Climate, monsoon and crops

India's geography and climate vary a lot, so different crops grow in different regions and at different times of the year.

A traveller noticed this 1,400 years ago. Xuanzang, a Chinese pilgrim in India in the 7th century, wrote that because the climate and soil differ from place to place, the produce of the land differs too — different flowers, plants, fruits and trees, with different names.

Remember the seven climate types from Part 1:

• Alpine — the high Himalayas
• Temperate — the lower Himalayas
• Subtropical — the northern plains
• Arid (dry) — the Thar Desert
• Tropical wet — the western coastal strip
• Semi-arid — the central Deccan Plateau
• Tropical — eastern India and the southern peninsula

Each gets different amounts of sunshine and rain, different temperatures through the year, and is touched differently by the monsoons.

To plan farming better, India is divided into 15 agroclimatic zones ('agro' = farming, 'climatic' = climate). Each zone combines climate, soil type, terrain and natural vegetation. This helps the government and others plan what, when and how to grow. Examples: the Upper Gangetic Plain Region, the Southern Plateau and Hills Region and the Western Dry Region.

The monsoon is the key to India's farming. It brings the rain that many crops need.

• The southwest monsoon brings rain from June to September. It is vital for the kharif (rainy-season) crops of northern and central India.
• The northeast monsoon blows from October to December, bringing rain to the east and south of India.

The coastal plains of Malabar (Kerala) and Coromandel (Tamil Nadu) get rain from both monsoons. Two rainy seasons instead of one changes a farmer's whole year.

With rain from both monsoons, farmers in the south can also grow crops in the gap between them. For farmers in the north this is a dry season; they must use groundwater, water from rivers, canals and ponds, and the moisture left in the soil. With monsoon rain plus irrigation, states like Tamil Nadu, West Bengal and Andhra Pradesh grow rice all year round.