作物生长离不开阳光,不同作物对阳光的需要有个“上限”和“下限”。所谓“下限”,就是在光照弱时,光合产物只够作物呼吸消耗之用,没有剩余产物用于生长发育,于是生长发育便停止,这个“下限”称之为“光补偿点”。意思是说,在这个光照强度时,只有人为的补充光照,才能进行生长发育。但是,当光照增加到一定强度以后,光 Crop growth is inseparable from the sun, the needs of different crops on the sun has a “ceiling” and “lower limit.” The so-called “lower limit” means that when the light is weak, the photosynthetic products are only enough for the consumption of the respiration of the crops, there is no surplus product for growth and development, and the growth and development will stop. The “lower limit” is called “light compensation point.” The implication is that at this level of light intensity, only artificial supplemental lighting can grow and develop. However, when the light increases to a certain intensity, the light