Response of Photosynthesis to Eco-physiological Factors of Summer Maize on Different Fertilizer Amounts

Fertilizer Application improved the photosynthetic ability of summer maize mesophyll cell, which made the limiting factor of photosynthetic rate from nonstomatal limitation to stomatal limitation gradually, enhanced photosynthetic rate in the post stage, prolonged the high photosynthesis period, and raised photosynthetic ability in the afternoon. In the field grown condition, the main eco physiological factors affecting photosynthetic rate (P n) were photogynthetic activity radiation (PAR) and stomatal conductance (S c), which had positively direct effects on photosynthesis. PAR and transpiration rate (T r) were eco physiological factors significantly correlated with P n.