土壤理化性状.docVIP

农牧交错带退耕还草对土壤理化性质的影响 郭彦军①② 韩建国①* （1 中国农业大学草地研究所，北京100094；2 西南大学动物科技学院，重庆400715） 摘要: 在北方农牧交错带以马铃薯地为对照，研究了退耕地建植多年生人工草地对土壤理化性质的影响。研究结果表明，退耕地种草可提高土壤的有机碳含量，增加表层土壤的全氮含量。人工草地0-10cm土层有机碳含量较耕地平均高20.84%，土壤氮素含量平均高18.21%。退耕地种草对土壤有效磷含量、电导率和pH水平无显著影响。土壤氨态氮和硝态氮含量的变化因季节不同差异较大。耕地与人工草地土壤理化指标之间的差异在很大程度上受生长季节的影响。在评价退耕地种草效果时，选择适宜的采样季节可能更为关键。 关键词：农牧交错带；人工草地；耕地；理化性质 Effects of returning cultivated land to artificial grassland on soil physical and chemical properties in the agro-pastoral transitional zone of north China GUO Yan-jun①② HAN Jian-guo①* (1 Institute of Grassland Science, China Agricultural University, 100094, Beijing; 2 College of Animal Science and Technology, Southwest University, 400715, Chongqing) Abstract: A study was carried out to analyze the effect of returning cultivated land to perennial artificial grassland on soil physical and chemical properties in agro-pastoral transitional zone of north China. The cultivated land was for potato plantation with one year fallowness. The results showed that contents of soil organic carbon and total nitrogen increased by 20.84% and 18.21% in 0-10 soil layer after returning potato lands to grasslands. Artificial grassland had no significant influence on soil available phosphorus content, electric conductivity and pH levels. Soil ammonia nitrogen and nitrate nitrogen contents changed significantly with seasons. The differences of physical and chemical indexes between cultivated land and grasslands depended upon growing seasons. It was suggested that suitable sampling season might be more important in evaluating the efficiency of artificial grasslands. Keywords: agro-pastoral transitional zone; artificial grassland; cultivated land; physical and chemical properties 北方农牧交错带是我国长期人类活动所形成的传统农业与传统牧业镶嵌结合区域，约占国土面积的30%。人口数量的不断增加，加剧了当地草地土壤的开垦力度，土壤物理、化学及生物学质量严重下降[1]，土壤碳、氮循环发生改变[2]，对环境造成严重不良影响[3]。 自国家施行退耕还草政策以来，北方农牧交错带人工草地面积不断扩大。退耕地种草被认 基金项目：国家十一五专项（2006BAD16B01） 作者简介：郭彦军（1974-），男，青海人，副教授，博士, 主要从事牧草营养与草地管理的教学与科研工作,email: qhgyj@swu.ed