混播草地牧草生长动态的研究

Study on Growth Dynamic of Alfalfa(Medicago sativa L.) in Mixed-seeding Grassland

对河南省黄河滩区紫花苜蓿与无芒雀麦和羊茅二种禾草的混播草地上、地下生物量的时空间动态进行了详细的分析与研究。结果表明:紫花苜蓿混播牧草地上和地下生物量季节动态均呈双峰曲线,地上生物量峰期分别在完熟期以及果后营养中期;地下生物量的峰期分别在种子完熟期和果后营养后期。地上部分生物量增长最快在抽穗期(现蕾期)到完熟期期间,紫花苜蓿与无芒雀麦以及羊茅的混播牧草的生长强度为11.92 g DM/m2.d和14.13 gDM/m2.d;地下部分增长最快分别在分蘖期(分枝期)到拔节期(抽茎期),紫花苜蓿与无芒雀麦以及羊茅的混播牧草根系生长强度分别为8.53 g DM/m2.d和8.94 g DM/m2.d。

Based on the soil and climate of Henan Yellow river beach,the characters of alfalfa（Medicago sativa L.） grassland mixed with two species of perennial Grasses[Smooth Brome（Bromus inermis Leyss） and Sheep Fescue（Festuca ovina L.）]were studied,and the spatial and temperal dynamic of above-ground biomass and under-ground biomass of mixed grasslands were analysed.The results showed that growth dynamic of above-ground biomass and under-ground biomass of mixed grassland presented a bimodal curve（full ripening stage and middle nutrition metaphase after ripening for above-ground biomass;seed full ripening stage and mutrition anaphase after ripening for under-ground biomass）.The above-ground biomass increased fast from sprouting stage to ripening stage,the growing density of mixed grass as alfalfa,Bromus inermisleyss and reed fescue are respectively 11.92 g DM/m2·d and 14.13 g DM/m2·d;the under-ground biomass has maximum increasing periods from tillering stage to elongating stage,with a root growing density of 8.53 g DM/m2·d and 8.94 g DM/m2·d.