5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops

1. Glasshouses and polythene tunnels can be used to increase the yield of certain crops
2. These houses protect the crops from the environment and help regulate the optimal temperature, CO2, water and fertilizers.
3. These give the crops best conditions for photosynthesis.
4. A note to point out is that all of these variables which affect a crops growth and health are all CONTROLLABLE, they can be changed due to the nature of being inside a greenhouse/glasshouse. This makes a definite advantage if mass farming to produce high yields.

Fertilizers can help increase yields, whilst chemicals control pests, weeds and diseases.