Wanyuan Potatoes

Wanyuan Potatoes

Wanyuan Potatoes are a product with a geographical indication for agricultural products.

　　Wanyuan Potatoes

　　“Early in the morning, wearing a straw hat, carrying a hoe, and a bamboo basket on the back, they head up the mountain. Upon reaching the field, they gently hook upwards with the hoe, and out roll one after another ‘golden eggs’ — round, plump, and even bigger than goose eggs — tumbling down the hillside...” This isn’t a legend, but the actual harvest scene of Wanyuan potatoes. The terrain of Wanyuan City is mostly mountainous with few flatlands, and most of the land lies on steep high mountains. Coupled with backward farming methods in earlier years, it was not uncommon to see potatoes rolling all over the hillsides once dug up.

　　Wanyuan potatoes are not only large and tasty, but also rich in the essential trace element selenium, making them highly popular. In May 2009, Wanyuan potatoes were awarded the "Agricultural Product Geographical Indication Registration Certificate" by the Ministry of Agriculture and given a new name — Wanyuan Potatoes — becoming a nationally renowned local specialty. So why have these small Wanyuan potatoes garnered such worldwide attention? Let’s take a look —

　　The “Golden Eggs” Dug from the Mountain Valleys

　　In Dazhou, potatoes are also called yangyu. The character yang means foreign or imported, implying novelty and surprise — a testament to how much people love potatoes. People in Dazhou love potatoes — they stir-fry potato strips, deep-fry mashed potatoes, and boil potato slice soup. But the people of Wanyuan love potatoes even more: not only are there potatoes in their soups and meals, but when hungry, they simply boil a few potatoes. No seasonings are needed for a satisfying meal.

　　Wanyuan features high mountains, steep slopes, shallow soil layers, and a distinct alpine climate — not ideal farming conditions. Yet it is precisely these conditions that are perfect for potato growth. Around December each year, farmers carry hoes up the mountain, dig small pits in the fields, sprinkle some grass ash, drop in seed potatoes, cover them with soil, and the planting process is complete. Maintenance is also very simple — aside from occasionally watering during severe droughts, almost no other work is needed. By May or June the following year, the potato fields are dotted with little mounds of earth. A hoe strike reveals big, plump potatoes — a heartwarming sight.

　　Unlike ordinary potatoes, Wanyuan potatoes have a smooth texture, mildly sweet without being cloying. Anyone who has been to Wanyuan is bound to be impressed. In restaurants across Wanyuan, dishes like stir-fried potato strips, fried potatoes, and steamed potatoes can be found on almost every menu. There’s a saying in Wanyuan: “No potatoes, no restaurant!” Potatoes may never be the main dish here, but they are absolutely indispensable.

　　“Delicious, so tasty!” Everyone who tries Wanyuan potatoes gives them rave reviews. Great taste is the hallmark of Wanyuan potatoes, and scientific research also shows that eating them regularly is very good for your health. Data shows that the selenium content in the soil across Wanyuan ranges from a maximum of 1.74 μg/g to an average of 0.51 μg/g, classifying it as medium to high in selenium — easy for plants to absorb and beneficial to humans. Selenium is one of the most important trace elements required by the human body; a deficiency can lead to organ dysfunction and many serious diseases. Scientific analysis confirms that Wanyuan potatoes are rich in selenium, hence earning the nickname “gold in grain.”

　　Generations of Potato Farmers in Wanyuan

　　Wanyuan has a long history of potato cultivation. According to some veteran experts, before the name “Wanyuan” even existed, Wanyuan potatoes were already somewhat famous in the Qinba region. This shows that the exceptional quality of Wanyuan potatoes is not only due to the area’s unique geographical conditions, but also inseparable from the careful nurturing by generations of hardworking Wanyuan people.

　　Geographical Scope

　　Wanyuan is located on the northeastern edge of the Sichuan Basin, at the junction of Sichuan, Shaanxi, and Chongqing (three provinces/cities), in the heart of the southern foothills of the Daba Mountains, between 107°29′–108°31′ east longitude and 31°39′–32°20′ north latitude. It borders Chengkou County of Chongqing to the east, Xuanhan County to the south, Pingchang and Tongjiang counties to the west, and Zhenba and Ziyang counties of Shaanxi to the north. Wanyuan City is 146 km south of Dazhou City and 71 km north of Zhenba County in Shaanxi. The Xiangyu Railway, National Highway 210 (Baonan Road), and the East Sichuan Power Grid run through the city. It serves as a major passage and gateway in and out of Sichuan, a vital transportation hub between Sichuan and Shaanxi, known as the “Lock and Key of Qinchuan,” and enjoys the reputation of being the “Source of Myriad Treasures.” The city covers an area of 4,065 square kilometers, and the protected area for Wanyuan Potatoes includes 12 towns, 40 townships, 373 villages, and 2,480 production teams.

　　Natural Ecological Environment and Humanistic Historical Factors

　　(1) Soil and Topography: Wanyuan features overlapping mountains, crisscrossing valleys, and great elevation differences, with relative heights reaching up to 2,000 meters. Most areas lie between 600–1,400 meters above sea level, accounting for 83% of the total area. The terrain slopes from northeast to southwest, and the landforms are mainly mountainous. The city has 605,000 mu of cultivated land, including 193,000 mu of paddy fields. The soil varies with deep hills, low, medium, and high mountains, with more tableland and terraces in the southwest and deeply dissected single-slope mountains in the northeast, showing clear regional differences.

　　Wanyuan’s soils are mostly dry gooseback soils developed from marine sedimentary siliceous cemented rocks, with relatively high fertility levels, slightly acidic, rich in organic matter. It is one of China’s three major selenium-rich regions, with large amounts of water-soluble, exchangeable, and organic selenium, close to the critical value of water-soluble selenium in China’s ecological landscape soils. The soil also

　　contains trace elements such as zinc and copper.

　　Soils are divided into 6 soil types, 13 subtypes, 29 soil genera, 64 soil species, and 88 soil varieties based on soil-forming conditions, processes, physicochemical properties, and productivity. Among them, paddy soil accounts for 38.6%, purple soil 23.8%, fluvo-aquic soil 0.4%, yellow soil 25.3%, mountain yellow soil 1.4%, and limestone soil 10.5%. The soil pH ranges from 6.5–7.5, organic matter content from 1.68–3.73%, total N from 0.96–1.72%, alkali-hydrolyzable N from 92–190 ppm, total P from 0.098–0.124%, available P from 3.4–5.7 ppm, total K from 1.11–1.72%, available K from 78–148 ppm, and selenium from 0.5–12 ppm.

　　(2) Hydrological Conditions: Wanyuan is located in the upper reaches of the Yangtze River and is known as the “Source of Ten Thousand Waters.” Major rivers within the area include Zhonghe, Houhe, Qinhe, Xishenhe, Xiaokouhe, Renhe, and Baishahe, belonging to the Qujiang and Hanjiang river systems. There are 52 rivers in the city with catchment areas over 20 km, and surface runoff amounts to 2.92

　　billion cubic meters. The city’s total water resources amount to 3.142 billion cubic meters.

　　(3) Climatic Conditions: Wanyuan has a northern subtropical humid monsoon climate, with mild weather, distinct seasons, abundant rainfall, a long frost-free period, and significant vertical climatic variations. The annual average temperature is 14.7°C, with extreme

　　maximum temperatures reaching 39.7°C and minimums dropping to -9.4°C. The annual effective accumulated temperature is 4,534°C, and the large diurnal temperature variation aids the accumulation of dry matter in potatoes. The average annual rainfall is 1,246 mm, the frost-free period lasts 236.8 days, and sunshine hours total 1,474.4 hours. During the potato growing season, sunlight reaches 15 MJ/m², creating favorable light conditions especially conducive to potato growth.

　　(4) Humanistic and Historical Background: Wanyuan is a land of revolution. In 1929, revolutionary martyr Li Jiajun led the earthshaking Gujianba Uprising, establishing Sichuan’s earliest revolutionary armed force — the First Route Guerrilla of the Sichuan Workers’ and Peasants’ Red Army. From 1932 to 1935, revolutionary leaders including the First Red Army (Note: likely referring to key figures such as Xu Xiangqian, Zhang Guotao, and Liu Bocheng, though not explicitly named here) led the Fourth Front Army westward into Sichuan. They fought the “Battle of Wanyuan” — described as the “largest in scale, longest in duration, fiercest in combat, and most glorious in achievements” in the history of the Fourth Front Army. This was a major event in modern Chinese history and a milestone in the revolutionary history of our Party and Army. Nearly 300 participating soldiers later became generals and marshals of the People’s Republic. During the grueling Battle of Wanyuan, potatoes served as a staple food for the Red Army, making an outstanding contribution to defending Wanyuan.

　　Wanyuan City has long been a traditional agricultural county. Due to its geographic location and climatic characteristics, local farmers have a long history of potato cultivation, with scattered household planting dating back to the late Qing Dynasty. Planting expanded significantly during the Republican era, gradually forming representative local varieties such as Mila, Taibai, Manyangyu, Dawuyangyu, Dayanpi, Hongkeng, Wanbulan, Bashanbai, and nearly thirty others. After the founding of the PRC, farmers began switching varieties from high to low mountain areas. In the 1970s, varieties such as Malke, Wushanyangyu, and Northeastern potatoes were introduced from the northeast and Wanzhou for variety replacement and propagation. In 1976, the Wanyuan County Agricultural Science Institute was established. In 1977, under the unified arrangement of the Provincial Science Commission, the Crop Cultivation Institute of the Provincial Academy of Agricultural Sciences promoted virus-free potato seed cultivation and breeding techniques across the northern Sichuan basin-mountainous region and Gan-A-Liang areas. The county institute then conducted related scientific experiments, performing virus-free meristem tip micropropagation in the lab and cultivating virus-free plantlets in test tubes. Starting in 1998, virus-free potato varieties were introduced for extensive trials, demonstrations, high-yield breakthroughs, and large-scale promotion. Virus-free potatoes gradually replaced the heavily degenerated, low-yield local varieties used for many years. Currently, the main promoted varieties include Atlantic, Favorita, Early White, Kexin No.1, Qinyu No.30, Bashu No.10, Eshu No.3, Eshu No.5, Chuyu Early, Chuyu No.56, and other early-, mid-, and late-season series for both culinary and processing purposes. Through years of cultivation, the city has developed and promoted a range of high-yield cultivation techniques focusing on potato planting and integrated pest management, cultivated numerous high-yield models and science demonstration sites (areas), accumulated rich scientific cultivation experience, and formed a comprehensive

　　and well-established cultivation system. In 1999, the Agriculture Bureau conducted a virus-free potato high-yield trial in Tianchiba Village, Batai Township, and achieved a yield of 3,636.5 kg per mu upon expert measurement — setting the highest single yield record for potatoes in the mountainous areas around the Sichuan Basin. In 2000, a similar trial in Jujiaba Village, Taiping Town, reached 4,230.3 kg per mu — the highest yield record for potatoes in all of Sichuan. In 2008, during the provincial grain and oil high-yield creation campaign, the highest net plot yield of potatoes in our city reached 4,931 kg per mu, with an average yield of 4,657.5 kg per mu — once again breaking the provincial record. The application of new technologies earned recognition and praise from potato experts at the Provincial Department of Agriculture.