外源碳酸钙对黔中喀斯特地区土壤有机碳矿化的影响

Effect of Exogenous Calcium Carbonate on Mineralization of Soil Organic Carbon in Karst Area of Central Guizhou

本研究以黔中喀斯特区典型黄壤和石灰土为研究对象,通过100 d室内土壤有机碳矿化培养试验,结合^(13)C同位素示踪技术,研究外源碳酸钙对土壤CO_(2)总释放量的贡献及对土壤有机碳矿化的激发效应,为提高喀斯特地区土壤有机碳稳定性提供理论依据。结果显示,Ca^(13)CO_(3)在培养前期(1~10 d)可释放13 CO_(2),后期(10~100 d)趋于稳定,Ca^(13)CO_(3)对黄壤和石灰土总CO_(2)累积释放量具有一定的贡献,其贡献率达到25.47%和20.76%;外源Ca^(13)CO_(3)对黄壤和石灰土有机碳矿化均产生了负激发效应,培养100 d后土壤有机碳累积矿化量分别减少了76.05%和45.14%,激发效应主要受土壤类型的影响,黄壤有机碳矿化的负激发程度高于石灰土。

In this study,the typical yellow soil and lime soil in the karst area of central Guizhou were studied as the research object,and Througha 100-daymineralization cultivationof soil organic carbonindoors,,combined with ^(13)C isotope tracing technology,the contribution of exogenous calcium carbonate to the total release of soil CO_(2)and its priming effect on soil organic carbon mineralization were conducted.It could provide a theoretical basis for improving the stability of soil organic carbon in karst areas.The results showed that Ca^(13)CO_(3)can release 13 CO_(2)in the early period of culture(1~10 d),and tends to be stable in the later period(10~100 d).Ca^(13)CO_(3)had a certain contribution to the total CO_(2)release of yellow soil and lime soil,and its contribution rate reached 25.47%and 20.76%;Exogenous Ca^(13)CO_(3)had a negative priming effect on the organic carbon mineralization of yellow soil and lime soil.After 100-days cultivation,the cumulative mineralization of soil organic carbon was reduced by 76.05%and 45.14%,respectively.The priming effect was mainly affected by soil type mainly.The degree of negative excitation of organic carbon mineralization in yellow soil was higher than that in lime soil.