Direct Measurement of CO_2 Retention in Arable Soils with pH Above 6.5 During Barometric Process Separation Incubation

作     者：Hannah CONRADS Joachim INGWERSEN JU Xiaotang Thilo STRECK 

作者机构：Institute of Soil Science and Land EvaluationBiogeophysics SectionUniversity of Hohenheim College of Agricultural Resources and Environmental SciencesChina Agricultural University 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2018年第28卷第5期

页      面：726-738页

核心收录：

学科分类：0818[工学-地质资源与地质工程] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 090301[农学-土壤学] 

基　　金：funded by the German Research Foundation (DFG) in the framework of the SinoGerman Research Training Group "Sustainable Resource Use in North China" 

主　　题：孵化期间 土壤 分离 气压 pH 测量 BaPS 孵化方法 

摘      要：The barometric process separation(BaPS)technique is a well-established incubation method to simultaneously measure gross nitrification and respiration rates in *** application,however,is still critical in soils with pH above ***,a substantial part of microbial CO_2 production is retained in soil solution(CO_2,aq)due to shifts in the carbonate *** may lead to substantial errors in gas balance ***,utilization of the BaPS technique is only reliable if the critical term is adequately *** present an easy,inexpensive,and direct method,the sterilization-CO_2-injection(SCI)method,to measure CO_2 retention during soil *** soil was incubated in the BaPS system,and defined volumes of CO_2 were injected to stepwise increase CO_2partial pressure(p CO_2)inside the chamber and to analyse the physicochemical equilibration *** exemplary agricultural soils from Northeast China and Southwest Germany were used for method establishment,presenting pH values between 4.4 and 7.6 and carbonate contents between 0% and 3.9%.We observed that in soils with pH6.5,70%–90% of the injected CO_2 was taken up by the soil until the equilibrium inside the chamber was *** expected,in soils with low pH(6.5),measured CO_2 retention was ***_2 retention patterns were sensitive to incubation temperature with tri-fold dissolution capacity at 5~?C compared to 25?C,but insensitive to variations in soil water *** resulting soil-specific relationship between p CO_2 and CO_2,aq concentration allowed the quantification of CO_2,aq concentration as a function of headspace p CO_2.