What fertilizer is good for sweet potato topdressing?

Sweet potato topdressing time

Sweet potatoes have a greater demand for nutrients during the root swelling period from August to October. This period is the critical period for yield formation and the time when the most fertilizer is needed.

What fertilizer should be used for sweet potato topdressing

In the early stage of sweet potato enlargement, crack fertilizer can be applied to allow its nutrients to flow downward, promote the enlargement of tubers, and effectively increase the yield. In the later stage of sweet potato enlargement, the root absorption capacity weakens, and foliar fertilizer can be applied to prevent premature aging.

Should I use urea or compound fertilizer for sweet potato topdressing?

Urea can only provide nitrogen to crops. Therefore, when crops need to grow quickly, urea can be chosen. In terms of fertilizer efficiency, since the nutritional structure of compound fertilizer is relatively balanced, it can supplement more nutrients and improve the nutrient deficiency of crops caused by the lack of multiple nutrients.

Sweet potato topdressing method

1. Hole topdressing method: Use a wooden stick to make a hole about 30 cm deep 25 cm away from the main root of the sweet potato, add a small amount of three-element compound fertilizer, and cover it with wet soil. This method is effective and can increase production by about 200%.

2. Crack topdressing method: During the period of sweet potato expansion, use potassium dihydrogen phosphate and water, or urea and superphosphate and water to make a fertilizer liquid to fill the cracks. After half a month, add wood ash and water (soak for 4 hours), water with the filtered clear liquid, and seal it tightly.

Precautions for topdressing sweet potatoes

When applying fertilizer to sweet potatoes, it is best to apply fertilizer in the morning and afternoon when the weather is good, not in the hot noon, otherwise fertilizer damage will occur. In addition, do not apply fertilizer too many times, and the concentration of fertilizer should not be too high. When applying base fertilizer, it must be fully decomposed, and water can be applied once after each fertilization.