根际激发效应对土壤有机碳累积及分解的影响  

Influence of rhizosphere priming effects on accumulation and decomposition of soil organic carbon

作　　者：莫朝阳 张鑫林 杨京平[1] MO Chaoyang;ZHANG Xinlin;YANG Jingping(College of Environmental and Resource Sciences,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]浙江大学环境与资源学院,杭州310058

出　　处：《浙江大学学报（农业与生命科学版）》2021年第4期527-533,共7页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家自然科学基金(31870419);国家重点研发计划(2016YFD0300203-4)。

摘　　要：借助13C自然丰度法,通过盆栽实验测试2种植物(玉米、高粱)、2种土壤(水稻土、土)在2个生育期中的根际激发效应以及土壤样品的轻组有机碳(ρ_(1)<1.7 g/cm^(3))和重组有机碳(ρ_(2)>1.7 g/cm^(3))含量。结果表明:种植作物显著增强了土壤有机质的分解;在水稻土中种植玉米的大喇叭口期,总二氧化碳(CO_(2))碳通量中来源于土壤的碳最多,达到18.49 mg/(kg·d)。在各个时期,玉米的根际激发效应比高粱的根际激发效应都要强,种植玉米将带来更多的CO_(2)排放。轻组有机碳含量在根际激发效应发生过程中显著改变,而重组有机碳含量则维持稳定。因此,根际激发效应可能直接作用于轻组有机碳。本研究为合理控制根际激发效应强度和降低全球CO_(2)排放量提供了理论基础。By using a 13C natural abundance method,this study investigated the rhizosphere priming effects(RPE)of sorghum and maize growing in two types of soil(paddy soil and lou soil)at two stages,and the contents of light fraction organic carbon(ρ_(1)<1.7 g/cm^(3))and heavy fraction organic carbon(ρ_(2)>1.7 g/cm^(3))of soil were also determined.The results showed that planting crops significantly enhanced the soil organic matter decomposition.And the maize induced the most CO_(2)-C flux derived from soil organic carbon at the trumpet stage in paddy soil,which reaching 18.49 mg/(kg•d).The maize induced stronger RPE than sorghum across all growth stages,which indicated that planting maize would bring more CO_(2) emission.The content of light fraction organic carbon of soil changed significantly,while the content of heavy fraction organic carbon remained stable during RPE process.Hence,RPE may directly function on the light fraction organic carbon.This study provides the theoretical basis for controlling the RPE intensity reasonably and reducing global CO_(2) fluxes.

关 键 词：根际激发效应 土壤有机碳 轻组有机碳 重组有机碳 

分 类 号：S154.4[农业科学—土壤学]