施肥量对福州平原稻田CO2排放及其温度敏感性的影响

为了阐明施肥量对稻田CO_2排放及其温度敏感性的影响,采用静态箱-气相色谱法,对福州平原稻田对照(CK)、常规施肥组(CG)和倍增施肥组(BZ)的CO_2排放及其温度敏感性进行了测定和分析.结果表明,CK、CG和BZ的CO_2排放通量变化范围分别为32.33~3181.97、30.68~3701.05和32.81~3206.29 mg·m~(-2)·h~(-1),CG的CO_2排放通量比较CK增加了14.16%,BZ的CO_2排放通量较CK增加了8.04%,CK、CG和BZ之间CO_2排放通量差异不显著(p0.05);稻田CO_2排放与土温(r=0.683,p0.01)、株高(r=0.820,p0.01)及含水量(r=0.309,p0.05)具有显著的正相关关系;CK、CG和BZ的CO_2排放通量与土温和气温均具有显著的正相关关系(n=42,p0.01);CK、CG、BZ的Q_(s10)值和Q_(a10)值分别为28.13、18.88、13.24和9.86、7.64、6.35,CK的温度敏感性显著高于CG和BZ(p0.05),施肥显著降低了稻田CO_2排放的温度敏感性(p0.05).

Effect of fertilizer rates on CO2 emission and its temperature sensitivity from paddy fields in Fuzhou plain

In order to determine the effect of fertilization rates on CO₂ emission and its temperature sensitivity,CO₂ emission and its temperature sensitivity under no fertilization (CK),normal rate of fertilization (CG) and double rates of fertilization (BZ) in paddy fields in Fuzhou plain were measured and analyzed using the static chamber-gas chromatograph technique.The results showed that the range of CO₂ emission fluxes were 32.33~3181.97,30.68~3701.05 and 32.81~3206.29 mg·m^-2·h^-1 for CK,CG and BZ,respectively.CO₂ emission fluxes of CG and BZ increased by 14.16% and 8.04%,respectively,in comparison with that of the CK.CO₂ emission fluxes under different treatments in the paddy fields were not significantly different (p>0.05).CO₂ emissions were significantly positively correlated with soil temperature (r=0.683,p<0.01) and plant height (r=0.820,p<0.01),and CO₂ emission fluxes was significantly positively correlated with water content (r=0.309,p<0.05).CO₂ emissions were significantly positively correlated with soil temperature and air temperature (n=42,p<0.01).The Q_s10 and Q_a10 values were 28.13,18.88,13.24 and 9.86,7.64,6.35 for CK,CG and BZ,respectively,and the temperature sensitivity of CK were significantly higher than those of the CG and BZ (p<0.05).Furthermore,fertilization significantly reduced the temperature sensitivity of CO₂ emission in paddy field.