The jointing and booting of wheat is the most important fertilizer in a lifetime. The jointing and booting stage is also the key period to determine the spike rate and seed setting rate of wheat, and it is the second period of peak fertilization for wheat. The amount of fertilizer needed during this period generally accounts for about 50% of the total fertilizer requirement. The scientific topdressing of panicle-fertilizer can ensure the growth of wheat and form large spikes. After the spring begins, the temperature gradually rises. Once wheat generally rises, it immediately enters the jointing and booting stage, which is an excellent period for the application of jointing and panicle-fertilizer.
According to the study, for every 100 kilograms of wheat produced, about 3.1 kilograms of pure nitrogen, 1.1 kilograms of phosphorus pentoxide and 3.2 kilograms of potassium oxide should be absorbed. Before winter, the demand of wheat for nutrients was small. After winter, with the increase of temperature and the increase of wheat population, the nutrient uptake increased rapidly until heading and flowering. The period from the jointing to the flowering stage was the peak period of wheat nutrient absorption. 55% of nitrogen, 80% of phosphorus, and 90% of potassium are absorbed at this stage. After flowering until maturity, it still needs to absorb 28% of nitrogen and a very small amount of phosphorus, basically no longer absorb potassium. At present, the wheat seedlings have a good foundation, but the percentage of long-standing seedlings and weak seedlings is high in all parts of the country. Therefore, joint-stocking and panicle-heading fertilizers must be scientifically and rationally applied due to land, seedlings, and conditions.
Determine the time of application according to local conditions. The jointing and panicle-fertilizer of wheat should generally be faded in the leaf color of the group, the death of the small tiller, the fixed length of the first internode of the base, and the extension of the second internode. The wheat field with normal growth is generally in the middle and late March. For late-seeding wheat, insufficient growth before winter, late-weak seedlings and wheat fields where individuals grow weak, and wheat fields with heavy yellowing and freezing in the leaves, fertilizer should be applied early in the middle of March, which can effectively increase the number of grains, and strive for spring. It is also useful to ensure that there are enough grains per acre to produce tillers. The leaf color fades slowly and the wax fertilizer is applied. In early spring, the plots that have returned to green manure can be reduced. The amount of fertilizer can be reduced according to the seedling quality, and the topdressing time for the jointing fertilizer is appropriately delayed.
Due to the seedling system, the amount of fertilization should be determined. The jointing and panicle fertilizer of wheat refers to the fertilizer applied from the jointing stage to the tip of the flag leaf. When the jointing, such as the base fertilizer, wax fertilizer application is less, should be applied as appropriate jointing fertilizer, urea can apply about 5 kg per acre and a certain amount of phosphorus and potassium fertilizer. At the time of jointing, the groups were large, the leaves were dark green, the leaves were drape, and the small pods were reluctant to return. The shades were heavier, indicating excessive growth. Appropriate control of the fertilizer was required for the wheat fields until the leaf color faded. Re-applying; if the leaf color does not fade, no fertilizer is applied. The joint development of the jointing group is insufficient, yellowing prematurely, leaves are narrow, thin and straight, is a typical lack of fertilizer performance, early fertilizer, combined with fertilizer and water, and actively promote the application of urea 6 to 8 kg per acre. The combination of rainwater fertilization allows the fertilizer to penetrate into the soil and increase the utilization rate.
Due to the system should apply the ratio. In general, dwarf, fertilizer-resistant and lodging-tolerant varieties can be applied in appropriate amounts; high-stalked and infertile varieties should be applied less. Insufficient base fertilizer, poor field plots, should be applied more than appropriate; soil fertilizer, stamina field, can be less applied. General fertilizer application of special compound fertilizer plus urea is appropriate; pregnant panicle fertilizer can only apply urea, so that accurate fertilization. General medium-gluten wheat fertilization uses 4 to 5 kg of pure nitrogen, 3 kg of phosphorus pentoxide and 4 kg of potassium chloride per mu. Usually 45% of NPK compound fertilizer 25-30 kg per acre. Fertilizer, which is 2 to 3 kg of pure nitrogen per mu, about 5 to 7 kg of urea per mu. Weak gluten wheat promotes one-time application of jointing and panicle fertilizer, that is, 2.6-2.8 kg of pure nitrogen per acre, 1.5 kg of phosphorus pentoxide, 2 kg of potassium oxide, and 45% of NPK composite fertilizer per acre. 15 kg. If the amount of nitrogen fertilizer is large in the early stage, the amount of jointing fertilizer should be appropriately reduced.
The activity of root system was significantly decreased in the middle and late stages of wheat growth, and trace element fertilizers were basically not absorbed from the soil. However, the demand for micronutrients in wheat in the middle and later stages is very important. It can increase the efficiency of photosynthesis and promote the transformation of the stale seedlings. It must seize the combination of spraying and preventing diseases in the middle and late stages of wheat, and spraying trace elements of foliar fertilizer to increase the yield. At the same time, the increase rate can reach 3% to 5%.
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