesis as the cumulative product of mineral weathering, biological activity, translocation, additions and losses, geomorphic transport, climate, and time.
92. The Human Impact on All Soil-Forming Factors During the Anthropocene
[doi:10.1021/acsenvironau.1c00010 | Ishai Dror, Bruno Yaron and Brian Berkowitz | ACS Environmental Au | 2021]
Shows how humans now modify parent materials, climate, organisms, relief, and time-dependent soil processes on a global scale.
93. Urban Anthropogenic Soils—A Review
[doi:10.1016/bs.agron.2020.08.001 | Authors | Advances in Agronomy | 2021]
Reviews soils formed or profoundly modified by construction, excavation, filling, contamination, compaction, and other urban processes.
94. Mineralogical and Surface Charge Characteristics of Andosols Experiencing Long-Term Land-Use Change in West Java
[doi:10.1080/00380768.2020.1820758 | Markus Anda et al. | Soil Science and Plant Nutrition | 2020]
Shows how long-term land use modifies the mineralogical and chemical characteristics inherited from volcanic pedogenesis.
95. Reviews and Syntheses: Agropedogenesis—Humankind as the Sixth Soil-Forming Factor
[doi:10.5194/bg-16-4783-2019 | Yakov Kuzyakov and Kazem Zamanian | Biogeosciences | 2019]
Argues that agriculture constitutes a powerful additional soil-forming force that can rapidly redirect natural pedogenic trajectories.
96. A Quantitative Model for Integrating Landscape Evolution and Soil Formation
[A Quantitative Model for Integrating Landscape Evolution and Soil Formation | Vanwalleghem et al. | Journal of Geophysical Research: Earth Surface | 2013]
Develops a coupled model in which soil development and changing landforms influence one another through time.
97. The mARM3D Spatially Distributed Soil Evolution Model
[doi:10.1029/2009JF001536 | S. Cohen et al. | Journal of Geophysical Research: Earth Surface | 2010]
Develops a three-dimensional model linking soil-profile evolution to erosion, deposition, topography, and landscape development.
98. A Process-Based Model Linking Pocket Gopher Activity to Sediment Transport and Soil Thickness
[A Process-Based Model Linking Pocket Gopher Activity to Sediment Transport and Soil Thickness | Kyungsoo Yoo et al. | Geology | 2005]
Quantifies the role of animal bioturbation in transporting soil downslope and helping regulate soil thickness.
99. Soil-Forming Processes and Rates on Uplifted Marine Terraces in Southwestern Oregon, USA
[doi:10.1016/0016-7061(96)00017-1 | Authors | Geoderma | 1996]
Uses marine terraces of known relative age to examine rates of weathering, mass loss, horizon development, and soil evolution.
100. A Comparative Study of Developmental Color in a Chestnut-Chernozem-Brunizem Soil Climosequence
[doi:10.2136/sssaj1965.03615995002900050029x | G. J. Buntley and F. C. Westin | Soil Science Society of America Journal | 1965]
Uses soil color changes along a climate gradient as an indicator of differences in pedogenesis.
