灌溉量和密度对垂穗披碱草生长性能和物质分配的影响

Effects of irrigation volume and density on growth performance and above/underground biomass of Elymus nutans

合理灌溉量和适宜密度是栽培草地管理的关键因子。本研究采用盆栽试验分析了不同密度(20、35、50株·盆^–1)和灌溉量(35%~40%,60%~65%,75%~80%的土壤饱和含水量)互作对垂穗披碱草(Elymus nutans)生物量及其构成要素的影响。结果表明,灌溉量显著影响垂穗披碱草株高、分蘖数、根系体积、地上地下生物量、地上地下生物量比,且随灌溉量增大,垂穗披碱草地上地下生物量、分蘖数、根系体积均呈增加趋势,而株高、地上地下生物量比先增加后减小。密度显著影响垂穗披碱草分蘖数和单株地上生物量,且随密度增大,其分蘖数和单株地上生物量均呈减小趋势,而密度对地上和地下生物量、株高、根系体积以及地上地下生物量比没有明显影响。灌溉量与密度互作仅显著影响了单株生物量(P<0.05),而对种群生物量没有明显影响,这为高寒牧区垂穗披碱草栽培草地的建植和管理提供了科学依据。

Appropriate irrigation volume and density are the key factors for managing pasture.A pot experiment was carried out to determine the effect of three irrigation volumes(35%~40%,60%~65%,and 75%~80%of saturated soil moisture)and three densities(20,35,and 50 plants per pot)on growth performance and above/underground biomass of Elymus nutans.The results of this study showed that there was an increasing trend in the aboveground and underground biomass,tillers per plant,and root volume with increasing irrigation volume.The plant height and the ratio of aboveground biomass to underground biomass first increased and then decreased as irrigation volume increased.With the increase of plant density,tillers per plant and aboveground biomass per plant decreased,but the density had no significant effect on aboveground and underground biomass,plant height,root volume,and the ratio of aboveground biomass to underground biomass.The interaction of irrigation volume and plant density only had a significant(P<0.05)effect on the biomass of individual plants but had no significant effect on the biomass of the plant population.These results will provide useful information for the establishment and management of E.nutans pastures in alpine pastoral areas of China.