When to fertilize sweet potatoes? How to fertilize?

The key to obtaining higher returns from growing sweet potatoes is to achieve high yields. The more uniform and fuller the sweet potato tubers are, the higher their economic value. All of this is inseparable from the method of fertilization. Let’s learn together when to fertilize sweet potatoes? How to fertilize?

1. Fertilization principles

Sweet potatoes have the greatest demand for potassium fertilizer, followed by nitrogen fertilizer, and relatively less demand for phosphorus fertilizer. When applying fertilizer, the amount of nitrogen fertilizer should be controlled, the amount of phosphorus fertilizer should be stabilized, and the amount of potassium fertilizer should be increased. Organic fertilizer is the main fertilizer, chemical fertilizer is the auxiliary fertilizer, base fertilizer is the main fertilizer, top dressing is the auxiliary fertilizer.

2. Apply enough basal fertilizer

Adequate application of basal fertilizer can meet the nutritional needs of sweet potatoes throughout the entire growth period and prevent nutrient deficiency and premature aging in the later stage. When preparing the land in winter and spring, scientifically determine the amount of fertilizer to be applied based on soil fertility and expected yield.

3. Apply fertilizer skillfully

When planting, use 3 kg of urea and 2 kg of potassium dihydrogen phosphate per mu of land, mix with 1000-1500 kg of water, and pour it into the planting holes, 0.5 kg per hole, to promote the growth of seedlings.

4. Check the seedlings and apply fertilizer

According to the growth stage of sweet potatoes, apply seedling-promoting fertilizer, vine-strengthening fertilizer, potato-promoting fertilizer, crack fertilizer and foliar fertilizer in a timely manner. Seedling-promoting fertilizer should be applied 3-5 days after planting, vine-strengthening fertilizer should be applied 30-40 days after planting, potato-promoting fertilizer should be applied 90-100 days after planting, crack fertilizer should be applied when the soil cracks, and foliar fertilizer should be sprayed in the middle stage of tuber expansion.

5. Apply crack fertilizer

For plots with low fertility or insufficient topdressing in previous times, apply urea, potassium sulfate and superphosphate when the soil cracks during the tuber swelling period, and irrigate along the cracks.

6. Notes

Sweet potatoes are incompatible with chlorine, and chlorine-containing fertilizers should not be used to avoid reducing the starch content and storage resistance of the tubers. Volatile fertilizers such as ammonium bicarbonate should not be broadcasted, but should be made into mixed fertilizer granules and applied deeply. Organic fertilizer should be fully decomposed before application to avoid root burn.

In short, as an economic crop , sweet potato is favored by farmers for its low planting cost, simple management, abundant yield and good economic benefits. To achieve high-yield, high-quality and high-efficiency cultivation of sweet potatoes, the key lies in reasonable fertilization and understanding of the growth requirements and fertilization rules of sweet potatoes.