Abstract: The plots were established on May 8,2003 at the experimental farm of Inner Mongolia University for Nationalities,Tongliao,Inner Mongolia Autonomous Region.The objective of this study was to determine the dynamics of soil organic matter,soil available nitrogen,and available potassium of Medicago varia Martyn.cv.Gannong No.1,Bromus inermis Leyss.,and mixture of M.varia and B.inermis stands during the subsequent years after the establishment.The results show that both soil organic matter and soil available potassium increased gradually in the three soil types with the development of time,and content of soil available nitrogen increased in 0~10 cm soil layer,but decreased in 10~30 cm soil layer.The accumulation of soil organic matter,available nitrogen,and available potassium was obviously influenced by the grassland types.Bromus inermis monoculture greatly increased soil organic matter and available potassium,while average content of soil available nitrogen was lowest,whereas,the mixture B.inermis and M.varia was more beneficial to the accumulation of soil available nitrogen.

Key words: Medicago varia Martyn, Bromus inermis Leyss., Soil, Organic matter, Available nutrient

摘要： 2003年5月在内蒙古自治区通辽市内蒙古民族大学试验农场建立试验小区,研究科尔沁地区不同生长年限的甘农1号杂花苜蓿(Medicago varia Martin. cv.Gannong No.1)、无芒雀麦(Bromus inermis Leyss.)单播与混播草地土壤有机质、速效氮和速效钾含量动态,旨在为该地区人工草地管理和生态恢复提供理论依据。结果表明:随着牧草生长年限延长,土壤有机质、速效钾含量呈递增趋势,速效氮含量仅在0~10cm土层呈增长趋势,而在10~30cm土层呈下降趋势;草地类型对土壤有机质、速效氮和速效钾积累有明显影响;无芒雀麦单播草地土壤有机质和速效钾平均含量最高,速效氮平均含量最低,混播草地则更有利于土壤速效氮的积累。

关键词: 杂花苜蓿, 无芒雀麦, 土壤, 有机质, 速效养分