Spring Nitrogen application for autumn planted crops
What is important to our topic is Green House Gas emissions. This is because of their effect on the world in which we all live and for business reasons they are a cost as well as a loss to business profitability.
So what is meant by “Green House Gas emissions” or “Global warming?”
A very simple description would be something like: Normally sun light that hits the earth, bounces back off the earth surface and out into space. By changing the composition of the gas layers (atmosphere) surrounding the earth (adding Green House Gas) light energy enters easily enough but cannot get back out again. End result, heat is trapped and the World over-heats.
Carbon dioxide is blamed for this overheating effect. However other gases and factors are also involved including:-
Cloro Fluro Carbons (CFC’s)
In Agriculture we are interested in the last two, Nitrous Oxide and Methane.
Now the tricky bit. VERY SIMPLY PUT…. One Carbon Dioxide unit can be though of as causing one unit of “over heating.” However one unit of methane needs to be thought of as 11 units of over-heating and Nitrous Oxide 290 units of heating damage.
Hence the push towards reducing these gases from agricultural sources.
So where do these gases come from? Again very simply put:-
Methane, from ruminant animals.
Nitrous Oxide, from applied inorganic fertiliser.
When nitrogenous fertiliser is applied to the soil a percentage is lost as a gas, Nitrous Oxide.
This is a biological and chemical process. Microbes found in almost all soils “reduce” Nitrites and Nitrates creating the gas Nitrous Oxide which is lost to the atmosphere.
This most commonly occurs on poorly drained soils (those, at or above field capacity) or in acidic conditions predominantly with Nitrites.
The four main management factors that help reduce Nitrous Oxide emissions from applied Nitrogen fertiliser are commonly known as the 4R’s:
Right Nitrogen application rate
Right formulation (fertiliser type)
Right timing of application