AP BIOLOGY

Detailed explanation-1: -Nitrification, the oxidation of NH4+ to NO3− (eqn [3]), occurs readily in oxic environments, such as well drained soils, through the activity of nitrifying prokaryotes. This process is important for soil fertility, as nitrate is readily assimilated by plants.

Detailed explanation-2: -Nitrification, that is, the conversion of ammonium via nitrite to nitrate by soil microorganisms, however, leads to nitrate leaching and gaseous nitrous oxide production and as such to an up to 50% loss of nitrogen availability for the plant.

Detailed explanation-3: -Denitrification most commonly occurs in wet or waterlogged soils where the oxygen supply for respiration is restricted. Some fungi can denitrify, but they are not considered significant. When Does It Occur? Denitrification proceeds rapidly when water-filled pore space in soils exceeds 60%.

Detailed explanation-4: -Denitrification is the chemical reduction of soil nitrates or nitrites by denitrifying bacteria leading to gaseous N losses. When oxygen is limited, some bacteria use nitrate to support respiration.

Detailed explanation-5: -Step 2: Nitrification This process is slow, but it’s the way that nitrogen is built as a nutrient in soil and aquatic and marine environments-terrestrial plants, for instance, can absorb ammonium and nitrate through their root hairs.