ENVI 201 Lecture Notes - Lecture 10: Dust Bowl, Soil Fertility, Soil Salinity
7 Mar 2017
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Document Summary
Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment. Productive potential of topsoil falls by 10% or more. Dust bowl severe wind erosion of top soil. Gradual accumulation of salts in the soil from irrigation water. Lowers crop yields and can even kill plants. 70% of the worlds drylands used for agriculture are threatened by desertification. Agriculture contributes to air pollution and climate change. Clearing and burning of forests for croplands. Of all human generated greenhouse gases. Since 1900, roughly of the genetic diversity of agricultural crops have been lost. So far genetically modified crops have failed to provide extensive benefits. Potenial environmental effects of genetically modified populations in the wild. Dense populations can be vulnerable to disease. Pests are organisms that prey on other organisms that we would prefer to eat/use. We use chemicals to repel or kill pest organisms as plants have done for millions of years pesticides.
