Wheat is an important food crop in China, and its planting area and total output are second only to rice. Wheat cultivation ranges from Hainan Island in the south to Heilongjiang in the north, Xinjiang in the west, and plain mountains in the coastal provinces. China grows both winter wheat and spring wheat.
1. Winter wheat fertilizer application technology
Fertilization of winter wheat in the vegetative growth stage (emergence, tillering, wintering, regreening, getting up, jointing), the main target is to promote tillering and earing, while in the reproductive growth stage (booting, heading, flowering, grouting, maturity), increase Grain weight gain is the main factor.
Due to differences in climate, soil, cultivation measures and variety characteristics, the amount of nitrogen, phosphorus and potassium absorbed by wheat plants during their lifetime and their distribution in different parts of plants also changed. Taken together, it is generally believed that for every 100 kilograms of wheat grain produced, it is necessary to absorb about 2.8-3.2 kilograms of pure nitrogen, 1-1.5 kilograms of phosphorus, 2-4 kilograms of potassium, and the ratio of nitrogen, phosphorus and potassium is about 1:0.4:1. . Nitrogen and phosphorus were mainly concentrated in Zizi, accounting for 76% and 82.4% of the total plant content, respectively. Potassium was mainly concentrated in stems and leaves, and the total plant content was 77.6%.
During the growth and development stages of winter wheat, the amount of nitrogen, phosphorus and potassium nutrients absorbed is: before the emergence to the greening stage, the absorbed nutrients and accumulated dry matter are less; after regreening, the absorption rate increases, from jointing to heading is the absorption of nutrients and The fastest period of accumulation of dry matter; after flowering, the absorption rate of nutrients gradually decreases. The absorption of nitrogen by winter wheat has two peaks: one is from tillering to wintering, and the other is from jointing to booting. The peak behind is much larger than the peak in front. According to the results of analysis of winter wheat plants with a yield of 6188 kg/ha, the soil and fertilizer plant of the Chinese Academy of Agricultural Sciences has absorbed 40% of the total growth period, 20% of phosphorus and 20% of potassium in the vegetative growth stage. At the peak of the absorption of nutrients, about 48% of nitrogen, 67% of phosphorus, and 65% of potassium. After the grain is formed, the absorbed nutrients are significantly reduced. Therefore, there should be sufficient nitrogen and appropriate amount of phosphorus and potassium nutrition in the wheat seedling stage. According to the fertility regularity and nutritional characteristics of wheat, base fertilizer should be reapplied and early topdressing should be applied. The amount of base fertilizer should generally account for 60% to 80% of the total fertilization amount, and the topdressing fertilizer should account for 40% to 20%.
(1) The base fertilizer of base fertilizer wheat should be based on farmyard manure and combined with fertilizer application. Applying the base fertilizer plays an important role in cultivating strong seedlings and promoting effective tillering and grain development. The application rate of top dressing varies greatly depending on the local conditions. Generally, based on 30-75 tons of farmyard manure per hectare, a certain amount of nitrogen and phosphate fertilizer should be applied in the north, and nitrogen should be applied in the southern winter wheat area. Potassium or nitrogen, phosphorus, potassium fertilizer. Generally, in the land with high soil fertility, 1/3 of nitrogen fertilizer can be used as the base fertilizer. Urea is 75-150 kg per hectare or 225-300 kg of ammonium bicarbonate. If the soil fertility is high, the farmer's fertilizer is used in a large amount, the base fertilizer may not be applied with nitrogen fertilizer, and the nitrogen fertilizer is used as the composting fertilizer. For medium-fermented plots, 1/2 of the nitrogen fertilizer can be used as the base fertilizer, applying 112.5-225 kg of urea per hectare or 375-600 kg of ammonium bicarbonate. For low-fermentation plots, 2/3 of the nitrogen fertilizer is used as the base fertilizer, applying 150-255 kg of urea per hectare or 450-750 kg of ammonium bicarbonate. In plots with low fertility and no irrigation water conditions, nitrogen fertilizer is usually used as the base fertilizer. Generally, in the wheat field where the soil available phosphorus is less than 20 mg, the phosphate fertilizer should be added. Apply 450-750 kg of calcium phosphate or calcium magnesium phosphate per hectare. The base fertilizer is preferably used after mixing or stacking the phosphorus moon bar with the farmyard manure, which can reduce the contact of the phosphate fertilizer with the soil, prevent the fixation of the water-soluble phosphorus, and utilize the absorption of the wheat. When the soil available potassium is lower than 50 mg/kg, potassium fertilizer should be added, and 75-150 kg of potassium chloride per hectare should be applied. It is best to apply potassium sulphate in saline-alkali soil. When the effective zinc in the soil is less than 0.5 mg/kg, zinc fertilizer can be applied every other year, and about 15 kg of zinc sulphate per hectare.
(2) When seeding wheat is planted, a small amount of chemical fertilizer can be used as seed fertilizer to ensure that the wheat can be absorbed into nutrients in time after emergence, which has a good effect on increasing the growth of wheat before and after tillering. The application of wheat seed fertilizer in the application of insufficient base fertilizer or poor soil and late-sown wheat field has a more significant effect on yield increase. The fertilizer can be used with urea of ​​30-45 kg per hectare, or ammonium sulfate of about 75 kg per hectare and 75-150 kg of superphosphate. Seeds and fertilizers are best spread separately. Ammonium bicarbonate should not be used as a seed fertilizer.
(3) Topdressing According to the needs of nutrients in various growth stages of wheat, topdressing is an important measure to obtain high yield. It is described as follows:
1 seedling stage topdressing: seedling stage topdressing referred to as "miaofei", generally in the early stage of seedling tillering, per hectare of ammonium bicarbonate 75-150 kg or urea 45-75 kg or a small amount of human excrement. Its role is to promote the growth of seedlings and increase the number of tillers before winter, especially for the lack of basic seedlings or late sowing. Low-yield soils such as muddy fields and wet fields with slow desertification and low nutrient decomposition have good effects on dry application of seedlings. However, for wheat fields with sufficient base fertilizer and seed fertilizer, it is not necessary to top dress in the seedling stage.
2 wintering period topdressing: also called "rhabe", the southern and the Yangtze River basin have heavy habits of applying fertilizer. The application of wax fertilizer is mainly based on the application of semi-fast-acting and late-acting farmyard manure. For the three types of seedlings, quick-acting fertilizer should be applied to promote long-root tillering, grow into strong seedlings, and promote the rapid transformation and upgrading of the three types of seedlings. For the northern winter wheat area, the three types of seedlings are planted late, the individual growth is poor, and there are few tillers. In the early stage of tillering, there is no top dressing. Generally, the measures of spring and winter application should be adopted, combined with pouring water and top dressing, and nitrogen fertilizer can be applied before and after small snow. , apply 75-150 kg of ammonium bicarbonate per hectare or 45-75 kg of urea, and do not apply "fertilizer" for the application of seedling fertilizer.
3 returning to the green period: for the fertility is poor, the base fertilizer is insufficient, the sowing is late, the winter is less, the weaker growing wheat field should be chased or regained back to the green fertilizer. It is advisable to apply 225-300 kg of ammonium bicarbonate or 45-75 kg of urea per hectare. For the wheat fields with sufficient base fertilizer and strong and strong feet before winter, it is generally not suitable to return to the green fertilizer.
4 jointing stage topdressing: jointing fertilizer is applied after the peak of winter wheat tillering, promote the formation of panicles, increase the rate of ear formation, promote the differentiation of small flowers, and strive for more large grains. The growth of young wheat at jointing stage is usually divided into three types, and corresponding topdressing and management measures are adopted.
Over the Miao Miao: The leaf shape is like a pig's ear, the leaves are black and green, the leaves are wide and soft, and the leaves are drooping down. There are many branches and there is a stagnation phenomenon. It is not advisable to apply nitrogen fertilizer to such seedlings, and watering should be controlled.
Strong seedlings: the leaves are shaped like ears, the leaves are longer and the color is green and green, the tips of the leaves are slightly oblique, and the branches are moderate. For this type of wheat seedlings, a small amount of nitrogen fertilizer can be applied, 150-225 kg of ammonium bicarbonate or 45-75 kg of urea per hectare, combined with phosphorus and potassium fertilizer, 75-150 kg of calcium phosphate per hectare, and 45-75 kg of potassium chloride. And with watering.
Weak seedlings: the leaves are shaped like horse ears, the leaves are yellow-green, the leaves are narrow and erect, and there are few tillers, which are lack of fertilizer. For this type of wheat, more quick-acting nitrogen fertilizer should be applied, 300-600 kg of ammonium bicarbonate or 150-225 kg of urea per hectare.
5 booting stage topdressing: the booting stage is mainly nitrogen fertilizer, the amount is small. Typically 75-150 kg of ammonium sulphate or 45-75 kg of urea per hectare.
6 Late fertilization: Some nitrogen, phosphorus, potassium and other elements are still needed after wheat heading. At this time, the wheat roots are aged and the absorption capacity is weakened. Therefore, the method of root dressing is generally adopted. From the heading to the milky stage, such as yellowing of leaves and yellowing, and dehydration and premature aging, the urea can be sprayed at a concentration of 1% to 2%, and the spray solution per hectare is about 750 liters. For wheat fields with thick green leaves and a late-maturing trend, 750 liters of potassium dihydrogen phosphate solution can be sprayed per hectare. In recent years, in the production practice, many places in the late growth stage of wheat sprayed with humic acid, nucleotides, amino acids and other growth regulators and trace elements, to play a role in increasing wheat yield.
2. Spring wheat fertilizer application technology
Spring wheat and winter wheat differ greatly in their growth and development. They are characterized by early spring sowing and short growing seasons, ranging from sowing to maturity for only 100-120 days. Spring wheat is mainly distributed in the northeast and northwest. According to the data of the spring wheat yield of 7500 kg/ha in the province, the Soil and Fertilizer Institute of Qinghai Academy of Agriculture and Forestry Sciences has a nitrogen content of 2.5-3.0 kg, phosphorus 0.78-1.17 kg and potassium 1.9-4.2 kg per 100 kg of grain. The ratio of nitrogen, phosphorus and potassium is 2.8:1:3.15. According to the Ningxia Academy of Agricultural Sciences, the yield of nitrogen, phosphorus and potassium in spring wheat has two peak periods: the first one is jointing to booting, the second is flowering to milking, the former is slightly higher than the field of 6195 kg/ha. The latter is high. The phosphorus absorption rate has been rising from emergence to milk ripening, from the sharp increase in jointing to the highest value in milk ripening. According to the growth rules and nutritional characteristics of spring wheat, the base fertilizer should be applied and the early application of top dressing should be applied.
(1) Base fertilizer Because the spring wheat is just frozen 5-7 cm in the early spring, the top is sowed, the ground temperature is very low, and the base fertilizer should be reapplied. The base fertilizer applies 30-60 tons of farmyard manure per hectare, 375-600 kg of ammonium bicarbonate and 450-600 kg of superphosphate. According to the investigation of the Heilongjiang Academy of Agricultural Sciences, the application of spring wheat to the base fertilizer was the best in the autumn and spring, and the application of the base fertilizer in the autumn was the second, and the fertilization before the spring was the worst.
(2) Fertilizer Because the fertilizer is concentrated in the vicinity of the seed, the wheat can be used after it has grown roots. The specific method is to make the land leveling before planting, and then ditch according to the predetermined row spacing, then spread and sow in the ditch. , covering soil, and suppressing. If the ground is dry, you can first sow and practise, then sprinkle, cover, and suppress. Generally, 150 kg of ammonium bicarbonate per hectare, 225-375 kg of superphosphate, mixed with 1500 kg of high-quality farmyard manure, or 150-300 kg of binary nitrogen-phosphorus compound fertilizer.
In recent years, the spring wheat producing area has been fertilized once, and all fertilizers have been used as base fertilizers and seed fertilizers. Generally, based on the application of farmyard manure, 600-750 kg of ammonia water per hectare or 600 kg of ammonium bicarbonate is applied, and 750 kg of calcium phosphate is applied. When planting, combined with a small amount of fertilizer, apply 75-120 kg of diammonium phosphate per hectare, and do not apply top dressing later. This method is suitable for dry land.
(3) Topdressing spring wheat is a crop that belongs to the "fetal rich". It develops earlier, and most varieties begin to grow cones at the 3-leaf stage and undergo cob differentiation. At the 4-leaf stage, young spikes begin to differentiate and require more nutrients. Therefore, the first top dressing should be carried out at the 3 leaf stage or 3 leaves 1 heart. This fertilizer is called split fertilizer, and it should be reapplied, accounting for about 2/3 of the amount of topdressing. Applying 225-300 kg of urea per hectare, it is mainly to increase the tillering rate of tillering, promote the early growth of seedlings, and lay a foundation for the large grains of the ear. The second top dressing during the jointing stage is called jointing fertilizer, which is generally lightly applied, accounting for about 1/3 of the amount of application, and 105-150 kg of urea per hectare. In plots that have not been applied to excessive manure, early application and heavy application of fertilizer should be applied. At the booting stage, the amount of grain and fertilizer is increased. After most of the jointing fertilizer has been applied, it will no longer be fertilized, mainly for foliar fertilization, the same as winter wheat.
1. Winter wheat fertilizer application technology
Fertilization of winter wheat in the vegetative growth stage (emergence, tillering, wintering, regreening, getting up, jointing), the main target is to promote tillering and earing, while in the reproductive growth stage (booting, heading, flowering, grouting, maturity), increase Grain weight gain is the main factor.
Due to differences in climate, soil, cultivation measures and variety characteristics, the amount of nitrogen, phosphorus and potassium absorbed by wheat plants during their lifetime and their distribution in different parts of plants also changed. Taken together, it is generally believed that for every 100 kilograms of wheat grain produced, it is necessary to absorb about 2.8-3.2 kilograms of pure nitrogen, 1-1.5 kilograms of phosphorus, 2-4 kilograms of potassium, and the ratio of nitrogen, phosphorus and potassium is about 1:0.4:1. . Nitrogen and phosphorus were mainly concentrated in Zizi, accounting for 76% and 82.4% of the total plant content, respectively. Potassium was mainly concentrated in stems and leaves, and the total plant content was 77.6%.
During the growth and development stages of winter wheat, the amount of nitrogen, phosphorus and potassium nutrients absorbed is: before the emergence to the greening stage, the absorbed nutrients and accumulated dry matter are less; after regreening, the absorption rate increases, from jointing to heading is the absorption of nutrients and The fastest period of accumulation of dry matter; after flowering, the absorption rate of nutrients gradually decreases. The absorption of nitrogen by winter wheat has two peaks: one is from tillering to wintering, and the other is from jointing to booting. The peak behind is much larger than the peak in front. According to the results of analysis of winter wheat plants with a yield of 6188 kg/ha, the soil and fertilizer plant of the Chinese Academy of Agricultural Sciences has absorbed 40% of the total growth period, 20% of phosphorus and 20% of potassium in the vegetative growth stage. At the peak of the absorption of nutrients, about 48% of nitrogen, 67% of phosphorus, and 65% of potassium. After the grain is formed, the absorbed nutrients are significantly reduced. Therefore, there should be sufficient nitrogen and appropriate amount of phosphorus and potassium nutrition in the wheat seedling stage. According to the fertility regularity and nutritional characteristics of wheat, base fertilizer should be reapplied and early topdressing should be applied. The amount of base fertilizer should generally account for 60% to 80% of the total fertilization amount, and the topdressing fertilizer should account for 40% to 20%.
(1) The base fertilizer of base fertilizer wheat should be based on farmyard manure and combined with fertilizer application. Applying the base fertilizer plays an important role in cultivating strong seedlings and promoting effective tillering and grain development. The application rate of top dressing varies greatly depending on the local conditions. Generally, based on 30-75 tons of farmyard manure per hectare, a certain amount of nitrogen and phosphate fertilizer should be applied in the north, and nitrogen should be applied in the southern winter wheat area. Potassium or nitrogen, phosphorus, potassium fertilizer. Generally, in the land with high soil fertility, 1/3 of nitrogen fertilizer can be used as the base fertilizer. Urea is 75-150 kg per hectare or 225-300 kg of ammonium bicarbonate. If the soil fertility is high, the farmer's fertilizer is used in a large amount, the base fertilizer may not be applied with nitrogen fertilizer, and the nitrogen fertilizer is used as the composting fertilizer. For medium-fermented plots, 1/2 of the nitrogen fertilizer can be used as the base fertilizer, applying 112.5-225 kg of urea per hectare or 375-600 kg of ammonium bicarbonate. For low-fermentation plots, 2/3 of the nitrogen fertilizer is used as the base fertilizer, applying 150-255 kg of urea per hectare or 450-750 kg of ammonium bicarbonate. In plots with low fertility and no irrigation water conditions, nitrogen fertilizer is usually used as the base fertilizer. Generally, in the wheat field where the soil available phosphorus is less than 20 mg, the phosphate fertilizer should be added. Apply 450-750 kg of calcium phosphate or calcium magnesium phosphate per hectare. The base fertilizer is preferably used after mixing or stacking the phosphorus moon bar with the farmyard manure, which can reduce the contact of the phosphate fertilizer with the soil, prevent the fixation of the water-soluble phosphorus, and utilize the absorption of the wheat. When the soil available potassium is lower than 50 mg/kg, potassium fertilizer should be added, and 75-150 kg of potassium chloride per hectare should be applied. It is best to apply potassium sulphate in saline-alkali soil. When the effective zinc in the soil is less than 0.5 mg/kg, zinc fertilizer can be applied every other year, and about 15 kg of zinc sulphate per hectare.
(2) When seeding wheat is planted, a small amount of chemical fertilizer can be used as seed fertilizer to ensure that the wheat can be absorbed into nutrients in time after emergence, which has a good effect on increasing the growth of wheat before and after tillering. The application of wheat seed fertilizer in the application of insufficient base fertilizer or poor soil and late-sown wheat field has a more significant effect on yield increase. The fertilizer can be used with urea of ​​30-45 kg per hectare, or ammonium sulfate of about 75 kg per hectare and 75-150 kg of superphosphate. Seeds and fertilizers are best spread separately. Ammonium bicarbonate should not be used as a seed fertilizer.
(3) Topdressing According to the needs of nutrients in various growth stages of wheat, topdressing is an important measure to obtain high yield. It is described as follows:
1 seedling stage topdressing: seedling stage topdressing referred to as "miaofei", generally in the early stage of seedling tillering, per hectare of ammonium bicarbonate 75-150 kg or urea 45-75 kg or a small amount of human excrement. Its role is to promote the growth of seedlings and increase the number of tillers before winter, especially for the lack of basic seedlings or late sowing. Low-yield soils such as muddy fields and wet fields with slow desertification and low nutrient decomposition have good effects on dry application of seedlings. However, for wheat fields with sufficient base fertilizer and seed fertilizer, it is not necessary to top dress in the seedling stage.
2 wintering period topdressing: also called "rhabe", the southern and the Yangtze River basin have heavy habits of applying fertilizer. The application of wax fertilizer is mainly based on the application of semi-fast-acting and late-acting farmyard manure. For the three types of seedlings, quick-acting fertilizer should be applied to promote long-root tillering, grow into strong seedlings, and promote the rapid transformation and upgrading of the three types of seedlings. For the northern winter wheat area, the three types of seedlings are planted late, the individual growth is poor, and there are few tillers. In the early stage of tillering, there is no top dressing. Generally, the measures of spring and winter application should be adopted, combined with pouring water and top dressing, and nitrogen fertilizer can be applied before and after small snow. , apply 75-150 kg of ammonium bicarbonate per hectare or 45-75 kg of urea, and do not apply "fertilizer" for the application of seedling fertilizer.
3 returning to the green period: for the fertility is poor, the base fertilizer is insufficient, the sowing is late, the winter is less, the weaker growing wheat field should be chased or regained back to the green fertilizer. It is advisable to apply 225-300 kg of ammonium bicarbonate or 45-75 kg of urea per hectare. For the wheat fields with sufficient base fertilizer and strong and strong feet before winter, it is generally not suitable to return to the green fertilizer.
4 jointing stage topdressing: jointing fertilizer is applied after the peak of winter wheat tillering, promote the formation of panicles, increase the rate of ear formation, promote the differentiation of small flowers, and strive for more large grains. The growth of young wheat at jointing stage is usually divided into three types, and corresponding topdressing and management measures are adopted.
Over the Miao Miao: The leaf shape is like a pig's ear, the leaves are black and green, the leaves are wide and soft, and the leaves are drooping down. There are many branches and there is a stagnation phenomenon. It is not advisable to apply nitrogen fertilizer to such seedlings, and watering should be controlled.
Strong seedlings: the leaves are shaped like ears, the leaves are longer and the color is green and green, the tips of the leaves are slightly oblique, and the branches are moderate. For this type of wheat seedlings, a small amount of nitrogen fertilizer can be applied, 150-225 kg of ammonium bicarbonate or 45-75 kg of urea per hectare, combined with phosphorus and potassium fertilizer, 75-150 kg of calcium phosphate per hectare, and 45-75 kg of potassium chloride. And with watering.
Weak seedlings: the leaves are shaped like horse ears, the leaves are yellow-green, the leaves are narrow and erect, and there are few tillers, which are lack of fertilizer. For this type of wheat, more quick-acting nitrogen fertilizer should be applied, 300-600 kg of ammonium bicarbonate or 150-225 kg of urea per hectare.
5 booting stage topdressing: the booting stage is mainly nitrogen fertilizer, the amount is small. Typically 75-150 kg of ammonium sulphate or 45-75 kg of urea per hectare.
6 Late fertilization: Some nitrogen, phosphorus, potassium and other elements are still needed after wheat heading. At this time, the wheat roots are aged and the absorption capacity is weakened. Therefore, the method of root dressing is generally adopted. From the heading to the milky stage, such as yellowing of leaves and yellowing, and dehydration and premature aging, the urea can be sprayed at a concentration of 1% to 2%, and the spray solution per hectare is about 750 liters. For wheat fields with thick green leaves and a late-maturing trend, 750 liters of potassium dihydrogen phosphate solution can be sprayed per hectare. In recent years, in the production practice, many places in the late growth stage of wheat sprayed with humic acid, nucleotides, amino acids and other growth regulators and trace elements, to play a role in increasing wheat yield.
2. Spring wheat fertilizer application technology
Spring wheat and winter wheat differ greatly in their growth and development. They are characterized by early spring sowing and short growing seasons, ranging from sowing to maturity for only 100-120 days. Spring wheat is mainly distributed in the northeast and northwest. According to the data of the spring wheat yield of 7500 kg/ha in the province, the Soil and Fertilizer Institute of Qinghai Academy of Agriculture and Forestry Sciences has a nitrogen content of 2.5-3.0 kg, phosphorus 0.78-1.17 kg and potassium 1.9-4.2 kg per 100 kg of grain. The ratio of nitrogen, phosphorus and potassium is 2.8:1:3.15. According to the Ningxia Academy of Agricultural Sciences, the yield of nitrogen, phosphorus and potassium in spring wheat has two peak periods: the first one is jointing to booting, the second is flowering to milking, the former is slightly higher than the field of 6195 kg/ha. The latter is high. The phosphorus absorption rate has been rising from emergence to milk ripening, from the sharp increase in jointing to the highest value in milk ripening. According to the growth rules and nutritional characteristics of spring wheat, the base fertilizer should be applied and the early application of top dressing should be applied.
(1) Base fertilizer Because the spring wheat is just frozen 5-7 cm in the early spring, the top is sowed, the ground temperature is very low, and the base fertilizer should be reapplied. The base fertilizer applies 30-60 tons of farmyard manure per hectare, 375-600 kg of ammonium bicarbonate and 450-600 kg of superphosphate. According to the investigation of the Heilongjiang Academy of Agricultural Sciences, the application of spring wheat to the base fertilizer was the best in the autumn and spring, and the application of the base fertilizer in the autumn was the second, and the fertilization before the spring was the worst.
(2) Fertilizer Because the fertilizer is concentrated in the vicinity of the seed, the wheat can be used after it has grown roots. The specific method is to make the land leveling before planting, and then ditch according to the predetermined row spacing, then spread and sow in the ditch. , covering soil, and suppressing. If the ground is dry, you can first sow and practise, then sprinkle, cover, and suppress. Generally, 150 kg of ammonium bicarbonate per hectare, 225-375 kg of superphosphate, mixed with 1500 kg of high-quality farmyard manure, or 150-300 kg of binary nitrogen-phosphorus compound fertilizer.
In recent years, the spring wheat producing area has been fertilized once, and all fertilizers have been used as base fertilizers and seed fertilizers. Generally, based on the application of farmyard manure, 600-750 kg of ammonia water per hectare or 600 kg of ammonium bicarbonate is applied, and 750 kg of calcium phosphate is applied. When planting, combined with a small amount of fertilizer, apply 75-120 kg of diammonium phosphate per hectare, and do not apply top dressing later. This method is suitable for dry land.
(3) Topdressing spring wheat is a crop that belongs to the "fetal rich". It develops earlier, and most varieties begin to grow cones at the 3-leaf stage and undergo cob differentiation. At the 4-leaf stage, young spikes begin to differentiate and require more nutrients. Therefore, the first top dressing should be carried out at the 3 leaf stage or 3 leaves 1 heart. This fertilizer is called split fertilizer, and it should be reapplied, accounting for about 2/3 of the amount of topdressing. Applying 225-300 kg of urea per hectare, it is mainly to increase the tillering rate of tillering, promote the early growth of seedlings, and lay a foundation for the large grains of the ear. The second top dressing during the jointing stage is called jointing fertilizer, which is generally lightly applied, accounting for about 1/3 of the amount of application, and 105-150 kg of urea per hectare. In plots that have not been applied to excessive manure, early application and heavy application of fertilizer should be applied. At the booting stage, the amount of grain and fertilizer is increased. After most of the jointing fertilizer has been applied, it will no longer be fertilized, mainly for foliar fertilization, the same as winter wheat.
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