How are sweet potato production areas distributed? A look at the latest producing regions
The sweet potato is an annual herbaceous vine of the genus Ipomoea in the family Convolvulaceae. Historical evidence shows that the sweet potato was introduced to Fujian and Guangdong in China from the South Seas at the end of the 16th century, and then spread to the Yangtze River and Yellow River basins and Taiwan, China, and other places. Today, China's sweet potato planting area and total output both rank first in the world. Let's take a look at the producing areas and distribution of sweet potatoes!
World distribution of sweet potatoes
Sweet potatoes are distributed worldwide in South America, the Greater Antilles, and the Lesser Antilles, and in tropical and subtropical regions around the globe (mainly produced south of 40°N).
Distribution of sweet potatoes in China
Sweet potatoes are mainly distributed in China's Beijing, Shanxi, Shandong, Henan, Tianjin, Hebei, the three northeastern provinces, Inner Mongolia, Yunnan, Sichuan, Hubei, Gansu, Anhui, Fujian, Shaanxi, Hunan, Guangdong, Jiangsu, Jiangxi, and other places. The main producing areas nationwide are Sian County in Anhui (China's home of sweet potatoes), Lulong in Hebei, Liancheng in Fujian, Kaifeng, Dengzhou, and Tongzhaipu in Tanghe in Henan, Sishui in Shandong, Nanchong in Sichuan, and other areas.
Producing area environment for sweet potatoes
1. Temperature: Sweet potatoes like warmth and fear cold. At a soil temperature of about 10°C they do not develop roots; at 15°C they need 5 days to develop roots; at 17-18°C they develop roots normally; at 20°C they develop roots in 3 days; at 27-30°C they can develop roots in just one day. When the air temperature is 25-28°C, the stems and leaves grow quickly; above 30°C, the stems and leaves grow even faster, but the tubers expand slowly. Above 38°C, respiration consumption is high and stem and leaf growth is slow; below 20°C, stem and leaf growth is also fast; at 15°C growth stops; if the temperature stays below 10°C for too long or frost occurs, the stems and leaves wither and die.
2. Light: Sweet potatoes like light. Under sufficient light, the leaves are darker in color, the leaf age is longer, the stems and vines are thick and strong, the conductive tissue of the stems is well developed, and the yield is relatively high. If light is insufficient, the leaves turn yellow, more leaves fall, the leaf age is short, the stems and vines are thin and long, the conductive tissue is poorly developed, less organic nutrition formed by assimilation is transported to the tubers, and the yield is low.
3. Water: Sweet potatoes are a drought-tolerant crop, but too much or too little water is unfavorable for increasing yield. Sweet potatoes are afraid of flooding, especially after tuber formation, when flooding has a great impact on yield. If the soil is alternately dry and wet, the internal and external growth rates of the tubers become uneven, and skin cracking often occurs. In short, sweet potatoes fear both waterlogging and drought. As people say: “Dry grows woody roots, wet grows fibrous roots, neither dry nor wet grows tubers.” To obtain high yields of sweet potatoes, irrigation should be timely and appropriate according to specific conditions, drainage should be thorough and prompt, and in dry land, cultivation and soil moisture conservation should be strengthened.
4. Nutrients: Sweet potatoes have a strong ability to absorb fertilizer and tolerate poor soil, but to achieve high yields, sufficient fertilizer must be applied. In addition to nitrogen, phosphorus, and potassium, sulfur, iron, magnesium, calcium, and others also play important roles. Among the three major elements, sweet potatoes require the most potassium, followed by nitrogen, and the least phosphorus. According to analysis, every 1000 jin of sweet potatoes contains 3.5 jin of nitrogen, 1.75 jin of phosphorus, and 5.6 jin of potassium. Therefore, increasing potassium fertilizer and applying nitrogen and phosphorus fertilizer timely and appropriately has a significant yield-increasing effect.
5. Soil: Deep soil with rich organic matter, loose texture, good aeration, and good drainage, such as sandy loam and sandy soil, is best. When the soil is heavy and clayey, the tuber skin color is poor and rough, the tuber shape is irregular, the yield is low, and it stores poorly. However, sandy loam and sandy soil generally have low fertility and poor water retention, so fertility should be gradually improved through measures such as fertilization before high yields can be obtained. Sweet potatoes are relatively tolerant of acidity and alkalinity, with a suitable pH range of about 4.5-8.5, but 5.2-6.7 is preferable. When the soil salt content exceeds 0.2%, sweet potatoes are not suitable for planting.