Sorghum is the fifth largest cereal crop and the fourth largest food crop in the world. It has unique drought resistance, waterlogging tolerance, and salt-alkali tolerance. It has high and stable yields and is known as the "iron stalk crop." The main functions are food, feed, brewing, broom making, sugar making and new energy.
1. Variety Selection
The sorghum varieties in Jilin Province are mainly spring sown in the early maturity period (110-128 days). Brewing type: including Si Za 25, Ji Za 123, Ji Za 118, Ji Za 124, Ji Za 127, Ji Za 138, Ji Za 218, Ji Za 319, Ji Za 356, etc.; edible type: including Ji Za 305, Ji Za Za 307, Ji Za 130; feed type: including Ji Cao 1; energy type: Ji Tian 1, Ji Tian Za 1. At present, the level of sorghum cultivation technology in our province is relatively low, and most of it is located in low-lying land and saline-alkali land, with poor soil and extensive field management. Most of the crops are red sorghum grown for brewing, and 80% of the annual output is supplied to the southern wine industry.
2. Preparation before sowing
1. Select the land. Sorghum has wide adaptability and strong tolerance to barrenness, and can obtain better harvests when arranged as the following crop of a variety of crops. However, there are obvious differences in the yield of different previous crops. Soybeans are used as the first crop, and sorghum can greatly increase production, followed by corn, peanuts, sweet potatoes, potatoes and other crops. Sorghum should be grown in black soil with flat land and high soil fertility.
2. Land preparation and crop rotation. Plots planted with sorghum should generally be plowed in autumn and harrowed in spring. The plowing in autumn should be deep, with a depth of more than 35 centimeters. Spring harrowing should be determined according to different soil conditions. If it is saline-alkali land, in order to reduce alkali return, no harrowing is required. It is best to adopt crop rotation in sorghum fields. Repeated cropping and early cropping will result in aggravation of diseases and insect pests, especially smut, one of the main diseases of sorghum.
3. Selection. In regular stores or seed stores, choose seeds with plump seeds, consistent grain shape, bright and shiny colors, and no insect bites. The seed germination rate must reach the national standard of 80%. Seeds should be selected as needed and varieties should be matched.
4. Seed treatment. If possible, use sorghum seed coating agent to coat the seeds, which can not only resist low temperature damage, but also prevent underground pests. Before sowing, it is best to dry the seeds in sufficient sunlight for 3-4 days to improve the seeds' resistance to diseases and insect pests. Prevention and control of sorghum head smut should be carried out at the same time as seed treatment, and pesticide seed dressing can be used. Use 2g of 25% triadimefon wettable powder to mix 1kg of sorghum seeds, or 35g of 50% carboxil powder to mix 5kg of seeds, and sow after seed dressing.
3. Sowing technology
1. Sow seeds at the right time. The sowing temperature requirements for sorghum are higher than those for corn and soybeans, and the ground temperature in the soil layer 5cm below the surface is required to be continuously stable above 12°C. Sowing is done in early May every year in the central region of Jilin Province. Sow seeds in Baicheng, Songyuan and other places in the western region in mid-May, and sow them early at the right time. The sowing rate of sorghum should be no less than 25 pounds per hectare. Under the current production conditions and the characteristics of sorghum seeds, sorghum in Jilin Province is not suitable for precision sowing. Sowing depth is 3-4 cm. When the soil moisture is poor, the bottom grid should be stepped on and suppressed in time after sowing.
4. Seedling preservation technology
The drought in the central and western parts of Jilin Province is severe, and seedling preservation has always been a major problem. In recent years, sorghum land destruction and blindness occur every year and are becoming increasingly serious. The main seedling preservation technologies include: using advanced technologies such as mechanized sowing, one-stop water seedling preservation technology, etc., to increase the seeding amount, ensure the seed germination rate, timely sowing, and ensure the sowing quality. The density of sorghum seedlings is related to variety characteristics, soil fertility, cultivation and management level, and planting methods. Generally, early-maturing varieties with compact plant type, narrow and short leaves, resistance to lodging, and medium-dwarf stalks should be planted densely; otherwise, they should be planted sparsely. At present, the seedling density of main varieties in our province is between 90,000 and 120,000 plants/hectare. Use a seed coating agent containing carbofuran (also known as carbofuran or Dafunong) or 50 ml of 40% isosulfate EC and 5kg-6kg of water for seed dressing (mix 50kg-60kg of seeds), which can effectively prevent and control the seedling stage. Underground pests include mole crickets, grubs, cutworms, etc.
5. Fertilization technology
Sorghum is resistant to barrenness, but requires more fertilizer. Generally, sorghum requires 3.25±1.37kg of nitrogen, 1.68±0.48kg of phosphorus and 4.54±1.14kg of potassium to produce 100kg of grains. The ratio of the three is approximately 1:0.52:1.37. The nitrogen absorbed during the seedling stage is 12.4%, phosphorus is 6.5%, and potassium is 7.5%; the nitrogen absorbed from jointing to heading and flowering is 62.5%, phosphorus 52.9%, and potassium 65.4%; the nitrogen absorbed from flowering to maturity is 25.1% and phosphorus 40.6 %, potassium 27.1%.
It is best to apply organic fertilizer as base fertilizer, 2-3 tons per acre. It is better to choose compound fertilizer with higher phosphorus content (12-18-15) as seed fertilizer. Generally, 250-350 kilograms of compound fertilizer per hectare can be applied as seed fertilizer.
6. Main field management techniques
1. Chemical weeding. The first is pre-emergence closed weeding, using 38% atrazine suspending agent 1710-2280 g/ha + 96% metolachlor 1152-1440 g/ha or 50% dibutyl atrazine suspending agent 1500-2250 active ingredients g/ha (the upper and lower limits of dosage are determined by the soil organic matter content). The second is post-emergence weeding. At the 3-6 leaf stage of sorghum, use 38% atrazine SC1008g + 50% quinclorac WP30g for stem and leaf spray treatment or use 38% atrazine SC1008g + 20% chlorofluoride than oxygen Spray treatment of stems and leaves with 180 grams of isooctyl acetate.
2. Plant closely and reasonably. Thinning the seedlings at the 3-4 leaf stage, and then setting the seedlings at the 6-7 leaf stage. Density varies by variety, with medium-stem varieties generally ranging from 110,000 to 120,000 plants/ha, and high-stem varieties from 90,000 to 100,000 plants/ha. It should not be too dense. If the temperature difference between day and night is small, nighttime respiration will be strong, which will consume nutrients and reduce the yield.
3. Fertilizer and water management. Top dressing during the jointing stage is mainly nitrogen fertilizer. Topdressing on joints can increase the number of third-level branches and stems (number of grains per ear) and increase yield. If possible, water can be irrigated once during the jointing and booting stage to prevent neck drought. Top dressing should be carried out when the sorghum has 9-10 leaves. Apply 250 kg of urea per hectare and add 30 kg of potassium fertilizer. The depth of top dressing should be about 8cm.
4. Cultivating. Sorghum is generally shoveled twice during the seedling stage. The first time can be carried out after the emergence of seedlings combined with the planting of seedlings, with shallow shoveling and fine plowing, and deep tilling until the bottom layer of the plow is free of soil to avoid crushing the seedlings and loosening the soil layer in the furrow; during the jointing stage, the second cultivating can be carried out in combination with top dressing. When the roots have not yet reached between the rows, you can shovel deeply to loosen the soil, and bring a small amount of soil with you when you walk on the ground, so as to suppress the grass but not the seedlings. At this time, the cultivating should be deep, which can be less than 10 cm. Cultivating should be carried out in conjunction with soil cultivation to promote early and rapid root growth and enhance the ability to resist wind, lodging, drought and retain water and moisture in the soil.