Download NITROGEN CYCLE We are surrounded by nearly 80

NITROGEN CYCLE
We are surrounded by nearly 80% Nitrogen gas in our atmosphere as N2 yet we are
supposedly short of Nitrogen in our soil. There are many natural mechanisms to harvest
and hold natural Nitrogen in the soil for plant production. The mechanisms rely on
healthy Legumes, Algae and a well balanced Micro Biological system consisting of
beneficial Fungi and Bacteria.
In legumes Rhizobium, are the vehicles that fix Nitrogen through Nodulation. When the
Nodules are a pinkie colour it is the number one sign the Rhizobium are doing their job.
It is also a sign you have available Cobalt as this is a necessary element in the Nodulation
process. You will also note that Calcium is the most necessary element to grow healthy
legumes.
Azobacter and Clostridium make up the biology which can directly access the N2 from
the atmosphere and change it to NO3 or NH3. For this to happen they will need well
balanced soils with a good food source, such as crop residues or decaying manures.
Algae are 90% more effective at Photosynthesis than any other plant forms and there
ability to process Carbon and Nitrogen are second to none. Algae are so often the first
form of life, which is the beginning of the food chain. There rapid reproduction with
excellent sources of Nitrogen and Carbon make great food sources to the Bacterium
which can process this into Humus.
There are many reasons why these systems will not function at optimum level. The three
main problems are:
1. Soils being out of balance, with low levels of available calcium and lack of Food for
the biology.
2. Using chemical sprays can kill off the microbiology in the soil as well as the Algae.
3. Over use of chemical fertilisers which destroy the food sources for the biology and
environment they thrive in.
Any one or all of these factors can shut down the natural Nitrogen cycle. To get the cycle
functioning again you may have to introduce the biology with inoculums and a food
source as you are rebalancing the soil mineral content. Fish concentrates from the sea are
a very good food source to go with the inoculums, but are of very little use unless you
have already supplied the mineral content to allow the biology to thrive once they have
been introduced.
The use of Probitas also has a very beneficial effect at this stage as well, as electrical
activity has been found to enhance biological activity and reproduction. In trials using
biology to break down waste is has been found that you could get up to 700% more
activity when electrical flow was added.
Forms of Nitrogen
There are two main forms of Nitrogen in our soils.
NO3 nitrogen which is nitrate. It is negatively charged and can therefore be regarded as
an anion.
Being of a negative charge does not allow it to hold onto the soil colloid. Thus it floats
about looking for a positive charge to hang onto. It will bond with Calcium readily and as
Calcium is the most abundant cat ion in the soil this is usually where it first heads to.
It will also bond with potassium readily and as in a lot of cases where large amount of
soluble Potassium fertiliser has been used this will be the preferred bond. Also because of
Potassium being at the top of the list in reactivity of elements it will naturally react faster
than the other cat ions and therefore there can be quantities of Potassium Nitrate floating
about in our soil.
This alone is a major worry as Potassium Nitrate is also called Salt Peter, other wise
known as gun powder.
All of the Nitrates are water soluble, which is one the first major concerns, mainly
because of the leaching possibilities. Heavy rainfall takes the nitrates out very quickly
and as we are seeing today these end up in our water ways and ground water. The health
connotations are endless for both the environment and us.
Secondly as a producer we should be extremely worried about the amount of cat ions that
are leached away out of the soil profile. As you can see this is why our pH tends to drop
when using Nitrogen based fertilisers.
Thirdly it takes a lot of energy to process the nitrogen into forms more readily available
for the plants. The energy that is required mostly comes from the humus in the soil as this
is fuel for the biology to handle all the extra nitrogen. They utilise the Carbon fraction of
the soil hence releasing all the other nutrients that were part of the humus colloid which
contains more nitrogen and pushes the system even harder. As most of the Nitrogen
fertiliser is still in a Nitrate form they latch onto the cat ions released and we end up with
more problems.
The answer to all this seems to be Nitrogen inhibiters, but you are really getting into
dangerous ground as really they are biological contraceptives. They are utilised to stop
the biology volatilising the NO3 to NO2, which ends up back in the atmosphere. As you
can see from the work done on soil biology, this is not the greatest of ideas to slow
biological activity as it is essential in all healthy soils.
In a natural system we know we do not end up polluting water ways, when the soil is
balanced. The reasoning behind this is that the nitrate fraction of the soil is in biological
form. This form can take many shapes but mainly it is in the bacteria in the soil. This
nitrogen is then made available as the predators devour the microscopic bacteria. These
are mainly protozoa and earth worms which excrete the nitrogen after digestion. If you
take a look at the Caution Earth Worms at Work table you are really seeing the result of
this process. This shows also the necessary work of all the biology in the soil to nutrient
availability.
The key issue in the soil microbiology is that bacteria create sticky glue, which they use
to hold onto the soil. This sticky glue is mainly calcium and when the soil is working well
you will get a good crumb structure. Although you cannot see the bacteria with the naked
eye the crumb structure can give you a good idea if the bacteria are functioning in the
soil.
This glue holds the key to holding the nitrates in the soil and as calcium is the most
available nutrient in the soil you can now see another use for this so called secondary
nutrient.
NH3 is Ammonium
Ammonium is positively charged and therefore can be treated as a cat ion. Its positive
charge allows it to stick the soil and humus colloids, which does not allow it to readily
leach.
The biggest problem we have is getting the balance right between the Nitrate and
Ammonium, is if we apply Ammonia based fertiliser in excess, it can act like a fumigant.
We all know what household ammonia can do to bacteria and this is what can happen in
your soil.
From what we know of the effects of using Nitrogen based fertiliser, either Nitrate or
Ammonia based products can do serious damage to soil mineral balance and biological
systems and the flow on effect into the crops is terrible.
The biggest problem we have is that when Laboratories test for Protein they only test for
Nitrogen and then multiply that figure by 6.25 to get the total Protein %. The reason for
this is that to do total Amino Acid break down it would cost an Absolute fortune and is
totally unreasonable.
But when you look at the total Protein % you have to wonder as most typical crops and
pasture have real trouble producing over 18 to 20 % true proteins. You get the test back
and it shows 4.5% nitrogen calculated to approx 28% protein. This is now a calculated
figure and not a true representation of the true protein in the plant.
Knowing the plant cannot produce this amount of Protein we have to assess how much of
the nitrogen is Non Protein Nitrogen and what effect this NPN will have on the animal
that consumes this feed.
As a rough guide the higher the Calcium content in the feed the higher the true protein
will be. If you have only .5% Calcium and 4.5% Nitrogen(28% Protein) you will have
high levels of NPN. This can be compounded if you have high levels of Potassium of
around 3.5 to 4%. It would be reasonable to assume you will have high levels of
Potassium Nitrate. This is definitely not good for Rumen biology or total animal health.
If you have over 1% Calcium in the feed 3% Nitrogen ( 18.75% Protein) and levels of 2.5
to 3% Potassium it would be a fair conclusion that you have mostly true protein.
The effect of all this on Ruminants can be extraordinary, especially when there are large
quantities of NPN. The animal turns the NPN to a product called Blood Urea Nitrogen.
(BUN). This has the effect of dropping the pH of the animal and just like in the soil this
can strip Nutrient from the animals system. This BUN gets to the Liver is processed there
and excreted as Urea. When in higher enough quantities this will leave burn patches in
the field. You don’t have to get all the tests done to know there is serious imbalance in
the soil then feed and finally the animal. These circumstances have ongoing effects on
livestock such as Milk Fever, Brittle Bones Inability to Conceive, Foetus reabsorbtion
and many other ailments.
The other rather nasty effect is that the high Nitrate levels drag oxygen out of the blood,
which in the worse case scenario brings on Nitrate Poisoning. The main effect is actually
oxygen deprivation otherwise known as asphyxia. The worst case is actual death, but
many animals are under stress constantly through lack of oxygen in their blood. Effects
can lead to viral attacks, abortion and general ill thrift with a lowering of production.
This high level dumping of Nitrogen in concentrated patches are then cause for more
leaching into water ways as the soil cannot handle this type of concentration. The biggest
problem is that the animals are blamed for all the run off when really what was needed
was balanced feed to start with.
What is required is excellent levels of available nitrogen that allow high production of
quality crops and feeds that is not going to leach or cause animal health problems.
To get this result we really have to set up the circumstances that will allow the biology to
do this for us. When the soil mineral profile has been put into balance, the electrical
effect restored and the right biology is present the nitrogen problem tends to sort itself
out, to the point where we need not apply any chemical nitrogen fertilisers at all.
The biology tends to be able to balance the NO3 against the NH3, although this may take
some time to get this right. The levels we like to see on the tests should be approximately
the same. These levels will rise and fall through the season depending on soil moisture
and biological activity, but when the system is working well they will stay reasonable
even.
The main reason is that the ammonium fraction of the Nitrogen is the pre curser to
amines, which is the pre curser to Amino Acids. (Protein) It takes less energy to utilise
the ammonia in the plant than it does to process the Nitrate to the forms required to make
Proteins and when we have excess we have nitrates in the feeds.
The Nitrates are still necessary for plant production and if all processes are in good order
the Nitrate fraction will be utilised into the proteins. Again the biggest problem is the
excess of Nitrate and lack of the calcium for true protein production.
The basic rules are to try and let nature do its work as it is far cheaper and healthier. All
we have to do is try and help nature do its work.