Step 1: Understanding the Concept:
Intensive subsistence agriculture is practised mainly in the densely populated regions of monsoon Asia (India, China, Southeast Asia) where land is scarce relative to the farming population.
Step 2: Feature 1 — Small landholding, intensive labour:
Farms are very small in size, but farmers use a very high amount of labour per unit of land to maximise output — hence 'intensive'.
Step 3: Feature 2 — High use of biochemical inputs and irrigation:
Farmers use large quantities of fertilisers, along with irrigation, to obtain very high yields per hectare, since land availability per farmer is limited.
Step 4: Feature 3 — Multiple cropping:
Because of the favourable growing season and intensive effort, more than one crop is grown on the same piece of land in a year (double/triple cropping).
Step 5: Feature 4 — Dominance of food crops, especially rice:
Rice is the dominant crop, though wheat, maize, and pulses are also grown depending on the region; the primary aim is subsistence — feeding the farmer's own family — rather than commercial sale.
Step 6: Final Answer:
Its main features are: small farm size, very high labour input per hectare, heavy use of fertiliser and irrigation, multiple cropping, and dominance of subsistence food crops like rice.