混播方式对无芒雀麦+红豆草混播草地植物生长效率及混播效应的影响

摘要

本研究从混播牧草相对生长效率和种间竞争动态的角度出发,利用盆栽试验分析和比较不同混播方式下无芒雀麦(Bromus inermis)、红豆草(Onobrychis viciaefolia)的相对生长速率、叶绿素荧光参数、牧草相对产量及相对产量总和,以期明确无芒雀麦+红豆草混播草地的种间竞争过程和混播优势产生机制.结果表明,两种牧草株高相对生长速率和密度相对生长速率均表现出混播大于单播,行距30 cm异行混播表现出较高的相对生长速率.异行混播下无芒雀麦相对密度(RDg)和红豆草相对密度(RDl)均高于同行混播,行距30 cm异行混播下红豆草RDl和相对产量(RY)均较高;同行混播和行距30 cm异行混播具有较高的相对产量总和(RYT).无芒雀麦叶片的初始荧光效率(Fo)和最大荧光(Fm)均为异行混播高于单播,叶片PSⅡ潜在活性(Fv/Fo)则是单播高于同行混播;在不同混播方式下两种牧草叶片单位面积捕获的光能(TRo/CSo)值相差较小;行距30 cm异行混播、行距45 cm异行混播下两种牧草均具有较高叶绿素荧光参数.因此,行距30 cm+异行混播具有较高群体光合效率和豆科牧草种间竞争力,形成了组分结构稳定、生产性能较高的群体.%This study aimed to determine the relative growth efficiency and interspecific competition dynamics of two kinds of forage grass (Bromus inermis and Onobrychis viciaefolia )under different mixed modes (i.e.,al-ternating rows and peer-mixed seeding patterns).A pot experiment was performed to analyse and compare the relative growth rates,chlorophyll fluorescence parameters,herbage yields,and relative yields (RY)of the grasses.The results showed that the relative growth rates of both grasses were higher with mixed seeding than with monocropping,and using a spacing of 30 cm between rows for the alternating rows mixed seeding pattern yielded the highest relative growth rates among the tested treatments.The relative density of B .innermis (RDg )and the relative density of O .viciaefolia (RDl )under the alternating rows mixed seeding pattern were both higher than that in the peer-mixed seeding pattern.A spacing of 30 cm between alternating rows yielded higher RDl and RY values of O .viciaefolia ,while peer-mixed seeding or a spacing of 30 cm between alterna-ting rows yielded a higher RYT (total relative yield)value.The initial fluorescence efficiency Fo and maximal fluorescence Fm of B .innermis in the mixed sowing treatments were higher than those in the monocropping treatment,and the photosystem Ⅱ potential active center Fv/Fo value of the monocropping treatment was higher than that in the mixed sowing treatments.Under different mixed seeding methods,the capture of light energy per unit area (TRo/CSo )values of the two kinds of forage grass were smaller,and a spacing of 30 or 45 cm between alternating rows yielded higher chlorophyll fluorescence parameters.Therefore,mixed seeding with a spacing of 30 cm or more between alternating rows can yield a high photosynthetic efficiency and high in-terspecific competition between legume forages,resulting in high component stability and performance for this mixed seeding pattern.