不同灌水水平对温室番茄地土壤CO_2排放影响

为分析不同灌水水平对温室番茄地土壤CO_2排放的影响,采用静态箱气相色谱法对2014年秋冬季和2015年春夏季番茄地土壤CO_2排放进行原位观测。试验设置2个灌水水平分别为:充分灌溉(FI)和亏缺灌溉(DI)。结果表明:番茄两个生长季中,不同灌水处理下土壤CO_2排放通量均呈波动性变化。2015年春夏季试验各处理土壤CO_2平均排放通量和排放量高于2014年秋冬季试验对应的各处理土壤CO_2平均排放通量和排放量,且两个生育期内高灌水处理的土壤CO_2排放在番茄生育期绝大多数时间内均高于低灌水处理。以2015年FI处理土壤CO_2累积排放量最大(5 641.57kg/hm~2),分别较2014年FI处理、2014年DI处理和2015年DI处理增加了3.9%、54.2%和16.7%。此外,研究还发现春夏茬试验中不同灌水处理下,土壤CO_2排放通量与土壤水分呈显著负相关关系。这为评估设施菜地温室气体减排提供一定的科学依据。

Effects of Different Irrigation Levels on CO2 Emissions from Soils of Greenhouse Tomato Fields

Field experiments by using the method of static chamber/gas chromatography were conducted to study the effects of differ-ent irrigation levels on CO2 emissions from soils of greenhouse tomato fields in autumn-winter season in 2014 and spring-summer season in 2015.Two treatments,full irrigation (FI)and deficit irrigation (DI),were conducted.The results showed that soil CO2 fluxes presented the fluctuation change during two tomato growth stage.The average CO2 fluxes under each treatment in 2015 were higher than the values under each corresponding treatment in 2014,and CO2 fluxes under treatment with high irrigation level were higher than those under treatment with low irrigation level most of the time in the growth stage.The maximum cumulative emissions of CO2 was 5641.57 kg/ha under FI treatment in 2015,increased by 3.9%,54.2% and 16.7% for FI treatment in 2014,DI treat-ment in 2014 and DI treatment in 2015,respectively.Furthermore,significant negative correlations between soil CO2 fluxes and soil moisture were observed under different irrigation levels in 2015.This study provides scientific basis for mitigating greenhouse gas e-missions to greenhouse soils.