agro-ecology

• Limiting factors:

  • Light 
  • Temperature 
  • CO2 
  • Soil moisture 
  • Soil nutrients 
  • Soil pH
  • Pests 
  • Food 
• Artificial light and wavelengths are used to promote growth, usually blue and red wavelengths. Light can stimulate flowering (autotrophs) and stimulate egg laying in hens (heterotrophs). 
• Light is involved in photosynthesis. It transfers solar energy into chemical energy which is used to make glucose to be stored in biomass (plant tissue). 
• Artificial lighting increased energy use - fossil fuel use. They produce light pollution - local people and wildlife. 
• Temperature limits enzyme activity, optimum temperature of 25 dc. Drops in temperature can cause frost which reduces photosynthesis. 
• Greenhouses and polytunnels control temperatures and protect from frosts, fields are covered in wraps to warm soils. 
• Livestock use more energy when they are cold so the growth efficiency decreases. 
• High temperatures can reduce CO2 uptake due to stomata closing to prevent water loss. 
• CO2 is used in the production of glucose. CO2 can be pumped into greenhouses. 
• Water in soil allows for ion exchange in plants and maintains cell turgidity. Crops can be irrigated. Potential for over abstraction. 
• pH can denature proteins and controls nutrient availability. Fields can be limed. 
• Wind causes damage and can increase evapotranspiration, it can also pollinate.