不同放牧强度对肃北高寒草原土壤肥力的影响  

Influence of Different Grazing Intensity to Soil Fertility in the Subei Alpine Steppes

作　　者：杨红善[1] 那·巴特尔 周学辉[1] 苗小林[1] 苏晓春 常根柱[1] 

机构地区：[1]中国农业科学院兰州畜牧与兽药研究所,兰州730050 [2]全球环境基金(GEF)项目肃北县项目办公室,甘肃肃北736300

出　　处：《水土保持学报》2009年第1期150-153,共4页Journal of Soil and Water Conservation

基　　金：全球环境基金(GEF)项目“放牧利用与草原退化关系研究”(052456CHA-GS-Y-2)

摘　　要：对肃北高寒草原不同放牧强度下不同土层的土壤肥力变化等进行了研究。结果表明:(1)高寒草原土壤物理性质的变化对土壤化学性质具有重要的调控作用,土壤化学性质对土壤肥力的演变则具有关键影响。(2)随着放牧强度的提高,0-10 cm,10-20 cm土层土壤容重均呈不同程度的增加,土壤孔隙度、土壤含水量则分别呈显著的递减趋势。(3)轻度放牧草地土壤有机质、土壤全氮含量高于中度放牧和重度放牧草地,20-30 cm土层有机质随放牧强度的增大呈明显下降趋势,即随放牧强度的增大草地深层土壤肥力呈退化趋势;肃北高寒草原的速效养分以多氮少磷富钾为特点,土壤速效氮、磷、钾含量在总体上随放牧强度的增加呈下降趋势。(4)在剖面上不同土层0-10 cm,10-20 cm,20-30 cm,随着土层深度的增加土壤有机质、pH值、土壤全氮、土壤速效氮、速效磷含量呈增加趋势,相反速效钾呈下降趋势。Characteristics of soil fertility variation and their relationships were studied in Subei alpine steppes. According to the classification standard of grazing intensity, we investigated four kinds of steppes （no grazing, light grazing, middle grazing and high grazing） and soil samples in 0--10 cm, 10--20 cm,20--30 cm layers were collected by a soil auger in steppes with different grazing intensity in each sampling area. The results were listed as follows： （1） Under the ecological conditions of the Subei alpine steppes, steppes grazing intensity had consistent effects on soil physical, chemical and biological fertilities. These soil physical, chemical and biological fertilities were associated with each other and set the direction of soil fertility evolvement in the alpine steppes. （2） With increased steppe grazing intensity soil bulk density at both 0--10 cm and 10--20 em layers showed a increased trend, while soil porosity and moisture content decreased significantly although steppe grazing intensity influenced soil moisture content more than soil porosity. （3） Soil organic matter and total N contents of light grazing steppes was higher than middle grazing and high grazing steppes, soil availa- ble N,P and K showed a increasing trend with steppe standard of grazing intensity. （4） Soil samples in 0--10 cm,10--20 cm,20--30 cm layers, soil organic matter content as well as the soil pH,total N and P contents were increased trend with the soil depth, but soil available K showed a decreasing trend.

关 键 词：高寒草原 放牧强度 土壤肥力 

分 类 号：S158.2[农业科学—土壤学] S181[农业科学—农业基础科学]