ESS205H1 Lecture Notes - Lecture 7: Soil Management, Secondary Treatment, Soil Contamination
19 Sep 2018
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Document Summary
Soil: uppermost layer of earth"s crust, contains minerals and organic matte, formed by natural processes and the breakdown of rock through weathering. Soil problem: soil pollution: physical or chemical change in soil, adversely affects health of organisms, some from fertilizers, pesticides, salinization through irrigation can render soil useless. Agroecosystems: require irrigation (water), fertilizers, and pesticides, a combination of these three can cause lots of environmental problems, haber-bosch process very intensive, excess fertilizers runoff into rivers, groundwaters. Earth"s freshwater: water may seem abundant, but drinkable water is rare, freshwater = relatively pure, with few dissolved salts - only 3% of earth"s water. Irrigation uses most freshwater then industry and households: rivers discharge can"t be contained and more disastrous today then before because, humans often remove water-absorbing plants and replace with buildings and concrete, people live in flood prone zones. Irrigation needed to increase agricultural productivity or arid and semiarid lands: areas are needed to produce food for increasing population.
