Chapter 12

1. Chapter 12 Effects of Agriculture on the Environment

2. Soil erosion Sediment transport and deposition downstream On-site pollution from fertilizers and pesticides Deforestation Desertification Degradation of water aquifers Salinization Accumulation of toxic metals and organic compounds Loss of biodiversity Many environmental problems result from agriculture:

4. Where Eroded Soil Goes: Sediments Also Cause Environmental Problems Ways to slow erosion: • Making Soil Sustainable • Contour Plowing • No-Till Agriculture • Combination of farming practices that include not plowing the land and using herbicides to keep down weeds.

7. Integrated Pest Management • Control of agricultural pests using several methods together, including biological and chemical agents • Goals: • To minimize the use of artificial chemicals • To prevent or slow the buildup of resistance by pests to chemical pesticides

10. The Terminator Gene • A genetically modified crop which has a gene to cause the plant to become sterile after the first year

11. Grazing on Rangelands • Overgrazing occurs when the carrying capacity is exceeded. It can cause severe damage to lands • It is important to properly manage livestock, including using appropriate lands for gazing and keeping livestock at a sustainable density

12. Desertification • Desertification is the deterioration of land in arid, semi- arid and dry sub humid areas due to changes in climate and human activities • Can be caused by • Poor farming practices • Conversion of marginal grazing lands to croplands