禾豆混播草地生长性能分析与生产动态的探讨

Study on Growth Index and Production Dynamics of Grass-Legume Mixture Grassland

在紫花苜蓿与无芒雀麦分别以4.5kg/hm^2和15.75kg/hm^2混播的情况下,研究混播草内部各组分的相互关系以及牧草的生长动态,以便更好地了解该类草地的生产规律和利用特点,为畜牧业服务。结果表明:(1)苜蓿和无芒雀麦的AGR(绝对生长率)均呈双峰动态模式,第1个峰值出现在开花到成熟期,第2个峰值出现在果后营养后期,第1个峰值显著高于第二个峰。在开花(扬花)期以前,无芒雀麦的AGR高于苜蓿,但之后却是苜蓿高于无芒雀麦,杂草的AGR值也呈双峰曲线,但第1个峰值在抽穗扬花期,第2个高峰在完熟期;(2)苜蓿和无芒雀麦的RGR(相对生长率)呈双峰动态模式,峰值分别在春季分蘖期和果后营养中期,杂草则呈现由高到低的动态规律;(3)混播牧草地上和地下生物量季节动态呈双峰曲线,地上生物量峰值分别在完熟期(1137.45gDM/m^2)和果后营养后期(985.63gDM/m^2),生产最快在4月中旬到6月中旬期间。根冠比呈现由高到低,再由低到高的V型动态模式,最大值在越冬期,最小值在成熟期。

Based on soil and climate conditions of Henan Yellow River beach,the relative relationship and growing dynamics of alfalfa（Medicago sativa L.）-smooth brome（Bromus inermis Leyss）mixed sowing grassland（sowing rate being 4.5kg/hm^2 and 15.75kg/hm^2 respectively）were studied in order to learn the growth principles and utilization characteristics better for animal production.The results showed that：（1）Absolute growth rate（AGR）of alfalfa and smooth brome had apparent dynamics with 2peaks which appeared in flowering stage and ripening stage,and the first was higher than the second.Meanwhile,AGR of smooth brome was higher than that of alfalfa before flowering stage;AGR of alfalfa was higher than that of smooth brome after flowering stage.AGR of weed also represented dynamics（from high to low）with 2peaks which appeared in heading stage and ripening period.（2）Relative growth rate（RGR）of alfalfa and smooth brome were also dynamic with 2peaks which appeared in spring tillering stage and middle growing after-ripening period,RGR of weed also represented dynamics from high to low.（3）Growth dynamic of above-ground biomass and under-ground biomass of mixture grassland appeared the same curve with two peaks at ripening period（1137.45gDM/m^2）and late growing period after-ripening（985.63gDM/m^2）.Forage had the fastest growth rate from middle April to middle June.Root-shoot ratio appeared＂V＂dynamic model（from high to low,from low to high）with peak in wintering stage and trough in ripening stage.