How to fertilize sunflowers?

How to fertilize sunflowers? Please give instructions for the cultivation of sunflowers can refer to the following methods of fertilization: 1 the law of fertilizer demand of sunflowers sunflower is a crop that needs more fertilizer. From the formation of the disk to the flowering stage, it is the peak of fertilizer demand for sunflowers. More phosphorus was needed from seedling emergence to disk formation, more nitrogen was needed from disk formation to the end of flowering, and potassium was absorbed most from disk formation to wax ripening stage. Therefore, the fertilization of sunflower is dominated by phosphorus in the early stage and nitrogen and potassium in the middle and later stage. For each production of 100kg sunflower seeds, it is necessary to absorb nitrogen (n) 4.59~6kg, phosphorus (p2o5) 2.6~3.04kg and potassium (K2o) 18.6~30kg from the soil. Phosphorus and potash fertilizer are mostly applied as base fertilizer or seed fertilizer, while nitrogen fertilizer is used as topdressing or 1amp 3 as base fertilizer, and 2max 3 as topdressing. (2) the principle of fertilization technology of sunflower is to apply sufficient base fertilizer, re-apply seed fertilizer and topdressing at the right time. The base fertilizer is mainly farm manure. Pig manure and rotten barnyard manure are the best. General field 1500~2500kg per mu, high-yield field should apply 3000~4000kg per mu. If phosphate fertilizer is used as base fertilizer, calcium superphosphate 30kg is applied in general field and 50kg is applied in high yield field. Potash fertilizer can be applied with 50~75kg plant ash per mu. But plant ash is not used in saline soil. To grow fertilizer, you should use available nitrogen, phosphorus, potassium fertilizer and fine manure of human, livestock and poultry. The dosage should be small but fine. Generally, calcium superphosphate 15~30kg, potassium chloride or potassium sulfate 10~15kg or plant ash 35kg can be applied per mu. In barren hillside land or sandy soil, ammonium nitrate 4~7kg or ammonium sulfate 10kg should be applied. Can be applied in holes or strips in the sowing ditch. Topdressing at seedling stage and flowering stage. Spring sowing sunflowers which are fertilized once a year at seedling stage are generally not topdressing when the base fertilizer or seed fertilizer is sufficient. Sunflowers sown in summer and autumn need to be fertilized with seedlings. The key period of topdressing sunflower in flowering stage is before budding. Nitrogen and potassium fertilizers are generally topdressing at 7-8 pairs of leaves, and topdressing without seed fertilizer should be made early. Topdressing fertilizer generally applied ammonium nitrate 10~15kg, ammonium bicarbonate 20~25kg, urea 7.5~10kg, calcium superphosphate 20kg, potassium chloride 15kg per mu. Strip application or acupoint application. Boron fertilizer has a good effect on increasing yield of sunflower. Boron fertilizer should be applied when the content of available boron in soil is lower than that of 0.4mg/kg. Seeds can be mixed with 150 grams of borax per mu, or sprayed with 0.1%-0.2% borax aqueous solution before flowering. The fertilization rate of sunflower in Heilongjiang Province is N (n) 13.5kg, P (p2p5) 4.5kg, N (n) ∶ P (p2o5) is 1 ∶ 0.33 per mu. That is, urea 29.35kg per mu and calcium superphosphate 9.8kg in three materials. In Jilin, the suitable dosage is nitrogen (n) 4kg, phosphorus (p2o5) 4kg and borax 1kg per mu. Click to get more sunflower planting techniques click to get more grain and oil crop planting techniques