Nitrates of soil are also leached deep into the Earth by . . . . . . .

Which of the following is a bacterium involved in denitrification?

List and describe the main phases of the nitrogen cycle.

Which of the following is true for nitrogen fixation?

Nitrifying bacteria are those which can convert

The process of conversion of nitrogen gas into ammonia is called $P$,and the process of decomposition of organic nitrogen in plants and animals into ammonia is called $Q$.