farming

• Respiratory losses limit the percentage of energy that passes between trophic levels. 
• Farming practices can reduce respiratory losses which can reduce energy loss and can increase the yield/biomass. 
• Intensive rearing of livestock minimises respiratory losses, the animals movement can be restricted, buildings can be heated to prevent energy loss in temperature maintenance. Feed is controlled to limit waste and exclude predators. 
• Food webs can be simplified using herbicides. 
• Weeds can compete with crops for nutrients, water, CO2, space and light. 
• Herbicides can be selective to prevent them killing crops or crops can be genetically modified to be resistant to herbicides. 
• Pesticides can prevent crops being impacted by pests. Pests can reduce photosynthesis, pesticides need to be cost effective and conserve our natural resources. 
• Organic farming means that no chemicals are used to grow crops or rear livestock.