Irrigation Management :: Transplanted Puddled Lowland Rice

Transplanted Puddled Lowland Rice Transplanted Rice

Sowing

Sow the sprouted seeds uniformly on the seedbed, having thin film of water in the nursery.

Water Management

Drain the water 18 to 24hrs after sowing
Care must be taken to avoid stagnation of water in any part of the seedbed.
Allow enough water to saturate the soil from 3rd to 5th day. From 5th day onwards, increase the water depth to 1.5cm depending on the height of the seedlings.
Thereafter maintain 2.5cm depth of water.

Dry nursery

Irrigation may be done to wet the soil to saturation.

Main Field Management

Land preparation

Plough the land during summer to economize the water requirement for initial preparation of land.
Flood the field 1 or 2days before ploughing and allow water to soak in. Keep the surface of the field covered with water.
Keep water to a depth of 2.5cm at the time of puddling.

Water management

Puddling and leveling minimizes the water requirement
Plough with tractor drawn cage wheel to reduce percolation losses and to save water requirement up to 20%.
Maintain 2.5cm of water over the puddle and allow the green manure to decompose for a minimum of 7 days in the case of less fibrous plants like sunnhemp and 15 days for more fibrous green manure plants like Kolinchi (Tephrosia purpurea).
At the time of transplanting, a shallow depth of 2cm of water is adequate since high depth of water will lead to deep planting resulting in reduction of tillering.
Maintain 2 cm of water up to seven days of transplanting.
After the establishment stage, cyclic submergence of water (as in table) is the best practice for rice crop. This cyclic 5cm submergence has to be continued throughout the crop period.

Days after disappearance of ponded water at which irrigation is to be given

Soil type	Summer	Winter
Loamy	1 day	3 days
Clay	Just before/immediately after disappearance	1 - 2 days

Moisture stress due to inadequate water at rooting and tillering stage causes poor root growth leading to reduction in tillering, poor stand and low yield.

Critical Stages of Water Requirement in Ricee

a) panicle initiation,
b) booting,
c) heading and
d) flowering.

During these stages, the irrigation interval should not exceed the stipulated time so as to cause the depletion of moisture below the saturation level.

During booting and maturity stages continuous inundation of 5cm and above leads to advancement in root decay and leaf senescence, delay in heading and reduction in the number of filled grains per panicle and poor harvest index.
Provide adequate drainage facilities to drain excess water or strictly follow irrigation schedule of one day after disappearance of ponded water.
Last irrigation may be 15 days ahead of harvest.

Precautions for irrigation

The field plot can be 25 to 50 cents depending on the source of irrigation.
Field to field irrigation should be avoided. Field should be irrigated individually from a channel.
Small bund may be formed parallel to the main bund of the field at a distance of 30 to 45cm within the field to avoid leakages of water through main bund crevices.
To minimize percolation loss, the depth of stagnated water should be 5cm or less.
In water logged condition, form open drains, about 60cm in depth and 45cm width across the field.
Care should be taken not to allow development of cracks.
In canal command area, conjunctive use of surface and ground water may be resorted to for judicious use of water.
In double cropped wetland of command area, raise groundnut / pulse in the place of Kuruvai rice if water is a constraint or go for rice cultivation