水稻在插秧后３天左右，秧苗叶片挺起，早晨叶尖吐水，晴天中午５０％秧苗心叶展开，并扎下新根，即为返青。水稻移栽以后，由于根系受到机械损伤，吸收水、肥的能力降低，因而地上部暂时停止生长，叶色变黄，不长新叶。新根生出以后，吸收能力才能逐渐增强，植株开始继续生长 Rice about 3 days after transplanting, seedling leaves tall, spit water in the morning, noon 50% sunny seedling leaf sprout, and take a new root, that is greening. After transplanting rice, due to mechanical damage to the root system, to absorb water, reduce the ability of fertilizers, and thus temporarily stop the growth of the shoots, leaves yellow, not long new leaves. After the new root is born, the absorptive capacity can be gradually increased and the plant begins to grow