Guidance on Scientific fertilization of Chinese Cabbage

? 1. Principles of fertilization

In view of the serious phenomenon of blind partial application of nitrogen fertilizer in the production of Chinese cabbage, excessive amount of fertilizer at one time, unreasonable ratio of nitrogen, phosphorus and potassium, blind application of high phosphorus compound fertilizer, insufficient application of organic fertilizer in some areas, serious soil acidification in vegetable fields and so on, the following fertilization principles are put forward:

(1) optimize the amount of nitrogen, phosphorus and potassium fertilizer according to soil fertility conditions and target yield.

(2) it is mainly based on base fertilizer and combined with base fertilizer and topdressing. Topdressing is mainly based on nitrogen and potassium fertilizer, with appropriate supplement of trace elements. To strengthen the management of topdressing after rosette stage, one more topdressing is needed in the early stage of Baoxin, but it is not suitable for topdressing 2 weeks before harvest.

(3) the contents of available boron in calcareous soils in the north and available molybdenum in soils with high acidity in the south are relatively low, so attention should be paid to the supplement of trace elements.

(4) when the vegetable land is acidified seriously, acid soil conditioners such as lime should be applied appropriately.

(5) avoid using organic fertilizers that are not fully mature, and advocate the application of commercial organic fertilizers and rotten farm manure to improve soil fertility.

? 2. Fertilization suggestion

(1) the yield level is 45006000kg / mu, applying organic fertilizer 4 square meters / mu, nitrogen fertilizer (N) 1013kg / mu, phosphate fertilizer (P2O5) 46kg / mu, potash fertilizer (K2O) 13,17kg / mu.

(2) the yield level is 35004500kg / mu, applying organic fertilizer 3000kg / mu, nitrogen fertilizer (N) 8kg / mu, phosphate fertilizer (P2O5) 3kg / mu, potash fertilizer (K2O) 10kg / mu. For plots that are prone to trace element boron deficiency or have shown symptoms of boron deficiency in previous years, 1 kg of borax per mu can be applied before sowing, or foliar spraying with 0.1% 0.5% borax or boric acid aqueous solution in the middle and later stages of growth, spraying every 5 to 6 days for 3 times. Chinese cabbage is a calcium-loving crop, in addition to basic application of calcium fertilizer (superphosphate), foliar supplement can also be adopted, spraying 0.3% 0.5% calcium chloride or calcium nitrate. When the pH of vegetable soil in southern China is less than 5, 100kg quicklime per mu is needed, which can reduce soil acidity and supplement calcium. All organic fertilizer and phosphate fertilizer were applied as base fertilizer, 30% of nitrogen fertilizer as base fertilizer, 70% of nitrogen fertilizer as base fertilizer and 70% of nitrogen fertilizer as topdressing fertilizer in rosette stage and early heading stage, respectively.