Water-seeded direct-seeded rice has many advantages; what exactly are they?

Depending on the soil moisture conditions at the time of land preparation and the method of land preparation and sowing, direct-seeded rice can be divided into dry direct seeding and water direct seeding. Dry direct seeding can further be divided into methods such as sowing on stubble first followed by shallow rotary tillage, and rotary tillage first followed by sowing. The land preparation and sowing procedure for water direct seeding is roughly as follows: after applying base fertilizer, add water and rotary tillage, open furrows, level the field with water, then sow and press the seeds into the soil.

Compared with dry direct-seeded rice, water direct seeding has the following advantages. First, more seedlings emerge and emergence is uniform, which is conducive to cultivating strong seedlings. In water direct-seeded fields, the bed surface is level, and there is mud slurry on top; after pressing the seeds into the soil, no seeds are left exposed, emergence is fast and uniform, a full stand of seedlings can be achieved, and the seedlings are strong. Dry direct-seeded rice has no water leveling process, so the bed surface is often uneven, sowing depth varies, and many seeds are left exposed, which easily leads to uneven emergence and a low emergence rate; generally, the emergence rate is 10-15% lower than that of water direct-seeded rice. Second, there are basically no weedy rice plants and fewer weeds. After processes such as rotary tillage, paddy raking with water, and leveling, weedy rice seeds are turned into the soil; water rotary tillage and water leveling prevent weedy rice seeds from getting oxygen, suffocating them in the soil layer and controlling their occurrence, while field weeds are also significantly reduced. Third, the field has good levelness, which helps improve chemical control effectiveness and facilitates water and slurry management. In dry direct-seeded rice fields, except for fields with a originally good leveling foundation, fields with poor levelness often have dry seeds on the high spots and submerged seeds on the low spots, seriously affecting rice germination and emergence and greatly reducing the seedling survival rate. Chemical weed control requires maintaining moist soil; low-lying water accumulation and exposed seeds both easily cause phytotoxicity, leading to seedling injury or death, and the weed control effect is also poor. If the field surface is uneven, it is also difficult to ensure the quality of field drying. Fourth, the seedling condition foundation is good, and the yield level is high. In water direct-seeded fields, rice emergence is good, the seedling survival rate is high, tillering occurs abundantly, and the ear-bearing tiller rate is high; on the basis of sufficient ears, a relatively high yield can be obtained.