生物质炭与强还原处理对退化设施蔬菜地土壤温室气体排放的影响

Effects of biochar and reductive soil disinfestation on greenhouse gas emissions in degraded facility vegetable soil

生物质炭和土壤强还原处理(Reductive Soil Disinfestation, RSD)可以有效地修复退化设施蔬菜地土壤,但2种修复技术联用对土壤温室气体(CO2、N2O和CH4)排放的影响研究报道较少.本研究采用室内培养实验,设置未修复土壤(CK)、生物质炭修复(BC)、RSD修复(RSD)和BC与RSD联合修复(BC+RSD)4个处理,35℃条件下培养15 d,研究BC与RSD单独以及联合修复对退化设施蔬菜地土壤温室气体排放和综合温室效应(Global Warming Potential, GWP)的影响.结果表明,与对照CK相比,BC处理土壤N2O排放量显著下降了50.0%,但CO2排放量和GWP均显著增加(p<0.05);RSD和BC+RSD处理土壤CO2、N2O、CH4排放量和GWP均大幅度增加.但与RSD处理相比,BC+RSD处理土壤N2O排放量和GWP分别下降了71.0%和30.0%.相关分析表明,土壤CO2、N2O、CH4排放量和GWP与可溶性有机碳(DOC)和铵态氮(NH+4-N)显著正相关,与pH和硝态氮(NO-3-N)显著负相关.可见,生物质炭可以减少退化设施蔬菜地RSD修复引起的GWP.

Both biochar and reductive soil disinfestation(RSD) are considered promising management practices to alleviate degraded facility vegetable soil. However, there are few reports about the effects of coupling biochar with RSD on greenhouse gas emissions in degraded facility vegetable soil. Four treatments were designed, soil without any amendments(CK), soil treated by biochar(BC), soil treated by RSD(RSD), soil treated by BC coupling with RSD(BC+RSD). All treatments were incubated at 35 ℃ for 15 days to investigate BC and RSD and their interactive impacts on greenhouse gas emissions and the global warming potential(GWP). Results indicated that the BC treatment significantly reduced the cumulative N2O emissions by 50.0%, while significantly increased the cumulative CO2 emissions and GWP in relation to CK. Both RSD and BC+RSD treatments significantly increased cumulative CO2, N2O, CH4 emissions and GWP compared with CK. However, compared with the RSD treatment, the BC+RSD treatment significantly reduced the cumulative N2O emissions and GWP by 71.0% and 30.0%, respectively. Pearson correlation analysis revealed that cumulative CO2, N2O, CH4 emissions and GWP were positively correlated to soil DOC and NH+4-N, but negatively correlated to soil pH and NO-3-N. It is concluded that biochar can reduce GWP from the process of RSD in degraded facility vegetable soil.