Effects of Nitrogen Fertilizer on Growth,Photosynthetic Characteristics and Leaf Essential Oil Yield of Cinnamomum camphora

Dong Enyuan; Zhang Ting; Wu Yanfang; Zhang Yueting; Wu Qiaohua; Liu Xinliang; Tang Ming

doi:10.14083/j.issn.1001-4942.2025.05.014

Abstract：In order to investigate the effects of nitrogen(N)on the growth,photosynthetic characteristics and leaf essential oil quality of Cinnamomum camphora seedlings,and to determine the most suitable amount of nitrogen fertilizer for the growth of C.camphora seedlings,2-year-old aromatic camphor tree seedlings were taken as the research objects,and the treatments of different amounts of N fertilizer were set with no fertilizer as control(CK)to analyze their effects on the growth,photosynthetic characteristics and leaf essential oil con-tent of C.camphora seedlings.The results showed that compared with CK,appropriate amount of nitrogen fer-tilizer significantly increased the height and diameter of C.camphora seedlings,as well as the biomass of roots,stems,leaves and the whole plant(P<0.05).Nitrogen fertilizer was conducive to increase the content of chlorophyll a and chlorophyll b in leaves of C.camphora seedlings,and it also improved photosynthesis and light acclimatization through increasing net photosynthetic rate(Pn),stomatal conductance(Gs),transpira-tion rate(Tr),water use efficiency(WUE),apparent quantum efficiency(AQY),maximum net photosyn-thetic rate(Pmax),light saturation point(Isp),light compensation point(Icp),and dark respiration rate(Rd)in leaves.Different fertilization treatments had no significantly effects on yield of leaf essential oil,and leaf linalool yield was significantly increased by 129.17%.The results of correlation analysis showed that lina-lool yield was significantly positively correlated with AQY,Pmax,Lsp and Rd,and significantly negatively correlated with intercellular CO2 concentration(Ci)(P<0.05).In conclusion,nitrogen fertilizer could signifi-cantly increase the height,diameter,whole plant biomass,photosynthetic characteristics and linalool yield of C.camphora seedlings,and the most suitable nitrogen addition concentration was 302 mg·L-1.The results of this study could provide a theoretical basis for nitrogen fertilizer application in the directional cultivation of C.camphora raw material forests and the high-quality and high-efficiency cultivation.