生物炭长期施入对燥红土有机碳及其组分的影响

Effects of long-term application of biochar on organic carbon and its fractions in dry red soil

为探究生物炭长期施入对土壤有机碳(SOC)及其活性组分的影响,通过室内培养试验,比较短期(1个月)施用生物炭(BF)和生物炭施入3 a(BA)对SOC及其组分的影响。结果表明:生物炭施入显著提高了SOC、颗粒有机碳(POC)、易氧化有机碳(EOC)、轻组有机碳(LFOC)和微生物生物量碳(MBC)含量。相比不施生物炭处理(CK),施用生物炭处理土壤的POC、EOC、LFOC和MBC分别增加了97.5%~241.5%、21.8%~59.4%、66.8%~202.7%和83.7%~199.9%。相较于BF,BA的SOC、EOC、POC和MBC含量显著降低,但溶解性有机碳(DOC)含量显著升高。相较于CK,施生物炭土壤的碳库管理指数(CPMI)显著提高,培养1个月的1%生物炭(BF1)和2%生物炭(BF2)及培养3 a的1%生物炭(BA1)和2%生物炭(BA2)处理的CPMI值分别提高了48.81%、89.73%、54.66%和157.48%。相关分析显示,MBC、POC、LFOC及EOC含量与SOC含量显著正相关。综上所述,施用生物炭能实现土壤固碳,但随着施用年限延长,CPMI显著降低,从而降低了SOC的稳定性。

This study aimed to investigate the effects of long-term application of biochar on soil organic carbon(SOC)and its active fractions.A laboratory experiment was conducted to investigate the effects of short-term(1 month)application of biochar(BF)and three year application of biochar(BA)on SOC and its fractions.The results showed that the application of BF significantly increased SOC content,particulate organic carbon(POC),easily oxidized organic carbon(EOC),light fraction organic carbon(LFOC),and microbial biomass carbon(MBC).The POC,EOC,LFOC and MBC increased by 97.5%-241.5%,21.8%-59.4%,66.8%-202.7%,and 83.7%-199.9%,respectively,relative to those observed with no biochar addition.Compared with BF,BA significantly reduced SOC,EOC,POC,and MBC levels but significantly increased dissolved organic carbon(DOC)content.Compared with no biochar addition,the carbon pool management index(CPMI)significantly increased in response to BF and BA treatments.The CPMI showed increases of 48.81%,89.73%,54.66%,and 157.48%in response to treatments with 1%BF,2%BF,1%BA,and 2%BA,respectively.The correlation analysis showed a significant and positive correlation between SOC content and MBC,POC,LFOC,and EOC levels.Therefore,the application of biochar can achieve soil carbon sequestration.However,with the extension of application years,the CPMI was significantly reduced,which reduced the stability of SOC.