Climate and agriculture
•Monsoon is a key source of water in agriculture
•Most of our rivers are seasonal fed by the monsoon; even irrigated agriculture depends on monsoon.
•Cropping pattern has evolved over years based on climate.
•Market forces influence cropping patterns in recent times.
Climatic factors and crops
•Rainfall drives water availability and determines sowing time (rainfed crops).
•Temperature drives crop growth, duration and influences milk production in animals.
•Temperature and relative humidity influence pest and diseases incidence on crops, livestock and poultry.
•Wet and dry spells cause significant impact on standing crops, physiology, loss of economic products (e.g. fruit drop).
•Extreme events (e.g. high rainfall, floods, heat / cold wave, cyclone, hail, frost) cause enormous losses of standing crops, livestock and fisheries.
Climate and seasons
•Rainy (June-September) season also known as Kharif, supports most of the rainfed crops (coarse cereals, pulses, oilseeds, etc.).
•Post-rainy (October-February) season also known as Rabi, supports the irrigated or stored moisture grown crops (wheat, mustard, chickpea, etc.).
•Summer season (March-May) supports short duration pulses and vegetables.
•Rabi production is more assured, has a higher yield and reduces pest and disease related problems.
•Over time, with irrigation development, the contribution of Kharif is declining and Rabi is increasing.
Climate, cropping pattern and agricul-tural production issues
•Cropping patterns based on climate and land capability are sustainable but market forces and farmers’ aspirations are forcing unsustainable systems.
•Farmers must innovate in producing more even from less endowed areas by adopting suitable technologies to cope with changing climate.
•Climate change will likely to cause further problems in our crop production and is likely to become the most important environmental issue in the 21st century.
Important agricultural related factors responsible for climate change
•Deforestation and forest degradation
•Burning of fuel and farm waste
•Water logged condition
•Excessive use of external input
•Large-scale conversion of land for non-agricul-tural purpose
Impact of climate change in India
•Rainfall: No long-term trend noted. However, regional variations seen, increased summer rainfall and less number of rainy days.
•Temperature: About 0.6 ºC rise in surface tem-perature during 100 years. Projected to increase 3.5 to 5 ºC by 2100.
•Carbon dioxide: Increasing at the rate of 1.9 ppm per year and expected to reach 550 ppm by 2050 and 700 ppm by 2100.
•Extreme events: Increased frequency of heat wave, cold wave, droughts and floods observed during last decade.
•Rising sea level: Rise of 2.5 mm/year since 1950.
•Glaciers: Rapid melting of the glaciers in the Himalayas.
•Rainfall distribution: Shift in peak rainfall dis-tribution also noticed in some parts of country.
Expected impact of climate change on agriculture
•Due to increase in temperature, crop may re-quire more water.
•Yield may be reduced in cereal crops especially in Rabi; i.e. wheat.