甜菜光合系统的大小明显受磷素水平的制约 ,二者呈极显著的正相关。增施磷肥能增加甜菜的叶绿素含量 ,提高单叶和群体的光合速率 The size of the sugar beet photosynthetic system was significantly restricted by the level of phosphorus, and the two showed a very significant positive correlation. The application of phosphate fertilizer can increase the content of chlorophyll in sugar beet and increase the photosynthetic rate of single leaf and population