不同地类红壤坡面土壤有机质及氮素分布研究  

Analysis of soil organic matter and nitrogen distribution on slopes under different land use types in red soil region

作　　者：蒋薇[1] 王克勤[1] 郭玲梅 苏备 

机构地区：[1]西南林业大学环境科学与工程学院,云南昆明650224

出　　处：《广东农业科学》2014年第15期61-65,共5页Guangdong Agricultural Sciences

基　　金：国家自然科学基金(30660037);云南省自然科学基金(2006D0041M);云南省科技计划项目(2006SG20)

摘　　要：选取我国云南地区抚仙湖流域典型流域尖山河小流域为试验区,以不同土地利用类型的径流小区作为试验对象,对径流小区内土壤不同土层有机质、全氮和速效氮含量进行测定。结果表明：在土地利用方式不同的红壤坡面上,土壤有机质、全氮和速效氮的含量均表现为坡下部﹥坡中部﹥坡上部;土壤剖面有机质、全氮和速效氮的含量均随着土层深度的增加而降低,即0～20 cm〉20～40 cm〉40～60 cm,且随深度增加含量差距减小;在坡耕地、次生林、人工林和灌草丛4种土地利用类型中,土壤有机质的含量表现为次生林〉人工林〉灌草丛〉坡耕地,土壤全氮的含量表现为灌草丛〉坡耕地〉人工林〉次生林,土壤速效氮的含量表现为坡耕地〉次生林〉灌草丛〉人工林。通过回归分析发现,土壤有机质、全氮和速效氮含量之间均具有显著的线性相关关系,土壤有机质是表征土壤供氮能力的重要指标;通过相关性分析得到土层深度与土壤有机质、全氮和速效氮的含量之间均具有显著的负相关关系;不同土地利用类型土壤有机质和全氮含量之间的换算系数不同,表现为坡耕地〉灌草丛〉人工林〉次生林。This study mainly studied the soil organic matter and nitrogen contents of four different land use types in typical small watershed of Jianshan river,Fuxian Lake.The results showed that,on the slopes of different land use types,the contents of soil organic matter and nitrogen were the highest on the lower slopes and the lowest on the upper slopes,and it＇s placed in the middle on the mid-slopes.Soil organic matter and nitrogen contents decreased with soil depth increasing,shouing 0-20 cm higher than 20-40 cm and 20-40 cm higher than 40-60 cm.With the increase of soil depth,the gap between contents decreased.The content of soil organic matter in sequence was secondary forest,planted forest,shrub-grassland and farmland.The content of total nitrogen in sequence was shrub-grassland,farmland,planted forest and secondary forest.The content of available nitrogen in sequence was farmland,secondary forest,shrub-grassland and shrubgrassland.Through regression analysis,we obtained that there was significant linear correlation among the contents of soil organic matter,total nitrogen and available nitrogen.The content of soil organic matter is an important index for soil nitrogen supplying capacity.Through correlation analysis,we got that there was significant negative correlation between soil depth and the contents of soil organic matter and nitrogen.The conversion coefficients between soil organic matter and total nitrogen were different in different land use types,the sequence was farmland,shrub-grassland,planted forest and secondary forest.

关 键 词：土地利用类型 有机质 全氮 速效氮 土层深度 

分 类 号：S153.6[农业科学—土壤学]