Before and after the Spring Festival, wheat has to be topdressed and returned to green fertilizer. Can only urea be used for topdressing of wheat? How much is the amount per mu? Maybe a lot of people are not sure about it. See what agricultural experts say?

One. Irrigated winter wheat area in North China Plain

Including all of Shandong Province and Tianjin City, central and southern Hebei Province, central and southern Beijing, central and northern Henan Province, Guanzhong Plain in Shaanxi Province, and southern Shanxi Province.

Fertilization recommendations

1. Before returning to green, the total number of stems per acre is less than 450,000, and the three types of wheat fields with lighter leaf color and poor growth should be managed in time. Spring topdressing can be divided into two. For the first time, 5~8 kg of urea per acre was applied with watering during the rejuvenation period; for the second time, 5~10 kg of urea per acre was applied with watering during the jointing period.

2. Before turning green, the total number of stems per acre is between 450,000 and 600,000, and the group is small in the second-class wheat field. During the wheat rise period, combined with watering, topdressing 10-15 kg of urea per acre.

3. The total number of stems per acre before returning to green is between 600,000 and 800,000. A type of wheat field that is suitable for the colony can be combined with watering during the jointing stage to chase urea 12-15 kg per acre.

4. For wheat fields with a total number of stems per acre greater than 800,000, dark green leaves and a trend of vigorous growth before turning green, intertillage suppression should be adopted during the turning green period to postpone the time of nitrogen fertilizer application and reduce the amount of nitrogen fertilizer to control the growth of populations and prevent lodging and Greedy and late mature. Generally, 8~10 kg of urea per mu can be applied in the late stage of jointing.

5. Wheat subject to freezing damage during the overwintering period or returning to the green period should be top-dressed and irrigated according to the occurrence of freezing damage. For severe frost damage, 5-10 kg of urea per mu and watering should be applied immediately to promote early tillering of wheat, increase the rate of tillering ears, and reduce Freezing damage.

6. Diammonium phosphate should be top-dressed on fields without phosphate fertilizer or phosphate deficiency. It is recommended to apply nitrogen and potassium compound fertilizer at the turning green or jointing stage if no or less potassium is applied; it is necessary to combine the prevention and control of sheath blight, one spray and three preventions to compensate for phosphorus and potassium fertilizer; if there is no irrigation or effective precipitation, Foliar sprays of urea and potassium dihydrogen phosphate in spring play a role in fertilizing water.

7. Potassium dihydrogen phosphate, boron fertilizer and zinc fertilizer can be sprayed on the leaf surface during the wheat grain filling period to prevent dry hot wind and lodging, improve grain filling intensity and increase grain weight.

8. For wheat fields in sulfur-deficient areas, if superphosphate, potassium sulfate, sulfur-based compound fertilizers are not used as the base fertilizer, ammonium sulfate should be selected for the first topdressing, and the amount of sulfur applied per mu is about 2 kg.

9. Many farmers do not harrow the land after rotating tillage, resulting in too deep sowing and weak seedlings of deep sowing, few tillers and weak seedlings, it is recommended to topdress 10-15 kg of urea during the greening period.

Two. North China rain-fed winter wheat area

Including the areas north of the Huaihe River in Jiangsu and Anhui provinces, and the southeast of Henan Province.

Fertilization recommendations

1. Take advantage of the early spring soil to turn green or rain and snow, use chemical fertilizers or ditching, apply 5~7 kg of urea per mu, cover the soil after fertilization, if rainfall occurs in the middle and late stages of growth, 5~8 kg of urea can be applied per mu . Use 7-10 kilograms of diammonium phosphate per mu for phosphorus-deficient fields, and 15-20 kilograms of nitrogen and potassium compound fertilizer for potassium-deficient fields; cover up after fertilization.

2. In order to prevent drought in the later stage, timely suppress the soil before it thaws and turn green, break the rubble, solidify the soil, and increase the moisture content. Suppression should be combined with cultivating and hoeing, first pressing and then hoeing. Before the wheat rows are closed, each mu shall be covered with wheat or corn stalks between rows to reduce soil moisture loss by evaporation.

3. If flourishing growth occurred a year ago and the total number of stems is greater than 800,000, due to the excessive nutrient consumption of the wheat population, the spring wheat seedlings will turn yellow or the pads will turn yellow, and the top dressing can be divided into 2 to 3 times during the return period to the jointing period. Topdressing high-nitrogen compound fertilizer 10 kg/time per mu.

4. The drought in the overwintering period causes the wheat population to be too small (the total number of stems per mu is less than 450,000 before returning to green, the three types of wheat fields with lighter leaf color and poor growth), fertilizer and water management should be carried out in time, and divided into 2 during the returning green to jointing period. Topdressing is done ~3 times, followed by rainfall, topdressing 5-8 kg of urea per mu per time.

5. It is necessary to combine the prevention and control of sheath blight, one spray and three preventions to carry out extra-root topdressing to compensate for the trace elements such as sulfur, zinc, boron, etc., spray urea and potassium dihydrogen phosphate, etc., to play the role of fertilizing water.

Three. Winter wheat area in the middle and lower reaches of the Yangtze River

Including the five provinces and cities of Hubei, Hunan, Jiangxi, Zhejiang and Shanghai, southern Henan, and the areas south of the Huaihe River in Anhui and Jiangsu.

Fertilization recommendations

1. Pay close attention to the weather and seedling conditions before the wheat turns green, especially the rainfall. If the drought persists, irrigate as soon as possible in early spring when the weather is warmer, the soil evaporation increases, and the wheat seedlings need soil moisture. Pay attention to temperature changes and master the amount and time of irrigation.

2. Comprehensive judgment based on winter freezing damage and group situation. If there are more large tillers that freeze to death or the population is seriously insufficient, the irrigation should be combined as soon as possible, and green fertilizer should be applied as soon as possible to promote large tillers in spring and ensure the number of ears.

3. The yield level is below 300 kg/mu, 6~8 kg/mu combined with irrigation and topdressing urea from the rising stage to the jointing stage; the yield level is 300~400 kg/mu, 8~11 kg combined with irrigation topdressing urea from the rising stage to the jointing stage /Mu and potassium chloride 1~3 kg/mu; the yield level is 400~550 kg/mu, combined with irrigation and topdressing urea 11-16 kg/mu and potassium chloride 3~5 kg/mu from the rise to jointing period; The level is above 550 kg/mu, and topdressing urea 17~20 kg/mu and potassium chloride 3~5 kg/mu from the rise to jointing stage.

4. In some areas lacking in trace elements, it is recommended to combine "one spray and three prevention", combined with the prevention and control of diseases, insects and weeds (aphids and scab), spraying trace element foliar fertilizer at the jointing stage, booting stage and filling stage of wheat ; And in the wheat grain filling period with 150 to 200 grams of potassium dihydrogen phosphate plus 0.5 to 1 kg of urea mixed with water 50 kg for foliar spray.

Four. Northwest rain-fed dry farming winter wheat area

Including northern Hebei Province, northern Beijing, southern Ulanchabu City, Inner Mongolia Autonomous Region, most of Shanxi Province, northern Shaanxi Province, western Henan Province, northern Ningxia Hui Autonomous Region, and eastern Gansu Province.

Fertilization recommendations

1. In order to prevent drought in the later stage, dryland wheat should take effective water conservation measures in time to prevent and reduce the massive loss of soil moisture before the early spring wheat is closed. Suppress or cut hoe at the right time before the soil is thawed and turn green, to break the rubbish, compact the soil, and improve and protect the moisture. For dry land that has been irrigated with overwintering water, hoe early before thawing and turning green to break hardening and eliminate cracks. Before the wheat rows are closed, 200 to 300 kilograms of wheat or corn stalks per mu can be used to cover the rows to reduce soil moisture loss by evaporation.

2. For fields with insufficient fertilizer input, it is necessary to seize the opportunity of rainfall and apply early spring topdressing of wheat at an appropriate time. The nitrogen-deficient fields use 5-7 kg of urea per mu, and the phosphorus-deficient fields use 7-10 kg of diammonium phosphate per mu, which are applied to the soil with a fertilizer applicator (columbine). For dry land with irrigated conditions, combined with spring irrigation, apply 6-8 kg of urea per mu for nitrogen-deficient fields and 8-10 kg of diammonium phosphate per mu for phosphorus-deficient fields.

3. Before sowing, the moisture content is good or the sowing is early, and the fertilization amount is high in the pre-winter long field, which is mainly controlled. Dry land without irrigation conditions should be suppressed and hoeed as early as possible to improve moisture content. The dry land that has been watered over the winter water should be hoeed as early as possible and watering in spring should be postponed to the late jointing stage.

4. For the fields with late sowing and weak seedling conditions, it is advisable to combine soil moisture conservation with shallow hoeing as soon as possible to increase the ground temperature and promote the weak seedlings to become stronger.

Five. Northwest Irrigated Wheat Area

Mainly spring wheat, including central Inner Mongolia Autonomous Region, northern Ningxia Hui Autonomous Region, central and western Gansu Province, eastern Qinghai Province and Xinjiang Uygur Autonomous Region.

Fertilization recommendations

1. Recommend NPK 17-18-10 (N-P2O5-K2O) or similar formula.

2. The yield level is 300-400 kg/mu, the recommended dosage of formula fertilizer is 20-25 kg/mu, and the top-dressing urea is 10-15 kg/mu combined with irrigation from the rise to the jointing stage.

3. The yield level is 400-550 kg/mu, the recommended dosage of formula fertilizer is 30-35 kg/mu, and 15-20 kg/mu of urea should be combined with irrigation and topdressing from the rise to the jointing stage.

4. The output level is above 550 kg/mu, the recommended dosage of formula fertilizer is 35-40 kg/mu, and 15-20 kg/mu of urea should be combined with irrigation and topdressing from the rise to the jointing stage.

5. The output level is below 300 kg/mu, the recommended dosage of formula fertilizer is 15-20 kg/mu, and the topdressing urea is 5-10 kg/mu combined with irrigation from the rise to the jointing stage.