High-yield sweet potato growing techniques: how should you fertilize for best results?

Sweet potato, also known as red sweet potato or fan shu, is one of the common crops in our daily lives. Sweet potato is a green, healthy food, containing large amounts of protein, sugar, fat and various vitamins and minerals, and is very nutritious. Regularly eating sweet potato not only lubricates the intestines and relieves constipation but also strengthens the stomach and boosts qi. Sweet potato has the reputation of being a “longevity food,” and as people's demand for sweet potato grows day by day, it is widely cultivated and planted by many farmers.High-yield sweet potato growing techniques: how should you fertilize for best results?

I. High-yield sweet potato growing techniques: how should you fertilize for best results?

1. Look at the seedling condition

During the branching and tuber-setting stage, the underground root network forms, the tubers begin to swell, and the ability to absorb fertilizer is strong. At this time the sweet potato leaf area increases, photosynthetic efficiency rises, and topdressing should be done early to achieve the goals of strengthening the plants, promoting tuber development, and ensuring fast yet steady growth. For those with good growth, the fertilizer rate can be reduced. If the seedling-promoting or cluster-setting fertilizer had a relatively large nitrogen rate, the tuber-promoting fertilizer can be potassium fertilizer only, applying about 10 kg of potassium sulfate per mu.

2. Look at the timing

The tuber-promoting fertilizer is generally applied about 45 days after transplanting the vines, when the aboveground part has already spread its vines down the ridges and the tubers have basically taken shape. On one side of the ridge, break open 1/3 with a plow, then fertilize immediately. Breaking the ridge and fertilizing can improve soil aeration and is favorable for tuber swelling. This fertilization is mainly potassium fertilizer; topdressing with potassium fertilizer can thicken the stems and leaf stalks, keep them in a tender state, and promote tuber swelling.

3. Look at the soil texture

Sandy soil has good aeration, but poor fertilizer- and water-holding capacity, its fertilizer effect is not long-lasting, and it is prone to leaching. Add more organic fertilizer to improve the soil, apply quick-acting fertilizers in small amounts, and appropriately increase the number of topdressings. Clay soil has poor air permeability and fertilizer decomposes slowly, but its fertilizer-holding capacity is strong, so the topdressing amount should not be too small; you can topdress a moderate amount more and appropriately reduce the number of topdressings.

4. Look at the moisture

An important principle of fertilizing sweet potato is that under conditions of good moisture, the nitrogen fertilizer rate should be controlled to avoid causing excessive vine and leaf growth. In high-temperature and drought-prone areas in July-August, apply sufficient nitrogen fertilizer before the drought to promote the stems and leaves in closing the ridges before the drought. In years with a lot of autumn rain, the amount and frequency of topdressing can be appropriately reduced; otherwise, it should be appropriately increased.

Sweet potato cannot be given fertilizers containing the element chlorine, as it lowers the starch content of the tubers and also makes the tubers less able to store.

II. How can sweet potato pest and disease problems be reduced?

1. Healthy tubers and healthy seedlings, crop rotation

For the main pest and disease targets to be controlled, select excellent disease-resistant (tolerant) varieties according to local conditions, establish disease-free seed plots, plant with healthy seedlings, and combine winter plowing to pick out insects and freeze the ridges. Carry out crop rotation, and plant on fresh land where sweet potato has not been grown within 3 years.

2. Clean fertilizer and clean water, strict management

Do not apply fertilizer made by composting rotten sweet potato tubers and vines; apply chemical fertilizer at the right time and in the right amount. Cut off the source of bacteria, and strictly achieve clean fertilizer, clean seedlings, and clean water to prevent underground pests and prevent the spread of pathogens. At every step, including taking tubers out of storage, raising seedlings, transplanting, and harvesting, thoroughly pick out diseased and residual plant material, and earnestly bury it deep in a centralized place or burn it, so as not to leave the pathogens any chance to survive.