Key points of fertilization in the growing period of Chinese Cabbage

Topdressing and fertilizing seedlings at seedling stage. From the development of cotyledons to the exposure of true leaves to 8-10 leaves, about 15-20 days is the seedling stage. At this time, the growth rate is faster, and it is the fastest period of root and leaf cell and tissue differentiation, although it does not need much fertilizer, but the lack of it has a great impact on the future yield. Therefore, 10 kg of ammonium nitrate should be applied per mu after seedling determination.

Topdressing is the key point in rosette stage. After Chinese cabbage enters the rosette stage, the root system occurs in large numbers, the growth is easy to increase sharply, and the fertilizer absorption is large, and the leaves that produce nutrients during the heading stage basically grow up at this stage. Therefore, the exuberant growth of the rosette stage plays a decisive role in the growth of the leaf ball. This period is a critical period for good or bad intentions in the future. The rosette period is generally 20-25 days, with 15 kg ammonium nitrate per mu and a certain amount of phosphorus and potassium fertilizer to promote the growth of outer leaves and lay the foundation for good intentions.

Top dressing during the pericardial period. The period of pericardium accounts for 1 / 2 of the growth period and 2 / 3 of growth, which is the key period for the formation of the core of Chinese cabbage. If you lose fat at this time, it will directly affect the compactness of the core and affect the yield and quality. The outer leaves near the heart leaves continued to grow in the early stage of the pericardium, which was also the fastest growing period of 1 to 5 core leaves, when 15 kg of ammonium nitrate was applied per mu; in the middle stage of the pericardium, the outer leaves almost no longer grew, and 10 kg of ammonium nitrate was applied per mu; in the later stage of the pericardium, due to short light and low temperature, the plant grew slowly, absorbed less nutrients, and the effect of topdressing was not obvious. And eastward