How to fertilize sweet potatoes for high yield?

How to fertilize sweet potatoes for high yield? Please introduce in detail the following three fertilization methods to increase the yield of sweet potato: a piece of wood is used for topdressing the hole, a hole about 30 cm deep is drilled at a distance of 20 cm to 30 cm from the main root, an appropriate amount of three-element compound fertilizer is put in, and sealed with wet soil. the effect is better if a hole is punched on each side of the ridge. Crack topdressing is the root expansion period of sweet potato in September, when cracks appear in the surface soil layer, the application of crack fertilizer can promote the root expansion of sweet potato. The fertilizers that can be used as irrigation seams are: 750 kilograms of human feces and urine per mu, mixed with 500 kilograms of water, and then irrigated at around 5 p.m.; 500 grams of potassium dihydrogen phosphate per mu, dissolved in warm water, then mixed with 500 kilograms of water, irrigated in the cracks; 2.5 kilograms of urea per mu, 10 kilograms of calcium superphosphate, dissolved with a small amount of water, and irrigated with 500 kilograms of water. Dissolve with 100 kg of plant ash per mu, soak for 5 hours, filter out impurities, and irrigate the root with 500 kg of water. In addition, it is worth noting that no matter which method is used to irrigate the root, the action should be slow, and the crack should be sealed with fine topsoil immediately after filling liquid, which can reduce the volatilization of fertilizer effect and the evaporation of water, and play the role of drought tolerance and seedling protection. There are many kinds of foliar fertilizer suitable for spraying sweet potato, such as 1%-2% urea solution, 2%-3% superphosphate leaching solution, 5%-10% plant ash leaching solution, 0.3% potassium dihydrogen phosphate solution, and so on. Spraying time, it is better to spray around 5: 00 p. M. in a day, generally spray 7500kg per mu, spray again every 5-7 days, even spray 2 times 3 times. Click to get more sweet potato planting techniques click to get more vegetable planting techniques