红薯施用裂缝肥处暑前后红薯的块根开始进入膨大的高峰期。此期随着块根的迅速增大，田间的地面开始出现裂缝。进入裂缝期，标志着红薯地上部生长优势已经结束并转入地下根部膨大生长阶段。随着裂缝的增加，薯块的膨大，地上部茎叶生长逐渐衰落，叶色变淡转黄。薯叶的这一... Sweet potato fertilizer cracks before and after the summer sweet potato tubers began to enter the inflated peak. This period with the rapid increase of roots, the ground began to crack the ground. Into the crack period, marking the growth of sweet potatoes above the ground has ended and transferred to the roots of the expansion phase of growth. With the increase of cracks, tubers expand, the growth of stems and leaves aboveground gradually decayed, leaf color turned pale yellow. This leaf of potato