Rainfed rice - IRRI books - International Rice Research Institute

Major Cropping Systems and Their Management
Rice-rice system
A considerable number of rainfed lowland and deepwater farmers in Bihar,
West Bengal and Assam practice this cropping system by utilising
accumulated surface water. The low air temperature (10°C) prevailing in
December and January causes injury to the seedlings of the second crop
( Boro ), thus prolonging crop maturity. As a consequence, the delayed second
crop suffers from high air temperature (35°-40°C) during the reproductive
stage, resulting in yield loss. To remedy this situation, research emphasises
identifying suitable cold-tolerant, early maturing rice varieties. Results of
on-farm trials have identified two rice varieties — UPR103-80-1-2 for West
Bengal and Swarnaprova for Assam — which escaped these hazards and
thus produced better yields than the farmers' varieties.
Jute-rice system
Rainfed lowland farmers in West Bengal and Orissa also plant jute before
rice. This practice is also followed in Assam and Bihar. The yields of local
jute varieties are quite low. Identifying suitable high-yielding varieties is
expected to increase the system's productivity. Trials conducted at
Chinsurah have identified two jute varieties (Nabin and Basudev) which
produced higher fibre yields (2.3 and 3.8 t/ha, respectively) than did the
local varieties (1.4 to 2.3 t/ha). Higher fibre yield (by 64%) was also noted
by the use of improved seed quality at Chinsurah.
Cropping systems management
Aside from identifying suitable varieties for the different cropping systems,
emphasis is also given to management practices to improve the systems’
productivity. The priority issues addressed are discussed below.
Crop establishment
In rainfed lowland areas, especially with puddled transplanted conditions,
establishment of succeeding crops in the cropping pattern is a major
problem faced by farmers throughout the region. The common
establishment practice for chickpea, mung, pea, lentil and mustard is to
broadcast seeds on the soil surface with or without fertiliser. In this method,
poor germination and uneven plant stand are common consequences. In the
utera system, the seed rate of these crops is increased by 30%.
On-farm tillage studies conducted at Raipur using “Navagaon plough”
showed better yield of chickpea with tillage due to improved tilth and soil-
seed contact and improved moisture availability. Likewise, the yield of lentil
and wheat was also superior with two ploughings than without it at
Masodha. The effects and interaction of land preparation and crop
establishment methods of rice on succeeding upland crops, especially wheat,
have been examined in detail. In high moisture areas, lentil sowing in
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