2. Fertilization technology: Fertilizer application rate is 2500-3000 kg (or 350-400 kg organic fertilizer) for the whole growth period of sweet potato in the whole growth period of medium-grown fertility, 12-14 kg of nitrogen fertilizer, 6-8 kg of phosphate fertilizer, and 9-kg of potassium fertilizer. 11 kg, nitrogen and potassium fertilizer sub-basal fertilizer and the second top-dressing fertilizer, phosphate fertilizer all as base fertilizer, fertilizer and farmyard fertilizer (or commercial organic fertilizer) mixed application. Basal fertilizer: Apply 2500-3000 kg of farmyard fertilizer or 300-400 kg of commodity organic fertilizer per mu, 4-5 kg ​​of urea, 13-17 kg of diammonium phosphate, and 5-7 kg of potassium sulfate. It is recommended to use long-acting fertilizers. Top-dressing: top-dressing fertilizer during the expansion of tubers, applying 16-19 kg of urea and 13-15 kg of potassium sulfate per acre. Fertilizers outside the roots: In the middle and late growth stages of sweet potato, 0.5% urea dilution, or 2%-3% superphosphate solution, or 5% plant ash water, or 0.2% potassium dihydrogen phosphate solution can be used for foliar application. Spray once every 6-7 days, spray 2-3 times. City Soil and Fertilizer Station Feed Spice Novelties Co.,Limited , https://www.wholesale-adult-toys.cn
1. Requirements of Fertilizer: The demand of sweet potato for nitrogen, phosphorus, and potassium is the most important factor, potassium is the most, nitrogen is the next, and phosphorus is the next. Potassium sweet potato, potassium fertilizer application has a significant effect on the yield and quality. Sweet potato absorbed less nutrients at the seedling stage, from the branching potato stage to the vigorous growth period of stems and leaves, the absorption of nutrients speeded up, the absorption amount increased, gradually decreased in the near future, to the rapid expansion of the tuber, nitrogen and phosphorus absorption decreased, and potassium The absorption level is maintained at a high level. In the absence of nitrogen, the old leaves first showed a lack of green, and the number of leaves and branches decreased, the leaves shrank, the internodes shortened, and the leaves were susceptible to premature yellowing, which seriously affected the yield. Phosphorus deficiency will cause the leaves to become smaller, dark green, and loss of luster. The elongation of the stems will be hindered, large patches of yellow spots will appear on the old leaves, and will become purple and soon fall off. The lack of potassium showed a small leaf, short internodes and petioles, dark green leaves, and brown spots on the back of the late leaves. Sweet potato avoid chlorine, the application of more than a certain amount of chlorinated fertilizer will reduce the starch content of the potato block, and the potato block is not resistant to storage.