to nitrous oxide (N2O), and to a nitrogen gas which is released into the atmosphere (Harrison, 2003; Pidwirny, 2006). 1-4-2 Nitrogen fixation The fixation of nitrogen is the process whereby dinitrogen gas (N2) is reduced to ammonium, an important process since it is the only way by which nitrogen gas from the atmosphere is fixed into ammonia (NH3) and made available to plants and microorganisms. (Park, 2010) Bacteria, such as (anaerobic) and Cyanobacterium, Clostridium Nostoc, Anabaena (aerobic), and (aerobic), Azotobacter, Beijerinckia, Acetobacer Pseudomonas and (facultative anaerobic), as well as Rhodospirillum, Klebsiella Bacillus actinomycetes, like are all capable of fixing dinitrogen. Fungi do not participate Frankia in this process, so nitrogen fixation is limited to bacteria (Soomro, 2000; Maier et al., 2009). Species of are the most important bacteria involved in the fixation of Rhizobium dinitrogen (Harrison, 2003). 1-4-3 Ammonification Ammonification is an important phase in the nitrogen cycle and involves a diverse group of microorganisms which live in soil and water, and which degrade organic nitrogen in the form of proteins and amino acids (present in dead plant and animal matter and faeces), releasing ammonia (NH3) into soil which is then absorbed by plants (Hart et al., 1994).
to nitrous oxide (N2O), and to a nitrogen gas which is released into the atmosphere (Harrison, 2003; Pidwirny, 2006). 1-4-2 Nitrogen fixation The fixation of nitrogen is the process whereby dinitrogen gas (N2) is reduced to ammonium, an important process since it is the only way by which nitrogen gas from the atmosphere is fixed into ammonia (NH3) and made available to plants and microorganisms. (Park, 2010) Bacteria, such as Cyanobacterium, Clostridium (anaerobic) and Nostoc, Anabaena (aerobic), Azotobacter, Beijerinckia, Acetobacer and Pseudomonas (aerobic), Rhodospirillum, Klebsiella and Bacillus (facultative anaerobic), as well as actinomycetes, like Frankia are all capable of fixing dinitrogen. Fungi do not participate in this process, so nitrogen fixation is limited to bacteria (Soomro, 2000; Maier et al., 2009). Species of Rhizobium are the most important bacteria involved in the fixation of dinitrogen (Harrison, 2003). 1-4-3 Ammonification Ammonification is an important phase in the nitrogen cycle and involves a diverse group of microorganisms which live in soil and water, and which degrade organic nitrogen in the form of proteins and amino acids (present in dead plant and animal matter and faeces), releasing ammonia (NH3) into soil which is then absorbed by plants (Hart et al., 1994).