Rainfed rice - IRRI books - International Rice Research Institute

RAINFED RICE A SOURCEBOOK OF BEST PRACTICES AND STRATEGIES IN EASTERN INDIA
Prepared by:
V. P. Singh and M. Hossain
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Analysis of drought and flooding patterns, water balance, selected land
characteristics and length of growing season in the rainfed lowland
ecosystem showed that 54.7% (5.8 million ha) is drought-prone, 24.5%. (2.6
million ha) is drought- and submergence-prone, 10.4% (1.1 million ha) is
submergence-prone and 10.4% (1.1 million ha) is favourable (Table 2).
The entire area in the medium-depth category of the rainfed lowlands is
submergence-prone. There is a wide fluctuation in the extent of the
deepwater ecosystem and the medium-deep category of rainfed lowlands,
depending on rainfall pattern and amount, and onset and cessation of the
monsoon.
Rice yields in all the rainfed ecosystems are low and vary greatly from
year to year. Yield in the irrigated area is 3.2 t/ha. The yield range is
0.6-1.5 t/ha in the uplands, 0.9-2.4 t/ha in the rainfed lowlands and
0.9-2.0 t/ha in the deepwater and very deepwater areas. The rainfed
lowlands are the first-priority ecosystem in eastern India because of their
area, larger dependent population and yield potential.
Table 2. Area (million ha) of the shallow (0-30 cm) sub-ecosystems of rainfed
lowland rice in eastern India
State Drought- Drought- and Favourable Submergence- Total
prone submergence- prone
prone
Assam – – 0.5 0.4 0.9
Bihar 0.9 0.7 – – 1.6
Orissa 0.7 0.5 0.3 0.3 1.8
Madhya Pradesh 2.7 – – – 2.7
Uttar Pradesh 0.8 1.1 – – 1.9
West Bengal 0.7 0.3 0.3 0.4 1.7
Total 5.8 2.6 1.1 1.1 10.6