I. Seedling Fertilizer: Celery cultivated in protected areas is generally cultivated and then planted. The preparation of nutrient soil can be referred to the nutrient soil preparation method of tomato, or it can be mixed with 1/2 vegetable garden soil and 1/2 of the decomposed or semi-fermented compost to make nutrient soil, and is incorporated by 2% to 3% by weight. Superphosphate. About 30 days after emergence, a low-concentration nitrogen fertilizer should be applied as appropriate, and 0.2 kg of ammonium sulfate per trace is applied.
Second, the base fertilizer: Because the roots of celery are shallow, the cultivation density is large, and the base fertilizer must be applied when the soil is prepared before planting. Apply 4000~5000 kg of organic fertilizer per acre, 30-35 kg of superphosphate, 20-25 kg of potassium sulfate, and apply 1~2 kg of borax per acre for boron-deficient soil. Third, top dressing: generally after the planting period, the seedlings are slow-growing, the plant grows slowly when the seedlings are slowed down. In order to promote the growth of new roots and leaves, the seedling fertilizer can be applied once, and 10 kg of ammonium sulfate per mu, or decomposed with water Human manure and urine fertilizer is 500-600 kg. When the plants enter a prosperous growth period, they must be topdressed in time. For the first time, 7-9 kg of urea or 15-20 kg of ammonium sulfate and 10-15 kg of potassium sulfate were applied per mu. After half a month, the second top dressing was carried out. The dosage was the same as the first time, and then the third time was about 15 days. The second top dressing, the same amount of fertilizer as the first time, or increase or decrease the amount of fertilizer according to the growth of celery.
Three: The application rate of nitrogen fertilizer and potassium fertilizer should not be too much. The excessive concentration of nitrogen and potassium in the soil will affect the absorption of boron and calcium, which will cause the young tissue of celery heart to brown, and dry edges will appear. When it is severe, it will die. Insufficient, soil drought and low ground temperature are more serious, so it is necessary to control the amount of nitrogen and potassium fertilizer, increase the application of boron fertilizer and calcium fertilizer, keep the soil moist, and avoid the soil temperature is too low. When the plant is deficient in boron, it is easy to produce stem cracks. The stem cracks appear on the inner side of the outer petiole; when the heart leaves are born, boron is deficient, the inner tissue becomes brown, and cracking occurs. The surface is sprayed with 0.5% borax aqueous solution. The occurrence of stem splitting of stem cracks can be avoided to some extent.