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采用室内培养法,对采自句容市华阳镇的水稻土进行5、15、25和35℃下的50 d培养实验,基于培养实验数据、6M HCl水解实验数据和三库一级动力学模型进行三库拟合,研究土壤有机碳矿化特征随培养温度的变化,并深入分析培养温度对Q10(土壤有机碳矿化温度敏感性系数)和三库拟合结果的影响。结果表明:(1)在5~35℃范围内,随培养温度升高水稻土有机碳矿化速率和累积矿化量均升高,15、25和35℃时土壤有机碳累积矿化量分别是5℃时的1.94倍、3.55倍、6.01倍。(2)培养温度的设定对三库拟合结果有较大影响,尤其是对活性碳库的影响,在不同培养温度下潴育、潜育、淹育水稻土活性碳的拟合值变异系数分别为64.9%、66.7%、48.5%。(3)Q10值变化范围在1.48~2.88,且随培养温度升高而降低、随培养时间增长而降低。Q10取2或者按照定义式测定的值对活性碳库和缓效性碳库拟合结果无影响,而对活性碳库和缓效性碳库平均驻留时间的拟合结果有影响。由此得出:利用在25℃下的培养结果估计的土壤有机碳库是存在一定误差的,应该进一步探索可行的三库拟合培养温度或寻找其他三库测定的方法;把Q10值取2代入三库一级动力学模型中对土壤有机碳进行三库拟合是可行的。
Fifty days incubation experiments at 5, 15, 25 and 35 ℃ of paddy soil collected from Huayang Town, Jurong City were conducted on the basis of culture experiment data, experimental data of 6M HCl hydrolysis and three primary kinetics Model was used to study the effects of incubation temperature on the Q10 (soil organic carbon mineralization temperature sensitivity coefficient) and the fitting results of three reservoirs. The results showed that: (1) In the range of 5 ~ 35 ℃, the organic carbon mineralization rate and cumulative mineralization increased in paddy soils with increasing incubation temperature. At 15, 25 and 35 ℃, respectively, 1.94 times at 5 ° C, 3.55 times, 6.01 times. (2) The setting of culture temperature has a great influence on the fitting results of three sinks, especially on the active carbon sink. The variation of fitted values of activated carbon in different incubation temperature, latent and submerged paddy soils The coefficients are respectively 64.9%, 66.7% and 48.5%. (3) The Q10 value ranged from 1.48 to 2.88, decreased with the increase of incubation temperature and decreased with the increase of incubation time. The value of Q10 of 2 or determined according to the definition has no effect on the fitting results of the active carbon pool and the slow-acting carbon pool, but has an effect on the fitting result of the average residence time of the active carbon pool and the slow-acting carbon pool. It is concluded that there is a certain error in estimating the soil organic carbon pool based on the culture results at 25 ° C. The feasible incubation temperature of the three pools should be further explored or other three-pool determination methods should be further explored. The Q10 value should be 2 Substituting into the three-compartment first-order kinetic model is feasible for the three-reservoir fitting of soil organic carbon.