Farming Practices
Laura Armstrong
Teacher
Recall Questions
This topic requires prior knowledge of the net production of consumers. Use the questions below to test yourself on this topic.
Why is energy lost from one trophic level to the next?
Energy is lost through respiration, faeces, urine, and as heat.
What does NPP stand for?
Net Primary Productivity – it represents the energy stored in biomass that is available to the next trophic level.
Topic Explainer Video
Check out this @JoeDoesBiology video that explains farming practices or read the full notes below. Once you've gone through the whole note, try out the practice questions!
Crop Farming Practices
Farmers aim to maximize NPP by reducing energy losses and improving the amount of energy transferred to useful biomass.
1. Fertilisers (Inorganic or Organic)
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Supply essential minerals (e.g., nitrates, phosphates, potassium) to plants.
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Increase rate of photosynthesis and biomass production.
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Leads to higher GPP and NPP in crops.
2. Pesticides (Insecticides, Fungicides, Herbicides)
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Insecticides: Kill insects that eat crops, preventing loss of biomass.
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Fungicides: Prevent fungal infections that reduce plant productivity.
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Herbicides: Kill weeds that compete for light, water, and minerals.
3. Selective Breeding & Genetically Modified Crops
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Crops selected for high yield, pest resistance, and rapid growth.
Animal Farming Practices
These aim to reduce respiratory losses (R) and increase net production (N) by controlling the animal’s environment.
1. High-Quality Feed
- Easily digestible food with balanced nutrients (e.g. grains, protein supplements).
- Reduces energy lost in faeces (F) and increases energy absorbed (I).
2. Restricting Movement
- Animals kept in pens or stalls to limit physical activity.
- Reduces respiratory losses (R).
3. Indoor Rearing (Climate Control & Heating)
- Animals kept warm and dry, preventing energy loss in thermoregulation.
- Stable conditions reduce stress and energy expenditure.
4. Use of Growth Hormones/Antibiotics
- Some systems use hormones to increase growth rate or antibiotics to reduce illness and energy expenditure of the immune system.
Key Terms
- NPP (Net Primary Productivity): Energy stored in plant biomass after respiration.
- Net production (N): Energy available for growth and reproduction in consumers.
- Respiratory losses (R): Energy used for metabolic processes such as movement and thermoregulation.
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Exam Tips
- Always link farming practices back to energy transfer efficiency (NPP or N).
- Don’t just describe the practice – explain why it improves efficiency.
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Explain how farming practices increase the efficiency of energy transfer in both crop and livestock production. (6 marks)
- Fertilisers increase the rate of photosynthesis and GPP, which increases NPP.
- Pesticides reduce energy losses to pests, so more energy is stored in plant biomass.
- High-quality feed is easier to digest, reducing energy lost in faeces.
- Restricting animal movement reduces respiratory losses.
- Indoor heating reduces energy used in thermoregulation.
- Overall, more energy is available for growth, so productivity increases.
Practice Question
Try to answer the practice question from the TikTok on your own, then watch the video to see how well you did!