【作者】 高雪松； 任秋容； 何鹏； 邓良基； 黄春；

【Author】 Gao Xue-song~1 Ren Qiu-rong~1 HE Peng~2 Dend liang-ji~1 Huang Chun~1 (1.Resources and Environment Institute,Sichuan Agricultural University Ya’an 625014) (2.S ichuan Academy of Agricultural Sciences,Institute of Agricultural Information and Rural Economy,Chengdu 610066)

【机构】 四川农业大学资源环境学院； 四川省农业科学院 农业信息与农村经济研究所；

【摘要】 通过实测对比分析了川中紫色土丘陵区三种土地利用方式下不同坡位的土壤有机碳和全氮的垂直分布特征。结果表明:土壤剖面有机碳含量在上坡位和中坡位的垂直分布是疏林地>坡耕地>荒草地,下坡位则为坡耕地>荒草地>疏林地;有机碳含量在土壤表层(0～5cm)富集,随土层深度的增加而减少;土层深度对有机碳分布的解释度在96.7%～68%之间。土壤全氮含量在上坡位和中坡位均是疏林地最高,其次是坡耕地,荒草地的全氮含量最低,下坡位则是坡耕地的全氮含量高于疏林地和荒草地;土层深度对全氮分布的解释度在83.7%～20.7%之间。土壤有机碳与全氮呈极显著正相关(p<0.01),与 C/N 呈显著正相关(p<0.05);疏林地和荒草地的全氮与 C/N 呈负相关(p<0.01),坡耕地的全氮与 C/N 呈正相关(p<0.05)。由此说明紫色丘陵区土壤的 C/N 大小主要取决于有机碳含量。更多还原

【Abstract】 The vertical distribution characteristics of soil organic carbon and total nitrogen under different slope positions of 3 land use patterns had been contrasted and discussed by sampling and laboratory analy- sis.The results showed that,the vertical distribution characteristic of SOC was the woodland>sloping land>grassland on the uphill and middlehill slope-place,but was the sloping land>grassland>woodland in the downhill slope-place; SOC contents were accumulated between 0～5cm,and decreased with increasing soil depth; the soil depth explained the distribution of SOC from 96.7% to 68%.Total nitrogen content in the woodland was higher than the grassland and sloping land both on the uphill and middlehill slope-place, on the downhill slope-place total nitrogen content in the sloping land was highest,the woodland has the lowest nitrogen content; the soil depth explained the distribution of soil total nitrogen from 83.7% to 20. 7%.Soil organic carbon was significantly positive correlated with total nitrogen(p<0.01),as to C/N rati- o,the correlation was positively correlated(p<0.05); total nitrogen was negatively correlated with C/N (p<0.01)in the woodland and grassland,but was positively correlated(p<0.05)in the sloping land.The characteristics above suggested that soil C/N ratio in the hilly region purple depending primarily on organic carbon content.更多还原