Nitrogen Cycle Quiz

The nitrogen cycle is part of multiple material cycles which consistently move materials around the world in a closed system. The water cycle and carbon cycle are two notable examples of other material cycles. 

Plants need nitrates to make the compounds that are found in proteins and in the four bases of DNA – adenine, thymine, cytosine and guanine. Proteins are made from amino acids which all contain nitrogen.  Nitrogen is therefore a key ingredient in plants as well as animals, this explains why we use artificial fertilisers to add nitrogen to the soil as well as natural fertilisers such as seaweed and manure. 

Farmers often practice a technique called crop rotation which aims to maintain a natural balance of nitrates as well as other important materials such as phosphorus. The acronym NPK is often used to explain which nutrients are most essential for plants as well as animals to grow and be healthy. Potassium is another, although less critical nutrient that has the chemical symbol K. 

Crop rotation typically involved planting a series of crops that require different amounts of nutrients, one harvest after another. Legumes or leguminous plants such as peas and beans can be included in this sequence to replenish the soil nitrates that are consumed by plants and then removed when they are harvested. Legumes are a special kind of plant that has a mutualistic relationship with nitrogen-fixing bacteria. These bacteria are able to take atmospheric nitrogen from the air and convert it into soluble forms that can be used by future crops. Take our Nitrogen Cycle Quiz to test your knowledge on this topic!