微咸水与淡水轮灌对春玉米土壤CO_2和N_2O排放的影响

Effects of alternative irrigation between brackish water and fresh water on CO_2 and N_2O emission from spring maize soil

为探究咸淡轮灌模式下春玉米土壤温室气体的排放特性,采用4种水质,即淡水和矿化度分别为2、3.5和5g/L的微咸水;2种轮灌方式,即淡水—微咸水(1∶1)和淡水—微咸水—微咸水(1∶2)循环轮灌进行滴灌试验,分析了不同处理对农田土壤CO_2、N_2O排放和春玉米产量的影响。结果表明:1)1:2轮灌处理CO_2和N_2O日平均排放通量比1∶1轮灌分别低10.26%、8.74%。2)矿化度为3.5和5g/L微咸水处理CO_2气体日均排放通量比2g/L分别低27.82%、31.16%,N_2O气体日平均排放通量比2g/L分别低4.46%、8.23%。3)相比2g/L处理,3.5和5g/L处理产量平均减少5.92%、11.05%;1∶2轮灌比1∶1轮灌产量平均减少2.00%。4)显著性分析表明:水质对CO_2气体日平均排放通量和玉米产量的影响显著(P<0.05),对N_2O气体排放通量无显著影响(P>0.05);轮灌方式对CO_2、N_2O气体排放通量和玉米产量的影响不显著(P>0.05)。

In order to investigate the influences of alternative irrigation between brackish water and fresh water on greenhouse gas emission from spring maize soil,drip irrigation experiments with four kinds of water quality and two different irrigation methods were conducted.The results showed that：The average daily emission of CO_2 and N_2O flux of 1∶2 alternative irrigation were respectively reduced by 10.26% and 8.74% compared with that of 1∶1 alternative irrigation.The average emission of CO_2 and N_2O flux were 27.82% and 31.16%lower than that of 2.0 g/L and the average emissions flux of N_2O gas were 4.46% and 8.23%lower than that of 2.0 g/L,respectively.Compared to2.0 g/L brackish water treatment,the corn yield of 3.5 g/L and 5.0 g/L treatment respectively decreased by 5.92%and 11.05% on average.The corn yield of 1∶2 alternative irrigation treatment was 2.00%lower than that of 1∶1 on average.The results significant difference analysis showed that：The water quality had a significant effect on the daily average emission of CO_2 flux and maize yield（P0.05）,whereas the water quality did not have significant effects on N_2O emission flux（P0.05）;The effect of alternative irrigation on CO_2 and N_2O emission fluxes and maize yield were not significant（P 0.05）.