氮磷化肥配合施用是提高化肥利用率,充分发挥化肥经济效益的重要措施。我们施用化肥的氮磷比例都要经过计算。例如,我们施用化肥时,需要氮素8公斤,那么,施用硝酸铵(含氮量为34％)的计算方法是:8÷34％=23.5公斤,若改用尿素 Application of nitrogen and phosphorus fertilizer is to improve fertilizer utilization, give full play to the economic benefits of fertilizer an important measure. The proportion of nitrogen and phosphorus we use fertilizer must be calculated. For example, when we use chemical fertilizers, we need 8 kg of nitrogen. Then, the calculation method of applying ammonium nitrate (nitrogen content is 34%) is: 8 ÷ 34% = 23.5 kg,