Nitrogen Cycle

Why is Nitrogen so important? As the soil fertility page explains, nitrogen is really important for plant growth (structure), plant food processing (metabolism), and the creation of chlorophyll. Without enough nitrogen in the plant, the plant cannot grow taller, or produce enough food (usually yellow).  But too much nitrogen is just as dangerous. It can result in the plant being burned so the leaves shrivel up, and an inability of plants to produce flowers (or grains), . Nitrogen can also cause a lot of environmental damage in groundwater, and in oceans. This is why it is so important to understand the nitrogen cycle, even though it is very complex. 


Nitrogen Deficiency

Most of the nitrogen in the world is a gas. Plants cannot take nitrogen out of the air, so bacteria needs to do it for them. Some plants called legumes (soybeans, peanuts, peas, and clover) have a special relationship with Rhizobia bacteria. These bacteria attach to the root in little nodules. When you cut these nodules open, it should be pink or red. This means that less fertilizer can be applied to future crops, saving money and the environment. 

Rhizobia bacteria can fix nitrogen from the air

The nitrogen cycle is shown below. For an interactive version of the Nitrogen Cycle check out ScienceLearn New Zealand

nitrogen cycle




For More Information

Check out this information sheet on the nitrogen cycle courtesy of ScienceLearn New Zealand. 


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