7- 10 days. Direct-seeded rice fields can be directly sown in 7- 10 days after leveling, and the average daily temperature in the suitable sowing period should be kept above 12℃, so sowing should be done in the cold tail and warm head. Rice is an annual gramineous plant with monocotyledonous leaves, which is warm and humid. When mature, it is about 1 m high, and the leaves are slender, about 50 to 100 cm long and 2 to 2.5 cm wide.