The advantage of raising seedlings is that the concentration of seedlings is beneficial to management. In particular, as a "stubble-grabbing" cultivation, seedlings should be raised first, and when the seedlings grow to 4-5 leaves, they should be put into the field, which can shorten the land occupation time. 0.67 ~ 1 hectare can plant 2 seedlings per 667 meters. In greenhouse, greenhouse and other protected cultivation, seedling transplanting can fully improve the utilization rate of facilities. In addition, after graded transplanting, the spacing is similar, and the nutritional area of each seedling is similar, so the growth size is similar, the uniformity is good, and the commodity rate is high.
According to different varieties, the density of rape is 30,000 ~ 50,000 plants per 667 ㎡ (the density varies greatly according to the size of harvest), so planting is really a time-consuming work. In addition, at present, people's requirements for rapeseed are gradually developing from big tree to small tree. After growing for 30-40 days, the seedlings with 5-6 leaves and a length of more than 65,438+00 cm are washed and fried. The leaves and petioles are thicker than those of rape, crisp and tender.
Rapeseed seedlings growing for 30 ~ 40 days are usually harvested and directly sown. After the emergence of seedlings, separate the over-dense seedlings and properly distance them so as to "harvest big and leave small" in the future harvest. In fact, it played a role in thinning seedlings. Because there are no specific requirements for rapeseed harvest, a big tree can be flexibly mastered according to market demand. Because of this feature, it is more suitable for protected production and intercropping between warm fruits and vegetables.