Ten taboos in the application of chemical fertilizer

1. Urea should not be watered immediately after use. Urea is a kind of soluble fertilizer with strong mobility and easy to cause loss. After spreading urea on dry land, do not immediately water it, nor should it be applied before the heavy rain. 2. Ammonium bicarbonate should not be applied on the soil surface. Ammonium bicarbonate is highly volatile and easy to burn seedlings. Therefore, ammonium bicarbonate should not be applied on the surface, it is best to apply it deeply and cover the soil after application. 3. Ammonium bicarbonate should not be applied in greenhouse and greenhouse. Ammonium bicarbonate is known as "gas fertilizer". When applied in greenhouses and greenhouses, ammonium bicarbonate is easily decomposed into ammonia 4 and ammonium nitrogen fertilizer should not be mixed with alkaline fertilizer. Ammonium bicarbonate, ammonium sulfate, ammonium nitrate, ammonium phosphate and other ammonium nitrogen fertilizers encounter alkaline substances, which will cause nitrogen loss. Do not volatilize with alkaline fertilizers such as plant ash, kiln ash and potash. And lime nitrogen and other mixed application. 5. Nitrate fertilizer should not be applied in rice fields. The nitrate ions dissociated from nitrate fertilizers such as ammonium carbonate are easy to be leached into the deep soil by water in the paddy field, resulting in denitrification, resulting in nitrogen loss. 6. Ammonium sulfate is not suitable for long-term application. Ammonium sulfate is a physiological acid fertilizer, which destroys the physical structure of soil. When applied in alkaline soil for a long time, the soil will become hardened and stiff because of the reaction between sulfate ion and calcium in the soil. 7. Phosphate fertilizer should not be applied separately. The mobility of phosphorus is small, it is easy to be absorbed and fixed by soil, and the fertilizer efficiency is reduced. When applying phosphate fertilizer, the contact area between phosphate fertilizer and soil should be reduced, and ditch application or hole application should be used, which should be concentrated near the root of crops. 8. Potash fertilizer should not be applied in the later stage of crops. Potassium can be transferred from the stems and leaves at the base of crops to the delicate parts at the top for reuse, so potassium deficiency occurs later than nitrogen and phosphorus. Therefore, potash fertilizer should be applied in advance in the early stage of crop production, or as base fertilizer at one time. 9. Chlorine-containing fertilizers should not be used alone for a long time, and avoid application in taboo crops. Long-term application of potassium chloride alone will increase the accumulation of chloride ions in the soil and lead to the destruction of soil nutrient structure and soil acidification. Application on sugar cane, sugar beet, watermelon, tobacco and other taboo crops will reduce the quality and quality. 10. Nitrogen-containing compound fertilizer should not be widely used in legume crops. There are nitrogen-fixing rhizobia near the roots of crops such as soybean, peanut, mung bean, broad bean, pea, alfalfa and so on. If a large amount of nitrogen-containing compound fertilizer is applied, it will not only cause waste of fertilizer, but also inhibit the activity of rhizobium and reduce its nitrogen fixation performance.