APES 1.5: Nitrogen Cycle

vocab for the parts of the nitrogen cycle

nitrogen cycle (short period of time)

movement of nitrogen containing molecules between sources & sinks/reservoirs

atmosphere

main nitrogen reservoir

nitrogen fixation

process of nitrogen gas being converted into biologically available ammonia (NH₃) or nitrate (NO₃)

bacterial fixation

certain bacteria that live in the soil, or in symbiotic relationship with plant root nodules covert nitrogen into ammonia (NH₃)

synthetic fixation

humans combust fossil fuels to convert nitrogen gas into nitrate (NO₃)

assimilation

plants & animals taking nitrogen in and incorporating it into their bodies

ammonification

soil bacteria, microbes, & decomposers converting waste & dead biomass back into NH₃ and returning it to soil

nitrification

conversion of NH₄ into nitrite (NO₂) & then nitrate (NO₃) by soil bacteria

denitrification

conversion of soil nitrogen into nitrous oxide (N₂O) gas which returns to atmosphere

climate

N₂O (nitrous oxide) = greenhouse gas which warm earth’s climate

ammonia volatilization

excess fertilizer use can lead to NH₃ gas entering atmosphere

leaching & eutrophication

synthetic fertilizer use leads to nitrates (NO₃) leaching, or being carried out of soil by water