亚热带稻田土壤碳氮磷生态化学计量学特征  

Ecological Stoichiometry of Carbon,Nitrogen,and Phosphorus in Subtropical Paddy Soils

作　　者：宋佳龄 盛浩[2] 周萍[3] 段良霞 周清[1] 张杨珠[2] SONG Jia-ling;SHENG Hao;ZHOU Ping;DUAN Liang-xia;ZHOU Qing;ZHANG Yang-zhu(College of Resources&Environment,Hunan Agricultural University,Changsha 410128,China;Institute of Soil Science,Hunan Agricultural University,Changsha 410128,China;Key Laboratory of Agro-Ecological Processes in Subtropical Region,Institute of Subtropical Agriculture,Chinese Academy of Sciences,Changsha 410125,China)

机构地区：[1]湖南农业大学资源环境学院,长沙410128 [2]湖南农业大学土壤研究所,长沙410128 [3]中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室,长沙410125

出　　处：《环境科学》2020年第1期403-411,共9页Environmental Science

基　　金：国家自然科学基金项目(41571234,41671242);国家科技基础性工作专项(2014FY110200A15);湖南农业大学2018大学生科技创新基金项目(2018ZK28)

摘　　要：为了解稻田土壤中是否存在稳定的土壤有机碳(C)、氮(N)和磷(P)比值,基于亚热带区110个水稻土剖面和587个发生层的土壤调查数据库,在区域尺度上分析了典型水稻土C∶N∶P比值的生态化学计量学特征,并应用相关分析和冗余分析,研究水稻土C∶N∶P比值与土壤-环境因子(地形和母质、土壤发生层、土壤类型和土壤理化性质)的关系.结果显示,亚热带区稻田土壤C∶N、C∶P和N∶P的剖面加权平均值分别为12. 6、49和3. 9,C∶N∶P为38∶3. 2∶1.不同母质起源、不同土壤亚类和不同发生层的水稻土C∶N变异相对较小;但C∶P和N∶P的变异很大,两者均值也远低于全球(186和13. 1)和中国土壤(136和9. 3)的C∶P和N∶P的平均水平.尽管稻田土壤剖面的C∶N∶P相对不稳定,但由于稻田表土生物与环境相互作用强烈,表土C∶N相对稳定(14. 2).这反映长期水耕熟化作用下,稻田表土中C和N仍存在紧密的耦合作用.然而,在稻田土壤剖面上,C∶P和N∶P并不稳定,SOC与全P含量、全N与全P含量也无显著相关性,表明环境变化可能导致土壤C∶N∶P解耦.地形、土壤质地、氧化铁和容重是调控稻田土壤剖面C∶N∶P的关键土壤环境因子.This study aims to understand the existence of stable soil organic carbon( C),nitrogen( N),and phosphorus( P) ratios in paddy soil. Based on a field soil survey database,the ecological stoichiometry of the C∶ N∶ P ratio of 110 subtropical paddy soil profiles and 587 genetic horizons were analyzed at a regional scale. Relevant analysis and redundancy analysis( RDA) are used to study the relationships between C∶ N∶ P ratios and soil-environmental factors( topography,parent materials,soil genetic horizons,soil groups,soil physical,and chemical properties). The results showed that the weighted averages of C ∶ N,C ∶ P,and N ∶ P in paddy soils of subtropical regions were 12. 6,49,and 3. 9,respectively,and C∶ N∶ P was 38∶ 3. 2∶ 1. The C∶ N of paddy soil did not vary significantly with parent materials,soil groups,or genetic horizons. However,the C∶ P and N∶ P variations were significantly different,and the mean values of the two were much lower than global ratios( 186 and 13. 1) and average levels of C∶ P and N∶ P in Chinese soils( 136 and 9. 3). Although the C∶ N∶ P ratio in the paddy soil profile was relatively unstable,the topsoil C∶ N( 14. 2) was relatively stable due to the strong interaction between the topsoil and the environment. This reflects the close coupling of C and N in the topsoil of paddy fields under long-term anthrostagnic maturation. However,in the paddy soil profile,C∶ P and N∶ P were not stable,and there was no significant correlation between soil organic carbon( SOC) and total P content,total N,or total P content,which suggests that environmental changes may lead to soil C∶ N∶ P decoupling. It was found that topography,soil texture,iron oxide,and bulk density are all key soil-environmental factors that regulate the soil profile of rice paddy C∶ N∶ P.

关 键 词：计量土壤学 土壤养分 底土 土壤剖面 土壤发生分类 土壤环境因子 

分 类 号：X144[环境科学与工程—环境科学] X171