28th Mar '20

The Nitrogen Cycle

Nitrogen is essential for life as it is used to build . Although plentifull in the air, organisms are unable to use it in this form. Nitrogen must first be converted to Nitrates in the soil. A Nitrate is a compound of and .

There is a amount of Nitrogen on planet Earth which is continually recycled in the Nitrogen Cycle.

Lightening can cause nitrogen and oxygen to combine to form nitrogen oxide. This dissolves in rain and is washed into the soil to form .

Nitrogen bacteria directly converts nitrogen from the air into nitrates. They can live in the soil, but are also found in root of some plants. These tend to be leguminous plants such as clover and peas. Farms often grow these types of crops during a field's 'rest year' and simply plough them back into the soil to improve fertility.

Artificial fertilises can be made in factories and then applied to the field. This takes nitrogen from the converts them into nitrates using alot of energy.

take up the nitrates in a process called assimilation. They convert the nitrates into .

Animals eat the plants, converting plant protein into animal proteins so they can also . Animals themselves can be eaten and the nitrogen in the protein gets passed up the food chain.

Animals and plants produce which contains organic matter which falls into the soil. When they die they also add to this matter in the soil.

The waste is broken down by (bacteria and fungi) converting it into ammonium in the soil.

This is then converted into by bacteria.

Some of the nitrates are converted back into atmospheric nitrogen by bacteria. These tend to live in waterlogged soils.