It is present in excess because it is an non-combustible gas which means it does not burns or supports burning. if it was not present then a small spark also could lead to large blasts.
plz mark as brainliest
He asked 'Why?' not the importance of nitrogen in atmosphere.
and nitrogen is important major nutrient for plants root
leguminous plants root live symbiotically with rhizodium bacteria so that bacteria can convert the atmospheric nitrogen to soluble nitrogen to the roots and in turn roots provides bacteria with water and food
some ammount of carbon dioxide wold be able to prevent such a spark
Its due to nitrogen cycle from many human factors like industrial smoke containing oxides of nitrogen may lead to this and when plants and animals dies the denitrifying bacterias convert the complex nitrogen molecules to the simple atmosperic nitrogen so this also adds nitrogen. even we as a humanbeing excrete urine and stool which contains a major ammount of urea mixed with water forming uric acid so this process too adds nitrogen.