The specific role and necessity of fertilizer The role of seed fertilizer is mainly to achieve strong seedlings, laying the foundation for high crop yields. The seedling period of spring sowing maize and soybeans requires less nutrient and requires a few and fine supply of seed fertilizers. However, the response of the crops to the nutrient level during the seedling period is very sensitive and sensitive. In particular, the critical period for the demand for phosphorus nutrition in general crops is at the seedling stage. If the phosphorus supply is slightly insufficient, the symptoms of phosphorus deficiency will affect the later yield, so the species Fertilizers are particularly demanding for the supply of phosphate fertilizers. For example, in the three-leaf period of maize, there is a purple leaf symptom, and the phosphorus deficiency of soybean seedlings occurs when there are two true leaves. Once the symptoms of phosphorus deficiency appear at the seedling stage, it will be difficult to make up for the loss caused by phosphorus deficiency even in the middle and later stages. Especially when planting corn and soybeans in soils with low fertility or no organic fertilizer all year round, it is necessary to combine planting techniques with phosphorus-containing seed fertilizers. The amount of fertilizer applied is much less than that of basal fertilizer. Fertilizers equipped with fertilizers can be used either as unit fertilizers or compound fertilizers. First, in the unit phosphate fertilizer, superphosphate is a quick-acting phosphate fertilizer, which can be used as seed fertilizer, and the appropriate amount is between 6-10 kg/mu; in the unit nitrogen fertilizer, ammonium sulfate is not harmful to the seed germination, so it is ideal. The amount of nitrogen fertilizer, 5 kg per acre is appropriate, other nitrogen fertilizers are not all suitable for fertilizer. For urea, because of its high nitrogen content, it is generally not suitable for seed fertilizer. If only urea is used as a seed fertilizer, the dosage should be controlled. It is appropriate to apply 2.5 kg of urea per acre, and it is required that the content of biuret in urea products should not be More than 1%. In the compound fertilizers, DAP is a fast-acting N- and P dual-component compound fertilizer with high total nutrients and is mainly supplemented with phosphorus, which is suitable for all types of crops. In the spring sowing of corn and soybeans in the northeastern region, farmers are accustomed to using diammonium phosphate as a seed fertilizer, with an average dosage of 3-5 kg/mu, which works well. High-nitrogen compound fertilizers, due to high nitrogen content and low phosphorus content, do not meet the requirements of seed fertilizers, and the application rate is a little higher. High concentrations of urea-based nitrogen will inhibit seed germination. In recent years, high-nitrogen compound fertilizers have been used as seeds. The burning of seedlings caused by fertilizers is more serious and widespread. Accurately grasp the application position of seed fertilizer Do not directly contact the seed with the seed fertilizer to prevent burning the roots. Phosphorus-nitrogen-phosphorus fertilizers should be applied under the seed to a certain depth below or to the side of the seed. It is advisable to isolate 2-5 cm between seed and fertilizer. Especially when high concentrations of phosphodiammonium and urea are used as seed fertilizers, the dosage must be controlled, and direct contact with the seed must be avoided. Under the conditions of mechanical sowing, the seeds and fertilizers should be separated from the two reserve tanks and the two pipes, so that the fertilizers and seeds are not on the same soil surface to ensure safe emergence. In short, one of the key to the application of seed fertilizer is to grasp the position of the fertilizer and apply it under the seed diagonally to separate the seed from the fertilizer; otherwise, the seedling will be burned; secondly, the seed fertilizer should be distributed with phosphorus as a proper amount of nitrogen. Strictly control the amount of nitrogen applied to achieve precise application and accurate location. Folding Half Face Mask,Disposable Face Cover for Self Use,Medical Kn95 Face Mask,Anti-fog Haze Dust Proof Face Dongguan Keyutai Mask Co., Ltd. , https://www.maskkytai.com