“Nitrogen is a vital element of all proteins, and therefore is essential for all plant life.”

A Plants Nitrogen Cycle in a Nutshell:

Deceased, rotting proteins housing organic nitrogen, is broken down by microbes to liberate ammonia, that is oxidized by bacteria into nitrite, after which it is further oxidized by other types of bacteria, so that it may then be absorbed by plants in the form of nitrate.

Nitrogen the Unavailable Abundant Element

We have a considerable availability of nitrogen within the planet’s atmosphere, which is 79% N2. Nonetheless, the nitrogen in the air is not available to be used by most microorganisms since there is the three-way bond amongst the 2 nitrogen atoms, leaving that molecule practically inert. To ensure that nitrogen is to be utilized for growth it needs to be fixed in a form of ammonium or nitrate. One way this can be fixed is with atmospheric nitrogen through legumes via their symbiosis with certain bacteria. The genera of bacteria which accomplish this form of nitrogen fixing are Azotobacter, Clostridium, Azospirillum and Rhizobium. All these live within the soil, except for the Rhizobium. They in fact reside inside the roots of  legumes, in which they will form noticeable nodules.

More Gluconacetobacter diazotrophicus Diazotrophic Information

Then there is Gluconacetobacter diazotrophicus (formerly Acetobacter diazotrophicus) which is a bacilli, aerobic, obligate endophytic (an endosymbiont), diazotrophic (bacteria that fix atmospheric N) bacterium discovered by Joana Dobereiner (1924 to 2000).  It has been undergoing lab and field tests in research institutions around the globe for the past 50 years.

Nitrogen’s Versatility

Nitrogen might possibly enjoy the distinction for being the element that can occur in the most diverse oxidation states. You will find nitrogen can have 9 distinct oxidation states. Only 3 of those 9 states, ammonia, nitrate, and nitrite, are part of the diagram below demonstrating the nitrogen cycle.  From the plant’s point of view, the main thing is to cycle down nutrients till they are immobilized within the body of bacteria and fungi. The most crucial of such nutrients is nitrogen being the fundamental building block of proteins and, therefor life. This biomass of fungi and bacteria establishes, the volume of nitrogen that may be accessible for plants.

Nitrogen’s Five Movements

There are 5 movements in the nitrogen cycle, all accomplished by microbes… fixation, uptake, mineralization, nitrification, and denitrification.

  1. Nitrogen fixation…  N2 to NH4+
  2. Nitrogen uptake… NH4+ to Organic N
  3. Nitrogen mineralization… Organic N to NH4+
  4. Nitrification… NH4+ to NO3
  5. Denitrification… NO3 to NO2 then to NO then to N2O lastly to N2.

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There is a step missing in the above diagram. Can you spot it?.

The missing step is associated with the very top circle Ammonia NH3+. Ammonia is NH3 not NH3+, and there is a missing step from NH3 to NH4+ before the bacterial oxidation to NO2-. To find out the difference in Ammonia forms, read the article in the below link.

Ammonia vs Ammonium The Difference

 

Recent Research | Bacteria Fungal Nitrogen Cycle

It was not till the eighties that researchers could properly determine the level of bacteria and fungi in the earth’s soils.For the first time Dr. Elaine Ingham at Oregon University published research which demonstrated the ratio of these two microorganisms in several kinds of soils. Normally, the least disrupted earth experienced much more fungus compared to bacteria, whilst disrupted soils possessed much more bacteria than fungus.

Dr. Ingham additionally observed a relationship among plants and their inclination for soils which were dominated by fungus vs  the ones that were dominated by bacterial. Generally, perennials, trees, and shrubs prefer soils dominated by fungus, whilst our precious herbs, vegetables and annuals prefer soils dominated by bacteria.

One particular inference from these conclusions, is nitrogen in fungi and bacteria. Whenever these types of microorganisms are ingested, some of the nitrogen will be stored by the predator, however most of it will be discharged as waste materials as plant available ammonium, NH4-. Depending on the bacteria in the potting soil, it may either endure as ammonium (not good for herbs) or be transformed into nitrate, NO3-, by specialized bacteria. Nitrification into nitrate, NO3-, will happen any time ammonium is released within soils which are dominated by bacteria. Therefore we should inoculate our soils destined for herbs & vegetable production with specific bacterias. Bacterias have an alkaline pH caused by the bacterial bio film, that, among other things, digests their food from without their bodies for the bacteria skin to absorb. The acids created by fungus for the breakdown of more complex molecules outside of the body, decreases the pH and the number of these bacteria. In soils dominated by fungus, most of the nitrogen stays in the ammonium form, NH4+. For this reason we should have our soil substrates for herbs and vegetables containing compost humus, alkaline and dominated by nitrobacter bacterias.