尿素含氮46％,素有“固体氮肥之冠”的美称。尿素含氮量高、剂型好,适用于各种土壤和作物。但施用时也应讲究科学施肥,否则会降低肥效。大体可归纳为“三宜”、“三不宜”。 “三宜”是: 1.宜深施 尿素不管作底肥还是作追肥,均应深施覆土。深施不仅可以控制尿素的水解速度,使其均匀地释放出氮素营养,而且可以防止氮的挥发损失,提高利用率。施用的深度一般以10厘米左右为好。 2.宜喷施 尿素属中性肥料,而且是有机化合物,不含副成分,对作物茎叶灼伤小。尿素分子体积小,容易渗透细胞膜,有利于叶片吸收,能在叶部迅速参与合成氨基酸,变成蛋白质,其数量和速度都超过其它氮肥。 46% urea nitrogen, known as the “crown of solid nitrogen,” the reputation. High nitrogen content of urea, good dosage form, suitable for all kinds of soil and crops. However, the application should pay attention to scientific fertilization, otherwise it will reduce fertilizer. Generally can be summarized as “three should”, “three should not.” “Three should be” is: 1. Should be deep urea regardless of as fertilizer or top-dressing should be deep soil. Deep application of not only can control the rate of urea hydrolysis, nitrogen nutrients to its uniform release, but also to prevent the loss of nitrogen volatility and improve utilization. Depth of application is generally about 10 centimeters as well. 2. Should be sprayed urea is a neutral fertilizer, but also organic compounds, non-sub-components, crop stems and leaves burns small. Urea molecules small size, easy to penetrate the cell membrane, is conducive to leaf absorption, can quickly participate in the leaf synthesis of amino acids, into protein, its quantity and speed than other nitrogen fertilizers.