一注意施肥后灌水时间。施肥后灌水时间的早晚对肥效的影响很大,需及时灌水的肥料有氨水、碳酸氢铵、硫酸铵、氯化铵和农家肥。氨水和碳酸氢铵必须沟施覆土并及时浇水。硫酸铵和氯化铵易被作物吸收,施用后灌水使肥料与土壤密接能尽快发挥肥效。农家肥所含的大量微生物必须在水份充足的条件下才能分解有机质并释放大量的养分。施用尿素要延迟灌水,因尿素中的酰 A note of fertilization after irrigation time. After fertilization, the effect of fertilizers on the efficiency of the fertilizers will be greatly influenced by the time of irrigation. There are ammonia, ammonium bicarbonate, ammonium sulfate, ammonium chloride and farmyard manure needed to be irrigated in time. Ammonia and ammonium bicarbonate must be furrowed and timely watered. Ammonium sulphate and ammonium chloride are easily absorbed by crops, and fertilizers can be exerted as soon as possible after irrigation. The large number of microorganisms contained in farmyard manure must decompose organic matter and release large amounts of nutrients under sufficient water conditions. Application of urea to delay irrigation, due to urea in the acyl