Detailed Explanation of Key Techniques for Napa Cabbage Planting and Management
For napa cabbage planting, first select and prepare the land, then apply base fertilizer, mainly organic fertilizer; then sow at the right time, and after the seedlings emerge, carry out field management. Field management includes thinning seedlings, topdressing, intertillage and earthing up, and irrigation.
Napa cabbage field management:
1. Thinning seedlings: when there are 2-3 true leaves, carry out the first thinning; at 5-6 leaves, carry out the second thinning; at 7-8 leaves, the seedlings can be finalized. Select different row and plant spacings according to different varieties, leaving 1 strong seedling per hole.
2. Topdressing: after napa cabbage is transplanted and established, topdressing can begin. Apply 15% decomposed human urine every 3-4 days. When napa cabbage enters the rosette stage, the concentration of topdressing should be increased, usually applying 30% decomposed human urine every 5-7 days. After heading begins, heavy topdressing and additional potassium fertilizer are necessary measures to increase yield. After the plants close the rows, generally no more topdressing is applied. If the base fertilizer is insufficient, urea may be applied as appropriate between the rows.
3. Intertillage and earthing up: to facilitate topdressing, loosen the soil and weed 2-3 times in the early stage. Especially after long rain turns to clear weather, intertillage and drying the soil should be done promptly to promote root growth. In the middle rosette stage, combine furrow application of cake fertilizer with earthing up to form ridges, with a ridge height of 10-13 cm. After ridging, manure should be poured into the furrows and must not adhere to the leaves; water should be poured into the furrows and must not wet the root crown. At the same time, keep the air circulating in the furrows to reduce air humidity between the plants.
4. Irrigation: during the seedling stage of napa cabbage, water lightly and frequently to maintain moisture; during the rosette stage, irrigate intermittently, alternating dry and wet, and harden the seedlings appropriately; during heading, the water requirement is relatively high, and furrow irrigation may be used when the soil is dry. Irrigation should be carried out in the evening or at night after the soil temperature drops. Pour slowly, and never fill the whole bed. After the water infiltrates the soil, drain the excess water promptly. Ensure there is no standing water in the furrows, no visible water on the bed surface, and no water shortage for the roots.
In addition, the sowing time of different cabbage varieties is different. For example, early-maturing varieties are generally sown in early to mid-August, and some are sown as early as late July. Mid-maturing varieties can be sown from late August to early September. Late-maturing varieties are best sown in late August. Everyone should determine the sowing time according to actual conditions.