Application methods and matters needing attention of long-acting nitrogen fertilizer

Long-acting nitrogen fertilizer, also known as coated nitrogen fertilizer, is a kind of nitrogen fertilizer coated with coated material. Its coating is sprayed by the solution of a small amount of nitrogen, potassium, magnesium, manganese, zinc, iron, boron and other nutrient elements. The coated nitrogen fertilizer does not change the original properties. Compared with ordinary nitrogen fertilizer, long-acting nitrogen fertilizer has the characteristics of good physical properties, slow nitrogen release, long fertilizer efficiency, high nitrogen use efficiency and so on. Long-acting nitrogen fertilizer has the effect of slow release, which is suitable for the whole growth process of crops from seedling stage to growth stage, and there is no shortcoming of excessive supply in the early stage and insufficient amount of expired nitrogen. The promotion of long-term nitrogen fertilizer can not only save energy and cost, but also improve the effective utilization rate of nitrogen fertilizer, but also alleviate the contradiction that the supply of nitrogen fertilizer falls short of demand. Therefore, the promotion and rational use of long-acting nitrogen fertilizer is an important means to improve the yield and quality of agricultural crystals. Long-acting nitrogen fertilizer is suitable for all kinds of crops and all kinds of soil conditions. At present, there are two kinds of long-acting nitrogen fertilizer widely used in China: long-acting urea and long-acting ammonium bicarbonate, and their application methods are basically the same as urea and ammonium bicarbonate. The specific application points are as follows: (1) the nitrogen release of long-acting nitrogen fertilizer is relatively slow, and the peak of nitrogen release is about 5 days later than that of urea, so it should be earlier than the conventional application period of urea. It is generally appropriate to advance 5-6 days in early spring and 3-4 days in summer. (2) the nitrogen retention capacity of long-acting nitrogen fertilizer in soil is relatively strong, and the utilization rate is also relatively high. As a result, it uses slightly less nitrogen fertilizer than ordinary nitrogen fertilizer. It is usually 10% less than constant, 15% less than constant. (3) due to the difference of soil quality, there are obvious differences in the absorption and preservation capacity of long-acting nitrogen fertilizer in soil. The absorption and preservation capacity of clay is strong, and the dosage can be more at one time, and a small amount of sandy soil should be applied many times. (4) according to the different oxygen absorption characteristics of crops, long-acting nitrogen fertilizer should be applied scientifically.