关键词: 放牧, 草地, 多年生黑麦草, 灰色关联分析, 土地利用方式, 土壤理化性质, 层次分析法, 川中丘陵区

Abstract: This paper studies the effect of grazing intensity of the tiller size, tiller density, pastureproductivity and tissue turnover in a perennial ryegrass pasture ecosystem.The resultsshow that hard grazing leads to a greater tiller density and a lesser tiller weight than laxgrazing does.The net productivity is higher under hard grazing, because under conditionof lax grazing, the higher growth rate of pasture is offset by its senescence rate.Thereare advantages to spring-summer pasture production from a flexible pasture management.

Key words: Grazing, Pasture, Perennial ryegrass, central Sichuan hilly area, land use type, soil physical and chemical property, grey correlation analysis., analy-tic hierarchy process