GEOG 1 Lecture Notes - Lecture 32: Cation-Exchange Capacity, Erosion, Soil Ph
Document Summary
Nitrogen xation: motionless nitrogen gas from the atmosphere must be xed; which happens when air in the top layer of soil comes in contact with various specialized nitrogen- xing bacteria, combustion also leads to nitrogen xation. Nitri cation: ammonium ions are rst converted into nitrite ions then into nitrate ions, plants can take up nitrate ions as nutrients through their roots. Denitri cation: occurs when bacteria convert nitrates in soil or water into gaseous forms of nitrogen. Deposition is the arrival of the eroded material at its new location: erosion is increased by overgrazing, over-cultivating, and clearing forest of steep slopes or large clear-cuts. Rill erosion has the greatest potential to move topsoil, then sheet erosion and splash erosion; gully erosion is more likely to occur with steep slopes. Practice of alternating the kind of crop grown in particular eld from one season to the next.
