温度对太谷县农田土壤有机碳矿化的影响

Effects of Temperature on Soil Organic Carbon Mineralization of Farmland in Taigu

土壤是个巨大的有机碳库,研究土壤有机碳矿化的影响因素以揭示其稳定性,可为区域土壤有机碳储量的估算提供依据。通过室内培养、碱液吸收法研究了温度变化对太谷县农田土壤有机碳矿化的影响。结果显示,土壤有机碳矿化量在同一温度下随土层加深呈下降趋势,在同一土层中随温度的升高呈上升趋势,当温度由10℃升高至30℃时,0~20,20~40,40~60,60~80,80~100 cm土层土壤有机碳矿化量的增幅分别为130.7%,164.6%,136.7%,98.1%,86.7%;各土层平均温度系数(Q_(10))变化在1.428~1.604,并无明显差异;各土层的矿化率随温度的升高呈上升趋势,同温度下,各土层间的矿化率均基本一致,无显著差异。研究结果反映了各土层土壤有机碳均参与了土壤碳循环,且当外界温度变化时,各土层土壤有机碳的稳定性均会受到影响,因此,估算该区域农田碳库时应充分考虑各土层土壤有机碳的变化。

Soil is a huge organic carbon pool. We can reveal its stability and provide the basis for soil organic carbon（SOC）storage by studying the SOC mineralization. In this paper, laboratory incubation experiments were carried out to investigate the effects of temperature on soil organic carbon mineralization by alkali absorption method. The results showed that with the soil depth increasing,there was a downward trend in the total SOC mineralization under different temperatures. The SOC mineralization increased with the rise of temperature in each soil layer. When the temperature was increased from 10 ℃ to 30 ℃,the growth rate of soil organic carbon mineralization was respectively 130.7%, 164.6%, 136.7%, 98.1%, 86.7% in the 0-20, 20-40, 40-60, 60-80, 80-100 cm soil layer. The average temperature coefficient（Q10）of each soil layer changed from 1.428 to 1.604, there was no significant difference between them.The mineralization rate of SOC increased with the rise of temperature in each soil layer. There was no significant difference in the mineralization rate of SOC in each soil layer under different temperatures. The results revealed that the SOC in each soil layer was involved in the whole globe carbon cycle. When the temperature changed, the stability of SOC would be affected. The change of SOC in each soil layer should be taken into account when estimating the SOC pool of farmland in Taigu.