Paddy Field Water Management

Water management is a critical technical component for achieving high and stable rice yields. During the tillering stage, maintain shallow water and irrigate frequently; during the seedling‑establishment stage, drain the field and allow it to dry; during the panicle differentiation stage, keep the soil moist with shallow irrigation; during heading and flowering, maintain a standing water layer; and in the grain‑filling and milky‑ripe stages, alternate between wet and dry conditions. These practices help ensure early establishment, early tillering, robust plant growth, enhanced overall stress resistance, and increased yield per unit area.
Regarding paddy field water management, you can keep in mind the “Twenty-Four-Character Guideline”:
Shallow-water transplanting, maintaining a thin layer of water for green-up, and applying light irrigation to promote tillering,
Sufficient sunlight for the seedlings, shallow water to promote panicle initiation, and moist conditions to strengthen the grains.

1. Transplanting rice seedlings in shallow water
During rice transplanting, a consistent water depth should be maintained to prevent seedlings from lodging and to avoid excessive water loss that could lead to wilting. The appropriate water depth should be adjusted according to the size of the seedlings; ideally, the water level should cover about one-third of the plants after transplanting.

2. Reviving with a drop of water
Within 7–8 days after rice transplanting, the crop is in the recovery phase; during this period, the paddy field must not be allowed to dry out to prevent wilting, which can hinder survival. A water depth of 3–3.5 cm is recommended at this stage.
3. Shallow-water tillering
After rice resumes green growth, it enters the tillering stage. To promote early and vigorous development, robust root systems, and strong plant growth, it is advisable to maintain a water depth of 1.5–2.0 cm in the field. This helps raise both water and soil temperatures, increase the diurnal temperature range, and ensure adequate light exposure at the base of the plants, thereby creating an optimal growing environment for early and rapid growth.
4. Seedlings are sufficiently exposed to the sun for field management.
When tillering reaches approximately 80% of the expected number of effective panicles, the paddy field should be drained and allowed to dry in the sun to suppress the development of ineffective tillers, further enhancing lodging resistance. At the same time, this practice promotes nutrient uptake by the rice plants, encourages deeper root penetration, increases the panicle‑setting rate, and ultimately boosts grain yield.
5. Promote panicle initiation with just a little water.
After tillering (or at the onset of tillering in some varieties), rice enters the panicle initiation stage, which is the period of highest water demand throughout its life cycle; water stress should be avoided. During this phase, it is advisable to maintain a water depth of 2–3 centimeters on the field surface.
6. Moisture-Enhancing Seed Strengthening
After rice enters the grain-filling stage, it still requires adequate water; however, excessive moisture can lead to insufficient soil oxygen, reduce root vitality, and cause premature leaf senescence, thereby hindering increases in 1,000-grain weight and compromising rice quality. During this period, irrigation should be managed using an intermittent approach, aiming to maintain consistently moist soil conditions.