Subsistence agriculture

Agriculture is practised in very different ways around the world. In subsistence agriculture, the farming family consumes nearly all it grows, with little left to sell. There are two main kinds.

Primitive subsistence agriculture, or shifting cultivation, is common among tribes in the tropics (Africa, South and Central America, south-east Asia).

• The vegetation is cleared by slash and burn: trees are cut and burnt, and the ashes add to the soil's fertility.
• Crops are grown on small patches with very simple tools such as sticks and hoes.
• After 3 to 5 years, the soil loses its fertility, and the farmers move to a new patch, letting the old one recover.

It has local names: jhuming in north-east India, milpa in Central America and Mexico, and ladang in Indonesia and Malaysia.

Intensive subsistence agriculture is found in the densely populated monsoon regions of Asia. Farms are small, and much human labour is used on every bit of land.

• Where there is enough water, wet paddy (rice) dominates. Farmers use family labour and little machinery, and manure from farm animals keeps the soil fertile. Yield per unit of land is high, but output per worker is low.
• Where conditions do not suit paddy, other crops are grown: wheat, soyabean, barley, sorghum and millets, often with irrigation.