Key Techniques for Fertilizer and Water Management of Chinese Cabbage in Autumn

For autumn Chinese cabbage, sowing 3 to 5 days before or after the Beginning of Autumn is generally advisable, and in high-temperature years it can be postponed to mid-August. Disease-resistant, long-growing late-maturing varieties can be sown appropriately earlier, while medium-maturing varieties with a short growing period can be sown a few days later. The following introduces fertilizer and water management for autumn Chinese cabbage for reference.

????Topdressing:

Chinese cabbage has high yield and a high fertilizer demand. On the basis of applying sufficient base fertilizer, topdressing should not be delayed. Topdressing should be determined according to different growth stages and seedling conditions; generally no topdressing is applied at the seedling stage. If the base fertilizer is insufficient, the first application can be at the 3 to 4 true-leaf stage, applying 10 kg of ammonium sulfate per mu, broadcast on both sides of the seedlings, and watered immediately, called "seedling-promoting fertilizer"; the second application after final thinning or after transplanting seedlings, applying 15 to 20 kg of ammonium sulfate per mu in furrows opened on both sides of the ridges, called "plant-developing fertilizer"; the third application at the rosette stage, applying 25 to 30 kg of ammonium sulfate and 10 to 15 kg of superphosphate per mu, placing the fertilizer into furrows or holes, then slightly earthing up and supporting the ridges, and then watering, called "major topdressing"; the fourth application at the mid-heading stage, applying 15 to 20 kg of ammonium sulfate per mu, which can be applied with irrigation water, called "heart-filling fertilizer".

????Watering:

From the cluster-forming stage to the rosette stage, the temperature gradually drops and the weather is mild; during this period, watering can be done appropriately. At the late rosette stage, water can be controlled appropriately for several days, and watering should be resumed after the third topdressing. After Chinese cabbage enters the heading stage, its water demand is greatest, so as soon as the seedling-restraining period ends, a thorough watering should be given. Then after 2 to 3 days, a second watering should follow. This one is very important; if the soil cracks at this time, the lateral roots may break and the fine roots may die, affecting head formation. After that, water generally every 5 to 6 days to keep the soil moist. Li Jiao