三江源高寒草地常见可食牧草在不同分布区的营养成分分析

Analysis of nutritional components of common edibleforages from different area of Sanjiangyuanalpine grassland

摘要:

为了解不同区域可食牧草的营养特征并在后期加以利用,对三江源地区常见可食牧草进行概略养分分析,采用随机取样方法并进行常规分析。结果表明:(1)莎草科物种以及禾本科垂穗披碱草的养分含量与海拔存在一定的相关,在三江源区域的分布为东部和南部较高而西部北部偏低;(2)两种杂类草以及紫花针茅的综合营养价值为西部高于东部,但主要营养物质粗蛋白的含量为东部高于西部;(3)禾本科牧草在盛草期营养价值较低,加之种子针芒的影响不适合放牧,以紫花针茅和垂穗披碱草为优势种的草地可在开花结种前进行适度放牧;(4)以矮嵩草和黑褐苔草为代表的莎草科牧草营养好又耐牧,对于以此类物种为优势种的草地,可根据实际情况进行划区轮牧以防止过度放牧。

Abstract:

In order to understand the nutritional characteristics of edible forage in different regions and make full use of them at later stages,we adopted random sampling method and routine analysis to analyze the nutrition of common edible forages in the Sanjiangyuan Region(SJY).The results showed that,the nutrient content of both Cyperaceae species and Elymus nutans correlated with altitude,with forage nutrition being higher in southeast while lower in northwest of SJY.The nutrient content of the two hybrid grasses and Stipa purpurea changed with longitude,and the comprehensive nutritional values(CP+EE+Ash+NFC)in west was higher than those in east,while crude protein content showed the opposite trend.The nutritive value of Gramineae was low at the peak of greening season,and the grassland was unsuitable for grazing.The grassland dominated with Stipa purpurea and Elymus nutans could be grazed moderately before flowering and seed setting.Grasslands dominated with Kobresia humilis and Carex nigrum were nutritious and tolerant to grazing,therefore suitable for rotational grazing according to the actual situation to prevent overgrazing.