Clay content is particularly influential on soil behavior due to a high retention capacity for nutrients and water.
Where soil mineral particles are both separated and bridged by organic-matter-breakdown products and soil-biota exudates, it makes the soil easy to work.
Acidification occurs when these elements are removed from the soil profile by normal rainfall or the harvesting of crops.
Geologists classify surface soils using the 1938 USDA soil taxonomy (Brevik 2002), but use the current version of USDA soil taxonomy to classify the buried soils that make up the paleopedological record.
The WRB borrows from modern soil classification concepts, including United States Department of Agriculture (USDA) soil taxonomy.
Soil is among our most important natural resources because of its position in the landscape and its dynamic, physical, chemical, and biologic functions.
Organic material tends to loosen up the soil and make it more productive for plant growth.
Where soil limitations preclude the use of a septic drain field, the soil treatment component is replaced by some combination of mechanical aeration, chemical oxidation, ultraviolet light disinfection, replaceable phosphorus retention media and/or filtration.
A major difference with USDA soil taxonomy is that soil climate is not part of the system, except in so far as climate influences soil profile characteristics.
Bison, elephants, and some other large animals cover themselves with soil for protection against sun and insects.
Soil erosional loss is caused by wind, water, ice, and movement in response to gravity.
Geologists have a particular interest in the patterns of soil on the surface of the earth.
A stable, shallow water table allowed capillary transport and evaporative enrichment of salts at the soil surface, depressing crop productivity below pre-project levels.
Preventing soil salination involves flushing with higher levels of applied water in combination with tile drainage.
Soil texture, color and chemistry often reflect the underlying geologic parent material and soil types often change at geologic unit boundaries.
Cultivation, earthworms, frost action, and rodents mix the soil.
Soil contamination at low levels are often within soil capacity to treat and assimilate.
Improvement in these areas severely hindered the advance of Croatia's prospects for further Euro-Atlantic integration.
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.
Little of the soil continuum of the earth is older than Tertiary and most are no older than Pleistocene (Hole and McCracken 1973).
The World Reference Base for Soil Resources (WRB) is the international standard soil classification system.
The wastes of animals enrich the soil and their digging mixes and loosens it; both of these activities benefit the further growth of plants.
Despite the duration of humanity's dependence on and curiosity about soil, exploring the diversity and dynamic of this resource continues to yield fresh discoveries and insights.
The solar constant is equal to approximately 1,370 watts per square meter of area at a distance of one AU from the Sun (that is, on or near Earth).
The WRB structure is either nominal, giving unique names to soils or landscapes, or descriptive, naming soils by their characteristics such as red, hot, fat, or sandy.
The technique for creating terra prкta do нndio in the Amazon basin appears to have started from knowledge of soil first gained at a household level of waste management.
How the soil "life" cycle proceeds is influenced by at least five classic soil forming factors: regional climate, biotic potential, topography, parent material, and the passage of time.
An example of soil development from bare rock occurs on recent lava flows in warm regions under heavy and very frequent rainfall.
Compost and anaerobic digestate (also termed biosolids) are used to benefit the soils of land remediation projects, forestry, agriculture, and for landfill cover.
Consequences include corrosion damage, reduced plant growth, erosion due to loss of plant cover and soil structure, and water quality problems due to sedimentation.
Soils altered or formed by man (anthropic and anthropogenic soils) are also of interest to archaeologists.
Clays are distinguished from other small particles present in soils such as silt by their small size, flake or layered shape, affinity for water and tendency toward high plasticity.
The classification is based mainly on soil morphology as an expression of pedogenesis, the creation of soil.
According to the theory of biorhexistasy, prolonged conditions conducive to forming deep, weathered soils result in increasing ocean salinity and the formation of limestone.
Other animals, such as pigs, dig into the soil to find food, and others, such as beavers and some birds, use soil as a building material.
Soil processes have limited treatment capacity for treating metal and salt components of waste.
The Red River of the United States carries sediment eroded from extensive reddish soils like Port Silt Loam in Oklahoma.
The long periods over which change occurs and the multiple influences of change mean that simple soils are rare.
Clay is another material taken from the soil that has been very important to humans, being used for eating and drinking vessels, storage containers, for works of art, and for other uses since prehistoric times.
Soil texture refers to sand, silt and clay composition in combination with gravel and larger-material content.
Extensive academic research is performed in an effort to expand the understanding of agricultural soil science.
Septic drain fields treat septic tank effluent using aerobic soil processes to degrade putrescible components.
Remembering or re-creating the Nativity (the birth of Jesus) is one of the central ways that Christians celebrate Christmas.
Soil is also relied on for chemically binding and retaining phosphorus.
Lighter soils, with their lower moisture content and better structure, take less effort to turn and cultivate.
Industrial waste management similarly relies on soil improvement to utilize waste treatment products.
New avenues of soil research are compelled by our need to understand soil in the context of climate change and carbon sequestration.
The earth's soil in general is sometimes referred to as comprising the pedosphere, which is positioned at the interface of the lithosphere with the biosphere, atmosphere, and hydrosphere.
Pathogenic organisms vulnerable to predation in an aerobic soil environment are eliminated.
Soil almost always contains water and air in the spaces between the mineral and organic particles.
The lighter-textured, surface soils are more responsive to management inputs, but also more vulnerable to erosion and contamination.
Contrary to popular belief light soils do not weigh less than heavy soils on an air dry basis nor do they have more porosity.
An example of soil salination occurred in Egypt in the 1970s after the Aswan High Dam was built.
Soils tend to develop an individualistic pattern of horizontal zonation under the influence of site specific soil-forming factors.
Soil-based wall construction materials include adobe, chirpici, cob, mudbrick, rammed earth, and sod.
Soil survey, or soil mapping, is the process of determining the soil types or other properties of the soil cover over a landscape, and mapping them for others to understand and use.
Plant growth, and many uses which rely on soil, tends to favor medium-textured soils, such as loam and sandy loam.
Soil acidification is accelerated by the use of acid-forming nitrogenous fertilizers and by the effects of acid precipitation.
Soil salination is the accumulation of free salts to such an extent that it leads to degradation of soils and vegetation.
Soil examined in shovel test pits is used by archaeologists for relative dating based on stratigraphy (as opposed to absolute dating).
The extensive and various iron minerals in soil are responsible for an array of soil pigmentation.
Soils are often initially acid because their parent materials were acid and initially low in the basic cations (calcium, magnesium, potassium, and sodium).
Homeowners and farmers alike test soils to determine how they can be maintained and improved.
Most soil organisms thrive best when the soil contains about equal volumes of water and air (Adams 1986).
Pedology is the study of soil in its natural setting, while edaphology is the study of soil in relation to soil-dependent uses.
The Yellow River in China carries yellow sediment from eroding loessal soils.
On the other hand, anthropogenic activities have included fostering soil erosion and desertification through clear-cutting and overgrazing livestock, and contaminating soils by the dumping of industrial or household wastes.
A sprouting seed sends into the soil roots, which absorb water and dissolved minerals that the new plant needs for its growth.
Due to superior aggregation, clay soils resist wind and water erosion better than silty and sandy soils.
Recently formed soil, for instance that formed from lava recently released from a volcano, is richer in nutrients and so is more fertile (Adams 1986).
What is considered most typical is to use soil profile features to determine the maximum reasonable pit depth than needs to be examined for archaeological evidence in the interest of cultural resources management.
Soil management tools include maintaining soil nutrient and organic matter levels, reduced tillage, and increased cover.
One of the main causes of soil erosion in is slash and burn treatment of tropical forests.
Clay particles act like electrostatic filters to detain viruses in the soil adding a further layer of protection.
Soil piping is a particular form of soil erosion that occurs below the soil surface.
Plant nutrients such as nitrogen, phosphorus, and potassium are tested for in soils.
Primary data for the soil survey are acquired by field sampling and supported by remote sensing.
Soils are the critical component in land degradation when it involves acidification, contamination, desertification, erosion, or salination.
An offset subsoil horizon indicates rupture during soil formation and the degree of subsequent subsoil formation is relied upon to establish time since rupture.
Using compost and vermicompost are popular methods for diverting household waste to build soil fertility and tilth.
Color development and distribution of color within a soil profile result from chemical weathering, especially redox reactions.
Turbulent flow removes soil starting from the mouth of the seep flow and subsoil erosion advances upgradient.
Despite the inevitability of soil retrogression and degradation, most soil cycles are long and productive.
Geologists and pedologists use soil profile features to establish the duration of surface stability in the context of geologic faults or slope stability.
Our interest in maintaining the planet's biodiversity and in exploring past cultures has also stimulated renewed interest in achieving a more refined understanding of soil.
Some ant workers' role is to maintain the hygiene of the colony and their activities include undertaking or necrophory, the transport of dead nest-mates (Julian 1999).
Soils are distinguished by obvious characteristics, such as physical appearance (e.g., color, texture, landscape position), performance (e.g., production capability, flooding), and accompanying vegetation.
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.
Soil structure influences aeration, water movement, erosion resistance, and root penetration.
Vines like honeysuckle, clematis and Boston ivy thrive in alkaline soil. A wide range of flowering and ornamental plants are perfectly suited to these soil conditions as well. Options include lily, iris, bluebell, crocus, geranium, hyacinth, maidenhair fern, morning glory, poppy and daisy.
Only a thin layer of decaying organic matter is found, unlike in temperate deciduous forests. Most tropical rainforest soils relatively poor in nutrients. Millions of years of weathering and torrential rains have washed most of the nutrients out of the soil. More recent volcanic soils, however, can be very fertile.