Talk:Soil science/Archive 1

Soil science as opposed to pedology
I understand that pedology means literally the same thing as soil science. I am also aware that several individual field soil scientists in the United States have preferred being introduced as pedologists to distinguish themselves from agronomists, geologists, geographers, sanitarians and engineers who opportunistically represent themselves as soil scientists, but who in fact have only minimal soil science training and experience. I am also aware that the term soil science doesn't translate as easily as the term pedology, and that some national soil science societies have chosen to call themselves pedological societies.

Despite the above I find very persuasive considerations in support of clarifying pedology as being one of several branches within the soil sciences. Most soil scientists known to me are not enthusiastic with the pedology term as a comprehensive term for soil science. Practice in the pure science aspects of soil chemistry, soil physics and soil minerology are particularly difficult to define as branches of pedology. Furthermore, the ascendancy of the International Union of Soil Sciences (IUSS) has made soil science the clearly preferable term.

I maintain my certification as a professional soil classifier, so I can certainly appreciate that soil science would not be what it is (a robust discipline independent of geology, agriculture or the biological sciences) if it wasn't for pedology. Pedology is the single most important and defining branch of soil science. I certainly can't fault anyone who defends promoting pedology as the preferred term. I just think that the world has moved on beyond the 1970's and 1980's, a time when pedology quite possibly could have supplanted soil science as the preferred term.

Paleorthid 19:29, 30 Oct 2004 (UTC)


 * Moved material to Soil science replaced redirect. Hope that is what you meant to do. -Vsmith 16:11, 1 Nov 2004 (UTC)

Justus von Liebig
The early concepts of soil were based on ideas developed by a German chemist, Justus von Liebig (1803 – 1873), and modified and refined by agricultural scientists who worked on samples of soil in laboratories, greenhouses, and on small field plots. The soils were rarely examined below the depth of normal tillage. These chemists held the "balance-sheet" theory of plant nutrition. Soil was considered a more or less static storage bin for plant nutrients—the soils could be used and replaced. This concept still has value when applied within the framework of modern soil science, although a useful understanding of soils goes beyond the removal of nutrients from soil by harvested crops and their return in manure, lime, and fertilizer. The early geologists generally accepted the balance-sheet theory of soil fertility and applied it within the framework of their own discipline. They described soil as disintegrated rock of various sorts—granite, sandstone, glacial till, and the like. They went further, however, and described how the weathering processes modified this material and how geologic processes shaped it into landforms such as glacial moraines, alluvial plains, loess plains, and marine terraces. Geologist N. S. Shaler's (1841 – 1906) monograph (1891) on the origin and nature of soils summarized the late 19th century geological concept of soils. Early soil surveys were made to help farmers locate soils responsive to different management practices and to help them decide what crops and management practices were most suitable for the particular kinds of soil on their farms. Many of the early workers were geologists because only geologists were skilled in the necessary field methods and in scientific correlation appropriate to the study of soils. They conceived soils as mainly the weathering products of geologic formations, defined by landform and lithologic composition. Most of the soil surveys published before 1910 were strongly influenced by these concepts. Those published from 1910 to 1920 gradually added greater refinements and recognized more soil features but retained fundamentally geological concepts. The balance-sheet theory of plant nutrition dominated the laboratory and the geological concept dominated field work. Both approaches were taught in many classrooms until the late 1920s. Although broader and more generally useful concepts of soil were being developed by some soil scientists, especially E.W. Hilgard (1833–1916) and G.N. Coffey (George Nelson Coffey) in the United States and soil scientists in Russia, the necessary data for formulating these broader concepts came from the field work of the soil survey.

V.V. Dokuchaiev
Beginning in 1870, the Russian school of soil science under the leadership of V.V. Dokuchaiev (1846– 1903) and N.M. Sibertsev (1860-1900) was developing a new concept of soil. The Russian workers conceived of soils as independent natural bodies, each with unique properties resulting from a unique combination of climate, living matter, parent material, relief, and time. They hypothesized that properties of each soil reflected the combined effects of the particular set of genetic factors responsible for the soil's formation. Hans Jenny later emphasized the functionally relatedness of soil properties and soil formation. The results of this work became generally available to Americans through the publication in 1914 of K.D. Glinka's textbook in German and especially through its translation into English by C.F. Marbut in 1927. The Russian concepts were revolutionary. Properties of soils no longer were based wholly on inferences from the nature of the rocks or from climate or other environmental factors, considered singly or collectively; rather, by going directly to the soil itself, the integrated expression of all these factors could be seen in the morphology of the soils. This concept required that all properties of soils be considered collectively in terms of a completely integrated natural body. In short, it made possible a science of soil. The early enthusiasm for the new concept and for the rising new discipline of soil science led some to suggest the study of soil could proceed without regard to the older concepts derived from geology and agricultural chemistry. Certainly the reverse is true. Besides laying the foundation for a soil science with its own principles, the new concept makes the other sciences even more useful. Soil morphology provides a firm basis on which to group the results of observation, experiments, and practical experience and to develop integrated principles that predict the behavior of the soils.

Marbut
Under the leadership of Marbut, the Russian concept was broadened and adapted to conditions in the United States.This concept emphasized individual soil profiles to the subordination of external soil features and surface geology. By emphasizing soil profiles, however, soil scientists at first tended to overlook the natural variability of soils which can be substantial even within a small area. Overlooking the variability of soils seriously reduced the value of the maps which showed the location of the soils. Furthermore, early emphasis on genetic soil profiles was so great as to suggest that material lacking a genetic profile, such as recent alluvium, was not soil. A sharp distinction was drawn between rock weathering and soil formation. Although a distinction between these sets of processes is useful for some purposes, rock and mineral weathering and soil formation are commonly indistinguishable. The concept of soil was gradually broadened and extended during the years following 1930, essentially through consolidation and balance. The major emphasis had been on the soil profile. After 1930, morphological studies were extended from single pits to long trenches or a series of pits in an area of a soil. The morphology of a soil came to be described by ranges of properties deviating from a central concept instead of by a single "typical" profile. The development of techniques for mineralogical studies of clays also emphasized the need for laboratory studies. Marbut emphasized strongly that classification of soils should be based on morphology instead of on theories of soil genesis, because theories are both ephemeral and dynamic. He perhaps overemphasized this point to offset other workers who assumed that soils had certain characteristics without examining the soils. Marbut tried to make clear that examination of the soils themselves was essential in developing a system of Soil Classification and in making usable soil maps. In spite of this, Marbut's work reveals his personal understanding of the contributions of geology to soil science. His soil classification of 1935 depends heavily on the concept of a "normal soil," the product of equilibrium on a landscape where downward erosion keeps pace with soil formation. Clarification and broadening of the concept of a soil science also grew out of the increasing emphasis on detailed soil mapping. Concepts changed with increased emphasis on predicting crop yields for each kind of soil shown on the maps. Many of the older descriptions of soils had not been quantitative enough and the units of classification had been too heterogeneous for making yield and management predictions needed for planning the management of individual farms or fields. During the 1930s, soil formation was explained in terms of loosely conceived processes, such as "podzolization," "laterization," and "calcification." These were presumed to be unique processes responsible for the observed common properties of the soils of a region.

Hans Jenny
In 1941 Hans Jenny's Factors of Soil Formation, a system of quantitative pedology, concisely summarized and illustrated many of the basic principles of modern soil science to that date. Since 1940, time has assumed much greater significance among the factors of soil formation, and geomorphological studies have become important in determining the time that soil material at any place has been subjected to soil-forming processes. Meanwhile, advances in soil chemistry, soil physics, soil mineralogy, and soil biology, as well as in the basic sciences that underlie them, have added new tools and new dimensions to the study of soil formation. As a consequence, the formation of soil has come to be treated as the aggregate of many interrelated physical, chemical, and biological processes. These processes are subject to quantitative study in soil physics, soil chemistry, soil mineralogy, and soil biology. The focus of attention also has shifted from the study of gross attributes of the whole soil to the co-varying detail of individual parts, including grain-to-grain relationships.

Guy Smith
In both the classification of Marbut and the 1938 classification developed by the U.S. Department of Agriculture, the classes were described mainly in qualitative terms. Classes were not defined in quantitative terms that would permit consistent application of the system by different scientists. Neither system definitely linked the classes of its higher categories, largely influenced by genetic concepts initiated by the Russian soil scientists, to the soil series and their subdivisions that were used in soil mapping in the United States. Both systems reflected the concepts and theories of soil genesis of the time, which were themselves predominantly qualitative in character. Modification of the 1938 system in 1949 corrected some of its deficiencies but also illustrated the need for a reappraisal of concepts and principles. More than 15 years of work under the leadership of Guy Smith culminated in a new soil classification system. This became the official classification system of the U.S. National Cooperative Soil Survey in 1965 and was published in 1975 as Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys. The Smith system was adopted in the U.S. and many other nations for their own classification system.

Another factor has had an immense impact on soil survey, especially during the 1960s. Before 1950, the primary applications of soil surveys were farming, ranching, and forestry. Applications for highway planning were recognized in some States as early as the late 1920s, and soil interpretations were placed in field manuals for highway engineers of some States during the 1930s and 1940s. Nevertheless, the changes in soil surveys during this period were mainly responses to the needs of farming, ranching, and forestry. During the 1950s and 1960s nonfarm uses of the soil increased rapidly. This created a great need for information about the effects of soils on those nonfarm uses.

source: [http://soils.usda.gov/technical/manual/ Soil Survey Staff (1993) Soil Survey Manual USDA Handbook 18]

Paleorthid 06:31, 30 Nov 2004 (UTC)

History (cont)
See public domain material at Soil and Health Ag Library including:
 * Albrecht, William A. (1938) "Loss Of Soil Organic Matter And Its Restoration". Soils and Men: USDA Yearbook of Agriculture. Washington, D.C., United States Department of Agriculture
 * Darwin, Charles. (1881) The Formation of Vegetable Mould through the action of worms with observations of their habits.
 * also listed at
 * von Liebig, Justus (1844) Chemical Letters, 2nd corrected edition. London: Taylor and Walton
 * Krasil'nikov, N.A. (1958) Soil Microorganisms and Higher Plants. Academy of Sciences of the USSR, Moscow. Translated in Israel by Dr. Y. Halperin. Printed in the USA by the Government Printing Office.
 * The scientific basis of soil science as a natural science was established by the classical works of Dokuchaev. Previously, soil had been considered a product of physicochemical transformations of rocks, a dead substrate from which plants derive nutritious mineral elements. Soil and bedrock were in fact equated.


 * Dokuchaev considers the soil as a natural body having its own genesis and its own history of development, a body with complex and multiform processes taking place within it. The soil is considered as different from bedrock. The latter becomes soil under the influence of a series of soil-forming factors--climate, vegetation, country, relief and age. According to him, soil should be called the "daily" or outward horizons of rocks regardless of the type; they are changed naturally by the common effect of water, air and various kinds of living and dead organisms.
 * KRASIL’NIKOV Nikolai Aleksandrovich. Born on 18.12.1896. Died on 11.07.1973 (http://hp.iitp.ru/eng/14/1446.htm), so not clear yet how soilandhealth.org places this as public domain. Hmm:


 * Steve Soloman at soilandhealth.org wrote me back saying:
 * It was originally published in the USA without any notice of copyright in the book. Look that situation up US copyright law.
 * My take is that SS' position is in error. The US (and AUS) subscribed to the Agreement on Trade-Related Aspects of Intellectual Property Rights of 1994, which holds that
 * Copyright terms must extend to 50 years after the death of the author (although films and photographs are only required to have fixed 50 and 25 year terms, respectively).
 * Copyright must be granted automatically, and not based upon any "formality", such as registrations or systems of renewal.
 * so this work won't truly be PD until November 7, 2023


 * 
 * 

History (Darwin)

 * In 1837 Darwin, then trained far more in geology than biology, presented a paper on how animals (worms) form soil, published in 1838. He produced other papers on this theme in 1840, 1844, and 1869. In 1881, the year before his death (in 1882), he published a synthesis titled On the Origin of Vegetable Mould, Through the Action of Worms, with Observations on Their Habits. This last work, which proved to be his last book, summarized 44 plus years of laboratory and field observations of worms and their effects on soil. Darwin showed how worms -- as a result of their bioturbational lifestyles (ingesting soil at depth and depositing it at the surface as fecal casts) -- caused stones and artifacts (Roman stones and coins) to be lowered to form a stone layer (stone-line), and in the process produce soil horizons. His was the first book on process pedology, an approach also used in his earlier papers. His 1840 paper, which expanded his 1837 paper, contained a woodcut that displayed bioturbationally produced soil horizons, to which he later assigned A, B, C and D notations. Ironically, Darwin’s work was given little credible visibility in the agronomically inspired late nineteenth and early twentieth century treatises on soil formation, treatises that led to the current soil genetic paradigm.


 * Source: D. L. Johnson (2004)

Additional content
I have stated a new page soil morphology additional sub headings that could exist on that page under the heading

Soil Mineralogical composition
--soilman 23:59, 7 March 2006 (UTC)

NPOV on University Section
I have two problens with this addition: 1) Obvious NPOV - This will not stand without a referenced reason why it is among the planet's greatest soil science departments. 2) Unwieldy structure: If kept, do we add every University soils department on the planet? Paleorthid 04:06, 31 March 2006 (UTC)

''Although some universities still offer undergraduate and graduate degrees in soil science, the oldest and perhaps most prominent Soil Sciences department in the United States is located at the University of Wisconsin-Madison in Madison, Wisconsin Established in 1897, it still functions today encompassing three separate buildings and housing advanced technologies and prominent faculty. With many distinguished alumnus and current faculty, the University of Wisconsin Soil Scienes Department is generally accepted as one of the best in the world.''

I have moved this content to the talk page in case someone wants to revise this to a neutral point of view. Paleorthid 21:14, 31 March 2006 (UTC)

Being associated with the UW, I don't want to get too deep into this issue, which obviously has POV issues written all over it. However, I don't think that a list of universities with a soils designation could be anything less than scores long, once we factor in the international nature of soil science. That can't serve any good purpose, even if 'encyclopedic' in length. Professional societies do, or should, serve that function. The list of universities should be removed entirely, IMHO.

On the other hand, in addition to the list of soil science notables it is reasonable to indicate the early start of soil science as an academic presence in the U.S. at the UW (and can link to the wikipedia article on F.H. King); other countries, some with yet earlier starts, could add in their academic roots too. PBarak 21:46, 31 March 2006 (UTC)

Outline for improved soil science article
Soil science (also known variously as pedology, edaphology, and agrology), is an all-embracing term for the sciences related to the pedosphere. There are both reductionist and holistic approaches to soil science. The major historic disciplines use physics, geography, mathematics, chemistry, and biology to build a quantitative understanding of the principal processes that affect soil.
 * Overview aka Concept of soil
 * There is little merit in attempting to give a rigorous definition of soil because of the complexity of its make-up and the physical, chemical and biological forces to which it is exposed.
 * White, Robert Edwin (1997) Introduction to the Principles and Practice of Soil Science: the Soil as a Natural Resource. Blackwell Science Ltd. ISBN 0-86542-960-X

Instead we observe that soils are polygenetic and polytemporal. Soil science is a young science in which still has many unanswered questions left and indications of new discoveries to make. Glomalin was discovered only in 1995, yet it constitutes 33% of all soil organic matter. The discovery of Terra preta is similarly humbling and exciting.
 * Principle concepts
 * Pedosphere
 * Body, soil
 * Classification and taxonomy
 * Edaphic conditions
 * Pedogenesis
 * Pedon
 * Solum
 * Principles of soil science (see fundamental principles of ecology for some ideas of structure)
 * Soils constitute a separate resource worthy of its own discipline (George Coffey)
 * endangered soil diversity
 * Soils have a living component that affects physics and chemistry (????)
 * Principles of soil formation
 * Principles of secondary mineral formation and translocation
 * Principles of plant nutrition - most limiting nutrient
 * Principle of reduction/oxidation in soil biology and soil chemistry
 * Principles of buffering and poise in soil chemistry
 * Principle of hysteresis in potential/water content relationship
 * Principle of water energy to break through boundaries.
 * Principle of biological zero
 * Principle of gas diffusion in soil
 * Principle of water potential. because solute, matric potential and the diurnal effect of plant water demand and temperature changes, Water potential is particularly complex in soil media.
 * Scope of soil science
 * History
 * Soil science techniques
 * Soil mapping
 * Soil sampling and analysis
 * Field evaluation
 * Common misconceptions
 * Soil is simple.
 * Clay soils have lower porosity than sand soils.
 * Clay is not silt (belongs in soil article, not soil science)
 * Matric potential water content relationship is repeatable.
 * Climax soil conditions exist.
 * Soil formation rate is a meaningful concept
 * Hydric soils (redox versus saturation)
 * Adequate sample size, soil uniformity
 * Stability/continuity of soil constituents (sulfer, phosphorus)
 * Future directions
 * See also
 * References
 * Further reading
 * Popular Reading
 * University Level Textbooks
 * Introductory
 * Undergraduate
 * Graduate
 * History
 * External links

More practical information
I know this could be construed as an asinine point, but I came here as a gardener looking for some practical information about soil and I found instead a lot of meta-information about the definition of soil science. It would be good if there was some basic, concrete soil science as it really relates to practical human needs. Or was I looking in the wrong place? —Preceding unsigned comment added by 91.105.241.61 (talk) 00:21, 24 March 2008 (UTC)
 * Information about soil as a subject, as opposed to soil science (here), may be found at soil, the first wikilink on the soil science pg. HTH, PBarak (talk) 04:47, 24 March 2008 (UTC)

Degradation
Land degradation is a human induced or natural process which impairs the capacity of land to function. Soils are the critical component in land degradation when it involves acidification, contamination, desertification, erosion, or salination.

While soil acidification of alkaline soils is beneficial, it degrades land when soil acidity lowers crop productivity and increases soil vulnerability to contamination and erosion. Soils are often initially acid because their parent materials were acid and initially low in the basic cations (calcium, magnesium, potassium, and sodium). Acidification occurs when these elements are removed from the soil profile by normal rainfall or the harvesting of crops. Soil acidification is accelerated by the use of acid-forming nitrogenous fertilizers and by the effects of acid precipitation.

Soil contamination at low levels are often within soil capacity to treat and assimilate. Many waste treatment processes rely on this treatment capacity. Exceeding treatment capacity can damage soil biota and limit soil function. Derelict soils occur where industrial contamination or other development activity damages the soil to such a degree that the land cannot be used safely or productively. Remediation of derelict soil uses principles of geology, physics, chemistry, and biology to degrade, attenuate, isolate, or remove soil contaminants and to restore soil functions and values. Techniques include leaching, air sparging, chemical amendments, phytoremediation, bioremediation, and natural attenuation.

Desertification is an environmental process of ecosystem degradation in arid and semi-arid regions, or as a result of human activity. It is a common misconception that droughts cause desertification. Droughts are common in arid and semiarid lands. Well-managed lands can recover from drought when the rains return. Soil management tools include maintaining soil nutrient and organic matter levels, reduced tillage and increased cover. These help to control erosion and maintain productivity during periods when moisture is available. Continued land abuse during droughts, however, increases land degradation. Increased population and livestock pressure on marginal lands accelerates desertification.

Soil erosional loss is caused by wind, water, ice, movement in response to gravity. Although the processes may be simultaneous, erosion is distinguished from weathering. Erosion is an intrinsic natural process, but in many places it is increased by human land use. Poor land use practices include deforestation, overgrazing, and improper construction activity. Improved management can limit erosion using techniques like limiting disturbance during construction, avoiding construction during erosion prone periods, intercepting runoff, terrace-building, use of erosion suppressing cover materials and planting trees or other soil binding plants.

A serious and long-running water erosion problem is in China, on the middle reaches of the Yellow River and the upper reaches of the Yangtze River. From the Yellow River, over 1.6 billion tons of sediment flow each year into the ocean. The sediment originates primarily from water erosion in the Loess Plateau region of northwest China.

Soil piping is a particular form of soil erosion that occurs below the soil surface. It is associated with levee and dam failure as well as sink hole formation. Turbulent flow removes soil starting from the mouth of the seep flow and subsoil erosion advances upgradient. The term sand boil is used to describe the appearance of the discharging end of an active soil pipe.

Soil salination is the accumulation of free salts to such an extent that it leads to degradation of soils and vegetation. Consequences include corrosion damage, reduced plant growth, erosion due to loss of plant cover and soil structure, and water quality problems due to sedimentation. Salination occurs due to a combination of natural and human caused processes. Aridic conditions favor salt accumulation. This is especially apparent when soil parent material is saline. Irrigation of arid lands is especially problematic. All irrigation water has some level of salinity. Irrigation, especially when it involves leakage from canals, often raise the underlying water table. Rapid salination occurs when the land surface is within the capillary fringe of saline groundwater. Salinity control involves flushing with higher levels of applied water in combination with tile drainage.


 * Moved it to soil. --Paleorthid (talk) 18:18, 14 May 2008 (UTC)