生物炭及与秸秆联用对我国热带地区稻田土壤CH_(4)和N_(2)O的影响

Effect of biochar and its combined application with straw on CH_(4) and N_(2)O in paddy field soils in tropical China

为了研究添加生物炭、秸秆、生物炭与秸秆联用对热带地区稻田温室气体排放的影响,通过盆栽培养试验,设常规施肥(CK)、常规施肥配施40 t·hm^(−2)椰糠生物炭(B)、常规施肥配施3 t·hm^(−2)水稻秸秆(C)、常规施肥配施40 t·hm^(−2)椰糠生物炭加3 t·hm^(−2)水稻秸秆(B+C)4个处理,采用静态箱-气相色谱法监测整个水稻种植季CH_(4)和N_(2)O排放,估算全球增温潜势(GWP)并测定收获后作物产量。结果表明,相比CK处理,B、C和B+C处理的N_(2)O累计排放量分别降低21.43%、21.89%和14.77%;B处理的CH_(4)累计排放量降低38.21%,而C和B+C处理的CH_(4)累计排放量分别增加14.63%和19.85%;C和B+C处理显著增加GWP,而B处理显著降低GWP;单独添加生物炭减排效果最佳。与CK相比,B、C处理的单株水稻产量分别增加5.22%、8.76%,而B+C处理的单株水稻产量降低18.39%(P<0.05)。因此,在我国热带地区稻田,单独施用40 t·hm^(−2)生物炭,可以实现温室气体减排和增产,值得在田间推广应用。

Effective measures of greenhouse gas emission mitigation in paddy field in tropical China are still unclear.In order to explore the effect of biochar,straw amendment and the mixture of biochar and straw on greenhouse gas emission in paddy fields in tropical China,a pot experiment was conducted,and four treatments were arranged,including conventional fertilizer application as control(CK),conventional fertilizer application plus 40 t·hm^(−2) of biochar(B),conventional fertilizer application plus 3 t·hm^(−2) of rice straw(C),conventional fertilizer application plus 40 t·hm^(−2) of biochar+3 t·hm^(−2) of rice straw(B+C).Static chamber-gas chromatography was used to monitor CH_(4) and N_(2)O emissions for estimation of global warming potential(GWP),and the crop yield was measured after harvest.The results showed that compared with CK Treatments B,C and B+C significantly reduced the cumulative N_(2)O emissions by 21.43%,21.89%,and 14.77%,respectively,but only Treatment B significantly reduced the cumulative emission of CH_(4) by 38.21%,while Treatments C and B+C significantly increased the cumulative emission of CH_(4) by 14.63%and 19.85%,respectively.Meanwhile,Treatments C and B+C significantly increased GWP,while Treatment B significantly decreased GWP(P<0.05),which indicated that Treatment B had better greenhouse gas emission mitigation effect as compared to the other treatments.Treatments B and C significantly increased rice yield per plant by 5.22%and 8.76%,respectively,while Treatment B+C significantly decreased rice yield per plant by 18.39%.Thus,application of 40 t·hm^(−2) of biochar in the paddy fields in tropical China is recommended to achieve greenhouse gas emission reduction and yield increase.