How to apply fertilizer to grow pollution-free cabbage?

How to fertilize pollution-free cabbage? Please introduce the method of planting pollution-free cabbage fertilization methods can refer to the following methods: Heavy application of base fertilizer, timely planting: protected cultivation cabbage yield than open field about 30%, and early market, therefore, than open field fertilizer 20%-40%, increase phosphorus and potassium fertilizer, nitrogen dosage can be reduced by 10%-20%, in order to reduce the nitrate nitrogen content in cabbage, one is to increase the application of organic fertilizer, especially the application of decomposed, with enzyme bacteria EM bacteria retting organic fertilizer, can greatly reduce the nitrate content in cabbage. Shandong vegetable farmers experience, greenhouse application of 75000-105000 kg/ha decomposed manure, cabbage yield can be guaranteed to reach 75000 kg/ha; second, the application of long-term organic and inorganic compound fertilizer. In recent years, controlled-release and slow-release inorganic organic compound fertilizer developed in soil is not easy to leach, fertilizer efficiency is long and stable, can reduce the amount of application, improve utilization rate, reduce nitrate pollution to cabbage, etc.; third, increase the application of biological fertilizer. Long-term application of chemical fertilizer in vegetable fields reduces microorganisms year by year. Therefore, the decomposition of organic matter is hindered and the effective utilization rate of nutrients is low. Application of nitrogen-fixing bacteria, phosphorus bacteria, potassium bacteria, mycorrhizal and other biological fertilizers has a significant effect on improving soil microbial activity, promoting the bioavailability of soil nutrients, and reducing nitrate content in vegetables. According to the fertilizer supplying capacity of soil and fertilizer requirement of cabbage, fertilizer application in proportion can increase yield and quality without causing nitrate pollution. According to Shandong Province vegetable area protected cultivation of spring cabbage, the general yield of 75000 kg/ha, pigsty fertilizer 90000 kg/ha, topdressing urea 600 kg/ha, ternary compound fertilizer 300 kg/ha, can fully supply cabbage nitrogen and phosphorus needs, and a little surplus, but potassium is slightly insufficient. Because available potassium in Shandong soil is rich, cabbage will not appear potassium deficiency symptoms. When conditions permit, 300 kg/ha potassium fertilizer can play a significant role in quality enhancement. Basal fertilizer can be spread, furrow or hole. Furrow and hole application is in the case of a small amount of base fertilizer, must apply decomposed organic fertilizer, can be planted after application. 3. Skillful topdressing: After planting, the growth speed of leaves and roots is fast, so fertilizer and water management should be strengthened to promote the formation of strong assimilation and absorption organs, laying a foundation for the formation of compact leaf bulbs. After planting, watering in time, on the basis of applying sufficient base fertilizer, applying a small amount of quick-acting nitrogen fertilizer in the early stage with planting water, and applying ammonium sulfate 225 kg per hectare can accelerate seedling slowing, enhance seedling cold resistance, and promote early maturity and high yield. Cultivate and squat seedlings in time. When the plant grows vigorously, the leaves obviously have wax powder, and the heart leaves begin to embrace, the squatting seedlings should be terminated in time, and then watered and topdressed, and the diluted human excrement per hectare is about 1050 kg. In the balling stage, fertilizer and water management should be strengthened. This period is the fastest growing cabbage period, the largest growth, fertilizer requirements are also large, should be early topdressing. From the beginning of core rolling to the early stage of ball setting, topdressing twice continuously. 10000 kg/ha of retting cake fertilizer solution or 500 kg/ha of organic and inorganic compound fertilizer are applied with water every time. Stop topdressing about 30 days before harvest. Click for more cabbage growing techniques Click for more vegetable growing techniques