TECHNICAL
Why we use it and how to use it
Nitrogen efficiency It is hard to escape from the fact that the cost of nitrogen fertilisers has increased significantly due to a range of factors placing strain on both supply and demand globally. With this in mind, it is useful to reconsider why we use nitrogen and how to use nitrogen efficiently to reduce costs and environmental harm and improve plant growth. Agrovista UK Technical Manager Dr. Abigail Graceson discusses nitrogen efficiency and why it’s important for plant growth
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hy are prices for nitrogen fertilisers increasing?
The price of nitrogen fertilisers is significantly influenced by costs of natural gas due to the importance of this resource in the fertiliser production process. Globally, the majority of synthetic fertilisers are produced industrially using the Haber-Bosch process in which nitrogen (N2) from the air is combined with hydrogen (H2) from natural gas to produce liquid ammonia (NH3). This energy intensive process utilises fossil fuels to achieve the high temperatures of 400-500°C and pressures of 150-300 bar that are required. The ammonia is then used
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to make nitric acid which can be combined with ammonia to create ammonium nitrate or with liquid carbon dioxide to create urea. In total, it is estimated that production of nitrogen fertilisers accounts for three to five percent of the global annual natural gas consumption (European Commission, 2019). The reliance on energy intensive processes and fossil fuels, in particular natural gas, is the primary driver for nitrogen fertiliser prices. Why is nitrogen important for plant growth? Nitrogen is a key component of proteins which help plants to grow by providing structural support for cells, helping cells to
interact with their environment, and reducing the energy requirements for biochemical reactions. Proteins also transport nitrogen through the plant and are nitrogen donors for other fundamental compounds such as: • Nucleic acids: The building blocks of DNA and RNA • Hormones: Chemicals which control activities within the plant • Chlorophyll: The pigments that enable plants to create food through photosynthesis Proteins are formed from the bonding of amino acids. Each amino acid has a basic