Dairy farmers make the most of their land and many grow crops that they use to feed their cows in winter.
Common crops to grow include maize and grass, which farmers will harvest in summer and ferment in a clamp to make silage, a nutritious winter feed. The process, called 'ensiling', sees the grass change colour from green to brown.
Many farmers also grow clover, which absorbs nitrogen - an important component for plant development - from the atmosphere and keeps it in the soil. White clover is particularly common in pastures and provides a tasty, nutritious feed for cows.
Our moovie about organic farming explains the process.