高寒牧区垂穗披碱草草地生物量及营养价值动态的研究  

Biomass and feeding value dynamics of Elymus nutans pasture in cold alpine pastoral areas

作　　者：严学兵[1] 汪玺[2] 郭玉霞[3] 周禾[1] 张德罡[2] 

机构地区：[1]中国农业大学草地所 [2]甘肃农业大学,甘肃兰州730070 [3]河南农业大学,河南郑州450002

出　　处：《草业科学》2003年第11期14-18,共5页Pratacultural Science

基　　金：国际原子能机构资助项目(RAS 5 035)

摘　　要：利用不同季节定点定期采样对高寒牧区垂穗披碱草草地地上生物量和营养成分含量动态变化进行了测定,并用3头装有瘤胃瘘管的牦牛,采用尼龙袋技术对牧草营养成分降解率进行了研究。结果表明,垂穗披碱草草地地上生物量在整个生长季呈"单峰"型表现,最大值呈现在8-9月,最低值出现在枯草末期(4月16日)。垂穗披碱草草地营养成分含量变化表现为:不同季节干质量略有不同,但变化幅度不大;有机质含量有逐渐增加的趋势;粗蛋白含量枯草期最低,6-7月含量最高,以后逐渐下降;酸性洗涤纤维含量恰好与粗蛋白含量相反,整个生长季呈"U"型曲线变化。在整个生长季各营养成分降解率表现为:青草期高于枯草期,但随着生育期的延长有逐渐下降的趋势,并且各营养成分降解率最大值出现的时间一致。然而营养成分含量和降解率最大值并不是出现在刚开始返青时,而是出现在6-7月。Aboveground biomass and nutrient contents of natural Elymus nutans pasture in a cold and humid alpine environment were determined, and three rumen cannulated yaks were used to study in situ digestibility of each nutrient at various periods, using the nylon bag technique Aboveground biomass showed a single peak curve for the full growth period with the highest value between August and September, and lowest at the end of the withered period in midApril Looking at changes in nutrient contents, there were slight differences in DM content between seasons; organic matter (OM) content gradually increased; crude protein (CP) content showed a single peak curve with highest value in JuneJuly and lowest during the withered period; and acid detergent fiber (ADF) content showed the opposite pattern to CP, showing a 'U' shaped change curve over the full growth period For the whole growth period,greater digestibility of each nutrient was seen during the green period than at the withered stage, digestibility decreased with increasing maturity, and the maximum digestibility levels of each nutrient appeared at the same time However, the highest values of nutrient contents and digestibility did not occur at the beginning of the regreening stage, but between June and July 

关 键 词：高寒牧区 地上生物量 营养成分含量 降解率 

分 类 号：S812[农业科学—草业科学]