以马缨杜鹃（Rhododendron delavayi Franch.） 1年生幼苗为材料，用体积分数10%、20%、30%和40%木炭或稻壳炭与木炭组成8组复合基质，比较各组复合基质的理化性质差异，分析幼苗生长及叶片光合生理指标和矿质元素含量的变化及其与复合基质理化性质的相关性。结果表明：木炭和稻壳炭形态结构和理化性质均不同。随木炭或稻壳炭体积分数的提高，复合基质的pH值、电导率、通气孔隙度、总孔隙度以及P、K、Mg、Na、Fe和Mn含量总体上逐渐升高，持水孔隙度和N含量总体上逐渐降低，Zn含量则无明显变化，且多数复合基质的各项理化指标与对照（泥炭）无显著差异。随木炭体积分数的提高，幼苗的株高、地径、单株叶片数、单株叶面积、单株各器官干质量和单株总干质量以及叶片的叶绿素相对含量（SPAD）、净光合速率（Pn）、蒸腾速率（Tr）和气孔导度（Gs）总体上先升高后降低，水分利用效率（WUE）逐渐降低；叶片的N、P、K、Mg、Na、Fe、Mn和Zn含量总体上逐渐升高。随稻壳炭体积分数的提高，除幼苗株高外，其他7项生长指标以及叶片的SPAD、Pn、Tr和Gs值总体上逐渐升高，WUE值总体上逐渐降低；叶片的P、Mg、Fe和Mn含量逐渐升高，N、K、Na和Zn含量波动变化。相关性分析结果表明：幼苗的株高和地径与复合基质各项理化指标均无显著相关性；叶片的胞间CO₂浓度和WUE值与复合基质总孔隙度呈显著负相关；单株的叶片数、叶面积、叶干质量和根干质量以及SPAD、Pn、Tr和Gs值与复合基质的总孔隙度和Mn含量呈极显著或显著正相关，与pH值、电导率和Na含量呈显著负相关。综合分析结果表明：木炭或稻壳炭与泥炭组成的复合基质均可不同程度促进马缨杜鹃幼苗的生长、光合代谢和矿质元素吸收；添加体积分数20%或40%稻壳炭时，马缨杜鹃幼苗长势较佳、光合能力较强。

Taking one-year-old seedling of Rhododendron delavayi Franch. as material， and peat was supplemented with 10%， 20%， 30% and 40% （volume fraction） wood biochar or rice husk biochar to compose 8 groups of composite substrates， the differences of physical and chemical properties among different groups of composite substrates were compared， and the variations of growth and photosynthetic physiological indexes and mineral element content in leaf of seedling as well as their correlations with physical and chemical properties of composite substrates were analyzed. The results show that morphological structures and physical and chemical properties of wood biochar and rice husk biochar are all different. With the increase of volume fraction of wood biochar or rice husk biochar， pH value， electrical conductivity， aeration porosity， total porosity， and contents of P， K， Mg， Na， Fe and Mn of composite substrates gradually increase in general， water holding porosity and N content gradually decrease in general， Zn content has no obvious change， and each physical and chemical index of most composite substrates have no significant differences with those of the control （peat）. With the increase of volume fraction of wood biochar， the height， ground diameter， leaf number per plant， leaf area per plant， dry mass  of each organ per plant and total dry mass per plant of seedling and relative content of chlorophyll （SPAD）， net photosynthetic rate （Pn）， transpiration rate （Tr） and stomatal conductance （Gs） of leaf first increase and then decrease in general， and water use efficiency （WUE） gradually decreases； contents of N， P， K， Mg， Na， Fe， Mn and Zn in leaf gradually increase in general. With the increase of volume fraction of rice husk biochar， except for height of seedling， other 7 growth indexes and SPAD， Pn， Tr and Gs values of leaf gradually increase in general， and WUE value gradually decreases in general； contents of P， Mg， Fe and Mn in leaf gradually increase， and contents of N， K， Na and Zn show a fluctuated variation. The correlation analysis result shows that there are no significant correlations of height and ground diameter of seedling with each physical and chemical index of composite substrates； intercellular CO₂ concentration and WUE value of leaf show significant negative correlations with total porosity of composite substrates； leaf number， leaf area， dry mass of leaf and dry mass of root per plant， and SPAD， Pn， Tr and Gs values all show extremely significant or significant positive correlations with total porosity and Mn content of composite substrates， and show significant negative correlations with pH value， electrical conductivity and Na content. The comprehensive analysis result shows that composite substrates composed of wood biochar or rice husk biochar and peat can promote growth， photosynthetic metabolism and mineral element absorption of R. delavayi seedling in different degrees； adding the volume fraction of 20% wood biochar or that of 40% rice husk biochar， the growth of seedling is relatively good and the photosynthetic ability is relatively strong.