生物质炭和腐殖质对稻田土壤CH_(4)和N_(2)O排放的影响

Effects of Biochar and Humus on CH_(4) and N_(2)O Emissions in Paddy Field

为探讨生物质炭与腐殖质单独施用与配合施用对稻田土壤CH_(4)和N_(2)O气体排放以及水稻产量的影响。以浙江临安潜育性水稻土的稻田系统为研究对象,设置2个水稻秸秆生物质炭添加水平(0,20 t/hm^(2))和3个腐殖质水平(0,0.6,1.2 t/hm^(2)),共6个处理,分别为:(1)B0F0(对照,不添加生物质炭和腐殖质);(2)B0F1(腐殖质用量为0.6 t/hm^(2));(3)B0F2(腐殖质用量为1.2 t/hm^(2));(4)B1F0(生物质炭用量为20 t/hm^(2));(5)B1F1(生物质炭和腐殖质用量分别为20,0.6 t/hm^(2));(6)B1F2(生物质炭和腐殖质用量分别为20,1.2 t/hm^(2)),研究生物质炭和腐殖质输入对水稻产量、稻田CH_(4)和N_(2)O气体排放的影响。结果表明:(1)与B0F0相比,单独施用生物质炭和腐殖质或生物质炭与腐殖质配施均降低了土壤CH_(4)累积排放量,但增加了土壤N_(2)O累积排放量;(2)生物质炭处理对GWP(global warming potential)和GHGI(greenhouse gas intensity)没有显著影响(P>0.05),腐殖质处理显著降低了GWP和GHGI(P<0.05),生物质炭和腐殖质对GWP和GHGI存在显著交互作用(P<0.05);(3)与B0F0相比,单独施用生物质炭和腐殖质或者生物质炭与腐殖质配施均能在一定程度上减少单位水稻产量的温室气体排放强度(GHGI),B0F2处理的GHGI最低,表明单施腐殖质处理(腐殖质用量为1.2 t/hm^(2))稻田土壤的减排效果和环境效应最好。研究结果为进一步探讨稻田土壤固碳减排提供数据支撑和理论依据。

To evaluate the effects of single and combined application of biochar and humus on CH_(4) and N_(2)O emission in paddy field and rice yield,taking the paddy field system of gleyic paddy soil in Lin'an,Zhejiang Province as the research object,two addition levels of rice straw biochar(0 and 20 t/hm^(2))and three addition levels of humus(0,0.6 and 1.2 t/hm^(2))were set in the experiment,and a total of six treatments were carried out,which were B0F0(control,without biochar or humus),B0F1(humus dosage of 0.6 t/hm^(2)),B0F2(humus dosage of 1.2 t/hm^(2)),B1F0(biochar dosage of 20 t/hm^(2)),B1F1(the amounts of biochar and humus were 20 t/hm^(2)and 0.6 t/hm^(2),respectively),B1F2(the amounts of biochar and humus were 20 t/hm^(2)and 1.2 t/hm^(2),respectively).Effects of biochar and humus addition on rice yield,CH_(4) and N_(2)O emissions in rice fields were studied.The results showed that:(1)Compared with B0F0,application of biochar and humus alone or combination all reduced cumulative CH_(4) emission and increased cumulative emission of N_(2)O in soil.(2)Biochar treatment had no significant effect on GWP(global warming potential)and GHGI(greenhouse gas intensity)(P>0.05).Humus treatment significantly decreased GWP and GHGI(P<0.05).Biochar and humus had significant interaction on GWP and GHGI(P<0.05).(3)Compared with B0F0,the application of biochar and humus alone or the combined application could reduce greenhouse gas emission intensity(GHGI)per unit rice yield to a certain extent.The GHGI of B0F2 treatment was the lowest,indicating that the application of humus alone(the amount of humus was 1.2 t/hm^(2))had the best emission reduction effect and environmental effect.The results could provide data support and theoretical basis for further discussion on carbon sequestration and emission reduction in paddy soil.