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| | Soil - Wikipedia, the free encyclopedia |
 | | Soils are vital to all life on Earth because they support the growth of plants, which supply food and oxygen and absorb carbon dioxide and nitrogen. | | | Both water and air components of soils are important to plant growth and other life in the soil profile of a particular ecosystem. | | | Human actions also can degrade soils through the depletion of nutrients, pollution, contamination, and compaction, and by increasing the rate of erosion, which is the relocation of soil through the movement of water or wind. |
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http://en.wikipedia.org/wiki/Soil
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| | USDA Agricultural Research Service |
| | Determination of suitability of a water for irrigation is dependent on the soil properties, chemical composition of the irrigation and soil water, climate, crop, and management practices, such as method of irrigation and leaching fraction. | | | The problems of soil salination, waterlogging, and water pollution are increasing as irrigation is being expanded and as less suitable waters and soils are being used to meet the ever increasing need for food in the world. | | | Surviving the salinity threat requires that the seriousness of the problem be widely recognized, that the processes contributing to salination be understood, and that effective control measured be developed and implemented that will sustain the viability of irrigated agriculture. |
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http://www.ars.usda.gov/id/riverside/riverside_acc.htm
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| | Soil salination - Wikipedia, the free encyclopedia |
| | Since soil salinity makes it more difficult for plants to absorb soil moisture, these salts must be leached out of the plant root zone by applying additional water. | | | Cities are often located on drylands, leaving the rich soils for agriculture. | | | Salinity from drylands can occur when the water table is between two to three metres from the surface of the soil. |
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http://en.wikipedia.org/wiki/Soil_salination
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| | Robert Goodland - Ecological Limits |
| | As a result of widespread deficiencies in fuel wood, crop residues and dung are being diverted from agriculture to fuel. | | | Pimentel et al.2 found that soil erosion is serious in most of the world's agricultural areas and that this problem is worsening as more marginal land is brought into production. | | | "World Agriculture and Soil Erosion." BioScience 37(4) 1987. |
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http://www.context.org/ICLIB/IC36/Goodland.htm
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| | Chapter 3 -- SOIL EROSION BASICS |
| | The soils of boreal, temperate, alpine and tropical forests and the soils of grasslands and tundra all have mycorrhizae. | | | Sand tends to be the coarsest-grained soil component; silt is finer-grained, and clay is the finest-grained. | | | Latosols, the reddish or yellowish-brown lateritic soils of the savannas and forests of tropical and subtropical regions, are the most severely weathered and leached soils in the world. |
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http://home.alltel.net/bsundquist1/se3.html
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| | CIA - The World Factbook 2002 -- Field Listing - Environment - current issues |
| | deforestation; soil erosion; overgrazing; desertification; air pollution from industrial effluents and vehicle emissions; water pollution from raw sewage and runoff of agricultural pesticides; tap water is not potable throughout the country; huge and growing population is overstraining natural resources | | | overuse of pastures and subsequent soil erosion attributable to population pressures; desertification; deforestation of tropical rain forest, in response to both international demand for tropical timber and to domestic use as fuel, resulting in loss of biodiversity; soil erosion contributing to water pollution and siltation of rivers and dams; inadequate supplies of potable water | | | draining of wetlands for agricultural use; deforestation; overgrazing; soil erosion; water hyacinth infestation in Lake Victoria; poaching is widespread |
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http://www.faqs.org/docs/factbook/fields/2032.html
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| | Chapter 5 -- Degradation of Irrigated Land |
| | Nearly all of Karakalpakia's agricultural land is either salinated or waterlogged. | | | Waterlogging and salinity have reduced yields of major crops by 30% (92P1). | | | Salinization reduces Mexico's crop output by one million tons of grain/ year (90P1). |
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http://home.alltel.net/bsundquist1/ir5.html
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| | The Academy of Natural Sciences - Education - Know Your Environment |
| | Loss of perennial vegetation leaves topsoil unable to resist forces of water and--more often--wind; eventually fertile soil may become eroded at a rate 10 to 40 times greater than is considered acceptable by agriculture experts. | | | Yet, as serious as salination of soil alone may be, it is only one part of the larger picture of desertification. | | | With the amount of arable land decreasing, there is greater effort to cultivate marginal land (the areas that are in fact the most vulnerable to becoming degraded) and greater efforts to clear forested land for farming, leading to further erosion. |
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http://www.acnatsci.org/education/kye/nr/kye32002.html
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| | PREFACE |
| | Once the soil or water is affected by salination, it requires years to treat and large amount of energy and costly efforts. | | | The primary objective of agriculture is to provide food and fiber needs of human beings. | | | The present rate of expansion in irrigation is less than 1 percent per year (2 million ha per year) and unfortunately fall below the rate of increase in population. |
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http://www.actahort.org/books/573/573_0.htm
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| | Amazon.com: Salinity Management for Sustainable Irrigation: Integrating Science, Environment, and Economics ... |
| | The term salinity refers to the presence in soil and water of various electrolytic mineral solutes in concentrations that are harmful to many agricultural crops. | | | Chapters include: The Nature of Salinity, Effects on Crops, Irrigation Water, Waterlogging and Drainage, Salinity Control, Early Warning Systems, Scaling up from the Field, and a Conclusion which addresses directly the question of whether or not irrigation is sustainable. | | | by Daniel Hillel "The term salinity refers to the presence in soil and water of various electrolytic mineral solutes in concentrations that are harmful to many agricultural crops..." (more) |
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http://www.amazon.com/exec/obidos/tg/detail/-/082134773X?v=glance
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| | food issues-food supply security |
| | Salination of fields has become more and more damaging as irrigated agriculture has spread. | | | Salination affects mainly dry lands used for grazing, or dry lands that have been irrigated to realize their productive potential for crops such as vegetables or cotton. | | | In the earlier part of the century, so much soil was damaged and thrown to the wind that in parts of the USA day sometimes became a 'dust night'. |
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http://naturalhub.com/food_issues_food_supply_security.htm
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| | RoguePundit: Random Nature #38 |
| | Another way to cause soil salination problems is when the source of the irrigation water is a bit salty. | | | Some soils naturally have fair concentrations of salt at some depth (or occasionally shallow, saline groundwater tables), but the earth near the surface is fertile for growing crops. | | | Sometimes soil salination can be more insidious, like in large areas of Western Australia. |
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http://roguepundit.typepad.com/roguepundit/2005/07/random_nature_3_1.html
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| | Egypt Environment - current issues - Geography |
| | acidification - the lowering of soil and water pH due to acid precipitation and deposition usually through precipitation; this process disrupts ecosystem nutrient flows and may kill freshwater fish and plants dependent on more neutral or alkaline conditions (see acid rain). | | | desertification - the spread of desert-like conditions in arid or semi-arid areas, due to overgrazing, loss of agriculturally productive soils, or climate change. |
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http://www.indexmundi.com/egypt/environment_current_issues.html
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| | Study Abroad Opportunities College of Natural Resources, University of Minnesota |
| | Explore natural resource issues including soil salination, conversion of native forests to farmland and tree plantations, and introduction of non-native plants and animals. | | | Learn how the distribution of vegetation and wildlife are related to soil, water, landforms, climate, and human intervention. | | | how natural vegetation (emphasizing forest vegetation) and its associated wildlife in a region are dependent on the soil, water, climate, and landforms. |
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http://www.cnr.umn.edu/ug/advising/australia/index.php
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| | Academic Learning Center - St. Cloud State Univeristy |
| | a) soil salination; b) evapotranspiration; c) sedimentation of canals and resivours d) all of these | | | a) planting of sod; b) digging up of prairie to farm the soil; c) another name for the great depression; d) what happens after grain prices rise. | | | What is the name of the legislation which causes farmers to lose government subsidies if the sodbust erodable soils? |
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http://www.stcloudstate.edu/alc/testing/biology/101/exam4/q-grasslands.asp
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| | soil salination |
| | The accumulation of soluble mineral salts near the surface of soil, usually caused by the capillary flow of water from saline ground water. | | | Where the rate of surface evaporation is high, irrigation can exacerbate the problem by moistening the soil and causing water to be drawn from deeper levels as water evaporates from the surface. | | | The evaporation of pure water leaves the salts behind, allowing them to accumulate, and they can reach concentrations that are toxic to plants, thus sterilizing the land. |
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http://www.eionet.eu.int/gemet/concept?cp=7889
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| | Reuse of Saline-Sodic Drainage Water for Irrigation |
| | Particular emphasis is placed on the need to control soil salination, avoid adverse effects on soil physical properties, and to select potential crops that are suitable for reuse systems. | | | Trace elements such as boron, selenium and molybdenum may also influence the feasibility of using saline-sodic drainage water for irrigation. | | | Several strategies have been proposed, tested and found successful over a number of years. |
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http://www.pubs.asce.org/WWWdisplay.cgi?0002072
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| | Islam Online- Environment |
| | They identified the following as some of the non-sustainable practices, which are of global importance: over-pumping of aquifers, destruction of wetlands, salination of soils, and the pollution of aquifers with persistent pollutants. | | | Scientists and representatives from water management authorities attending the conference said that sustainable water management “is a practice, which avoids irreversible or quasi-irreversible damage to the resource water and other natural resources linked to it, such as soil and ecosystems”. | | | Over-pumping of aquifers is one of the non-sustainable practices of water use |
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http://www.islamonline.net/english/science/2004/08/article07.shtml
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| | Articles - Desalination |
| | The benthic community cannot accommodate such an extreme change and many filter feeding animals are destroyed when the water is returned to the ocean. | | | Regardless of the method used, there is always a highly concentrated waste product consisting of everything that was removed from the created "fresh water". | | | Reverse Osmosis, for instance, removed 50% or more of the water, doubling the salinity of ocean was. |
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http://www.ufbn.com/articles/Desalination
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