通过大田试验,采用静态暗箱-气象色谱法研究玉米农田不施生物炭(C0), 施生物炭分别为15 t /hm~2(C15) 、 30 t /hm~2(C30)和45 t /hm~2(C45)后温室气体(CO_2、CH_4和N_2O)的排放特征,并估算CH_4和N_2O的综合增温潜势(GWP)及排放强度(GHGI) 。结果表明:添加生物炭显著降低CO_2和N_2O的季节累积排放总量,与C0处理相比, CO_2最大降幅为24.6%(C15), N_2O最大降幅为110.35%(C45), 且其随着生物炭施用量的增加而降低; CH_4的季节累积排放总量由小到大依次为: C15、C30、C0、C45,其中,C15处理较C0处理降低幅度最大为259.62%,添加生物炭同时也降低CH_4和N_2O的综合增温潜势(GWP)及排放强度(GHGI), 处理C15、C30和C45的GWP值较对照C0分别降低88.2%、123.2%和109.9%,GHGI分别降低88.86%、121.60%和100.03%。施用适量的生物炭可以有效增加玉米产量,处理C15、C30和C45的增幅分别为6.28%、7.27%和1.69%。处理C30显著降低CH_4和N_2O的综合增温潜势及其排放强度,并且产量的增幅最大。因此,在当前玉米农田管理措施下,生物炭施用量为30 t /hm~2时可实现玉米增产和固碳减排的目标。
英文摘要:
A field experiment was conducted by using the static chamber-gas chromatography method to analyze the emission behavior of greenhouse gas(CO_2, CH_4 and N_2O), and estimate the global warming potentials(GWP) of CH_4 and N_2O and the greenhouse gas intensity(GHGI) through different straw biochar application treatments in a maize field,including none biochar application(C0), biochar application rate of 15 t /hm~2(C15), 30 t /hm~2(C30) and 45 t /hm~2(C45). Results showed that biochar application can significantly decrease the seasonal emissions of CO_2 and N_2O. The emissions of CO_2 and N_2O were decreased with the increase of biochar application rate,and the maximum decreases of CO_2 and N_2O emission were 24.6%(C15) and 110.35%(C45), respectively,compared with those of C0. The seasonal CH_4 emission followed a decreasing order of C15,C30,C0 and C45,in which the maximum decrease of CH_4 emission for C15 was 259.62% compared with that of C0. Biochar application can also decrease the comprehensive temperature increasing potentials(GWP) and the emission intensity(GHGI) of CH_4 and N_2O. The GWP of C15,C30 and C45 were reduced by 88.2%,123.2% and 109.9%, respectively, and the GHGI were reduced by 88.86%,121.60% and 100.03%, respectively, compared with those of C0. In addition,biochar application was able to increase maize yield. Compared with that of C0,the maize yield increases were 6.28%,7.27% and 1.69% for C15,C30 and C45, respectively. The experiment demonstrated that C30 reached the most decrease of GWP and GHGI and increase of maize yield. Therefore,biochar application with a rate of 30 t /hm~2 can achieve the purposes of yield increase,carbon fixation and emission reduction under the current maize filed management measures.