Effects of Density and Nitrogen Fertilizer on The Yield, Agronomic Traits and Photosynthetic Characteristics of

In order to understand the optimal planting density and nitrogen fertilizer application amount of barley variety ‘Yundamai 12’, a two-factor randomized block experiment was designed to explore the effects of density, nitrogen fertilizer and their interactions on the yield, agronomic traits and photosynthetic parameters of ‘Yundamai 12’. The results showed that different densities had no significant effect on yield, but no effect on a single plant tiller. There were no significant effects of density and nitrogen application rates on four photosynthetic parameters and chlorophyll content. Dense nitrogen interaction did not affect yield, agronomic traits, stomatal conductance, intercellular CO 2  concentration, transpiration rate and chlorophyll significantly were not significant, but only had a significant effect on the net photosynthetic rate; the planting density was 850 000 hm 2 . The yield reached the maximum when the amount of nitrogen was 112.5 kg/hm 2 , which was the optimal density and nitrogen fertilizer scheme for ‘Yundamai 12’.