main processes

• 6- Nitrogen Fixation

  1. Nitrogen gas converted into nitrates in root nodules of legumes by nitrogen-fixing bacteria

  2. Bacteria gain carbohydrates from legumes, legumes gain nitrates from bacteria

  3. AEROBIC PROCESS
• 5- Feeding

  1. Plants absorb nitrates from soil and turn them into protein

  2. Animals feed on plant protein
• 4- Decomposition

  1. Plants and animals die

  2. Decomposed by bacteria and fungi

  3. Turns nitrogen-containing protein into ammonia and ammonium compounds

  4. AEROBIC process
• 3- Nitrification

  1. Conversion of ammonia to nitrates by nitrifying bacteria in soil

  2. Plants can only absorb nitrogen as nitrates

  3. AEROBIC process
• 2 - Active Transport

  1. Plants take in soluble nitrates by active transport in root hair cells

  2. Movement of nitrates against concentration gradient, from low to high

  3. Requires energy from respiration, therefore requires oxygen

  4. AEROBIC process
• 1 - Denitrification

  1. In waterlogged soils, anaerobic conditions prevail

  2. Soil converts nitrates into nitrogen gas by denitrifying bacteria

  3. Reduces amount of nitrates available for plants, causing them to struggle in waterlogged soils
• the nitrogen cycle

  1.denitrification, 2. active transport, 3. nitrification, 4. decomposition, 5. feeding, 6. nitrogen fixation