How to sow seeds when planting round yam?

1. Sowing date: the determination of sowing date is mainly based on two factors, one is the germination stage of tuber, the other is the external temperature conditions. The tuber goes into dormancy soon after harvest. When the spring temperature reaches 13-14 ℃, the tuber will sprout and new plants begin to grow, which is the suitable time for sowing. Sowing too early will not germinate, or the germination time is too long; sowing too late, the bud is too big, sowing difficult, and late planting and late harvest, affecting tuber hypertrophy and reducing quality. The conditions are different in different places. In some areas, the average temperature is 12 ℃, and in some areas, sowing can be advanced to 11 ℃. Seeds are usually sown in central China in mid-April. 2. Sowing method sowing depth: round yam grows in shallow soil and should not be sown too deep. The depth of the hole is 7cm to 8cm. The soil in the hole must be finely broken, cut the section upward when sowing, and let the surface layer of tuber come into contact with the soil as far as possible. This is not only conducive to rooting and sprouting, but also can avoid drought. However, according to scientific experiments, the downward contact of the cortex with the soil is beneficial to the temperature conditions needed for growth and germination, and will not affect the upward budding. Therefore, the sowing method of upward incision and downward cortex is still advocated. After placing the potato pieces, gently cover the soil for 1 cm, and then sprinkle it with rotten manure. When the covered soil is thick, it sprouts unevenly and is easy to rot. The soil cover is 1 cm, plus the composting pit soil, etc., it is 2-3 cm thick. Planting density: round yam is divided into scaffold cultivation and climbing cultivation, which have different planting distances. Judging from the current planting density in various places, it is generally appropriate to plant 3000 to 4000 plants per mu. Two rows are planted on the 1.5-meter border and one row on the 1-meter border, with a distance of 30 centimeters. At the same time, we should grasp the following principles: dense support cultivation, climbing cultivation should be sparse; fertile soil should be dense, barren land should be sparse; seed cultivation should be sparse.