Sweet potato is an important staple and cash crop with extensive planting prospects. Although it has advantages of drought tolerance and resistance compared to other crops, to achieve high yields, it is also necessary to do scientific fertilization work. So, what fertilizer should be used for sweet potatoes? Let's find out together.
What Fertilizer to Use for Sweet Potatoes?
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Fertilization Requirements: Sweet potatoes require a considerable amount of nutrients. For every 500 kilograms of fresh sweet potatoes, they need to absorb 2 kilograms of nitrogen, 1 kilogram of phosphorus, and 3.1 kilograms of potassium. According to the fertilization requirements of sweet potatoes, potassium is the most needed nutrient for tuber growth, followed by nitrogen.
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Fertilization Principles: The principles of fertilization are to prioritize organic fertilizers, with chemical fertilizers as supplements; prioritize base fertilization, with top dressing as supplements; and prioritize early-stage top dressing, with late-stage top dressing as supplements.
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Fertilization Timing and Methods:
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Seedling Fertilization: Seedling fertilization is generally dominated by nitrogen fertilizer and is performed around 4 days after planting seedlings. Small holes are opened about 7-10 centimeters below the side of the seedling, and 1.5-3.5 kilograms of urea per mu are applied. After application, water is immediately poured and covered with soil.
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Vine Fertilization: About a month after planting sweet potato seedlings, vine fertilization is applied, mainly with nitrogen fertilizer and potassium sulfate. About 4.5 kilograms of urea or 100 kilograms of wood ash per mu is generally applied, depending on the growth of sweet potatoes.
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Tuber Fertilization: During the swelling period of sweet potatoes, approximately 90 days after planting, when the roots and stems of sweet potatoes enter the rapid swelling period, it is the critical period for yield formation and the period of highest fertilization demand. Generally, a 1% solution of potassium dihydrogen phosphate is applied at a rate of 100-150 kilograms per mu. For depleted soil, 5 kilograms of urea can be added and irrigated along the cracks.
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Foliar Fertilization: Although foliar fertilization belongs to the category of top dressing, it is often combined with growth regulators and other operations, so it differs from traditional top dressing. For example, if excessive stem elongation occurs during the vigorous growth season of sweet potato seedlings, a solution of 50-70 milligrams/kilogram of effective concentration of paclobutrazol can be sprayed on the stems and leaves 1-2 times.
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Base Fertilization: Base fertilization should be applied before sowing, integrated with land preparation. Generally, about 70% of organic fertilizer is applied, with around 3000 kilograms of organic fertilizer per mu (commonly used are chicken manure, cow manure, and sheep manure), supplemented with appropriate amounts of superphosphate (25-40 kilograms) and wood ash (100-150 kilograms).
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Top Dressing:
In conclusion, there are many types of fertilizers used for sweet potatoes, and the nutrient characteristics vary at different growth stages. It is essential to grasp the timing and methods of fertilization and implement targeted fertilization.
