紫花苜蓿与禾草混播草地生长动态研究

在河南省黄河滩区土壤和气候条件下，对紫花苜蓿与无芒雀麦和羊茅二种多年生禾草的混播草地特点进行了研究，并对其地上、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11.92gDM/(m2·d)和14.13gDM/(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8.53gDM/(m2·d)和8.94gDM/(m2·d)。

Studies on Growth Dynastics of Lucerne (Medicago Sativa L.) grasslands Mixed with Grasses

Based on soil and climate of Henan yellow river beach， the paper studied characters of Lucerne (Medicago sativa L.) grasslands Mixed with two species of perennial Grasses Smooth Brome(Bromus inermis Leyss) and Sheep Fescue(Festuca ovina L.)] and analysed temporal and spatial dynastics of above-ground biomass and under-ground biomass of mixed grasslands carefully. The results showed that growth dynastics of above-ground biomass and under-ground biomass of mixed grassland appear growth curve with two peaks (ripe period and middle growing period after ripe for above-ground biomass; ripe period and late growing period after ripe for under-ground biomass respectively). Above-ground biomass have maximum increasing periods from heading stage to ripening stage when growing intensities were 11.92gDM/(m2·d) and 14.13gDM/(m2·d) for Lucerne-Smooth Brome mixed grassland and Lucerne-Sheep Fescue mixed grassland respectively;under-ground biomass have maximum increasing periods from tillering stage to elongating stage when growing intensities of roots were 8.53gDM/(m2·d) and 8.94gDM/(m2·d) for two above-mentioned mixed grasslands respectively.