Kōngshān Walnuts

Kōngshān Walnuts

Kōngshān walnuts are a protected geographical indication product.

　　Kōngshān walnuts are a specialty of Kōngshān Township, Tōngjiāng County, Bāzhōng City, Sìchuān Province. They are known for their thin shells, large size, and plump kernels. In 2006, Kōngshān walnuts were certified as pollution-free food by Sìchuān Province.

　　"Tōngjiāng Kōngshān Walnuts" feature thin shells and thick flesh, rich in linoleic acid, linolenic acid, amino acids, vitamins, high oil yield, and a mellow, nutritious profile. With over 1,500 years of cultivation history in Tōngjiāng County, they now form a core production zone centered around Kōngshān Township, along with 32 demonstration bases in Nùshuǐhé Town, Tiěxī Town, Yǒng'ān Town, Liǎnghékǒu Township, Níxī Township, Yānxī Township, Hóngkǒu Town, and others. In 2012, the planted area of "Tōngjiāng Kōngshān Walnuts" reached 120,000 mu (approximately 8,000 hectares) with over 5.4 million trees, yielding 1.8 million kg annually and generating an output value of over 100 million yuan. By 2015, the county aims to expand cultivation to 200,000 mu, nurture two provincial-level leading enterprises, achieve an annual output value exceeding 200 million yuan, and increase the income of 30,000 farming households.

　　Kōngshān Township boasts vast land and abundant resources, with huge potential for developing distinctive industries. Walnut cultivation in Kōngshān has existed almost as long as human activity in the region, with the oldest surviving walnut tree over a century old. Nearly every household in the township has walnut trees, commonly found in front of homes, behind houses, and along field edges. The township has a total of 180,000 walnut trees, including 30,000 producing trees, yielding an average of 300,000 jin (150,000 kg) per year and generating 2.4 million yuan in output value.

　　Kōngshān walnuts are known for their thin shells, large size, and plump kernels. Their crude fat content reaches up to 70%, and crude protein up to 17%, with oil yield and protein content seven and three percentage points higher, respectively, than national standard elite varieties. In 2006, Kōngshān walnuts were certified as pollution-free food by Sìchuān Province.

　　The current administrative region of Tōngjiāng County, Sìchuān Province

　　"Report of Tōngjiāng County People’s Government on Delimiting the Protected Geographical Indication Area of 'Kōngshān Walnuts'," Tōng Fù Hán [2013] No. 61

　　Bāzhōng City Local Standard: DB511900/T5-2010 "Production Technical Regulations for Kōngshān Walnuts"

　　Quality and Technical Requirements for Kōngshān Walnuts

　　I. Varieties

　　Walnut varieties such as Tōng Hé 0035 and Tōng Hé 0147.

　　II. Site Conditions

　　Altitude within the production area ranges from 500m to 1,600m. The soil type is purple soil, with a sandy loam texture and a pH value of 5.5 to 7.5. The soil organic matter content is ≥1%. The annual average temperature is 12°C to 17°C, and annual rainfall ranges from 1,100mm to 1,800mm.

　　III. Cultivation Management

　　1. Seedling Cultivation: Grafting using local walnut seedlings as rootstocks.

　　2. Planting: Spring planting occurs from mid- to late March, while autumn planting takes place from late October to early November. Planting density should not exceed 330 trees per 667㎡ (1 mu).

　　3. Pruning: Adopt a central leader branching system.

　　4. Fertilization: Apply ≥25kg of well-rotted organic fertilizer per young tree annually, and ≥50kg per mature fruit-bearing tree annually.

　　5. Watering: Water once before bud break, during fruit development, before fruit maturity, and before soil freezing.

　　6. Environmental and Safety Requirements: The use of pesticides, fertilizers, and other inputs must comply with national regulations, ensuring no environmental pollution.

　　IV. Harvesting

　　Harvesting begins in mid- to late September when the green husk turns yellow, some husks crack at the top, and the inner sutures turn black.

　　V. Quality Characteristics

　　1. Sensory Characteristics: The fruit is oval or round in shape, with a relatively smooth surface and low, flat sutures. The kernel is white and plump.

　　2. Physicochemical Indicators: Average single fruit weight ≥7g, kernel rate ≥39%, crude fat content ≥63%, protein content ≥11%.

　　3. Safety and Other Quality Technical Requirements: Product safety and other quality technical requirements must comply with national regulations.