nitrogen cycle

• nitrogen is stored in the biosphere as DNA, proteins, dead organic matter
• nitrogen is stored in the atmosphere as nitrogen and oxides of nitrogen
• nitrogen is store in the lithosphere as soil and rocks
• nitrogen is stored in the hydrosphere as dissolved nitrates and ammonium ions
• ionisation is when processes such as lighting or meteor trails provide energy for atmospheric nitrogen and oxygen to react producing oxides of nitrogen
• nitrogen fixation is when some microorganisms (nitrogen fixing bacteria) chemically reduce nitrogen to Ammonia
• nitrogen passes between organisms as amino acids and proteins in food
• nitrification involves oxidation of ammonium ion to nitrites to nitrates by nitrifying bacteria
• denitrification is chemical reduction of nitrates in soil to nitrogen and nitrogen oxides gases
• denitrifying bacteria in soil reduces soil fertility, this normally occurs under anaerobic conditions
• leaching is when nitrates in the soil are leached out of the soil in water bodies due to an increased solubility
• nitrates act as nutrients for aquatic plants and algae
• plants absorb nitrogen as soluble ions, mostly as nitrates and ammonium ions
• ammonification is when the amino acid groups in proteins are released as ammonium ions by bacteria action, fungi and detritovores as they decompose dead organic matter
• haber process is an industrial process to produce ammonia from nitrogen and hydrogen using an iron catalyst at a high temperature and high pressure
• Haber process' main purpose is to manufacture agricultural fertilisers
• human use of nitrogen is agriculture, humans make use of nitrate fertilisers, however this may increase leachate problems such as eutrophication
• drainage of water makes soil more aerobic, this increases the number of aerobic nitrifying bacteria and decreases the number of anaerobic denitrifying bacteria
• soil disturbance such as ploughing increases rate of decomposition of dead organic matter, this released more nitrous oxide gas into the atmosphere
• leguminous plants can be grown to increase levels of nitrogen compounds in soil, which crops absorb
• control of combustion processes: reduction in the use of fossil fuels reduces nitrous oxide releases
• reduction is fossil fuels can be caused due to a depletion of fossil fuel sources
• adoption of principles of circular motion involves increase in low temperature manufacturing processes
• control of oxides of nitrogen releases involves using less post-combustion processes such as catalytic converters and urea sprays
• management of biological waste: decomposition of biological waste involves ammonium ions as amino acids are de-aminated
• enzymes produced by bacteria in biological waste remove amine groups which dissolve ammonium ions
• eutrophication can be caused by biological wastes washing into water by runoffs or deliberate dumping
• wastes such as manure, sewage , food production can be used as organic fertilisers to increase nutrient and humus levels
• managemnet of soil processes involve: cultivation of legumes crops, crop rotation, control of nitrate leaching n