Pedology is a discipline within soil science which focuses on understanding and characterizing soil formation, evolution, and the theoretical frameworks for modeling soil bodies, often in the context of the natural environment. Pedology is often seen as one of two main branches of soil inquiry, the other being edaphology which is traditionally more agronomically oriented and focuses on how soil properties influence plant communities. In studying the fundamental phenomenology of soils, e.g. soil formation, pedologists pay particular attention to observing soil morphology and the geographic distributions of soils, and the placement of soil bodies into larger temporal and spatial contexts. In so doing, pedologists develop systems of soil classification, soil maps, and theories for characterizing temporal and spatial interrelations among soils. There are a few noteworthy sub-disciplines of pedology; namely pedometrics and soil geomorphology. Pedometrics focuses on the development of techniques for quantitative characterization of soils, especially for the purposes of mapping soil properties whereas soil geomorphology studies the interrelationships between geomorphic processes and soil formation.
In soil science, podzols are the typical soils of coniferous or boreal forests and also the typical soils of eucalypt forests and heathlands in southern Australia. In Western Europe, podzols develop on heathland, which is often a construct of human interference through grazing and burning. In some British moorlands with podzolic soils, cambisols are preserved under Bronze Age barrows.
Tilth is a physical condition of soil, especially in relation to its suitability for planting or growing a crop. Factors that determine tilth include the formation and stability of aggregated soil particles, moisture content, degree of aeration, soil biota, rate of water infiltration and drainage. Tilth can change rapidly, depending on environmental factors such as changes in moisture, tillage and soil amendments. The objective of tillage is to improve tilth, thereby increasing crop production; in the long term, however, conventional tillage, especially plowing, often has the opposite effect, causing the soil carbon sponge to oxidize, break down and become compacted.
A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. Horizons are defined in many cases by obvious physical features, mainly colour and texture. These may be described both in absolute terms and in terms relative to the surrounding material, i.e. 'coarser' or 'sandier' than the horizons above and below.
The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. It is edited by a working group of the International Union of Soil Sciences (IUSS).
This is an index of articles relating to soil.
Originally mapped in Cecil County, Maryland in 1899, more than 10 million acres (40,000 km²) of the Cecil soil series are now mapped in the Piedmont region of the southeastern United States. It extends from Virginia through North Carolina, South Carolina, Georgia and Alabama, with the typic Cecil pedon actually located in Franklin County, NC.
Brown earth is a type of soil. Brown earths are mostly located between 35° and 55° north of the Equator. The largest expanses cover western and central Europe, large areas of western and trans-Uralian Russia, the east coast of America and eastern Asia. Here, areas of brown earth soil types are found particularly in Japan, Korea, China, eastern Australia and New Zealand. Brown earths cover 45% of the land in England and Wales. They are common in lowland areas on permeable parent material. The most common vegetation types are deciduous woodland and grassland. Due to the reasonable natural fertility of brown earths, large tracts of deciduous woodland have been cut down and the land is now used for farming. They are normally located in regions with a humid temperate climate. Rainfall totals are moderate, usually below 76 cm per year, and temperatures range from 4 °C in the winter to 18 °C in the summer. They are well-drained fertile soils with a pH of between 5.0 and 6.5.
Soil morphology is the study of the formation and description of soil types within various soil horizons. C.F. Marbut championed reliance on soil morphology instead of on theories of pedogenesis for soil classification because theories of soil genesis are both ephemeral and dynamic.
Orovada series soil is the official state soil of Nevada. The soil series has an extent of 367,853 acres (148,865 ha), primarily in northern and central Nevada, and extending into southern Idaho and Oregon. They are common soils on semiarid rangeland with sagebrush-grassland plant communities. Orovada soils are arable, able to be cultivated, when irrigated and are considered prime farmland. Alfalfa for hay and seed, winter wheat, barley, and grasses for hay and pasture are the principal crops grown on these soils.
San Joaquin is an officially designated state insignia, the state soil of the U.S. state of California.
The Canadian System of Soil Classification is more closely related to the American system than any other, but they differ in several ways. The Canadian system is designed to cover only Canadian soils. The Canadian system dispenses with the sub-order hierarchical level. Solonetzic and Gleysolic soils are differentiated at the order level.
Myakka soil is the official state soil of Florida, which has more than 1,500,000 acres (6,100 km2) of land composed partly or entirely of Myakka soils, out of its total acreage of 42,084,928 acres (170,311.66 km2). Its name derives from a Native American word that means "Big Waters". This soil is primarily located in broad flatwoods in irregularly shaped areas ranging from 5 to 500 acres in size. The organic matter content and fertility of the soil is low. Most areas where this soil occurs are native range or improved pasture, although some is used for citrus or vegetable farming. Some counties in Florida where this soil occurs are Hendry, Collier, Glades, and Lee.
In 1988, the Professional Soil Classifiers Association of Mississippi selected Natchez silt loam soil to represent the soil resources of the State. These soils exist on 171,559 acres of landscape in Mississippi.
The Jory series consists of very deep, well-drained soils that formed in colluvium derived from basic igneous rock. These soils are in the foothills surrounding the Willamette Valley of the United States. They have been mapped on more than 300,000 acres (1,200 km2) in western Oregon. They are named after Jory Hill, Marion County, Oregon, which itself is named for the Jory family, who settled in the area in 1852, after traveling along the Oregon Trail.
Albeluvisol was a Reference Soil Group of the first edition (1998) and the second edition (2006) of the World Reference Base for Soil Resources (WRB). In the third edition of the WRB (2014), Albeluvisols were replaced by the broader defined Retisols. An Albeluvisol is a soil with a thin, dark surface horizon on a bleached subsurface horizon that tongues into a clay illuviation (Bt) horizon. The Bt horizon has an irregular or broken upper boundary resulting from the tonguing of bleached soil material into the illuviation horizon. Albeluvisols correlate with Glossaqualfs, Glossocryalfs and Glossudalfs in the USDA soil taxonomy.
A Stagnosol in the World Reference Base for Soil Resources (WRB) is soil with strong mottling of the soil profile due to redox processes caused by stagnating surface water.
The geology of Rhode Island is based on nearly one billion year old igneous crystalline basement rocks formed as part of the microcontinent Avalonia that collided with the supercontinent Gondwana. The region experienced substantial folding associated with its landlocked position during the Alleghanian orogeny mountain building event. The region accumulated sedimentary rocks, including small deposits of coal. The region was covered with thick Atlantic Coastal Plain sediments, with the erosion of the Appalachians and the creation of the Atlantic Ocean throughout the past 200 million years. These surficial sediments and soils were substantially reworked by the Pleistocene glaciations. The state's geology is part of the broader geology of New England.
The Western Corn Belt Plains is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in seven U.S. states, though predominantly in Iowa.
