Key Technical Points for Field Water and Fertilizer Management of Chinese Cabbage in Autumn and Winter

Water and fertilizer management is a key factor for high yields of Chinese cabbage. When growing Chinese cabbage in autumn and winter, proper management should be carried out according to climatic conditions and the water and fertilizer requirements of Chinese cabbage at each stage of production.

I. Seedling stage: The root system is not well developed and its absorption capacity is weak. In autumn, high temperatures and drought often occur, so sufficient water must be supplied in a timely manner, and frequent light watering should be maintained to promote root growth. Apply one topdressing at the heart-breaking stage, and each time seedlings are thinned, combine it with intertillage and apply a light topdressing to promote seedling growth.

II. Rosette stage: This is a period of rapid growth for Chinese cabbage. During this period, water and fertilizer management must be strengthened to promote vigorous plant growth. After final thinning or after the plants have recovered from transplanting, apply fertilizer in holes or small furrows between rows or between plants, with a topdressing of 20 kg of compound fertilizer or 20 kg of ammonium sulfate per mu. After topdressing, irrigate thoroughly once, and thereafter water according to the dry and wet condition of the soil.

III. Head-forming stage: This is the period when the Chinese cabbage product is formed, and it requires large amounts of fertilizer and water. Water and fertilizer management during the head-forming stage should focus on the early and middle stages of head formation, namely the "barrel-drawing fertilizer" and the "heart-filling fertilizer." Both applications should use quick-acting fertilizers and must be applied in advance. Apply topdressing immediately when head formation begins, with 15-20 kg of ammonium sulfate per mu, and apply another topdressing after the plants have drawn barrels. After topdressing, combine with irrigation, and the irrigation method should preferably be slow, gentle watering. Stop irrigation 10 days before harvest to prevent the leaf heads from being unsuitable for storage due to excessive water content. Zhao Yun