describe briefly 1 biological & 1physical method of conversion of nitrogen to form nitrities& nitrates
- Rhizobium, is found in the root nodules of leguminous plants like pulses. It lives in symbiotic association with plants and fixes the atmospheric nitrogen in leguminous plants.It converts the atmospheric nitrogen into absorbable forms such as nitrate and nitrite so that plants can take them up from the soil. This is the biological method of fixng atmospheric nitrogen.
- During lightening, the high temperatures and pressures created in the air convert nitrogen into oxides of nitrogen. These oxides dissolve in water to give nitric and nitrous acids (HNO3 and HNO2 respectively which give the nitrate and the nitrite ion) and fall on land along with rain. These are then utilised by various lifeforms.