6.5.3(Increasing transfers of biomass)

Describe how farmers have increased primary productivity

1. Plants are planted early to provide longer growing season

2. Plants are grown under light banks

3. Plants have been bred to become drought-resistant

4. Crop rotation is used - growing a different crop in each field on a rotational cycle

5. Plants have been bred to respond to high levels of fertilisers

6. Plants are sprayed with pesticides and some plants are bred to be pest-resistant

State how planting plants early helps to increase primary productivity

• Allows for a longer growing season to harvest more light

• This is light levels do not limit the rare of photosynthesis

Explain why growing plats in green houses is useful

• Temperatures in green houses are higher and so rate of photosynthesis increases and so the rate of biomass production increases

Explain the usefulness of crop rotation

• Crop rotation stops the reduction of soil levels of inorganic materials such as nitrates and potassium

• This mean that nutrients are available in soil at all times and so production of biomass by photosynthesis is never slowed

Explain why spraying plants with pesticides or breeding pest resistant plants is useful

• This is because pests eat crop plants

• This removes biomass from the food chain and lowers the yield

• Pesticides kill pests so they do not eat crop plants

Describe how secondary productivity is improved

• By harvesting animals right before reacting adulthood

• Selectively breeding individuals which produce breeds which grow faster, produce more eggs and milk

• Treating animals with antibiotics

• Stopping animals from moving and controlling environment temperature

State how treating animals with antibiotics improves secondary productivity

• It avoids unnecessary loss of energy to fighting pathogens and parasites

State how stopping animals from moving and controlling temperature environment improves secondary productivity

• It prevents loss of energy due to movement and regulating body temperature

• This maximises energy allocated to muscle and so more biomass is produced