Hint: All the processes which are done because of this process will get disturbed and there are so many important functions of nitrogen fixation for the organisms which will get affected.
Nitrogen fixation is a process in which free nitrogen present in the air gets converted into ammonia and nitrate which is further taken up by plants and then in plants this nitrate is converted into amino acids, nucleotides, proteins and some more nitrogenous compounds in soil. All these are important for the growth of organisms as most of the organisms are unable to use this atmospheric nitrogen. It is essential for life as this fixed nitrogen is required for the biosynthesis of all the nitrogen containing compounds and this is also used in nitrogen cycle where it is important for agriculture and manufacturing of fertilisers.
If this process does not take place then organisms will be unable to grow and some nitrogen fixing bacteria have symbiotic relationships with plant groups like legumes then that will also stop their functions. There will be no formation of root nodules in the leguminous plants. All the processes in the organisms which used to be done with the help of nitrogen will get disturbed. This is also used for agriculture and for the manufacturing of fertilisers as I said above then these processes will also get disturbed.
When plants lack nitrogen, they appear yellowish or pale, these also produce less fruit and flowers. When plants do not get required Nitrogen, the amino acids will not be formed due to which plant cells won't be able to grow as they require special proteins to grow which is obtained by amino acids.
Note: Nitrogen fixation is a really important process for organisms as it is the key for their structural and functional growth. If this will not take place then organisms will not be able to grow and function properly, they will start showing different signs as in plants, they start to become yellowish and they produce less fruits and flowers.