任务提出的背景化肥在提高单位面积农作物产量中所起的作用一般占40%左右,我国化肥的施用量近年来虽有较大增长,但氮磷钾比例失调的问题一直未能解决,其中氮与磷之比近年来一直在1:0.3左右,与农业部门的要求(1:0.5)有相当大的距离,这样不仅未能充分发挥这两种养 Tasks proposed Background The role of chemical fertilizers in improving crop yields per unit area generally accounts for about 40%, although the application of chemical fertilizers in China in recent years, although a larger increase, but the problem of imbalance in N, P and K has been unable to solve the problem, of which nitrogen The ratio of phosphorus to phosphorus has been around 1: 0.3 in recent years, and there is a considerable distance from the requirements of the agricultural sector (1: 0.5), thus not only failing to give full play to both