Objectives We investigated the effect of mixing planting with Hypnum plumaeforme on the growth indicators and nutrient absorption of garden plants, and the nutrient change in growth substrate, in order to provide reference for suitable bryophyte-garden plant assortment.

Methods A pot experiment was carried out in a greenhouse located in Guizhou University, using 5 commonly used garden plants and a moss (H. plumaeforme) as test materials. The treatments were composed of monoculture of the 5 plants and the moss, and the mixed planting of the five garden plants with the moss. The mixed planting treatments were denoted as J1, J2, J3, J4, and J5 for Euryops pectinatus, Calendula officinalis, Zephyranthes carinata, Zephyranthes candida, and Oxalis corywbosa, respectively. At the 30, 60, and 90 days of growth, the biomass, chlorophyll a+b, soluble sugar, and nutrient contents of garden plants and moss were measured. At the same time, the surface shading and moisture of substrates were measured, and the total N, P, K and organic carbon content in the substrates were determined. The relative neighbor effect index (RNEI) was used to judge the effect of mixed planting on the growth of garden plants and moss, and the fuzzy membership function was used to evaluate the overall growth of hybrid plants.Results1) Mixed planting increased the growth of E. pectinatus, Z. carinata and Z. candida in biomass, chlorophyll a+b, SS, N, P, K and C content, while the promotion only appeared on the SS, P, K and C contents in C. officinalis and O. corywbosa. Mixed planting with the five garden plants affected the growth and nutrient absorption of moss in different degrees. J1, J3 and J4 treatments significantly increased the biomass, and the contents of chlorophyll a+b, P and C in moss, while J2 and J5 treatments inhibited the growth and significantly decreased chlorophyll a+b, soluble sugar (SS), N and C contents of moss. The RNE of mixed planting were all positive for the growth of the five garden plants, while that for the moss in J1, J3 and J4 treatments were positive and in J2 and J5 were negative, indicating that J1, J2 and J3 treatments were beneficial while J2 and J5 were against the growth of moss. 2) Compared with monocultiral controls, all the five mixed planting treatments increased substrate moisture; J1, J2, J3 and J4 treatments increased the total N, P, K and organic C contents, and J5 treatment increased organic C but reduced total N, P and K contents in the substrates. 3) According to the comprehensive evaluation of membership functions, the highest comprehensive evaluation index of moss was in J1 (0.93) and the lowest in J2 (0.18); Except O. corywbosa, the membership function values of the other four garden plants under mixed planting were all higher than under monoculturing.

Conclusions E. pectinatus, Z. carinata and Z. candida are suitable for mixed planting with H. plumaeforme, they promote the growth of each other, and increase the substrate nutrient content and moisture. The prospect mixed planting garden plants are H. plumaeforme and E. pectinatus.