The Ministry of Agriculture issued technical guidance on wheat planting in autumn and winter in 2014 and 2015.

Wheat expert guidance Group of the Ministry of Agriculture

National Agricultural Technology extension Service Center

This year, the yield of winter wheat continued to increase, and the per unit yield increased significantly, the highest increase in recent years. At a high starting point, to maintain the stable development momentum of winter wheat next year, we need to start from autumn and winter, and pay close attention to the implementation of key technical measures. The meteorological department predicts that affected by the El Nino event, the precipitation in autumn and winter in the northern winter wheat area is less, the temperature is generally high, and continuous autumn and winter droughts may occur in some areas, which is disadvantageous to timely sowing and safe overwintering of winter wheat. In order to effectively improve the sowing quality of winter wheat and consolidate the foundation for a bumper harvest of summer grain next year, the wheat expert guidance group of the Ministry of Agriculture, together with the National Agricultural Technology extension Service Center, put forward technical guidance on wheat planting in autumn and winter in 2014 and 2015.

1. Huang-Huai and northern winter wheat area

This area includes Hebei, Shandong, Henan, northern Jiangsu, northern Anhui, south-central Shanxi and Guanzhong, Shaanxi. It is the largest winter wheat producing area in China. This area has good production conditions, rich in light and heat resources, annual precipitation of 400-900 mm, flat terrain and fertile soil. The planting system is mainly wheat and corn cropping twice a year. Wheat is sown in the first and middle of October and harvested from the end of May to the first and middle of June. The main factors affecting wheat production are shortage of water resources, frequent natural disasters such as drought, freezing injury, dry and hot wind, and serious damage to stripe rust, sheath blight, powdery mildew and scab. The key management points of wheat sowing in autumn and before winter in this area include the following aspects:

(1) preparation before broadcast

1. Selection of varieties. Suitable varieties are selected according to local climate, soil, soil fertility, planting system, yield level, diseases and insect pests and so on. One is the selection of seeds due to heaven. According to the temperature conditions, winter and semi-winter varieties are selected, cross-regional planting and selection of unapproved varieties are strictly prohibited, winter varieties are strictly selected in the northern winter wheat region, and winter semi-winter varieties are selected in Huang-Huai winter wheat area. The second is the selection of seeds because of the land. Fertilizer-resistant and lodging-resistant varieties with high yield potential were selected in high-yield fields with good fertilizer and water conditions. Drought-tolerant, water-saving and stable yield varieties were selected in water shortage areas. Drought-resistant and barren-tolerant varieties were selected in dry and thin land. Drought-resistant and fertilizer-tolerant varieties were selected in the dry and fertile land with thicker soil layer and higher fertility. Third, seed selection due to disaster. In areas with heavy dry and hot wind, varieties with appropriate prematurity, resistance to premature senility and resistance to wilt should be selected to avoid or reduce the harm of dry and hot wind. The fourth is to select seeds because of illness. Varieties resistant to rust should be selected in areas with serious rust infection, while varieties resistant to moisture, scab and long dormancy period should be selected in areas with too much precipitation and serious waterlogging. Fifth, seed selection according to quality. According to the market demand, select high-quality varieties with good nutritional quality, processing quality in line with the requirements of finished products, full grains and high bulk density. Sixth, strict introduction and replacement. Change new varieties according to the change of production conditions and increase yield, prevent a large number of introduction, adjustment and frequent replacement of improved varieties without experimentation; while planting main varieties, pay attention to actively introducing new varieties for experiment and demonstration, and do a good job in seed reproduction, determine "succession" varieties, and maintain the quality of seeds used in production.

2. Seed treatment. Strengthen the treatment of wheat seeds, do a good job of seed coating or chemical seed dressing, reduce the incidence of autumn seedlings, depress the source of overwintering bacteria, and control the harm of underground pests at seedling stage, which can postpone the incidence of wheat stripe rust, powdery mildew, sheath blight and other diseases. According to the disease resistance, disease degree, climatic conditions and cultivation methods of wheat varieties in different places, the fungicides were selected reasonably. Strictly apply the amount of medicine used in seed dressing, prohibit excessive use of medicine; sow seeds immediately after seed dressing, mix and use now, and finish sowing on the same day; appropriately increase the amount of seeds used after seed dressing.

3. Straw is returned to the field. The corn straw should be crushed and returned to the field, and the length of ≤ should be 10 cm, which should be scattered evenly on the surface. To turn the crushed straw into the ground, if the deep loosening technology is adopted, the straw must be cut into the soil layer, the rotary tillage depth is more than 15 cm, and the straw should be irrigated firmly after returning to the field, and rake pressure in time if the soil moisture is suitable.

4. Deep ploughing (deep loosening) rake pressure. Deep ploughing 23-25 cm and then rake pressure, or deep loosen 30-35 cm and then rotary ploughing and rake pressure, in order to break the bumpy, solid soil, conducive to the root system to tie, prevent ventilation and moisture, and keep the seedlings safe through the winter. The effect of deep ploughing or subsoiling can last for 2 years, 1 year deep ploughing or subsoiling, and rotary ploughing and soil preparation within 2-3 years. Deep ploughing and deep loosening of dry land leisure wheat fields should be carried out in early July, which is beneficial to storing soil moisture in rain and raking before sowing.

5. Water to make soil moisture. Persist in sowing seeds in sufficient moisture to ensure that the whole seedling is sown. When the relative water content of the 0-40 cm soil layer is less than 75%, the soil moisture should be made before sowing. It is necessary to hoe the wheat fields that cannot produce soil moisture in time and irrigate the head water after sowing, so as to prevent soil cracks and reduce the loss of soil moisture.

6. Apply base fertilizer. Soil testing formula fertilization, nitrogen, phosphorus and potassium fertilizer, supplementary application of trace element fertilizer. The high-yield field adopts nitrogen fertilizer backward transfer technology, with 50% bottom application and 50% topdressing of nitrogen fertilizer, and all other fertilizers are applied at the bottom. According to the production experience, the reference values of suitable fertilizer application rates for different soil fertility levels are as follows: 6-10 kg of pure nitrogen (N), 3-5 kg of phosphorus (P2O5) and 2-4 kg of potassium (K2O) per mu in low-yield fields with a yield of 200kg to 300kg per mu. The middle-yield fields with a yield of 300kg / mu apply 10-12kg of pure nitrogen (N), 4-6kg of phosphorus (P2O5) and 4-6kg of potassium (K2O) per mu, 70% of the bottom application of nitrogen fertilizer, 30% topdressing at the start stage, and all the bottom application of phosphorus and potassium fertilizer. 12-14 kg of pure nitrogen (N), 6-7 kg of phosphorus (P2O5), 5-6 kg of potassium (K2O) per mu, 60% bottom application of nitrogen fertilizer, 40% topdressing at jointing stage or jointing stage, and all phosphorus and potassium fertilizer were applied at the bottom of the high yield field with a yield of 400,500kg per mu. In the super high-yield fields with a yield of more than 500kg per mu, pure nitrogen (N) 14-16kg, phosphorus (P2O5) 7-8kg, potassium (K2O) 6-8kg, nitrogen fertilizer 50% bottom application, 50% topdressing at jointing stage, all phosphorus and potassium fertilizer were applied.

(2) sowing seeds

7. Suitable sowing time. The daily average temperature for general winter varieties and semi-winter varieties is 16-18 ℃ and 14-16 ℃ respectively. To cultivate strong seedlings before winter, winter and semi-winter varieties should ensure that the effective accumulated temperature before winter can reach 550600 ℃. At the same time, weather conditions, fertility level, diseases and insect pests and safe overwintering should be taken into account. In general, the suitable sowing time is from the end of September to the first ten days of October in the northern winter wheat region, from October 5 to 15 in the north and middle of Huang Huai winter wheat region, and from October 10 to 20 in the south of Huang Huai winter wheat region.

8. Reasonable sowing quantity. Reasonable sowing rate and suitable basic seedling number are not only the starting point for establishing high-quality population, but also an important measure to build a reasonable population structure and coordinate the relationship between population and individual, wheat growth and development and environmental conditions. The principles to be mastered are as follows: first, the varieties with strong tillering ability and high panicle rate should appropriately reduce the sowing rate. Second, sowing sooner or later, the sowing amount of early sowing is appropriately less, and the sowing amount of late sowing is appropriately increased. Third, the soil fertility level, the basic seedlings with better soil fertilizer and water conditions should be rare, and the sowing rate should be less. Generally, the basic seedlings per mu in the northern winter wheat area is 20-300000, the northern and central Huang-Huai winter wheat region is 15-250000, and the Huang-Huai south is 15-180000. When the daily average temperature of sowing is lower than 15 ℃, the basic seedling will increase by about 10 000 per day, but it should not exceed 350000 at most.

9. Fine sowing. Sow seeds with wheat planters that meet the requirements and quality, and determine the suitable row spacing according to the actual situation in various places, so that the row spacing is the same, the sowing amount is accurate, the depth is the same, the sowing depth is 3-5 cm, and there is no missed sowing and no replay.

10. Crackdown after broadcast. The seeder with ballast should be pressed with sowing, and the seeder without ballast should be suppressed with ballast after sowing. It is necessary to ensure the intensity of suppression, ensure the quality of suppression, stabilize the soil, reduce the loss of soil moisture in the field, promote the growth of wheat seedlings, cultivate strong seedlings before winter, and expand the proportion of strong seedlings.

(3) pre-winter management

11. Water over the winter. For wheat fields that lack moisture and straw returning, rotary tillage and sowing, and wheat fields where the soil is not solid, it is necessary to timely pour over-winter water to ensure safe survival of seedlings. The winter irrigation time is generally carried out when the daily average temperature is stable at 3-4 ℃, the night freezes and the day dissipates, and the water can seep in time, and it is completed before the heavy freezing. Advocate water-saving irrigation, prohibit flood irrigation, hoe in time after irrigation, loosen the soil to preserve soil moisture, prevent surface cracking, and prevent ventilation from damaging roots and seedlings. For wheat fields with suitable soil moisture, high quality of soil preparation, sufficient bottom fertilizer, normal growth and suitable population, winter water can not be watered before winter. For wheat fields without watering conditions, it is necessary to hoe and preserve soil moisture in time after each rainfall.

12. Chemical weeding. In recent years, malignant weeds of Gramineae have a gradual development trend, which has a great influence on wheat yield. It is necessary to base on the treatment of spring grass in autumn and do a good job of chemical weeding in autumn, generally from mid-November to early December, wheat with 3-4 leaves and weeds from 2 leaves and 1 heart to 3 leaves. Control wild oats, Aegilops tauschii, ryegrass and other Gramineae weeds. Spray the leaves with 6.9% Puma EC 60-70 ml plus water per mu. To control Aegilops tauschii and brome, use 30 grams of 3% Shima or 20 grams of 3.6% Kushima per mu, and add water spray. To control broad-leaved weeds such as Artemisia annua, shepherd's purse, pig calamity, etc., use 75% benzosulfuron dry suspension 1.0-1.8 g, or 10% benzosulfuron-methyl wettable powder 10 g, or 20% make it EC 50-60 ml plus water 30-40 kg, spray evenly. To control alkali grass and hard grass, use 500-600 grams of 25% isoproturon wettable powder per mu after wheat emergence and add water spray.

13. Prevention and control of diseases and pests. For wheat fields that are seriously harmful to grubs, golden needles and other underground pests, each mu is irrigated with 40% methyl isosphos EC or 50% phoxim EC 500 ml plus water 750 kg, or 50% phoxim EC or 48% chlorpyrifos EC 250-300 ml, mixed with water 10 times, mixed with fine soil 40-50 kg, combined with hoeing into the soil. Wheat black leaf miner occurred in serious wheat fields, 40% omethoate 80 ml per mu, 4.5% cypermethrin 30 ml, 40-50 kg water spray, or 1% avermectin 3000-4000 times spray to control wheat aphids and red spiders. To control wheat sheath blight, 12.5% diniconazole wettable powder 20-30 g per mu, or 15% triadimefon wettable powder 100 g, 50 kg of water were sprayed evenly. Wheat cyst nematode occurred in serious fields, with 5% of line enemy granules 3.7 kg per mu, spread along the ridge in the seedling stage, and timely watering to improve the control effect.

14. It is strictly forbidden to eat green. It is necessary to strengthen the management and protection of wheat fields before winter, take good care of livestock and poultry, put an end to the gnawing of livestock and poultry, and ensure the normal growth of wheat seedlings and safe passage through the winter.