How to Fertilize Sweet Potatoes for Higher Yields: A Detailed Guide to Practical Methods

The sweet potato is an important food crop and also an important livestock feed. Ordinary rural households generally grow it. Sweet potato yields are usually decent, but if it suffers flooding, or if there is too much rain, yields will decline; in fertile, deep soil the yields are higher, so increasing sweet potato yields generally depends on fertilizer supply. Let's take a look at how to increase yields through fertilization.

1. Fertilization Principles

Nitrogen fertilizer enhances leaf photosynthesis and promotes stem and leaf growth. Use it in moderation. Using too much will cause the root cells to become suberized. Phosphorus fertilizer promotes root cell division and can also help nutrient absorption. Potassium fertilizer can improve photosynthetic efficiency somewhat, help root growth, and increase the number and weight of storage roots. In fact, potassium fertilizer has the greatest effect on sweet potato growth, followed by nitrogen fertilizer and phosphorus fertilizer. Using them in combination gives the most obvious results.

2. Soil Testing and Fertilization

The sweet potato has strong adaptability to soil and soil pH, and can be grown at pH 4.2 to 8.3. It prefers fertile, loose soil with good drainage and irrigation. Before planting, you need to test the soil's nitrogen, phosphorus, and potassium content, as well as its organic matter content; in some cases the soil pH also needs to be tested. After testing, you can fertilize according to need, or improve the planting soil. You can also use formula fertilization.

3. Fertilization Methods

Generally, per mu (666.7 sq m) you can apply 200 jin of dual-patent high-potassium compound fertilizer, in which the ratio of nitrogen, phosphorus, and potassium is 2 to 1 to 3. Do not use too much nitrogen fertilizer, as it easily causes excessive vine growth without forming sweet potatoes. Some livestock manure can be used after fermentation; poultry manure is too hot and not suitable for use. Do not use nitrate nitrogen fertilizer, as sweet potatoes easily crack. Use 400 jin of biological bacterial fertilizer and plant ash per mu as base fertilizer.

4. Fertilization Techniques

With potassium deficiency in the early stage, the internodes are short and the leaves are small; with potassium deficiency in the later stage, the leaf veins lack green color. For sandy soil, use semi-decomposed organic fertilizer as base fertilizer. For clay soil, use fully decomposed fertilizer. Then apply 300 jin of plant ash per mu. Do not use plant ash together with ammonium bicarbonate, as it affects nitrogen absorption. Sweet potato does not use potassium chloride, as it is sensitive to chlorine. Soaking vines in potassium speeds up growth. Use 1 jin of potassium sulfate plus 50 jin of water. Soak the vine seedlings, without soaking the terminal buds, take them out after one hour and let them dry. More than one month after planting, apply 20 jin of potassium sulfate per mu in holes. When the vines grow to 1 m, apply another 100 jin of plant ash, broadcast in the morning.

To increase sweet potato yields, you need to fertilize according to fertilization needs, apply fertilizer skillfully, and fertilize correctly. Growth will be promoted, and yields will increase accordingly.