摘要
以黄土高原王东沟小流域为研究对象,分析了小流域地貌单元和土地利用方式对氮空间分布的影响。结果表明:研究区表层(0—20 cm)土壤全氮、硝态氮和铵态氮含量的均值分别为0.99,9.80,2.61 mg/kg。土地利用类型和地貌单元对土壤全氮和硝态氮的空间分布有显著的影响,并且两个因素存在着显著的交互作用,而对铵态氮含量空间分布影响不显著。不同土地利用类型土壤全氮分布规律为:林地>果园>荒草地>农田>废弃果园;硝态氮分布规律为:果园>农田>林地>废弃果园>荒草地;铵态氮分布规律为:林地>荒草地>果园>农田>废弃果园。不同地貌单元土壤全氮分布规律为:塬面>沟道>塬坡;硝态氮分布规律为:塬面>塬坡>沟道;铵态氮分布规律为:沟道>塬面>塬坡。上述研究结果对指导黄土高原沟壑区土地资源利用、施肥和植被恢复管理有重要参考价值。
Wangdonggou watershed with the area of 8.3 km^2 is located in the gully-hilly region of the Loess Plateau.The objective of this study is to analyze the effects of different land use types and geomorphic units on the spatial distribution of soil nitrogen of topsoil in Wangdonggou watershed.The results indicated that the mean contents of total nitrogen,nitrate nitrogen and ammonium nitrogen in the surface layer of the study area were 0.99 g/kg,9.80 mg/kg,2.61 mg/kg,respectively.Land use types and geomorphic units had significant effects and interaction on the spatial distribution of soil total nitrogen and nitrate nitrogen,while the spatial variability of ammonium nitrogen content was not significant.The content of soil total nitrogen under different land use types decreased in the order:woodland>orchard>natural grassland>farmland>abandoned orchard;the content of nitrate nitrogen decreased in the order:orchard>farmland>woodland>abandoned orchard>natural grassland;the contents of ammonium nitrogen decreased in the order:woodland>natural grassland>orchard>farmland>abandoned orchard.The content of soil total nitrogen under different geomorphic units decreased in the order:loess tableland>gully>slope land;the content of nitrate nitrogen decreased in the order:loess tableland>gully>slope land;the content of ammonium nitrogen decreased in the order:gully>loess tableland>slope land.Understanding the spatial distribution of soil nitrogen and its components in the small watershed of the Loess Plateau can help improve management efficiencies of land use,fertilizer,and vegetation restoration on small watershed scale on the Loess Plateau.
作者
赵晓芳
黄明斌
ZHAO Xiaofang;HUANG Mingbin(College of Natural Resources and Environment,Northwest A&F University,Yangling,Shaanxi 712100,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China)
出处
《水土保持研究》
CSCD
北大核心
2019年第4期62-67,共6页
Research of Soil and Water Conservation
基金
国家自然科学基金国际合作项目“黄土高原关键带植被—侵蚀相互作用及其对碳氮循环的影响”(41571130082)
关键词
全氮
硝态氮
铵态氮
土地利用类型
地貌单元
total nitrogen
nitrate-nitrogen
ammonium-nitrogen
land use type
geomorphic unit
