Soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil.Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three-state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an ecosystem.
Most soils have a dry bulk density (density of soil taking into account voids when dry) between 1.1 and 1.6 g/cm3, though the soil particle density is much higher, in the range of 2.6 to 2.7 g/cm3. Little of the soil of planet Earth is older than the Pleistocene and none is older than the Cenozoic, although fossilized soils are preserved from as far back as the Archean.
Collectively the Earth's body of soil is called the pedosphere. The pedosphere interfaces with the lithosphere, the hydrosphere, the atmosphere, and the biosphere. Soil has four important functions:
* as a medium for plant growth * as a means of water storage, supply, and purification * as a modifier of Earth's atmosphere * as a habitat for organisms
All of these functions, in their turn, modify the soil and its properties.
Soil science has two basic branches of study: edaphology and pedology. ''Edaphology'' studies the influence of soils on living things. ''Pedology'' focuses on the formation, description (morphology), and classification of soils in their natural environment. In engineering terms, soil is included in the broader concept of regolith, which also includes other loose material that lies above the bedrock, as can be found on the Moon and other celestial objects. Provided by Wikipedia
-
261
-
262
-
263Soil organic matter dynamics and sustainability of tropical agriculture Soil organic matter dynamics and sustainability of tropical agricultureby Mulongoy, K. (ed.), International Inst. of Tropical Agriculture, Ibadan (Nigeria) eng, Merckx, R. (ed.), Katholieke Univ. Leuven (Belgium). Lab. of Soil Fertility and Soil Biology oth
Published 1993Texto bibliotecaFAO IT -
264
-
265by Soil Research Inst., Bogor (Indonesia) eng 32834, ASEAN Soil Conf eng 18-21 Jul 1972 2 Jakarta (Indonesia), Ministry of Agriculture, Jakarta (Indonesia) eng
Published 1973Texto bibliotecaFAO IT -
266
-
267
-
268
-
269Soil testing sampling, correlation, calibration, and interpretation Soil testing sampling, correlation, calibration, and interpretationby Brown, James Richard, American Society of Agronomy, Soil Science Society of America, Annual Meetings of the American Society of Agronomy and Soil Science Society of America 1-5 Dec. 1985:
Published c198Texto bibliotecaUBA FA -
270Texto bibliotecaFEDEPALMA
-
271Texto bibliotecaIICA
-
272
-
273bibliotecaIICA
-
274
-
2757th International symposium on soil and plant analysis : fine tuning soil and plant analysis for economic and environmental betterment, Saturday July 21 to friday July 27 2001 the... 7th International symposium on soil and plant analysis : fine tuning soil and plant analysis for economic and environmental betterment, Saturday July 21 to friday July 27 2001 the...by International symposium on soil and plant analysis (7: 2001: Edmonton, Alberta Canada)
Published 2001Texto bibliotecaCOLPOS -
276Texto bibliotecaUNC AR
-
277Texto bibliotecaFAO IT
-
278Texto bibliotecaFAO IT
-
279
-
280by Ministry of Forests, Kathmandu (Nepal). Dept. of Soil Conservation and Watershed Management eng
Published 1984Texto bibliotecaFAO IT