Detailed Explanation of High-Yield and High-Quality Safflower Cultivation Techniques
Safflower, also known as grass safflower, is an annual or perennial plant of the Asteraceae family. It is mainly produced in Henan, Shandong, Sichuan, ** and other provinces, and can be grown in most parts of the country. Its flowers are used medicinally, with effects such as promoting blood circulation and regulating menstruation, removing blood stasis, reducing swelling and relieving pain. It is also a widely used natural pigment and dye today. The seeds produced after harvesting the safflower medicinal material have an oil content of over 30%, and the processed safflower seed oil is an important industrial raw material.
I. Selection of Plots
1. Soil selection: Neutral loam or light clay soil with a pH value between 6.5—8.5 should be selected for planting. If the soil is too sandy, its water and fertilizer retention capacity is poor, the nutrients needed cannot meet the growth requirements, the plants grow weak and spindly, and diseases are severe in the later stage. The resulting flower heads are small, the safflower seeds are shriveled and thin, and the plants are prone to lodging in the later growth stage, resulting in low yield and poor quality. If the soil is too heavy or is heavily saline-alkaline (pH value greater than 8.5), it has poor aeration and water permeability, a dense structure, and is prone to soil compaction. Nitrogen metabolism and protein synthesis cannot proceed normally, and harmful substances decomposed in the soil cannot be discharged in time, significantly inhibiting root growth and, in severe cases, causing the death of safflower plants.
2. Selection of terrain: Terrain refers to the elevation and slope of the plot location, including mountainous land, hilly land and flat land. The terrain for planting safflower should be high and dry, with no water accumulation. For mountainous land, low mountains with abundant sunlight on sunny slopes or semi-sunny slopes should be selected; for hilly plots, the slope should not be too steep, generally not exceeding 20 degrees; for flat land, there should be unobstructed drainage facilities, and high beds should be made for planting, with drainage ditches dug around the perimeter or in the middle of the plot to ensure that no water accumulates after heavy rain.
3. No continuous cropping: The preceding crop in the plot for planting safflower should preferably be a legume or grass crop, and a crop rotation system of more than three years should be implemented. This deprives certain pests and diseases of host conditions, thereby economically and effectively suppressing or reducing the damage of certain pests and diseases to safflower plants, lowering production costs and labor investment, and laying a good foundation for high quality and high yield.
II. Timely Sowing
Because the entire growth period of safflower (140 days) has different requirements for temperature, light, moisture and other environmental conditions, the most suitable sowing time should be selected according to the patterns of climate change throughout the year in the planting region and the biological characteristics of safflower.
1. In terms of temperature, safflower seeds can germinate above 5 degrees; the most suitable temperature for the vegetative growth stage is 15—20 degrees, and the best for the reproductive growth stage is 20—28 degrees.
2. In terms of sunlight, during the vegetative growth stage, short-day conditions are favorable for plant development; while entering the flowering and seed-setting stage, longer-day conditions can promote flower head enlargement and full seed formation, thereby achieving a high yield.
3. In terms of moisture, because safflower has a well-developed root system, apart from the seedling stage and flower bud formation stage which require a certain amount of moisture, there are no strict moisture requirements in other stages. Based on the above three main biological characteristics of safflower, autumn sowing is most suitable in North China, with the sowing time around the Autumn Equinox to Frost's Descent; in areas south of the Yangtze River and in the ** northwest region, either autumn or spring sowing is acceptable. Sowing method: For small-area planting, hole sowing can be adopted. After applying fertilizer and harrowing the soil fine and even, dig holes 5 cm deep at a row spacing of 35—40 cm and a plant spacing of 25 cm, sow 5—6 safflower seeds per hole, cover with soil, and lightly press. If conditions permit, mechanical sowing can be implemented, with the same row spacing as hole sowing. Use 3—5 kg of seeds per mu.
III. Field Management
1. Thinning and replanting: When seedlings have 3 true leaves, keep 1 strong seedling every 10 cm; when seedlings grow to 8 cm tall, keep one seedling every 15—20 cm, and for hole sowing, keep 2 strong seedlings per hole. Fill in gaps where seedlings are missing with the strong seedlings removed during thinning.
2. Cultivation and weeding: In the early growth stage, carry out shallow cultivation 1—2 times to break up compaction, loosen the soil and raise soil temperature. Along with cultivation, carry out appropriate hilling to prevent lodging. After the plants close the rows, cultivation is no longer necessary.
3. Topping and topdressing: After final thinning in early spring, apply 10 kg of urea per mu; after the plants bolt and branch but before row closure, apply 50 kg of nitrogen fertilizer and 25 kg each of phosphorus and potassium fertilizer per mu. At the same time, carry out topping to promote more branching and more flower buds, increasing yield.
IV. Harvesting and Processing
In mid-to-late May, safflower begins to bloom one after another, and enters full bloom two days later. Harvest in the morning—before 10 a.m., when the top of the safflower flower head turns from yellow to red. This continues for 15—20 days until harvesting is complete. The freshly harvested safflower should be spread flat and thin on reed mats and dried in a ventilated place in the shade, or covered with newspaper and dried in the sun, or dried at 50 degrees, but note that it must not be stirred during the drying process. Twenty days after the safflower harvest is complete, when the stems and leaves wither, the plants can be cut and the seeds threshed.
V. Advantages of Growing Safflower:
(1) Short time (autumn sowing and summer harvest, same as wheat).
(2) Extensive sowing and management (mechanical sowing, simple management).
(3) Low soil requirements and relatively simple techniques.
(4) Stable yield and good returns.
(5) Broad market prospects.