Problems in fertilization and principles of fertilization
The blind application of nitrogenous fertilizer in the production of Chinese cabbage is serious. The amount of once-fertilized fertilizer is too large, the ratio of nitrogen, phosphorus and potassium is unreasonable, the high-phosphorus compound fertilizer is blindly applied, the application amount of organic fertilizer is insufficient in some areas, and the soil acidification in vegetable fields is serious. , propose the following fertilization principles:
(1) Optimize the amount of nitrogen, phosphorus, and potassium fertilizers based on soil fertility conditions and target yield; (2) Combine basic fertilizer with top-dressing fertilizer. Topdressing mainly nitrogenous fertilizer, nitrogen, phosphorus, potassium reasonable fit, appropriate to add trace elements. After the rosette period, the management of topdressing is strengthened. The top-dressing stage requires an additional top-dressing and the top two are not suitable for recovering nitrogen fertilizers; (3) The effective boron content in the northern calcareous soil, the effective acid content of molybdenum and other trace elements in the south are low, and attention should be paid. Supplementation of trace elements; (4) The acidity of vegetable fields should be properly treated with lime and other acidic soil conditioners; (5) Do not use organic fertilizers that are not adequately decomposed, promote the use of commercial organic fertilizers and decomposed farmyard manures, and fertilize fertility.
Fertilizer amount and method
(1) The amount of organic fertilizer applied: the yield level is 4500-6000 kg/mu, organic fertilizer is applied at 2-3 squares/mu; the yield level is 3500-5000 kg/mu, and organic fertilizer is applied at 2 squares/mu. (2) Output level 4500-6000 kg/mu: nitrogen fertilizer (N) 18-23 kg/mu, phosphate fertilizer (P2O5) 5-8 kg/mu, potassium fertilizer (K2O) 16-20 kg/mu. (3) Output level 3500-4500 kg/mu: nitrogen fertilizer (N) 15-20 kg/mu, phosphate fertilizer (P2O5) 4-6 kg/mu, potash fertilizer (K2O) 13-17 kg/mu.
If basal fertilizer is not applied with organic fertilizer, it may be appropriate to increase nitrogen fertilizer (N) 3-5 kg/mu and potassium fertilizer (K
2O) 2-3 kg/mu. For plots prone to the absence of boron micronutrients, or for plots that have exhibited boron deficiency symptoms in previous years, one kilogram of borax can be applied per acre before sowing, or 0.1%-0.5% of borax or boric acid can be used in the late growth stage. The aqueous solution is sprayed on the foliage (it can also be sprayed with pesticides) and sprayed once every 5-6 days, spraying 2-3 times in succession; when the soil pH of the southern vegetable field is less than 5, 100-150 kg of quick lime should be applied per acre. Can reduce soil acidity and calcium supplement. All organic fertilizers and phosphorus and potassium fertilizers were planted or applied as base fertilizers, nitrogen fertilizer was used as the base fertilizer at 30%, and 70% were used as top dressings during the rosette stage and the early filling stage combined with irrigation twice.
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