中国生态农业学报2017，Vol.25Issue(10)：1433-1443,11.DOI:10.13930/j.cnki.cjea.170266
外源磷输入对农区湿地土壤碳库有效性 及周转特性的影响
Effect of exogenous phosphorus input on the availability and turnover characteristics of soil carbon pool in agro-riparian wetlands
摘要
Abstract
Exogenous nutrients significantly influence wetland ecosystems. In particular, the invasion of exogenous nitrogen (N) and phosphorus (P) significantly influences carbon cycle in wetland soils which further changes global carbon cycle in soil-atmosphere continuum. While there are currently several studies on exogenous N, the study of exogenous P is still lacking. To explore the effect of the input of exogenous P on the availability and turnover characteristics of soil carbon pool in wetlands, an experiment was de-signed for the simulation of the dynamics of exogenous P accumulation. The study simulated additive P gradient rates of 0 (P-0), 5% (P-5), 10% (P-10), 20% (P-20), 30% (P-30) and 60% (P-60) relative to initial total phosphorus (TP) content of sampled soils. Super-phosphate was the mode of addition of P to the soil coupled with the simulation of laboratory data. The changes in characteristics of soil carbon composition and biochemical indicators of P with the input of different levels of exogenous P were analyzed using con-ventional biochemical testing methods. The study also integrated several other factors for Pearson correlation analysis. The results showed that soil TP and Olsen-P contents strictly followed the loading rates of superphosphate, with a notable increase in microbial biomass phosphorus (MBP). The activity of acid phosphatase (AcP) was significantly suppressed by P addition. Dissolved organic carbon (DOC) and microbial biomass carbon (MBC) increased with increasing inputs of exogenous P, while total organic carbon (TOC) decreased at a maximum rate of 23%. For active organic carbon components of the soil, highly labile organic carbon (HLOC) was 54% higher under P-60 treatment than under the control group (P-0). Then recalcitrant organic carbon (ROC) content remarkably decreased with increasing input of exogenous P, with a maximum rate of decline of 22%. To certain extent, the results indicated that soil carbon pool was activated and the efficiency of availability increased. However, mid-labile organic carbon (MLOC) and labile organic carbon (LOC) almost had no change with increasing input of exogenous P. The MLOC and LOC ingredients were stable in the soil. The activities ofβ-1,4-glucosidase (βG) and cellobiohydrolase (CBH) significantly increased with increasing levels of ex-ogenous P, but the activity of dehydrogenase (DH) remained largely unchanged. For the analysis of mineralization characteristics of soil organic carbon (SOC), exogenous P addition significantly accelerated SOC mineralization rate. The cumulative mineralization increased with increasing addition of exogenous P. Potential mineralization potential of SOC was positively correlated with the addi-tion of exogenous P. From the above, exogenous P input increased the consumption of soil carbon pool and transformed soil carbon pool from steady state to unstable state. It also increased the activity and content of biological enzyme by stimulating microbial activ-ity. In summary, the availability and turnover rates of wetland soil carbon pool and the risk of wetland soil carbon output significantly increased under exogenous P input.关键词
外源磷输入/农区湿地/土壤碳库/碳库有效性/碳库周转特性Key words
Exogenous phosphorus/Agro-riparian wetland/Soil carbon pool/Carbon availability/Carbon turnover分类
农业科技引用本文复制引用
孙星照,沈建国,王忠,刘萌,楼莉萍,岳春雷,张志剑..外源磷输入对农区湿地土壤碳库有效性 及周转特性的影响[J].中国生态农业学报,2017,25(10):1433-1443,11.基金项目
国家自然科学基金项目(41373073, 41371447)和浙江省科技计划项目(2015F5002)资助 The study was supported by the National Natural Science Foundation of China (41373073, 41371447) and Zhejiang Province Science and Technology Project (2015F5002). （41373073, 41371447）
