soil Reference library
Robert E. White
The Oxford Companion to Wine (4 ed.)
... , mineral material at the Earth’s surface formed by weathering of underlying bedrock ( see geology ), or transported sediments, which form the parent material of a soil. The main distinction between soil and parent material is a soil’s enrichment with plant and animal remains that undergo decomposition to form soil organic matter . Because soil formation is an ongoing process, determined by climate , vegetation, topography , and time, the boundary between a soil and its parent material is usually indistinct. Over very long periods, episodes of erosion...
soil Quick reference
A Dictionary of Plant Sciences (4 ed.)
... The natural, unconsolidated, mineral and organic material occurring on the surface of the Earth; it is a medium for the growth of...
soil Quick reference
A Dictionary of Agriculture and Land Management
...are vital to soil health. There are gaps between the soil particles that are filled with air or water. Nutrients may be adsorbed onto the surface of soil particles, especially clay. All soils are made up of these particles, with the soil type determined by the precise composition and the underlying rock. The main soil types are: clay, silt, sand, peat, chalk, and loam, with names for particular soils, such as podzol and rendzina . The profile of the soil consists of the topsoil over the subsoil over the underlying rock. Soil structure is...
soil Quick reference
World Encyclopedia
... Surface layer of loose material resting on top of the rock which makes up the surface of the Earth. It consists of undissolved minerals produced by the weathering and breakdown of surface rocks, organic matter, water, and gases. The organic remains provide the humus and the inorganic particles provide vital minerals. Soils are classified by structure and texture. The structure is determined by the aggregation of particles (peds). The four main textures of soil are sand , silt , clay , and loam. Loam soils are best for cultivation, since they are able...
soil Quick reference
A Dictionary of Biology (8 ed.)
...soil The layer of unconsolidated particles derived from weathered rock, organic material ( humus ), water, and air that forms the upper surface over much of the earth and supports plant growth. The formation of soil depends on the parent material (i.e. the original material from which the soil is derived), the climate and topography of the area, the organisms present in the soil, and the time over which the soil has been developing. Soils are often classified in terms of their structure and texture. The structure of a soil is the way in which the individual...
soil Quick reference
A Dictionary of Geography (5 ed.)
... The naturally occurring, unconsolidated, upper layer of the ground, made of humus and weathered rock. Major factors affecting soil formation are: climate, relief, parent material, vegetation, and time; see Svoray and Shoshany (2004) Rem. Sens. Env. 92, 2 . Soil is the medium on which we produce 99% of our food; a major store of carbon; and regulator of climate, holding two to three times more carbon than exists in the atmosphere ( Davidson et al. (2000) Nature 408, 789 ). Soils are also a regulator of water resources, attenuating hydrological...
soil Quick reference
The Concise Oxford Dictionary of Archaeology (2 ed.)
... [Ge] A general term describing the organic‐rich surface layer that forms naturally on the top of most bedrock types as a result of the weathering of the parent material, the addition of water‐borne, air‐borne, and anthropogenically introduced extraneous material, and the build‐up of organic matter through colonization by plants. The study of soils is known as pedology. See also soil profile...
soil Quick reference
A Dictionary of Geology and Earth Sciences (5 ed.)
... 1. The natural, unconsolidated, mineral and organic material occurring above bedrock on the surface of the Earth; it is a medium for the growth of plants. 2. In engineering geology, any loose, soft, and deformable material, e.g. unconsolidated sands and clays...
Soil Reference library
Timothy BEACH
Berkshire Encyclopedia of Sustainability
...are soils formed in recent volcanic materials and cover less than 1 percent of the Earth’s soil surface. Gelisols have dark, organic surfaces and form in permafrost; these cover almost 9 percent of the Earth’s soil surface, including most of Alaska. Histosols are peat and muck, forming from organic matter; they cover only about 1 percent of the Earth’s soil surface. Defining the remaining soil orders requires a bit more elaboration. Mollisols are the world’s most nutrient-rich and organic-matter-rich soils, making up about 7 percent of the Earth’s soil...
soil Quick reference
A Dictionary of Environment and Conservation (3 ed.)
... The layer of disintegrated rock particles, organic matter, water, and air that covers most of the land surface. Soil is a typical open system with inputs, throughputs, and outputs of matter and energy, and it is intimately linked with other environmental systems , particularly climate and vegetation. Through weathering and erosion , soils are linked to the lithosphere system and have a place (albeit a short‐term one) within the rock cycle . See also pedogenesis...
soil Quick reference
A Dictionary of Ecology (5 ed.)
... 1 The natural, unconsolidated, mineral and organic material occurring on the surface of the Earth; it is a medium for the growth of plants. 2 In engineering geology, any loose, soft, and deformable material (e.g. unconsolidated sands and clays...
Soil and Soil Conservation Reference library
The Oxford Encyclopedia of Economic History
...Soil and Soil Conservation . Human-induced soil erosion occurs whenever and wherever rain or wind hits soil that has been disturbed. The more sloping the land where the disturbance occurs and the more torrential the rain or the stronger the wind, the greater the amount of erosion. Thus road building and urban construction can and do promote significant erosion. But the main source is agriculture, and agriculturally induced erosion and soil conservation practices to control it are the foci here. Why Is Soil Erosion a Problem? Soil erosion creates two kinds of...
cohesive soil Quick reference
A Dictionary of Construction, Surveying and Civil Engineering (2 ed.)
...soil A soil that exhibits cohesion , i.e. granular soil...
basic soil Quick reference
A Dictionary of Plant Sciences (4 ed.)
...soil A soil with a pH greater than 7.0. See also alkaline soil...
soil fitment Quick reference
A Dictionary of Construction, Surveying and Civil Engineering (2 ed.)
... fitment ( soil appliance ) A sanitary appliance that is connected to the soil pipe...
basic soil Quick reference
A Dictionary of Geology and Earth Sciences (5 ed.)
...soil A soil with a pH greater than 7.0. See base . Compare alkaline soil...
soil profile Quick reference
A Dictionary of Construction, Surveying and Civil Engineering (2 ed.)
... profile The vertical layers of soil at a particular...
soil vent Quick reference
A Dictionary of Construction, Surveying and Civil Engineering (2 ed.)
... vent A vent pipe used to ventilate a soil stack...
soil water Quick reference
A Dictionary of Construction, Surveying and Civil Engineering (2 ed.)
... water Water that is discharged from a soil fitment...
soil classification Quick reference
A Dictionary of Geography (5 ed.)
... classification A naming system to describe and identify soils. http://www.landis.org.uk/downloads/downloads/Soil_classification.pdf National soil...
