Energy & Food production

Modern Intensive Farming

Comparison of natural ecosystems and those based on modern intensive farming in terms of energy input and productivity. Net productivity = Gross productivity – Respiratory loss or: Growth = food taken in – energy used to live

A Natural Ecosystem in Florida 1.What are the respiratory losses for the 2ndry consumers? 2.What is the % efficiency of conversion for the producers? 3.Compare this to the efficiency for the primary and secondary consumers.

Estimate the Net Productivity of these Ecosystems (in kilocalories/m 2 /year) Temperate deciduous forest Tropical rain forest Tropical rain forest Desert Coastal marsh Ocean close to shore Open ocean Clear (oligotrophic) lake Lake in advanced state of eutrophicationeutrophication Corn (maize) field, U.S. Rice paddies, Japan Lawn, Washington D.C. Sugar cane, Hawaii

Temperate deciduous forest5,000 Temperate deciduous forest Tropical rain forest15,000 Tropical rain forest Desert500 Desert Coastal marsh12,000 Coastal marsh Ocean close to shore2,500 Ocean close to shore Open ocean800 Open ocean Clear (oligotrophic) lake800 Clear (oligotrophic) lake Lake in advanced state of eutrophication2,400eutrophication Corn (maize) field, U.S.4,500 Rice paddies, Japan5,500 Lawn, Washington D.C.6,800 Sugar cane, Hawaii25,000

Increasing efficiency of energy conversion by…. 1.the use of natural and artificial fertilisers 2.the use of chemical pesticides, biological agents and integrated systems in controlling pests on agricultural crops 3.the intensive rearing of domestic livestock.

Candidates should be able to… apply their understanding of biological principles to explain how these and other farming practices affect productivity evaluate economic and environmental issues involved with farming practices that increase productivity consider ethical issues arising from enhancement of productivity.

2. Controlling pests on agricultural crops chemical pesticides biological agents integrated systems

Integrated Pest Management