氮肥是农作物需要量最大的一类化学肥料,按照农作物的生长状况和阶段营养需要量来确定氮肥的精确施肥量一直是十分困难的,但现在则可以用便携式叶绿素仪来完成这一工作了。 大田农作物在缺氮时,一般会表现出一些明显的缺素症状,如叶片叶绿素含量降低导致颜色变浅,而氮素过多则植物颜色变深,也就是说叶片中的叶绿素含量与氮含量密切相关,通过精确测定叶片的变化就可了解作物营养状况,便携式叶绿素仪就是根据这一特点和原理研制成的。如日本生产的SPAD-501、502两种型号的叶 Nitrogen fertilizer is one of the most needed chemical fertilizers for crops. It has been very difficult to determine the precise amount of nitrogen fertilization according to the growth status of crops and the stage nutritional requirements. However, portable chlorophyll meters can now be used to accomplish this task. Field crops in nitrogen deficiency, the general will show some obvious signs of deficiency, such as the leaf chlorophyll content led to lighter color, while too much nitrogen is darker plant, which means that the leaf chlorophyll content and nitrogen content Closely related, through the precise determination of leaf changes can understand crop nutrition, portable chlorophyll instrument is based on this feature and principle developed. Such as Japan’s SPAD-501,502 produced two types of leaves