Abstract:Objective To explore the optimal coupled management mode of light intensity and nitrogen application for Coffea arabica seedlings.Method We set three shading levels:No shade (S0, natural light), light shade (S1, 65% natural light) and severe shade (S2, 30% natural light), and three nitrogen levels:No nitrogen (N0,0 g·kg−1), medium nitrogen (N1, 0.20 g·kg−1), high nitrogen (N2, 0.40 g·kg−1). The effects of shading and nitrogen levels on growth, daily photosynthetic characteristics and biomass accumulation of C. arabica seedlings were studied.Result With the increase of shading degree, the total chlorophyll content increased. Compared with S0 treatment, the net photosynthetic rate, stomatal conductance, light radiation use efficiency and total biomass of C. arabica in S1 treatment increased by 13.54%, 18.54%, 127.77% and 12.41%, respectively. The total biomass decreased by 11.55% in S2 treatment. Compared with N0 treatment, the net photosynthetic rate, stomatal conductance, light radiation use efficiency and total biomass of C. arabica in N1 treatment increased by 27.25%, 20.77%, 10.80% and 18.47%, respectively, and these traits in N2 treatment increased by 14.85%, 25.99%, 41.65% and 21.02%, respectively. Compared with S0N0, with the increases of shading and nitrogen levels, leaf transpiration rate and light radiation use efficiency increased, leaf water use efficiency firstly increased and then decreased.Conclusion The optimal mode of light and nitrogen management of C. arabica is the combination of light shade and high nitrogen (S1N2). This mode is suitable for obtaining high leaf water-radiation use efficiency and biomass.