The nitrogen needed for wheat growth and grain formation is mainly obtained from soil, and the effect of soil nitrogen application on wheat grain quality is very obvious. The amount of nitrogen fertilizer applied depends on soil fertility, varieties and other cultivation conditions. Under general high-yield conditions, the total amount of nitrogen applied per hectare is 225-270 kg of pure nitrogen, and the ratio of base fertilizer to topdressing is 6:4 or 5:5. Topdressing should be divided into three stages: overwintering stage, jointing stage and booting stage, with the ratio of l:l: 1, especially topdressing at jointing stage and booting stage. In addition to nitrogen application in soil, foliar spraying can also be carried out. Urea is the best fertilizer, and the spraying period is from most seeds to the end of milk ripening. The spraying concentration and quantity should not be too high to avoid burning the leaves. The concentration is generally 2%- 10%, and the dosage is 37.5-75 kg of pure nitrogen sprayed per hectare.

Rational application of potassium fertilizer

Studies have proved that the application of potassium fertilizer in potassium-deficient wheat fields has a good yield-increasing effect. Because potassium is closely related to nitrogen metabolism, potassium can promote the synthesis of protein, thus increasing the content of protein. Therefore, under the condition of sufficient supply of nitrogen and phosphorus, increasing application of potassium fertilizer is beneficial to improve grain yield and quality. According to research, the yield is the most stable when applying 45 ~ 90kg potassium nitrate per hectare. When 60- 105Kg of active ingredients were applied, the yield was stable and the protein content was high. As far as the application period is concerned, with the delay of application period, the protein content in grain gradually increased, and the best period was flowering. Proper application of potassium fertilizer can improve wheat quality, but it is necessary to provide sufficient nitrogen and phosphorus to achieve good results.

Correct application of micro-fertilizer

Except nitrogen, phosphorus and potassium, the demand for nutrients in wheat is very small, but it has a great influence on the yield and quality of wheat.

Boron is necessary for the synthesis of nucleic acids and protein. Applying a proper amount of boron fertilizer to the soil with insufficient available boron can effectively increase the protein content and amino acid content of wheat grains, thus improving the nutritional quality of wheat.

Zinc is a component of many enzymes and an activator of some enzymes, and participates in many metabolic activities of plants. Zinc deficiency will hinder the growth of wheat plants, reduce yield and deteriorate quality.

Manganese is the activator of nitrate reduction, and the lack of manganese in plants will affect its utilization of nitrate. Under the condition of manganese deficiency in soil, proper application of manganese can also improve the quality of wheat.

Among the three elements, spraying at booting stage is the best, with 0. 1% boric acid solution for boron, 0. 1% manganese sulfate solution for manganese and 0.04% zinc chloride or 0.2% zinc sulfate solution for zinc.

Adequate supply of organic fertilizer

Organic fertilizer is a complete fertilizer, which is rich in organic matter and various nutrients. Generally speaking, increasing the application of organic fertilizer can increase the protein content of grain. Under different fertility conditions, increasing the application of different organic fertilizers can increase the yield, but the effect of improving the yield and quality is different, and the effect is better when the fertility is poor. In a certain range, the yield and quality will increase with the increase of fertilization, but from the principle of economic fertilization, we should choose the best fertilization according to local conditions.

Timely and moderate irrigation

It is generally believed that the yield of wheat decreased due to insufficient water, while the protein content of grain increased, but the yield of protein was not high in the end. Under the condition of sufficient moisture, the yield can be greatly increased, but the protein content will not increase or decrease. Therefore, irrigation frequency and irrigation quantity should be determined according to meteorological conditions. In the year of water shortage, increasing irrigation times and total irrigation amount can improve the yield and quality, and in the year of abundant water, appropriate less irrigation can also improve the protein content of grain, but too much irrigation is unfavorable to the quality. Irrigation frequency should be before winter, after getting up, jointing and grouting, and the total irrigation amount is 2250-3000m 3 per hectare. Adopt chemical adjustment

The growth and development of wheat can be regulated by chemical regulation, and its yield and quality can be changed. Paclobutrazol (PP333), which is widely used in wheat at present, can dwarf wheat plants, effectively inhibit vegetative growth and promote reproductive growth, and has a good effect on improving wheat quality, especially when the nitrogen application level is low, the application of PP 333 can greatly increase the protein content. Spraying paclobutrazol in the early and middle growth stages of wheat has a positive effect on improving yield and quality, with the best spraying effect from the second leaf to the fourth leaf, and it is more suitable to spray winter wheat in the north from winter to the green turning stage, with the spraying concentration of 200-400 UI/L.

Among them, reasonable fertilization can especially improve the quality of wheat.

It is unfair to scientifically plant wheat to make it yield high, but also to improve the nutritional quality of wheat grain, that is, the content of protein in the grain and the content of essential amino acids, especially lysine. First, rational application of ammonia fertilizer

The principle of applying ammonia fertilizer is to ensure that plants do not lodging and the photosynthetic conditions of the population are good. It is better to apply 2-3 kg of pure nitrogen in stages from jointing stage to heading stage. In addition, attention should be paid to the application of flag leaf fertilizer, and appropriate wax fertilizer should be applied in large-scale production. Second, reduce phosphorus fertilizer and increase potassium fertilizer.

The application of phosphate fertilizer in the middle and late growth period of wheat will indirectly reduce the protein content per unit grain. The application of potassium fertilizer can promote the speed of amino acid transfer from grain to grain and the speed of amino acid transformation to protein, thus increasing the protein content. From jointing stage to booting stage, apply 20-25 kg of vegetation per mu and spray it at heading stage. In order to increase wheat yield and improve wheat quality, nitrogen, phosphorus and potassium can be applied together or combined with nitrogen and potassium, which is better than using one fertilizer alone. 3. Appropriate application of calcium and magnesium fertilizer.

When the content of nitrogen, phosphorus, potassium and other nutrients in the soil is high, proper application of calcium fertilizer and magnesium fertilizer can improve the nutritional quality of wheat seeds, while when the nitrogen nutrient is medium, the effect of applying magnesium fertilizer is also good, generally 20 kg of calcium and magnesium fertilizer can be applied per mu. Fourthly, the supplementary application of sulfur fertilizer

Sulfur and nitrogen are both components of protein. Sulfur deficiency in wheat growth will reduce the synthesis of protein, so zinc sulfate solution can be added to supplement both sulfur and zinc, especially in sandy black soil.

5. Spraying urea on the foliage and along the surface of the soil with insufficient or no base fertilizer can significantly increase the grain yield and protein content, which can generally be increased by 8%- 13% and 10%- 16% respectively, and the concentration is 0.5%-2% each time, and 50 kg of solution can be sprayed per mu.