In order to investigate the photosynthetic characteristics of Onobrychis viciaefolia seedlings and the main environmental factors directly influencing photosynthesis of the seedlings

the photosynthetic characteristics of Onobrychis viciaefolia seedlings and the diurnal variations of the factors were measured using Li-6400 photosynthesis system by a pot experiment.Meanwhile

the effects of the factors on photosynthetic rate(Pn) were analyzed using correlation analysis and stepwise multi-regression analysis.Results showed that the diurnal variation of the Pn presented a feature of single peak curve with its peak value appearing at 12:00 am

about 27.63 μmol/(m2·s).The daily average Pn over the observation time was calculated to be 22.33 μmol/(m2·s).Besides

according to correlation analysis

photosynthetically active radiation(PAR) was found to be the main environmental factor directly influencing the daily Pn of Onobrychis viciaefolia seedlings and the PAR had a highly significant positive correlation with the Pn.