Asparagus is a kind of asteraceae plant, which is resistant to heat and cold and can be cultivated throughout the year. Lettuce cultivated in the autumn, with a short growth period and a supply market, has higher economic benefits. 1. Field and species selection: lettuce has a wide adaptability, shallow roots and dense, mostly distributed in 20-30cm soil layer. The cultivation requires soil PH value is neutral, fertile, drainage and irrigation is convenient; early autumn varieties have blue hanging silk, white hanging silk, spring and autumn white skin, spring and autumn green skin. 2. Nursery: early autumn cultivation sowing period of early June to early August, seedling age 20-30 days. Seeds soaked before sowing first germination, the seeds soaked in water for 12-24 hours, washed with water, and then moisturizing pregermination, seed germination and dew white 80% prevail. After 2-3 days germination can be sown. When raising the seedlings, put the clay on the surface of the car and pour the mud into the surface. Drain the surface with water and smooth it with a sand board. When the slurry is not dry, sprinkle the 1g/m2 dry seed evenly, and then use 40% Dixon. / Square water evenly sprayed the car once, can be sprinkled with a small amount of fine soil cover species. With a small arch shading nets shade rain, autumn seedlings planted early. 3. Apply base fertilizer and timely planting: (1) Apply 2500kg of organic fertilizer per acre, 23kg of urea, 17kg of ammonium phosphate and 17kg of potassium sulfate. For the long-term cultivation of vegetables in the field can use lime to spray 100kg per acre to adjust the acidity of the soil; when the preparation is done on the fine coarse, smooth and consistent. (2) Carriages: Open with 4.0m, depth 20cm, depth 30cm. (3) Apply 1500kg per hectare of farmyard fertilizer and 50kg of superphosphate before transplanting. Be sure to mix the soil with fertilizer evenly. It is more appropriate to transplant the lettuce in autumn and winter according to 43cm40cm. The depth of the ditch is 30cm, and the depth of the ditch is 20cm. When transplanting, the seedlings are transplanted with soil. It is not appropriate to plant them too deeply. 4. After planting management: (1), weeding, weeding, top dressing and water transplanting. 10-15 days, we carry out cultivating and weeding, regulate soil ventilation, temperature and humidity, and promote root growth. General spring and autumn lettuce can be 2-3 times cultivating. The lettuce planted in the spring and autumn can be seen as seed dressing, and the early growth of the seedlings is 10kg of urea plus fertilizer. (2) Prevention and control of pests and diseases. Diseases of lettuce mainly include downy mildew, sclerotinia, and soft rot, etc., and can be used alternately with agents such as Rhizoctonia, Jinleiduomier, Velosilon, chlorothalonil, etc.; Control locusts. 5. Harvesting: After harvesting flat, the harvest time is the best. However, in recent years, the market demand standards have been different. Therefore, the harvest period can be determined according to the specific circumstances.
