<P> Nitrogen fixation is essential for some forms of life because inorganic nitrogen compounds are required for the biosynthesis of the basic building blocks of plants , animals and other life forms , e.g. , nucleotides for DNA and RNA , the coenzyme nicotinamide adenine dinucleotide for its role in metabolism ( transferring electrons between molecules ) , and amino acids for proteins . Therefore , as part of the nitrogen cycle , it is essential for agriculture and the manufacture of fertilizer . It is also , indirectly , relevant to the manufacture of all chemical compounds that contain nitrogen , which includes explosives , most pharmaceuticals , dyes , etc . Nitrogen fixation is carried out naturally in the soil by nitrogen fixing bacteria such as Azotobacter . Some nitrogen - fixing bacteria have symbiotic relationships with some plant groups , especially legumes . Looser relationships between nitrogen - fixing bacteria and plants are often referred to as associative or non-symbiotic , as seen in nitrogen fixation occurring on rice roots . It also occurs naturally in the air by means of NOx production by lightning . </P>
<P> Nitrogen fixation is essential for some forms of life because inorganic nitrogen compounds are required for the biosynthesis of the basic building blocks of plants , animals and other life forms , e.g. , nucleotides for DNA and RNA , the coenzyme nicotinamide adenine dinucleotide for its role in metabolism ( transferring electrons between molecules ) , and amino acids for proteins . Therefore , as part of the nitrogen cycle , it is essential for agriculture and the manufacture of fertilizer . It is also , indirectly , relevant to the manufacture of all chemical compounds that contain nitrogen , which includes explosives , most pharmaceuticals , dyes , etc . Nitrogen fixation is carried out naturally in the soil by nitrogen fixing bacteria such as Azotobacter . Some nitrogen - fixing bacteria have symbiotic relationships with some plant groups , especially legumes . Looser relationships between nitrogen - fixing bacteria and plants are often referred to as associative or non-symbiotic , as seen in nitrogen fixation occurring on rice roots . It also occurs naturally in the air by means of NOx production by lightning . </P>
how nitrogen fixation takes place in the soil
how nitrogen fixation takes place in the soil
by nitrogen fixing bacteria such as Azotobacter
by nitrogen fixing bacteria such as Azotobacter