Today we are covering from the specification:

What is an agricultural ecosystem?

• Animals and plants used to produce food for humans.

• Aims to increase productivity – how?

What is productivity?• Rate at which useful biomass is

produced.• Plants produce new biomass using…

light energy.• Animals produce new biomass

using…chemical energy from plants/animals

What is productivity?• The rate at which organisms assimilate

energy taken in is called gross production.• Units – energy/area/time (kJm-2year-1)

• Organisms use some of the new biomass in respiration – what’s left is the net production.

Net Productivity = Gross productivity – Respiratory loss

5

Agricultural Productivity

Net Productivity = Gross productivity – Respiratory loss

Similar to a business…

Net profit = Gross Profit – Operating Costs

How can agricultural productivity be increased?

6

Task – Agricultural ProductivityCreate a 10-15 minute presentation on one of the topics below. For each one, include:

• What it is;• How it increases productivity;• What ethical/environmental issues can it lead to?

Produce a handout for the rest of the class – it could include notes, fill-in-the-gaps, questions etc..

The use of natural and artificial fertilisers.

Intensive rearing of livestock.

The use of pesticides (chemical and biological) and integrated pest control.

Email/give me a copy of the handout by the end of the lesson on Tuesday. Presentations will be on Thursday 16th October.