GEOG 203 Lecture Notes - Lecture 7: Nitrogen Cycle, Environmental Issue, Nitrogen Fixation
Document Summary
Soils play an important role in environmental processes. Biochemical cycling in environmental systems: movement of chemicals within the environment, fluxes, storage and residence time, disturbed/ undisturbed intensive agriculture/ deforestation/ acid precipitation, resilience, how capable you can withstand a disturbance. Input from output to vegetation and atmosphere soil: storage and transformation of energy, water, nutrients and chemical. Calcium cycle: storage evenly balanced. Nutrient cycling in ecosystem: tight cycling. Input = output: disturbed, clear cut, cycling is loose, outputs > inputs, ease of loss is generally n>k>ca>p, retention of nutrients, base cations/ exchange complex, phosphorus absorbs clay, nitrogen limited absorption. Input can occur through precipitation: decomposition of organic matter, nitrification conversion, soluable and weakly held anion complex. Nitrogen cycles processes: nitrogen fixation: incorporation of n2 from atmosphere, mineralization, dependent on ph in soil, rocks, vegetation, nitrification and soil ph higher the ph the higher the nitrification.
