磷是作物生长所必需的 17种营养元素之一，而且为作物所必需的大量元素。它的作用不能被其它元素所取代。要使作物能达到最佳生长状态和获得最佳产量，必须施足磷肥。作物的需磷量大，而且磷肥施用量常常不足。那么怎样才能知道作物缺磷呢 ?这就需要识别作物的缺磷症状，以便 Phosphorus is one of the 17 nutrients required for crop growth and is a large number of essential elements for crops. Its role can not be replaced by other elements. To make the crop to achieve the best growth status and obtain the best yield, we must apply sufficient phosphate fertilizer. Phosphorus demand of crops is large, and the amount of phosphate fertilizer is often not enough. So how can we know the shortage of phosphorus in crops? This needs to identify the phosphorus deficiency symptoms in crops so that