Yuanzhou Oil Flax

Yuanzhou Oil Flax

Yuanzhou Oil Flax is a product certified under the Agricultural Products Geographical Indication program.

　　Geographical Scope

　　Yuanzhou District of Guyuan City is situated in the western part of China’s Loess Plateau, at the eastern foothills of the Liupan Mountains. It neighbors Huan County and Zhenyuan County of Gansu Province to the east; Pingliang City of Gansu Province and Jingyuan County and Longde County of Ningxia to the south; Xiji County and Haiyuan County to the west; and Tongxin County to the north. The region spans between 105°58′ and 106°30′ east longitude and 35°34′ and 36°38′ north latitude. Covering an area of 3,505.9 square kilometers, it has approximately 120,666.7 hectares of arable land, with a total production area of 6,700 hectares and an annual output of 6,000 metric tons.

　　Natural Ecological Environment and Humanistic Historical Factors

　　(1) Soil and Topography: The terrain features a complex and diverse landscape, with black loam and sandy loam as the main soil types, having a pH of around 7.8. These soils contain 1.0–1.5% organic matter, 0.021–0.111% total nitrogen, 0.10–0.215% total phosphorus, and 2.19–2.53% total potassium.

　　(2) Hydrology: The main river within Yuanzhou District is the Qingshui River, a tributary of the Yellow River. It originates from Heicigou Nao in Kaicheng Town of Yuanzhou District, flows from south to north through towns such as Yuanzhou and Sanying, and exits at Gaoya in Qiyi Town before entering the Yellow River via Tongxin and Zhongning. The upstream section of the Qingshui River, from Kaicheng to the Guyuan County urban area, has a mineral content of 0.7 grams per liter, classifying it as fresh water; this increases to 2.6 grams per liter in Sanying and 6 grams per liter in Qiyi.

　　(3) Climate: The area has a temperate semi-arid climate, with elevations ranging from 1,470 to 2,920 meters. The average annual temperature ranges from 5.7°C to 7.5°C, the accumulated temperature above 10°C is 2,160°C to 2,560°C, the frost-free period is 135–160 days, and the annual sunshine duration is 2,400–2,600 hours. Annual rainfall ranges from 350 to 650 mm. Precipitation is influenced by topography, decreasing gradually from south to north as elevation drops, with a north–south difference of up to 300 mm. The main oil flax production areas are located in the eastern arid zone and the northern…

　　…plain region.

　　(4) Humanistic and Historical Background: In ancient times, Yuanzhou was primarily a pastoral area. Since the mid-Ming Dynasty, due to border defense and land reclamation efforts, the population grew rapidly and cultivation expanded. From the late Qing Dynasty onward, crop farming expanded quickly while animal husbandry declined. Oil flax cultivation in Yuanzhou has a history of nearly 2,000 years. As an edible oil, oil flax is favored for its premium quality and pleasant taste, and is especially popular among people in northwestern and northern China.

　　Production Technical Requirements

　　(1) Site Selection: The crop should be planted in fields previously used for wheat, legumes, or vegetables, and potato stubble should be avoided. Crop rotation should be maintained for at least three years. Before planting, selected fields must undergo timely deep plowing after the previous crop is harvested to improve soil structure. Fields should be harrowed promptly at Bailu (a traditional solar term), and compacted during winter and spring to conserve moisture, thus ensuring optimal soil conditions for sowing and seedling emergence.

　　(2) Variety Selection: For dryland farming, varieties include Ningya 10 and Ningya 14; for irrigated land, recommended varieties are Ningya 17, Ningya 11, Ningya 16, and Longya 8.

　　(3) Production Process Management, Including Special Regulations on Agricultural Inputs: Timely Sowing: Planting is generally carried out around the Qingming Festival in April. In irrigated fields, mechanical seeding is used, while ridge sowing is applied on tableland. Seeding rates are 150–225 kg per hectare for irrigated fields and 60–75 kg per hectare for dryland.

　　Field Management:

　　① Ensuring Full Emergence: At sowing, the field must be finely prepared so that the topsoil is loose and the subsoil is firm. After sowing, the soil should be compacted once when it is not sticky, or immediately if moisture is poor—this is crucial for seedling emergence. If rain falls after sowing and seedlings have not yet emerged, causing crust formation, use a rake to break the crust horizontally to prevent seedling yellowing and failed emergence.

　　② Hoeing and Weeding: Ensure good soil moisture and keep the field clean and free of weeds. First hoeing is done when seedlings reach 6–9 cm; second hoeing is performed at 12–15 cm.

　　③ Fertilization and Irrigation Management: The first irrigation takes place 30 days after seedling emergence (around May 20), with 75–150 kg of urea per hectare applied along with the water. The second irrigation is during the bud stage (late May to early June), and a third may be needed during grain formation in extremely dry conditions. In dryland areas, urea is applied at 60 kg per hectare depending on rainfall during this period.

　　Rational Fertilization:

　　Fertilization methods combine base fertilizer and supplemental fertilizer, using inorganic fertilizers to enhance organic content, improve poor soils, and regulate water use. Increased fertilization is key to balanced yield improvement of flax. The primary method is autumn application. Typically, autumn-applied manure is 15,000 kg per hectare for dryland, along with 255 kg of ammonium bicarbonate and 240 kg of single superphosphate; for irrigated land, it’s 45,000 kg manure, 402 kg single superphosphate, and 426 kg ammonium bicarbonate. In fields where autumn fertilization isn’t applied, fertilize before sowing.

　　Pest and Disease Control:

　　The most common diseases in our area are wilt and damping-off, while pests include darkling beetles. General agricultural practices for disease and pest management include crop rotation for over three years, deep plowing and sunning, removal of infected plants, and selection of resistant varieties.

　　(4) Timely Harvesting: Oil flax should be harvested when the upper leaves turn yellow and wither, lower leaves have fallen, 75% of the seed capsules have turned yellow, and the seeds have hardened. Harvesting too early leads to insufficient maturity and reduced yield, while harvesting too late can cause seed capsules to burst and seed coats to thicken, lowering oil yield.

　　(5) Production Record Requirements: Accurately and truthfully document the entire production process of oil flax from site selection to harvest.

　　Product Typical Quality Characteristics and Safety Standards

　　(1) External Sensory Characteristics: Oil flax (Linum usitatissimum) belongs to the Linaceae family and Linum genus. It is an annual or perennial herbaceous plant. There are about 15 species and subspecies cultivated worldwide, but the most widely grown is the common flax variety (Linum usitatissimum), which includes five widely cultivated variants: oil-type, oil-and-fiber type, fiber-type, large-seed type, and semi-winter multi-stem prostrate type. In our region, the oil-type flax is cultivated, with main varieties being Ningya 17, Ningya 10, Ningya 11, and Ningya 16. It is widely planted in the dry plateau areas and northern irrigated plains, making it one of the main oil crops in the region. Flaxseeds are flat and oval-shaped, glossy, and come in colors such as yellow, white, brown, and tan.

　　(2) Internal Quality Indicators: The seeds and fibers of oil flax have high economic value, and their by-products are also widely useful. Oil flax seeds typically contain 35–40% oil, with some reaching over 45%. The oil is of premium quality, flavorful, and a staple cooking oil in northwestern and northern China.

　　(2) Internal quality indicators: The seeds and fibers of oil flax have high economic value, and its by-products also have many uses. Oil flax seeds generally contain 35-40% oil, with a maximum of over 45%. Oil flax oil is of excellent quality, fragrant and delicious, and is a staple cooking oil for people in the northwest and north China regions.

　　Linseed oil contains a high proportion of unsaturated fatty acids and has a very high iodine value. It easily oxidizes and dries upon exposure to air, making it an excellent drying oil with a wide range of industrial applications in paints, inks, coatings, leather, rubber, and more. The seed coat of oil flax contains 6–10% linseed gum, which serves as a good adhesive and is widely used in tanning, food processing, medicine, national defense, and other fields.

　　Oil flax is an important green food resource for improving people's living standards and health. Oil flax oil is a high-grade edible oil, containing 16.7% linoleic acid, 40–60% alpha-linolenic acid, along with 18 essential amino acids, three vitamins (A, E, B1), eight trace elements, dietary fiber, and more. After oil extraction, the remaining cake and meal have a protein content of 33.3%, fat content of 8.6%, 31.7% nitrogen-free extractives, and 7.8% cellulose, making them suitable as livestock feed and important raw materials for producing compound feed. The cake and meal also contain the three nutrients—nitrogen, phosphorus, and potassium—and can be turned into high-quality organic fertilizer for crops after composting and fermentation. Dual-purpose oil and fiber varieties of oil flax can produce fibers from their stalks, typically yielding 12–15% fiber. The leftover fiber scraps can be compressed into fiberboard as a wood substitute. The remaining stalks and waste fibers are also excellent raw materials for papermaking. The shells and shriveled seeds left after threshing, commonly known as "oil flax husks," can be used as pig feed.

　　The health-promoting active component in oil flax oil is alpha-linolenic acid, which accounts for about 45% of the fatty acid composition in oil flax seeds. Research has shown that alpha-linolenic acid can be converted in the human liver, under the action of desaturase and elongase enzymes, into eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

　　This means that alpha-linolenic acid is not only one of the omega-3 fatty acids but also the precursor to the other two members of the omega-3 family, EPA and DHA. Therefore, if the body lacks omega-3 fatty acids, one can either directly supplement with EPA and DHA or obtain them by consuming oil flax oil.

　　(3) Safety Requirements: Following the principle of “prevention first, integrated control,” comprehensive physical, agricultural, and biological pest control measures should be employed to minimize the use of chemical pesticides. The use of highly toxic and high-residue chemical pesticides must be strictly prohibited. Attention must be paid to the type, dosage, timing, target, and safety interval of pesticide use to ensure that chemical pesticide residues do not exceed standards. Pesticides recommended by the National Agro-Tech Extension and Service Center for use in the production of pollution-free agricultural products should be selected. Chemical pesticides should be used scientifically and rationally, with strict control over residue levels and adherence to safe usage intervals. Products from this origin are subject to spot checks by household and location. Sampled products are packaged in plastic bags and transported to qualified quality inspection departments, where they are tested according to the NY5306-2005 standard “Pollution-Free Food Edible Vegetable Oil.” The production environment must comply with the “Pollution-Free Food Origin Environment Evaluation Criteria” (NY/T5295-2004) and the “Pollution-Free Food Vegetable Origin Environmental Conditions” (NY/T5010-2002) standards.

　　Packaging, labeling, and related regulations

　　(1) Grading: Grade 1: Oil content (based on standard moisture and impurities) 36.0%, moisture 9.0%, impurities 3.0%, normal color and odor. Grade 2: Oil content (based on standard moisture and impurities) 35.0%, moisture 9.0%, impurities 4.0%, normal color and odor. Grade 3: Oil content (based on standard moisture and impurities) 34.0%, moisture 9.0%, impurities 5.0%, normal color and odor.

　　(2) Packaging: When using gunny bags for packaging, requirements of GB8115 must be met. Each package must contain the same variety, quality, and grade. Packaging containers should meet hygiene standards, being clean, dry, non-toxic, and odorless, and must be suitable for transportation and storage.

　　(3) Labeling: Comply with the regulations for marking geographical indications of agricultural products. Additionally, product labels should be printed, affixed, or hung on the outside of the packaging. Labels should be clear, not easily detached or faded, and must include the following information:

　　— Name and variety of the geographical indication of the agricultural product;

　　— Place of origin, producer’s name, address, and trademark;

　　— Packaging specifications, net weight, and grade;

　　— Packaging date and quality inspector code.

　　(4) Storage: Linseed storage shall comply with the regulations set forth in the “Grain and Oil Storage Technical Specifications” issued by the former Ministry of Commerce of the People’s Republic of China.

　　(5) Transportation: Linseed transportation shall comply with the regulations regarding “Issues Concerning the Implementation of National Grain and Oil Standards” in the grain and oil transport guidelines of the former Ministry of Commerce of the People’s Republic of China. Transport vehicles should be clean and hygienic, equipped with rainproof and ventilation facilities.