How to manage water in rice cultivation? Mastering these methods is key

   According to the water requirements of rice, scientific and rational water management at different growth and development stages is a technical measure for achieving high and stable rice yields. The key points of water management techniques are: 

    Shallow-water transplanting, moist seedling establishment. The transplanting water should be shallow, so that seedlings do not float during transplanting; after transplanting, drain the water appropriately to keep the field surface moist, which helps rapid seedling establishment. 

    One-cun water for green-up, thin water for tillering. After seedling establishment, the paddy field should maintain a shallow water layer of 0.5-1 cun for green-up and to promote tillering. Too deep a water layer will inhibit tillering and delay tillering time, and cause high-position tillering; too shallow a water layer will lead to excessive tillering, consume plant nutrients, and form a large number of ineffective tillers. 

    When enough seedlings are present, dry the field to control seedlings and build the framework. When the number of seedlings in the field reaches 80% of the expected panicle number, drain the water moderately and dry the field to control ineffective tillering in the later stage. When drying the field, drain and let it dry for 3-5 days, then add fresh water and retain it for 2-3 days, then drain and let it dry again, repeating this for 2-3 rounds; however, field drying must be carried out according to local and timely conditions. In places where water sources are not guaranteed and summer drought or dog-day drought may occur, the field must not be dried blindly, otherwise it will cause water shortage and drought stress in the middle and late stages of rice and reduce yield. 

    Sufficient water for booting, alternate drying and wetting for plump grains. The booting stage of rice requires sufficient water, and the paddy field should maintain a 1-2 cun water layer to ensure large panicles and many grains. During the heading period, the paddy field water layer should be 0.5-1 cun; if the field has no water and suffers drought at this time, not only will heading be uneven, but it may even be impossible for the panicles to emerge. After the grain-filling and maturing stage, alternate drying and wetting intermittent irrigation should be carried out to promote the transport of organic substances in the plant to the grains, reduce empty and shriveled grains, and increase 1000-grain weight. After entering the yellow-ripe stage, the paddy field should be drained and dried, which not only helps the grains become full and plump, but also facilitates field harvest and improves the cultivated land quality for the next season's crops.