不同载牧量对苜蓿放牧地植被的影响

研究于１９９２年在甘肃河西半荒漠地区杂花苜蓿型人工草地进行，试验采用单因子设计，衣载牧量分轻牧、中牧、重牧３个处理６个重分区轮牧。结果表明，试验当年，草地类型未发生演变，披碱草随放牧加强而衰退，无芒雀麦和红豆草在中牧下得到促进，紫羊茅在重牧下受抑。由牧草产量和质量的分析表明，在西北干旱地区，苜蓿型草地可于６月初刈草后，连续放牧３次，且载牧量以中等为宜。

EFFECTS OF DIFFERENT STOCKING RATE ON VEGETATION OF ALFALFA GRAZING LAND

This trial was conducted on the artificial grassland of alfalfa (Medicago varia ) type in the semiarid Hexi Corridor in 1992, and was designed in single-factor, 2 replicates in three stocking rates i.e. low, medium and high. In the present year, Elymus sibiricus declined with the enhanced grazing density, Bromus inermis and Onobrychis viciaefolia were promoted by the medium grazing, and Festuca rubra were inhibited by the heavy grazing. The analysis according to the herbage yield and quality showed that alfalfa type pasture in the arid region, northwest of China, could be grazed rotationally three times with the medium stocking rate (intake rate about 50%) after being mowed in earlier June.