Analysis on the difference of growth state and forest soil properties of Ophiopogon japonicus under interplanting of different tree species

【Objective】The purpose of the study was to evaluate the difference of growth state and forest soil properties of Ophiopogon japonicus interplanting under different tree species, in order to study the influence of the under-forest environment on the growth of O. japonicus, to screen the suitable interplanting model for its growth, and to provide a reference for the optimization of the under-forest cultivation of O. japonicus and the rationalization of the cultivation of under-forest medicinal plants. 【Method】Four types of planting models of O. japonicus were set: model 1,O. japonicus interplanted under Ligustrum lucidum; model 2,O. japonicus interplanted under Taxodium distichum; model 3,O. japonicus interplanted under Prunus serrulata + Zelkova schneideriana; model 4, non-under-forest single cropping of O. japonicus(control). The leaf length, leaf width, fresh weight, dry weight of O. japonicus in different models were compared.The content of leaf chlorophyll, root tuber nutrient content and soil nutrients in forest were measured. And comprehensive evaluation was performed by analysis of variance and correlation analysis. 【Result】The environment of the sample plots varied among the different interplanting models. The average annual temperature and light intensity were model 4>model 2>model 1>model 3. Compared with the control, the biomass and chlorophyll content of O. japonicum were increased by the three interplanting models. Under model 3, the leaf growth state of O. japonicus was the best, and the biomass and chlorophyll content were the highest. The growth of O. japonicum under model 1 was the second best. The flavonoid and polysaccharide contents in root tuber of O. japonicum were different among the four models. In model 3, the flavonoid content of O. japonicum root tuber was the highest(0.43 mg/g), and the polysaccharide content of O. japonicum in model 1 was the highest(171.02 mg/g). The interplanting models also increased the under-forest soil nutrient content. Among them, the contents of total nitrogen, total phosphorus, total potassium and total nitrogen in the soil in model 3 were the highest. The correlation analysis results showed that the leaf index of O. japonicum was significantly(P<0.05, the same below) or extremely significantly(P<0.01, the same below) negatively correlated with the average annual temperature and average annual light intensity, and the root tuber traits were significantly or extremely significantly positively correlated with soil nutrients. 【Conclusion】Compared with non-under-forest single cropping, the three interplanting models produce moderate shading effect and improvement of soil nutrients which are favorable to the growth of O. japonicus, but there are differences in the effects of different tree species on O. japonicus, among which the interplanting of P. serrulata+Z. schneideriana and L. lucidum with O. japonicus are more effective.