The Agreement on Agriculture (AoA) is an international treaty of the World Trade Organization.
It was negotiated during the Uruguay Round of the General Agreement on Tariffs and Trade, and entered into force with the establishment of the WTO on January 1, 1995.
The WTO Agreement on Agriculture negotiated in the Uruguay Round (1986–1994) includes the classification of subsidies by "boxes" depending on consequences of production and trade:
Amber (most directly linked to production levels)
Blue (production-limiting programmes that still distort trade)
MSP
Green (minimal distortion)
