Affected by such factors as Chl and CA activity, the Pn of all leaves were also increased by zinc fertilization, and the highest Pn also occurred at the Zn level of 11.25 kg hm-2, just as the Chl and CA activity were.

• 小麦叶片光合速率受叶绿素含量和酶活性等因素的影响，施锌后叶绿素含量增加，CA活性提高，叶片光合速率也提高。 与叶绿素含量和CA活性一样，施锌过量光合速率下降，基本以施锌量11.；25 kg hm~(-2)光合速率最高。